JP2018144778A - Wheel driving apparatus - Google Patents

Abstract

An object of the present invention is to provide a wheel drive device capable of effectively taking measures against lubricant leakage. A speed reduction mechanism (20) for reducing the rotation transmitted from a drive source, a rotation body (22) having the rotation reduced by the reduction mechanism (20) transmitted thereto and having wheels integrated, and a rotating body (22) rotatable. An oil seal 26 that is disposed between the rotating body 22 and the fixing members 24-A and 24-B to seal a space in which the speed reduction mechanism 20 is housed; A lubricant 60-A, 60-B sealed in the sealed space 28 sealed by the seal 26, wherein the lubricants 60-A, 60-B have different mixing penetration rates. It includes at least two types of lubricants 60-A and 60-B, and the amount of the lubricants 60-A and 60-B is 35% or less of the volume of the sealed space 28. [Selection diagram] FIG.

Description

  The present invention relates to a wheel drive device.

  2. Description of the Related Art Conventionally, as a wheel driving device for driving a wheel of a transport carriage or the like, a device in which a speed reduction mechanism is incorporated is known. This type of wheel drive device may be used in a place where cleanliness is required, such as a clean room. In this case, countermeasures against leakage of the lubricant enclosed in the wheel drive device may be required. As a wheel drive device that takes this measure, Patent Document 1 discloses a bearing that supports a rotating body in a rotatable manner as a bearing with a seal, and a seal member is disposed on the outer space side of the bearing with a seal. Yes.

JP 2012-71810 A

  As a result of investigation by the present inventor, it was recognized that the technique of Patent Document 1 has insufficient measures against lubricant leakage and there is room for improvement.

  An aspect of the present invention has been made in view of such circumstances, and one of its purposes is to provide a wheel drive device that can effectively take measures against leakage of lubricant.

  An aspect of the present invention relates to a wheel drive device, a speed reduction mechanism that reduces rotation transmitted from a drive source, a rotation body that transmits rotation reduced by the speed reduction mechanism and has a tire integrated therein, and the rotation. A fixing member that rotatably supports the body, an oil seal that is disposed between the rotating body and the fixing member and seals a space in which the speed reduction mechanism is housed, and an enclosed space that is sealed by the oil seal The lubricant includes at least two kinds of lubricants having different miscibility, and the amount of the lubricant enclosed is equal to the volume of the enclosure space. 35% or less.

  Another aspect of the present invention relates to a wheel drive device, a reduction mechanism that reduces rotation transmitted from a drive source, a rotation body that transmits rotation reduced by the reduction mechanism, and a tire is integrated; A fixing member that rotatably supports the rotating body, an oil seal that is disposed between the rotating body and the fixing member and seals a space in which the speed reduction mechanism is accommodated, and an enclosure that is sealed by the oil seal A wheel drive device including a lubricant enclosed in a space, the wheel drive device including a swing plate that rotates integrally with the rotating body and shakes off the lubricant leaking from the oil seal arrangement portion.

  Another aspect of the present invention relates to a wheel drive device, a reduction mechanism that reduces rotation transmitted from a drive source, a rotation body that transmits rotation reduced by the reduction mechanism, and a tire is integrated; A fixing member that rotatably supports the rotating body, an oil seal that is disposed between the rotating body and the fixing member and seals a space in which the speed reduction mechanism is accommodated, and an enclosure that is sealed by the oil seal And an oil pan that receives the lubricant leaking from the location where the oil seal is disposed.

  ADVANTAGE OF THE INVENTION According to this invention, the wheel drive device which can aim at the leakage countermeasure of a lubricant effectively can be provided.

It is front sectional drawing which shows the wheel drive device of 1st Embodiment. It is an enlarged view which shows the deceleration mechanism of 1st Embodiment with a periphery structure. It is a figure for demonstrating distribution of the lubricant in the enclosure space of 1st Embodiment. It is a figure for demonstrating the path | route which a lubricant follows from the arrangement | positioning location of a 1st oil seal. It is a one part enlarged view of FIG. It is the fragmentary sectional view which looked at a part of wheel drive device of Drawing 1 from the anti-vehicle body side. It is the external view which looked at a part of wheel drive device of Drawing 1 from the non-vehicle body side. It is a top view which shows the 1st oil pan and 2nd oil pan of 1st Embodiment. It is the sectional view on the AA line of FIG. 10A to 10C are a view of the pan support member as viewed from the counter-rotating body side, a view as viewed from the rotating body side, and a view as viewed from one side in the traveling direction Y. It is a figure which shows a part of 1st oil pan and pan support member of 1st Embodiment. It is a front sectional view of a part of a wheel drive device of a 2nd embodiment. It is side surface sectional drawing which shows the circumferential direction edge part of the wheel cover of 2nd Embodiment.

  Hereinafter, in the embodiment and the modification, the same reference numerals are given to the same components, and the duplicate description is omitted. In the drawings, for convenience of explanation, some of the components are omitted as appropriate, and the dimensions of the components are appropriately enlarged and reduced. In addition, different components having a common point are distinguished and collectively named by adding “first, second” or the like at the beginning of the name and adding “−A, −B” or the like at the end of the code. Sometimes these are omitted.

(First embodiment)
FIG. 1 is a front sectional view showing a wheel drive device 10 according to the first embodiment. The wheel drive device 10 of the present embodiment is assembled to a vehicle body 12 of a transport carriage and is used to drive a tire 14 of the transport carriage. The transport carriage of this embodiment is a tracked carriage, and the tire 14 of this embodiment travels on a travel surface 16a provided on a rail 16 laid on the floor surface. Hereinafter, the direction along the rotation center line La of the tire 14 will be referred to as the axial direction X of the tire 14, and the circumferential direction and radial direction around the rotation center line a will be simply referred to as “circumferential direction” and “radial direction”. The traveling direction of the tire 14 is a horizontal direction orthogonal to the axial direction X.

  The wheel driving device 10 mainly includes an input shaft 18, a speed reduction mechanism 20, a rotating body 22, carriers 24 -A and 24-B, and a first oil seal 26. The wheel drive device 10 according to the present embodiment is roughly divided into a lubricant (not shown in the figure) enclosed in an enclosed space 28 (described later) on the inner peripheral side of the rotating body 22, and an external structure of the enclosed space 28. There are main characteristics. The former will be explained first.

  The input shaft 18 is for receiving the rotation transmitted from the output shaft 30 of the drive source. The drive source in the present embodiment is a motor, but may be a gear motor in which the motor and the speed reducer are integrated. The input shaft 18 is connected to an output shaft 30 of a drive source that protrudes outward from the vehicle body 12 in the vehicle width direction. The input shaft 18 is rotatably provided integrally with the output shaft 30, and the rotation of the drive source is transmitted from the output shaft 30. The rotation center line of the input shaft 18 is provided coaxially with the rotation center line La of the tire 14.

  FIG. 2 is an enlarged view showing the speed reduction mechanism 20 together with the peripheral structure. The deceleration mechanism 20 is for decelerating the rotation transmitted from the drive source. The speed reduction mechanism 20 of this embodiment is an eccentric oscillating speed reduction mechanism. The speed reduction mechanism 20 mainly includes eccentric bodies 32-A and 32-B, an external gear 34, an eccentric bearing 36, and an internal gear 38.

  The eccentric body 32 is formed integrally with the input shaft 18 and is provided so as to be rotatable integrally with the input shaft 18. The eccentric bodies 32-A and 32-B include a first eccentric body 32-A and a second eccentric body 32-B that are adjacent to each other in the axial direction X. The shaft centers of the first eccentric body 32-A and the second eccentric body 32-B are eccentric in opposite directions across the rotation center line La of the tire 14.

  The external gear 34 is individually provided corresponding to each of the first eccentric body 32-A and the second eccentric body 32-B. The external gear 34 is supported by the corresponding eccentric bodies 32-A and 32-B via the eccentric body bearing 36, and is swung by the eccentric bodies 32-A and 32-B. Specifically, when the corresponding eccentric bodies 32 -A and 32-B rotate around the rotation center line La of the tire 14, the external gear 34 rotates its own axis around the rotation center line La of the tire 14. It is made to rock.

  The external gear 34 is formed with a central hole 34 a that penetrates the axis of the external gear 34 in the axial direction X. Corresponding eccentric bodies 32 -A and 32-B and eccentric body bearings 36 are arranged inside the central hole 34 a of the external gear 34.

  A plurality of pin holes 34 b penetrating in the axial direction X are formed in the external gear 34. The pin hole 34b is provided at a position offset from the axis of the external gear 34 with a gap in the circumferential direction. The inner pin 40 is inserted through the pin hole 34b with play. An inner roller 42 that is rotatably supported by the inner pin 40 is provided on the outer peripheral side of the inner pin 40. Both end portions of the inner pin 40 are fixed to a pair of carriers 24 and supported by the pair of carriers 24.

  The eccentric body bearings 36 are individually provided corresponding to the first eccentric body 32-A and the second eccentric body 32-B. The eccentric body bearing 36 is provided between the corresponding eccentric bodies 32 -A and 32-B and the external gear 34.

  The eccentric body bearing 36 of the present embodiment is a roller bearing. The eccentric body bearing 36 includes a plurality of first rolling elements 36a, a retainer 36b, a first inner ring 36c, and a first outer ring 36d. The first rolling elements 36 a are provided with a space around the rotation center line La of the tire 14. The retainer 36b holds the relative positions of the plurality of first rolling elements 36a and rotatably supports the plurality of first rolling elements 36a.

  The first inner ring 36c of the present embodiment is configured by a member different from the eccentric body 32, and is integrated with the outer peripheral surface of the eccentric body 32 by an interference fit or the like. The outer peripheral surface of the first inner ring 36c constitutes a first inner rolling surface 36e on which the first rolling element 36a rolls in the circumferential direction.

  In the first outer ring 36d of the present embodiment, the inner peripheral surface of the central hole 34a of the external gear 34 is configured. The first outer ring 36d is constituted by a part of the same member as the external gear 34. The inner peripheral surface of the first outer ring 36d constitutes a first outer rolling surface 36f on which the first rolling element 36a rolls in the circumferential direction.

  The external gear 34 is in mesh with the internal gear 38. The internal gear 38 of the present embodiment includes a plurality of outer pins 38a supported on an inner peripheral portion of a casing 46 (described later) and a plurality of outer rollers 38b rotatably supported on the plurality of outer pins 38a. And have. Each of the plurality of outer rollers 38 b constitutes an internal tooth of the internal gear 38. The number of internal teeth of the internal gear 38 (the number of external rollers 38b) is one more than the number of external teeth of the external gear 34 in this embodiment.

  Please refer to FIG. The rotation that has been decelerated by the reduction mechanism 20 is transmitted to the rotating body 22. The rotating body 22 has the tire 14 integrated therein. The rotating body 22 has an annular shape as a whole, and the speed reduction mechanism 20 and the carrier 24 are disposed on the inner peripheral side thereof.

  The rotating body 22 includes, in addition to the tire 14 in contact with the traveling surface 16a, a wheel 44 on which the tire 14 is mounted, and a casing 46 in which the internal gear 38 of the speed reduction mechanism 20 is provided on the inner peripheral portion.

  The tire 14 is attached to the outer periphery of the wheel 44 by adhesion or the like. The tire 14 is configured using a soft material, and the wheel 44 is configured using a hard material that is harder than the soft material of the tire 14. For example, the soft material is an elastic body such as urethane rubber, and the hard material is a metal such as steel.

  The casing 46 is a casing of the speed reduction mechanism 20 and also serves as an output member for taking out the rotation decelerated by the speed reduction mechanism 20. The casing 46 is arrange | positioned at the inner peripheral side of the wheel 44, and is integrated with the wheel 44 by the volt | bolt B1.

  The carriers 24-A and 24-B include an inner carrier 24-A arranged on the vehicle body side from the external gear 34 and an outer carrier 24-B arranged on the side opposite to the vehicle body from the external gear 34. . In the present specification, the vehicle body side refers to the vehicle body 12 side in the axial direction X with reference to the component (external gear 34 in this case) referred to, and the anti-vehicle body side refers to the vehicle body 12 in the axial direction. The opposite side of X. The inner carrier 24-A is fixed to a wheel cover 48 described later by a carrier bolt B2. The outer carrier 24-B is fixed to a part of the wheel cover 48 by fitting.

  Please refer to FIG. A main bearing 50 that rotatably supports the rotating body 22 is provided between the casing 46 of the rotating body 22 and the inner carrier 24-A, and between the casing 46 of the rotating body 22 and the outer carrier 24-B. . The inner carrier 24-A and the outer carrier 24-B function as a fixing member that rotatably supports the rotating body 22 via the main bearing 50.

  The main bearing 50 of this embodiment is a roller bearing. The main bearing 50 includes a plurality of second rolling elements 50a, a second inner ring 50b, and a second outer ring 50c. The second rolling elements 50 a are provided around the rotation center line La of the tire 14 with a space therebetween. The second inner ring 50b of the present embodiment is configured by a member different from the carrier 24, and is integrated with the outer peripheral surface of the carrier 24 by an interference fit or the like. The outer peripheral surface of the second inner ring 50b constitutes a second inner rolling surface 50d on which the second rolling element 50a rolls in the circumferential direction. The second outer ring 50c of the present embodiment is configured by a member different from the casing 46 of the rotating body 22, and is integrated with the inner peripheral surface of the casing 46 by an interference fit or the like. The inner peripheral surface of the second outer ring 50c constitutes a second outer rolling surface 50e on which the second rolling element 50a rolls in the circumferential direction. A space formed between the second inner ring 50b and the second outer ring 50c is open toward both sides in the axial direction X.

  A first through hole 24a is formed in the inner carrier 24-A so as to penetrate the central portion in the radial direction. A first input shaft bearing 52-A is provided inside the first through hole 24a, and the inner carrier 24-A rotatably supports the input shaft 18 via the first input shaft bearing 52-A. The first through hole 24a is covered with a shaft cover 54 disposed on the vehicle body side from the first input shaft bearing 52-A, and the input shaft 18 passes through the shaft cover 54 in the axial direction X. A second oil seal 56 is provided between the shaft cover 54 and the input shaft 18, and the first through hole 24 a is sealed by the shaft cover 54 and the second oil seal 56.

  A second through hole 24b is formed in the outer carrier 24-B so as to penetrate the central portion in the radial direction. A second input shaft bearing 52-B is provided inside the second through hole 24b, and the outer carrier 24-B rotatably supports the input shaft 18 via the second input shaft bearing 52-B. The second through hole 24b is sealed by a seal cap 58 disposed on the side opposite to the vehicle body from the second input shaft bearing 52-B and the input shaft 18.

  The first oil seal 26 is disposed between the casing 46 of the rotating body 22 and the inner carrier 24-A, or between the casing 46 of the rotating body 22 and the outer carrier 24-B. The first oil seal 26 forms a sealed space 28 in which a lubricant (not shown in the figure) is sealed by sealing a space in which the speed reduction mechanism 20 is stored. Although the plurality of first oil seals 26 of the present embodiment are arranged in the axial direction X, the number is not particularly limited. The 1st oil seal 26 is comprised by the elastic body which makes | forms a ring shape. The cross-sectional shape of the first oil seal 26 along the rotation center line La of the tire 14 forms a groove shape that opens toward the enclosed space 28 that is sealed by the first oil seal 26.

The operation of the wheel drive device 10 will be described.
When the rotation of the drive source is transmitted from the output shaft 30 to the input shaft 18, the input shaft 18 rotates. When the input shaft 18 rotates, the rotation of the input shaft 18 is decelerated by the speed reduction mechanism 20 and transmitted to the casing 46 of the rotating body 22. When rotation is transmitted to the rotating body 22 from the speed reduction mechanism 20, the tire 14 that is integrated with the rotating body 22 rotates, so that the tire 14 travels on the traveling surface 16a.

  Here, when the input shaft 18 rotates, in the deceleration mechanism 20, the eccentric body 32 rotates around the rotation center line La together with the input shaft 18. When the eccentric body 32 rotates around the rotation center line La, the external gear 34 swings so that the axis of the external gear 34 rotates around the rotation center line La. When the external gear 34 swings, the meshing positions of the external gear 34 and the internal gear 38 are sequentially shifted. As a result, each time the input shaft 18 makes one rotation, the internal gear 38 rotates relative to the external gear 34 by an amount corresponding to the difference in the number of teeth from the external gear 34, and the rotation component thereof. Is transmitted to the casing 46 of the rotating body 22. At this time, the rotation of the input shaft 18, that is, the rotation transmitted from the drive source, is decelerated at a reduction ratio corresponding to the difference in the number of teeth between the external gear 34 and the internal gear 38 and is rotated from the internal gear 38 to the rotating body. 22 is transmitted.

  FIG. 3 is a view for explaining the distribution of the lubricants 60 -A and 60 -B in the enclosed space 28. The enclosure space 28 is a space defined by being surrounded by the rotating body 22 and the carrier 24, and is sealed by a shaft cover 54, a second oil seal 56, a seal cap 58 and the like in addition to the first oil seal 26. It is a closed space. The enclosed space 28 can also be regarded as a closed space defined by objects other than the lubricants 60-A and 60-B. Here, the objects other than the lubricants 60-A and 60-B are the input shaft 18, the speed reduction mechanism 20, the rotating body 22, the carrier 24, the first oil seal 26, the main bearing 50, the input shaft bearing 52, and the shaft cover. 54, a second oil seal 56, a seal cap 58, and the like.

  The enclosed space 28 includes a storage space 28 a in which the speed reduction mechanism 20 is stored, and a gap space 28 b provided between the rotating body 22 and the carrier 24. The storage space 28 a of this embodiment is formed between the pair of carriers 24 on the inner peripheral side of the rotating body 22. The gap space 28b is provided so as to extend in the axial direction X from the storage space 28a on the radially outer side of the eccentric body 32 and the eccentric body bearing 36 of the storage space 28a, and a first oil seal is provided at the end position in the axial direction X. 26 is provided. A main bearing 50 is provided in the gap space 28b at a position closer to the storage space 28a than the first oil seal 26. The main bearing 50 is disposed between the rotating body 22 and the carrier 24 at a position closer to the enclosed space 28 than the first oil seal 26.

  The lubricants 60-A and 60-B in the present embodiment are greases. The lubricants 60-A and 60-B include a hard lubricant 60-A and a soft lubricant 60-B having different blending degrees. In this figure, the portions with double hatching indicate the hard lubricant 60-A, and the portions with dot pattern indicate the soft lubricant 60-B. The “mixed penetration” here is a characteristic value indicating the hardness and fluidity of the grease. This penetration is a value obtained by allowing the tip of a prescribed cone to penetrate the grease by a prescribed method and multiplying the penetration depth by 10 in units of millimeters. “Mixing penetration” is a measured value immediately after the grease is mixed 60 times under the specified conditions. The United States Lubricating Grease Association (NLGI) classifies greases using the penetration number based on the numerical range of the penetration, and the Japanese Industrial Standard (JIS) also follows this. In the present embodiment, the lubricant 60 is specified using the penetration degree measured in accordance with the conditions specified in JIS K2220 and the penetration degree number specified in JIS K2220.

  As the hard lubricant 60-A, one having a low penetration is used, and as the soft lubricant 60-B, one having a higher penetration than the hard lubricant 60-A is used. That is, the hard lubricant 60-A is a hard lubricant having a higher viscosity and less fluidity than the soft lubricant 60-B, and the soft lubricant 60-B has a lower viscosity than the hard lubricant 60-A and flows. It is a soft and soft lubricant. As the hard lubricant 60-A, a lubricant having a blending consistency number in a small blending consistency range is used. As the soft lubricant 60-B, a lubricant having a blending consistency number larger than the blending consistency range corresponding to the blending consistency number used by the hard lubricant 60-A is used. Specifically, in the present embodiment, the hard lubricant 60-A is a lubricant having a penetration number of No. 2, and the penetration range is 265 to 295 [1/10 mm]. In the present embodiment, the soft lubricant 60-B is a lubricant having a blending consistency number of 00, and the blending consistency range is 400 to 430 [1/10 mm].

  The wheel drive device 10 of this embodiment includes the encapsulated amounts of the lubricants 60-A and 60-B and the volume of the encapsulated space 28 in which the lubricants 60-A and 60-B are encapsulated (hereinafter referred to as encapsulated space volume). There is one feature in the relationship. The “encapsulation amount of the lubricants 60-A and 60-B” means the total encapsulation amount of the hard lubricant 60-A and the soft lubricant 60-B. The “enclosed space volume” does not include a portion occupied by the “objects other than the lubricants 60-A and 60-B” (the input shaft 18, the speed reduction mechanism 20, and the like) forming the enclosed space 28.

  The amount of lubricant 60-A, 60-B enclosed is set to 35% or less of the enclosed space volume. More preferably, it is set to 30% or less of the enclosed space volume. This is set based on the results of experimental studies by the present inventors. In this experiment, the first oil seal 26 is used under various conditions in which the amount of lubricant 60-A, 60-B enclosed with respect to the enclosed space volume is changed using the wheel drive device 10 incorporating various speed reduction mechanisms. The presence or absence of leakage of lubricant from the location of the was confirmed. In this experiment, the forward rotation of the input shaft 18 for 30 seconds at a rotational speed of 2680 [rpm] and the reverse rotation of the input shaft 18 for 30 seconds at the same rotational speed were repeated for 2 days. Checked for leaks. These various reduction mechanisms include a parallel shaft gear reduction mechanism, an orthogonal shaft gear reduction mechanism, a planetary gear reduction mechanism, and the like in addition to the eccentric oscillating type reduction mechanism of the present embodiment. As a result, the leakage of the lubricant was confirmed when the amount of the lubricant 60 enclosed was 40% of the enclosed space volume. On the other hand, when the amount of lubricant 60 enclosed was 35% or less of the enclosed space volume, no leakage of lubricant was observed. Based on the experimental results, the amount of the lubricant 60 is set.

  Here, when only a single type of lubricant is enclosed in the enclosure space 28 in the above-described experimental examination, the present inventor determines the amount of the lubricant 60-A, 60-B enclosed by the enclosure space volume. It has been found that if it is 35% or less, required lubricity cannot be stably obtained at a plurality of lubrication required locations in the enclosed space. This is considered to be because it is difficult to spread the lubricant over the entire lubrication required location when the amount of the lubricant 60 enclosed is 35% or less of the enclosed space volume using only a single type of lubricant. In addition, the lubrication required location here means the location predetermined as a location which needs lubrication in the enclosed space 28 in particular. In the present embodiment, the eccentric body bearing 36 and the main bearing 50 are determined as lubrication points.

  Therefore, in the present embodiment, as described above, the hard lubricant 60-A having a low fluidity and the soft lubricant 60-B having a high fluidity are used in combination. As a result, the soft lubricant 60-B is distributed to some lubrication required locations by flowing the soft lubricant 60-B, while the hard lubrication is difficult in other lubrication required locations where the soft lubricant 60-B is difficult to spread. By applying the agent 60-A, the lubricity can be ensured regardless of the flow state of the soft lubricant 60-B. As a result, while the required lubricity is stably obtained at a plurality of lubrication required locations in the enclosed space 28, the amount of the lubricants 60-A and 60-B is set to 35% or less of the enclosed space volume. Is now allowed. As a result, a design in which the same required lubricity is stably obtained and the amount of the lubricant 60-A, 60-B is set to 30% or less of the enclosed space volume is allowed. .

  Here, since the eccentric body bearing 36 is subjected to a large load as the eccentric body 32 rotates, it is necessary to ensure lubricity. Further, since the eccentric body bearing 36 has a higher peripheral speed than other parts in the enclosed space 28, the lubricant is easily shaken off by the centrifugal force or the like, so that the lubrication is easily lost. Therefore, in the present embodiment, the eccentric body bearing 36 is defined as one of the lubrication points that require lubrication in the enclosed space 28. The eccentric bearing 36 according to the present embodiment corresponds to the above-described lubricated location where the soft lubricant 60-B is difficult to spread even when the soft lubricant 60-B is flowed.

  A hard lubricant 60-A is applied to the eccentric bearing 36 defined as the lubrication required portion. Specifically, the hard lubricant 60-A is applied to the location where the first rolling element 36a of the eccentric body bearing 36 is in rolling contact. More specifically, the hard lubricant 60-A is applied to the outer peripheral surface of the first rolling element 36a for all of the plurality of first rolling elements 36a. Further, the hard lubricant 60-A is continuously applied over the entire circumference in the circumferential direction of the first inner rolling surface 36e and the first outer rolling surface 36f on which the first rolling element 36a rolls. . As a result, the required lubricity can be stably obtained in the eccentric bearing 36 that is prone to lubrication. In addition to this, with respect to each of the plurality of first rolling elements 36a and the retainer 36b, the hard lubricant 60-A is also applied to the contact portion between each of the plurality of first rolling elements 36a and the retainer 36b.

  Further, since the main bearing 50 is likely to be subjected to a large load when the tire 14 is traveling, it is necessary to ensure lubricity. Therefore, in the present embodiment, the main bearing 50 is defined as one of the lubrication points requiring lubrication in the enclosed space 28, and the hard lubricant 60-A is also applied to the main bearing 50. Specifically, the hard lubricant 60-A is applied to a location where the second rolling element 50a of the main bearing 50 comes into rolling contact. More specifically, the hard lubricant 60-A is applied to the outer peripheral surface of the second rolling element 50a for all of the plurality of second rolling elements 50a. Further, the hard lubricant 60-A is continuously applied over the entire circumference in the circumferential direction of the second inner rolling surface 50d and the second outer rolling surface 50e on which the second rolling element 50a rolls. . When the hard lubricant 60-A is applied to the main bearing 50 as described above, the following effects can be obtained in addition to ensuring the lubricity at the main bearing 50 which is a lubrication required portion.

  When the rotating body 22 is stationary, the soft lubricant 60-B is present in the lower part of the gap space 28b of the enclosed space 28 as shown in FIG. 3, and the other part of the gap space 28b. Will not exist. When the rotating body 22 rotates under this state, the soft lubricant 60-B receives centrifugal force or the like so as to fill the other part of the gap space 28b where the soft lubricant 60-B does not exist. Try to flow into. At this time, a part of the soft lubricant 60-B tends to flow toward the first oil seal 26 in the gap space 28b. Under this influence, the first oil seal 26 is given a dynamic pressure from the soft lubricant 60-B toward the opposite side of the sealed space 28 in the axial direction X, that is, toward the external space.

  Here, when the hard lubricant 60-A is applied to the main bearing 50, the passage area in which the soft lubricant 60-B can flow in the main bearing 50 by the volume of the hard lubricant 60-A. Will decrease. Thereby, compared with the case where the hard lubricant 60-A is not applied, the soft lubricant 60-B is less likely to flow toward the first oil seal 26 inside the main bearing 50. The filling of the space 28c on the first oil seal 26 side with the soft lubricant 60-B can be delayed. As a result, the dynamic pressure applied from the soft lubricant 60-B to the first oil seal 26 can be reduced at the initial stage when the rotating body 22 starts to rotate, and the lubricant from the place where the first oil seal 26 is disposed can be reduced. Leakage can be suppressed.

  The lower limit value of the enclosed amount of the lubricants 60-A and 60-B is not particularly limited in relation to measures against leakage of the lubricants 60-A and 60-B, but it is 25% or more of the enclosed space volume. It may be set. If this condition is satisfied, the lubricants 60-A and 60-B can be easily distributed to the entire portion where lubrication is required in the enclosed space 28, and the necessary lubrication is performed throughout the portion where the lubrication is required. It becomes easy to ensure the property. In this embodiment, the places where lubrication is required include the eccentric body bearing 36 and the main bearing 50, as well as the meshing position of the gear of the speed reduction mechanism 20, the input shaft bearing 52, and the like.

  According to the wheel drive device 10 of the present embodiment, the amount of lubricant 60-A, 60-B filled is set to 35% or less of the enclosed space volume, and therefore lubrication from the location where the first oil seal 26 is disposed. Effective countermeasures against agent leakage.

Next, a description will be given of the external structure of the enclosed space 28 of the wheel drive device 10.
Consider an example of a path followed by the lubricant 60 when the lubricant 60 leaks outside from the position where the first oil seal 26 is disposed. FIG. 4 is a view for explaining a path followed by the lubricant 60 from the place where the first oil seal 26 is disposed. The lubricant 60 leaking to the outside is transmitted to the side surface portion 22a of the rotating body 22 while transmitting the inner peripheral portion of the rotating body 22 outward in the axial direction (see arrow Pa1). When the rotating body 22 is stationary, the lubricant 60 transmitted to the side surface portion 22a of the rotating body 22 is transmitted to the outer peripheral end portion by its own weight and from there to the running surface 16a of the rotating body 22. It tries to propagate toward the contact surface 22b (see arrow Pa2). If the lubricant 60 is transmitted to the contact surface 22b of the rotating body 22, there is a concern about an adverse effect. Therefore, countermeasures are required.

  FIG. 5 is an enlarged view of a part of FIG. Therefore, as shown in FIGS. 1 and 5, the wheel drive device 10 of this embodiment includes a swing plate 62 that is fixed to the rotating body 22 and can rotate integrally with the rotating body 22. The swing-off plate 62 of the present embodiment is individually fixed to the side surface portions 22 a on both sides in the axial direction X of the rotating body 22. The swing-off plate 62 is for swinging off the lubricant 60 leaking from the place where the first oil seal 26 is disposed.

  The swing plate 62 is a plate body having a ring shape extending outward in the radial direction as a whole. The swing plate 62 of the present embodiment includes a ring portion 62a having a flat ring shape, and a bent portion 62b bent from the outer peripheral end portion of the ring portion 62a toward the counter-rotator in the axial direction X. The counter-rotating body side in this specification refers to the side opposite to the side where the rotating body 22 in the axial direction X is present, with reference to the component (here, the ring portion 62a) referred to.

  The ring portion 62a is superimposed on the side surface portion 22a of the rotating body 22, and is detachably fixed to the side surface portion 22a of the rotating body 22 by a bolt B1 penetrating the ring portion 62a. In the present embodiment, the inner peripheral surface of the ring portion 62a is provided at a position aligned with the inner peripheral surface 22c of a part of the rotating body 22 adjacent to the swing plate 62 in the axial direction X. The bent portion 62b has a tapered shape that increases in diameter toward the counter-rotating body. The bent portion 62b of the present embodiment has a frustoconical shape that extends continuously around the rotation center line La of the tire 14 over the entire circumference.

  In the present embodiment, the outer peripheral end 62 c of the swing plate 62 is provided at a position offset radially inward from the boundary surface 64 between the tire 14 and the wheel 44. It can be understood that the outer peripheral end 62c of the swing plate 62 is provided at a position offset radially inward from the contact surface 22b of the rotating body 22. In this embodiment, the outer peripheral end 62c of the swing plate 62 is the outer peripheral end of the bent portion 62b.

  The lubricant 60 leaking outside from the place where the first oil seal 26 is disposed is transmitted to the outer surface of the swing-off plate 62 in the middle of transmitting the outer surface of the rotating body 22. When the rotating body 22 rotates, the lubricant 60 transmitted to the outer surface of the swinging plate 62 rotates radially from the outer peripheral end 62c of the swinging plate 62 by rotating the swinging plate 62 integrally with the rotating body 22. It is shaken off in the direction Pb to go. Thus, the lubricant 60 can be separated from the rotating body 22 before being transmitted to the contact surface 22b of the rotating body 22. Therefore, according to the present embodiment, even when the lubricant 60 leaks out, it is possible to prevent the adverse effect caused by the lubricant 60 being transmitted to the contact surface 22b of the rotating body 22 and to effectively prevent the lubricant 60 from leaking. I can plan.

  Further, the swing plate 62 has a bent portion 62b bent from the ring portion 62a to the counter-rotating body side. Consider the case where the swinging plate 62 does not have the bent portion 62b. In order to separate the lubricant 60 from the rotating body 22, it is necessary to dispose the outer peripheral end portion 62 c of the swing plate 62 at a position away from the side surface portion 22 a of the rotating body 22. When the swing plate 62 does not have the bent portion 62b, in order to satisfy this condition, in the example of this figure, the swing plate 62 is swinged to a position offset at least radially outward from the boundary surface 64 of the tire 14 and the wheel 44. It is necessary to arrange the outer peripheral end 62c of the plate 62 (the outer peripheral end of the ring portion 62a). For this reason, the outer diameter dimension of the swinging plate 62 increases excessively.

  In this regard, when the swinging plate 62 has a bent portion 62b, the outer peripheral end 62c of the swinging plate 62 is located at a position away from the side surface 22a of the rotating body 22 regardless of the shape of the side surface 22a of the rotating body 22. Can be placed. Therefore, when separating the lubricant 60 from the rotating body 22, the outer diameter of the swing plate 62 can be reduced, and the swing plate 62 can be reduced in size. Further, by reducing the outer diameter dimension of the swing plate 62, the peripheral speed at the outer peripheral end 62c of the swing plate 62, which is the location where the lubricant 60 is swinged, can be reduced. Thereby, the speed of the lubricant 60 shaken off from the swing-off plate 62 can be suppressed, and scattering of the lubricant 60 around the portion that has received the lubricant 60 can be suppressed.

Next, other features of the wheel drive device 10 will be described.
As shown in FIG. 1, the wheel driving device 10 includes a wheel cover 48 that covers the rotating body 22. FIG. 6 is a partial cross-sectional view of a part of the wheel drive device 10 of FIG. As shown in FIGS. 1 and 6, the wheel cover 48 includes an outer peripheral cover portion 48 a that covers the rotating body 22 from the outer peripheral side, side cover portions 48 b and 48 c that cover the rotating body 22 from the axial direction X, and the rotating body 22. An opening 48d protruding downward is provided.

  The cross-sectional shape orthogonal to the axial direction X of the outer peripheral cover portion 48a is an arc shape that opens downward. Inner flange portions 48f projecting from one circumferential end portion 48e toward the other circumferential end portion 48e are provided at both circumferential end portions 48e of the outer peripheral cover portion 48a.

  The side covers 48b and 48c include an inner side cover 48b disposed on the vehicle body 12 side in the axial direction X from the rotating body 22, and an outer side cover portion disposed on the side opposite to the vehicle body in the axial direction X from the rotating body 22. 48c. The inner carrier 24-A is fixed to the inner side cover portion 48b by a carrier bolt B2, and a part of the outer carrier 24-B is fixed to the outer side cover portion 48c by fitting. Thus, the wheel cover 48 functions as a member integrated with the carrier 24 (fixing member).

  A cylindrical portion 48g extending in the axial direction X is provided on the radially inner side of the inner side cover portion 48b. The input shaft 18 is inserted inside the cylindrical portion 48g. The end of the cylindrical portion 48g on the vehicle body is abutted against the vehicle body 12 and connected by bolts. Thereby, the wheel cover 48 is assembled to the vehicle body 12.

  As shown in FIGS. 5 and 6, the opening 48 d is formed at the lower end of the wheel cover 48 and opens downward. Each of the opening portions 48d is formed by both circumferential end portions 48e of the outer peripheral cover portion 48a and lower edge portions 48h of the respective side cover portions 48b. A first gap 66 is formed between the lower edge portion 48 h forming the opening 48 d of the side cover portion 48 b and the rotating body 22. A second gap 68 is formed between the rotating body 22 and a circumferential end 48e that forms the opening 48d of the outer cover 48a. The first gap 66 is formed on both sides of the rotating body 22 in the axial direction, and the second gap 68 is formed on both sides of the rotating body 22 in the running direction.

  Consider a path followed by the lubricant 60 leaking outside from the location where the first oil seal 26 is disposed. The route followed by the lubricant 60 leaked to the outside is between the wheel cover 48 and the rotating body 22 and the first path passing through the first gap 66 between the wheel cover 48 and the rotating body 22. There is a second path passing through the second gap 68. In the first path, in addition to the lubricant 60 that is transmitted through the side surface portion 22 a of the rotating body 22, the lubricant 60 that is transmitted along the inner surface of the side cover portion 48 b of the wheel cover 48 attempts to pass. In the second path, the lubricant 60 that falls along the inner peripheral surface of the outer peripheral cover portion 48a of the wheel cover 48 tends to pass. The lubricant 60 adhering to the inner surface of the side cover portion 48b of the wheel cover 48 and the inner peripheral surface of the outer peripheral cover portion 48a is shaken off by the swing plate 62 and leaks from the location where the first oil seal 26 is disposed. It becomes a part of the lubricant 60. That is, the lubricant 60 passing through either the first path or the second path leaks from the location where the first oil seal 26 is disposed.

  The wheel drive device 10 includes oil pans 70 and 72 for receiving the lubricant 60 leaking from the place where the first oil seal 26 is disposed. The oil pans 70 and 72 include a first oil pan 70 that receives the lubricant 60 that passes through the first gap 66 described above, and a second oil pan 72 that receives the lubricant 60 that passes through the second gap 68 described above. . The wheel drive device 10 also includes a pan support member 74 that supports the first oil pan 70.

  As shown in FIG. 5, the first oil pan 70 of the present embodiment is disposed below the first gap 66 described above on one axial side of the rotating body 22. The first oil pan 70 of this embodiment is disposed at a position offset radially inward from the boundary surface 64 between the tire 14 and the wheel 44. The first oil pan 70 of the present embodiment is individually provided corresponding to each of the first gaps 66 on both sides in the axial direction of the rotating body 22 (see FIG. 1).

  FIG. 7 is an external view of a part of the wheel drive device 10 of FIG. 1 as viewed from the side opposite to the vehicle body. The first oil pan 70 is a long member that is long in the running direction Y of the tire 14. In other words, the first oil pan 70 extends in the traveling direction Y of the tire 14. As shown in FIGS. 5, 7, and 8, the first oil pan 70 has a first pan portion 70 a that receives the lubricant 60. The first pan portion 70a has a box shape that opens upward, and can store the lubricant received inside. The first pan portion 70 a is disposed vertically below the outer peripheral end portion 62 c of the swing plate 62. As a result, the first pan portion 70a receives the lubricant 60 that has been shaken off in the direction Pb from the outer peripheral end 62c of the swing plate 62 toward the radially outer side. Further, both end portions 70 b in the longitudinal direction of the first pan portion 70 a are disposed below the outer peripheral surface of the outer peripheral cover portion 48 a of the wheel cover 48.

  FIG. 8 is a plan view showing the first oil pan 70 and the second oil pan 72. As shown in FIGS. 6 and 8, the second oil pan 72 of the present embodiment is disposed below the second gap 68 on one side in the traveling direction Y from the rotating body 22. The second oil pan 72 of the present embodiment is individually provided corresponding to each of the second gaps 68 on both sides in the traveling direction Y of the rotating body 22.

  The second oil pan 72 extends in the axial direction X of the tire 14. The second oil pan 72 includes a second pan portion 72 a that receives the lubricant 60 and a second fixing portion 72 b that is fixed to the wheel cover 48. The second pan portion 72a is long and long along the axial direction X, and has a groove shape that opens upward. Both end portions 72c in the longitudinal direction of the second pan portion 72a of the present embodiment have a shape opened toward both outer sides in the longitudinal direction.

  9 is a cross-sectional view taken along line AA in FIG. The second pan part 72 a of the present embodiment is disposed above the first pan part 70 a of the first oil pan 70. As a result, the lubricant 60 in the second pan part 72a is transferred from the longitudinal end part 72c into the first pan part 70a in the direction Pc. Thus, the second oil pan 72 is provided so that the lubricant in the second oil pan 72 can be guided into the first oil pan 70.

  As shown in FIG. 6, the 2nd fixing | fixed part 72b comprises the plate shape piled up from the lower side to the inner collar part 48f of the wheel cover 48, and is detachably fixed by the volt | bolt B3. The second oil pan 72 is fixed to the circumferential end portion 48 e of the outer peripheral cover portion 48 a of the wheel cover 48.

  Each of FIGS. 10A to 10C is a view of the pan support member 74 viewed from the side opposite to the rotating body, a view viewed from the rotating body side, and a view viewed from one side in the traveling direction Y. The pan support member 74 is a long member that is long along the traveling direction Y of the tire 14. As shown in FIGS. 5 and 10, the pan support member 74 has a pan storage portion 74 a in which the first oil pan 70 is stored inside. The bread storage part 74a has a groove shape that extends along the longitudinal direction of the bread support member 74 and opens upward. The bread storing portion 74a is disposed below the first gap 66 described above. Further, the pan storage portion 74 a is disposed at a position offset radially inward from the boundary surface 64 between the tire 14 and the wheel 44.

  The pan storage portion 74a includes a bottom wall portion 74b that supports the first oil pan 70, an inner wall portion 74c that rises from the rotating body side of the bottom wall portion 74b, and an outer wall portion 74d that rises from the counter-rotating body side of the bottom wall portion 74b. Have The outer wall portion 74d extends upward from the inner wall portion 74c and is disposed on the counter-rotating body side from the side cover portion 48b of the wheel cover 48. The outer side wall portion 74d is overlapped with the side cover portion 48b of the wheel cover 48 in the axial direction X, and is fixed to the wheel cover 48 so as to be detachable by a bolt B4. The pan support member 74 is integrated with the carrier 24 together with the wheel cover 48. The first oil pan 70 is supported by a pan support member 74 that is integrated with the carrier 24.

  The first oil pan 70 and the pan support member 74 of the present embodiment are made of a soft magnetic material such as steel. As shown in FIGS. 5 and 7, a magnet 76 is attached to the lower surface of the first pan portion 70 a of the first oil pan 70 by adhesion or the like. The magnet 76 of the present embodiment is a long plate-like body that is long along the longitudinal direction of the first pan portion 70a. The magnet 76 of this embodiment is attached to the 1st pan part 70a in the range from the one end part of the longitudinal direction of the 1st pan part 70a to the other end part. The magnet 76 attracts the pan support member 74 by magnetic force. Thereby, the first oil pan 70 is held by the magnetic force of the magnet 76 with respect to the pan support member 74.

  The bread storing portion 74a has inclined portions 74e that rise from the ends on both sides in the longitudinal direction of the bottom wall portion 74b. The inclined portion 74e has a plate shape having a smaller dimension in the width direction perpendicular to the longitudinal direction than the bottom wall portion 74b.

  FIG. 11 is a diagram illustrating a part of the first oil pan 70 and the pan support member 74. The inclined portion 74 e of the bread support member 74 is inclined upward toward the outside in the longitudinal direction of the bread support member 74. Here, the outside in the longitudinal direction means the outside in the longitudinal direction of the bread support member 74 from the space in the bread storage portion 74a.

  Consider a case where one end of the first oil pan 70 is pulled in the pulling direction Pd toward the one side in the longitudinal direction of the pan support member 74. As shown in FIG. 11A, after pulling until one end of the first oil pan 70 comes into contact with the inclined portion 74e of the pan support member 74, if the first oil pan 70 is pulled strongly in the same direction, The oil pan 70 is guided to move upward by the inclined portion 74e. At this time, since the first oil pan 70 is separated from the bottom wall portion 74b of the pan support member 74, the holding force by the magnet 76 is weakened, and the first oil pan 70 is easily pulled out. The first oil pan 70 is pulled out from the pan support member 74 by continuously pulling the first oil pan 70 in the pulling direction Pd. When the first oil pan 70 is pulled out, the first oil pan 70 is pulled out of the pan support member 74 while being slid with respect to the pan storage portion 74a of the pan support member 74.

  Thus, the first oil pan 70 can be pulled out in the pulling direction Pd toward the one side in the longitudinal direction of the pan support member 74. The first oil pan 70 of this embodiment is not fixed to the pan support member 74 by bolts, pins, or the like, and can be pulled out from the pan support member 74 only by pulling out. Here, “can be pulled out” includes the case where the first oil pan 70 is fixed to the pan support member 74 with bolts, pins, etc., and these bolts, pins, etc. are removed and then pulled out. Of course, it is preferable that the first oil pan 70 can be pulled out from the pan support member 74 only by the pulling out operation as in the present embodiment.

  The first oil pan 70 pulled out from the pan support member 74 can be pushed into the pan support member 74 by moving in the direction opposite to the pulling direction Pd. Thus, it can be said that the first oil pan 70 can be inserted and removed in the longitudinal direction of the bread support member 74 with respect to the bread storage part 74 a of the bread support member 74.

  As shown in FIGS. 8 and 11, the first oil pan 70 is provided at a location different from the inner wall surface of the first pan portion 70 a, and an object is removed when the first oil pan 70 is pulled out from the pan support member 74. It has the hook part 70c which can be hooked. The object here is an operator's finger or tool. The hook 70c is provided at the end of the first oil pan 70 on the pulling direction Pd side. Specifically, the first pan portion 70a has a standing wall portion 70d that forms a lubricant storage chamber and rises from the bottom wall portion at an end portion on the drawing direction Pd side. The hanging portion 70c has a plate shape extending in the drawing direction Pd from the upper end portion of the standing wall portion 70d of the first pan portion 70a. A hanging hole 70e for inserting an object is formed in the hanging portion 70c, and the object is hooked by inserting the object through the hanging hole 70e.

The effect of the wheel drive device 10 will be described.
The wheel drive device 10 includes oil pans 70 and 72 that receive the lubricant 60 leaking from the first oil seal 26. Therefore, the lubricant leaking from the first oil seal 26 can be prevented from falling to the floor surface by the oil pans 70 and 72, and a countermeasure for leakage of the lubricant 60 can be effectively achieved.

  When attaching and detaching the first oil pan 70, it is often difficult to secure a working space on both sides of the wheel drive device 10 in the axial direction X. For example, there is a vehicle body 12 on the vehicle body side with respect to the wheel drive device 10 and structures are often present on the side opposite to the vehicle body. In this example, the structure here is a storage shelf in which luggage is delivered to and from the transport carriage. On the other hand, if it is the space on either side of the traveling direction Y with respect to the wheel drive device 10, it is easy to secure a work space used for attaching / detaching the first oil pan 70. In the present embodiment, the first oil pan 70 can be pulled out in the longitudinal direction of the pan support member 74 that is the running direction Y of the tire 14. Therefore, the operation of pulling out the first oil pan 70 is facilitated while avoiding interference with surrounding structures of the wheel drive device 10. In addition, there is an advantage that the first oil pan 70 can be removed and attached without disassembling the wheel drive device 10.

  The first oil pan 70 is held on the pan support member 74 by the magnetic force of the magnet 76. Accordingly, it is possible to prevent the first oil pan 70 from being detached from the pan support member 74 due to vibration during traveling of the wheel drive device 10 while easily detaching the first oil pan 70 from the pan support member 74.

  The inclined portion 74 e of the bread support member 74 is inclined upward toward the outside in the longitudinal direction of the bread support member 74. Therefore, by pulling the first oil pan 70 strongly, the first oil pan can be pulled out from the pan support member 74 while being guided by the inclined portion 74e of the pan support member 74.

  The first oil pan 70 has a hooking portion 70 c on which an object is hooked when the first oil pan 70 is pulled out from the pan support member 74. Therefore, by hooking an object such as a finger on the hanging portion 70c of the first oil pan 70, it becomes easy to apply a pulling force to the first oil pan 70, and the workability when pulling out the first oil pan 70 is improved. .

  The oil pans 70 and 72 include a first oil pan 70 and a second oil pan 72. Therefore, the lubricant passing through both the first gap 66 and the second gap 68 can be received by the oil pans 70 and 72, and the oil pans 70 and 72 can be used to take measures against leakage of the lubricant 60 over a wide range.

  The second oil pan 72 is provided in the first oil pan 70 so that the lubricant 60 can be guided. Therefore, the lubricant 60 received by the second oil pan 72 is also collected in the first oil pan 70. For this reason, only the lubricant of the first oil pan 70 needs to be recovered during the recovery operation of the lubricant 60, and the number of work steps required for the recovery operation can be reduced.

  The first oil pan 70 is disposed vertically below the outer peripheral end 62 c of the swing plate 62. Therefore, the lubricant swung off by the swinging plate 62 is received by the first oil pan 70 and collected in the first oil pan 70.

  A part (both end portions) of the first oil pan 70 is disposed below the outer peripheral surface of the outer peripheral cover portion 48 a of the wheel cover 48. Therefore, compared with the case where the first oil pan 70 is disposed only inside the wheel cover 48 or below the opening 48d, it becomes easier to visually check the storage state of the lubricant in the first oil pan 70 from the outside. As a result, it is possible to easily determine whether or not it is necessary to recover the lubricant in the first oil pan 70 without removing the first oil pan 70 from the wheel drive device 10.

  As shown in FIG. 10, a bread recess 74 f that is recessed downward is formed on the upper part of the inner wall 74 c of the bread support member 74. The second pan 72a of the second oil pan 72 is disposed inside the bread recess 74f of the first pan 70a, so that interference with the second oil pan 72 is avoided. A swing plate recess 74g that is recessed downward is formed on the upper portion of the inner wall 74c of the first pan portion 70a. A part of the bent portion 62b of the swing plate 62 is disposed inside the swing plate recess 74g of the first pan portion 70a, and interference with the bent portion 62b of the swing plate 62 is avoided.

(Second Embodiment)
FIG. 12 is a front sectional view of a part of the wheel drive device 10 of the second embodiment. The wheel drive device 10 of the second embodiment does not include the oil pans 70 and 72 of the first embodiment. Further, the wheel drive device 10 of the second embodiment is different from the first embodiment mainly in the point of the swing plate 62 and the point provided with a lubricant absorbent 78 described later.

  The swing plate 62 of the second embodiment does not have the bent portion 62 b of the first embodiment, and the outer peripheral end portion of the ring portion 62 a becomes the outer peripheral end portion 62 c of the swing plate 62. The outer peripheral end 62 c of the swing plate 62 is provided at a position offset radially outward from the boundary surface 64 between the tire 14 and the wheel 44. The outer peripheral end 62c of the swing plate 62 of the present embodiment is provided at a position offset radially inward from the contact surface 22b that contacts the running surface 16a of the tire 14. Thereby, the lubricant 60 is spun off in the direction Pb from the outer peripheral end 62c of the swing plate 62 at a position away from the side surface 22a of the tire 14 of the rotating body 22. That is, also in the present embodiment, the lubricant 60 can be separated from the rotating body 22 before being transmitted to the contact surface 22b of the rotating body 22. Therefore, according to this embodiment, even when the lubricant 60 leaks out, it is possible to prevent the adverse effect caused by the lubricant 60 being transmitted to the contact surface 22b of the rotating body 22, and to effectively prevent the lubricant 60 from leaking. I can plan.

  FIG. 13 is a side sectional view showing the circumferential end 48e of the wheel cover 48. As shown in FIG. Please refer to FIG. 12 and FIG. The lubricant absorber 78 is for absorbing the lubricant 60 leaking from the location where the first oil seal 26 is disposed. The lubricant absorbent 78 includes a first lubricant absorbent 78-A attached to the rotating body 22 and a second lubricant absorbent 78-B attached to the wheel cover 48. The lubricant absorbent 78 is made of a material that absorbs liquid. Examples of the material include woven fabric and non-woven fabric.

  The first lubricant absorber 78 is provided in a path through which the lubricant leaking from the location where the first oil seal 26 is disposed travels on the outer surface of the rotating body 22. As this path, there is a joint 80 between the first oil seal 26 and the rotating body 22, and the first lubricant absorbent 78 of the present embodiment is provided so as to close the joint 80. Although not shown, the first lubricant absorber 78 is individually provided on both sides of the rotating body 22 in the axial direction X.

  The position of the first lubricant absorbent 78 with respect to the rotating body 22 is held by the swing plate 62. Specifically, the swing plate 62 has a pressing portion 62d bent from the inner peripheral end portion of the ring portion 62a toward the rotating body in addition to the ring portion 62a. The holding portion 62 d sandwiches the first lubricant absorbent 78 between the inner periphery of the rotating body 22 and holds the position of the first lubricant absorbent 78 with respect to the rotating body 22. As described above, the swing plate 62 is detachably fixed to the rotating body 22 and functions as a holding member that holds the position of the first lubricant absorbent 78. Since the swinging plate 62 also serves as the function of the holding member, the first lubricant absorbing material 78 -A can be detached from the rotating body 22 when the swinging plate 62 is detached from the rotating body 22. The holding member may be provided separately from the swing plate 62.

  The second lubricant absorbent 78-B is provided on a path along which the lubricant 60 attached to the inner peripheral surface of the outer peripheral cover portion 48a of the wheel cover 48 is transmitted. As this path, there is an upper surface of the inner flange portion 48f of the wheel cover 48, and the second lubricant absorbent 78-B of the present embodiment is provided on the upper surface of the inner flange portion 48f. The second lubricant absorber 78-B is disposed on the inner flange portion 48f of the wheel cover 48, and is held between the heads of the bolts B5, whereby the position with respect to the wheel cover 48 is maintained. The lubricant 60 adhering to the inner peripheral surface of the wheel cover 48 is shaken off by the swinging plate 62 and becomes a part of the lubricant 60 leaking from the place where the first oil seal 26 is disposed. That is, both the first lubricant absorbent 78 and the second lubricant absorbent 78-B absorb the lubricant 60 leaking from the location where the first oil seal 26 is disposed.

  According to the wheel drive device 10 described above, even when the lubricant 60 leaks from the location where the first oil seal 26 is disposed, the lubricant 60 is absorbed by the lubricant absorbent 78, so that the periphery of the lubricant 60 can be obtained. Can be prevented from spreading.

  In the above, the example of embodiment of this invention was demonstrated in detail. The above-described embodiments are merely specific examples for carrying out the present invention. The contents of the embodiments do not limit the technical scope of the present invention, and many design changes such as changes, additions, deletions, etc. of constituent elements are possible without departing from the spirit of the invention defined in the claims. Is possible. In the above-described embodiment, the contents that can be changed in the design are described with the notation of “embodiment”, “in the embodiment”, and the like. Changes are not unacceptable. Moreover, the hatching given to the cross section of drawing does not limit the material of the hatched object.

  Although the wheel drive device 10 has been described as being incorporated into a transport carriage, the assembly partner is not particularly limited. Moreover, although this conveyance trolley demonstrated the tracked trolley as an example, a trackless trolley | bogie may be sufficient.

  The speed reduction mechanism 20 has been described by taking an eccentric oscillating speed reduction mechanism as an example, but the type thereof is not particularly limited. For example, any of a planetary gear mechanism, a parallel shaft gear mechanism, an orthogonal shaft gear speed reduction mechanism, a flexure meshing speed reduction mechanism, and the like may be included.

  The eccentric body 32 has been described as an example separate from the input shaft 18, but may be provided as a part of the same single member as the input shaft 18. The example in which the first inner ring 36c of the eccentric body bearing 36 is configured by a member different from the eccentric body 32 has been described, but may be configured by a part of the same member as the eccentric body 32. Although the first outer ring 36 d of the eccentric body bearing 36 has been described as being configured by a part of the same member as the external gear 34, it may be configured by a member different from the external gear 34.

  Although an example in which a lubricant having a consistency number 2 is used for the hard lubricant 60-A and a lubricant having a consistency number 00 is used for the soft lubricant 60-B has been described, the present invention is not limited thereto. . For example, hard lubricant 60-A and soft lubricant 60-B use lubricants having the same consistency number, and soft lubricant 60-B uses a lubricant with a blending consistency greater than hard lubricant 60-A. It may be used. In addition, the consistency number of the lubricant used by the hard lubricant 60-A and the soft lubricant 60-B is not particularly limited. Even in this case, as the soft lubricant 60-B, a lubricant having a consistency number greater than the consistency range corresponding to the consistency number used by the hard lubricant 60-A is used. It may be.

  Moreover, although the example in which the lubricant 60 includes two types of lubricants having different blending degrees has been described, three or more types of lubricants may be included. That is, the lubricant 60 only needs to contain at least two types of lubricants having different blending degrees. Moreover, although the lubricant 60 demonstrated the example of grease, the kind is not limited to this, For example, you may make soft lubricant 60-B into lubricating oil.

  In the case where the encapsulating amount of the lubricant 60 is set to 35% or less of the enclosing space volume, the example in which the hard lubricant 60-A is applied to both the eccentric body bearing 36 and the main bearing 50 has been described. You may apply | coat and may apply | coat to another lubrication required location.

  Further, when combined with one or both of the swing plate 62 and the oil pans 70 and 72, the amount of the lubricant 60 enclosed may be set to be more than 35% of the enclosed space volume. Further, the oil pans 70 and 72 have been described by way of example in combination with the swing-off plate 62, but may be used without being combined with the swing-off plate 62.

  The example in which the swing plate 62 is fixed to the side surface portion 22a of the rotating body 22 has been described. However, the lubricant 60 leaking from the location where the first oil seal 26 is disposed is fixed on a path along the outer surface of the rotating body 22. If so, the position is not particularly limited. For example, the swing plate 62 may be fixed to the outer peripheral portion of the rotating body 22 in addition to the side surface portion 22 a of the rotating body 22.

  The example in which the first oil pan 70 can be extracted from the pan support member 74 only by the extraction operation has been described. The example in which the pulling direction Pd of the bread support member 74 is the longitudinal direction of the bread support member 74 has been described, but is not limited thereto, and may be, for example, the vertical direction intersecting the longitudinal direction of the bread support member 74. The first oil pan 70 may be fixed to a fixing member such as the pan support member 74 or the carrier 24 using a bolt or the like.

  The pan support member 74 has been described by taking the configuration having the inclined portion 74e as an example, but may be configured without the inclined portion 74e. When the first oil pan 70 is not fixed to the pan support member 74, the inclined portion 74 e of the pan support member 74 has a function of guiding the first oil pan 70 and a contact with the first oil pan 70. The function of regulating the relative displacement in the longitudinal direction of the first oil pan 70 by the contact is exhibited.

  Although the magnet 76 demonstrated the example attached to the lower surface of the 1st oil pan 70, the attachment position is not specifically limited. For example, it may be attached to another part of the first oil pan 70 or may be attached to the pan support member 74.

  The specific shape of the hanging portion 70c of the first oil pan 70 is not particularly limited as long as it is a shape that can hook an object. For example, the convex part used as the handle which protrudes from the 1st bread | pan part 70a, the hollow etc. which can hook the object provided in the outer wall surface of the 1st bread | pan part 70a may be sufficient.

  Although the example in which the pan support member 74 is fixed to the wheel cover 48 has been described, it may be fixed to the carrier 24. Moreover, if there is another member integrated with the carrier 24, the pan support member 74 may be fixed to the integrated member.

  Since the second oil pan 72 is provided so that the lubricant in the second oil pan 72 can be guided into the first oil pan 70, the longitudinal end portion 72c of the second pan portion 72a faces outward in the longitudinal direction. Although the example which made it the open shape was demonstrated, the specific structure is not specifically limited. For example, a through hole may be provided in the bottom wall portion of the end portion 72c of the second pan portion 72a so that it can be guided into the first oil pan 70 from the through hole.

  Further, the example in which the second oil pan 72 is provided so that the lubricant received by the second oil pan 72 can be guided to the first oil pan 70 has been described. In addition, the first oil pan 70 may be provided so that the lubricant received by the first oil pan 70 can be guided by the second oil pan 72. In this case, in order to easily collect the lubricant 60 collected in the second oil pan 72, the second oil pan 72 is supported by the pan support member 74, and the second oil pan 72 is pulled out from the pan support member 74. It may be possible.

  The shape of the first oil pan 70 and the second oil pan 72 is not particularly limited as long as it can receive the lubricant 60. Moreover, although the case where both the 1st oil pan 70 and the 2nd oil pan 72 were used together was demonstrated to the example, only any one may be used.

DESCRIPTION OF SYMBOLS 10 ... Wheel drive device, 14 ... Tire, 20 ... Deceleration mechanism, 22 ... Rotating body, 28 ... Enclosed space, 32-A, 32-B ... Eccentric body, 34 ... External gear, 36 ... Eccentric body bearing, 44 ... Wheel, 46 ... casing, 48 ... wheel cover, 48a ... outer periphery cover, 48b ... side cover, 48d ... opening, 50 ... main bearing, 60-A ... hard lubricant, 60-B ... soft lubricant, 62 ... swinging plate, 62a ... ring part, 62b ... bent part, 64 ... boundary surface, 66 ... first gap, 68 ... second gap, 70 ... first oil pan, 70c ... hanging part, 72 ... second oil pan, 74: Pan support member, 74e: Inclined portion, 76: Magnet, 78 ... Lubricant absorber.

Claims (15)

A speed reduction mechanism that decelerates the rotation transmitted from the drive source;
A rotating body in which rotation reduced by the speed reduction mechanism is transmitted and a tire is integrated;
A fixing member that rotatably supports the rotating body;
An oil seal that is disposed between the rotating body and the fixing member and seals a space in which the speed reduction mechanism is stored;
A wheel drive device comprising a lubricant sealed in a sealed space sealed by the oil seal,
The lubricant includes at least two kinds of lubricants having different penetrations,
The wheel drive device, wherein an amount of the lubricant enclosed is 35% or less of a volume of the enclosure space.   The wheel drive device according to claim 1, wherein an amount of the lubricant enclosed is 25% or more of a volume of the enclosure space. The deceleration mechanism is
An eccentric body,
An external gear that is swung by the eccentric body;
An eccentric body bearing disposed between the eccentric body and the external gear,
The lubricant is
A hard lubricant applied to the eccentric body bearing;
The wheel drive device according to claim 1, further comprising a soft lubricant having a higher miscibility than the hard lubricant. A main bearing disposed between the rotating body and the fixing member at a position closer to the enclosed space than the oil seal;
The lubricant is
A hard lubricant applied to the main bearing;
The wheel drive device according to any one of claims 1 to 3, further comprising a soft lubricant having a higher miscibility than the hard lubricant. A speed reduction mechanism that decelerates the rotation transmitted from the drive source;
A rotating body in which rotation reduced by the speed reduction mechanism is transmitted and a tire is integrated;
A fixing member that rotatably supports the rotating body;
An oil seal that is disposed between the rotating body and the fixing member and seals a space in which the speed reduction mechanism is stored;
A wheel drive device comprising a lubricant sealed in a sealed space sealed by the oil seal,
A wheel drive device comprising a swing plate that rotates integrally with the rotating body and shakes off the lubricant leaking from the location where the oil seal is disposed.   The wheel drive device according to claim 5, wherein the swing plate includes a ring portion that is fixed to the rotating body, and a bent portion that is bent from the outer peripheral end of the ring portion toward the counter-rotating body in the axial direction. The rotating body has a wheel on which the tire is mounted on an outer periphery,
The wheel drive device according to claim 5 or 6, wherein an outer peripheral end portion of the swing plate is provided at a position offset radially outward from a boundary surface between the tire and the wheel. Comprising a lubricant absorbent that absorbs the lubricant leaked from the location of the oil seal;
The wheel drive device according to any one of claims 5 to 7, wherein the swing plate is detachably fixed to the rotating body and holds a position of the lubricant absorbent with respect to the rotating body. A speed reduction mechanism that decelerates the rotation transmitted from the drive source;
A rotating body in which rotation reduced by the speed reduction mechanism is transmitted and a tire is integrated;
A fixing member that rotatably supports the rotating body;
An oil seal that is disposed between the rotating body and the fixing member and seals a space in which the speed reduction mechanism is stored;
A wheel drive device comprising a lubricant sealed in a sealed space sealed by the oil seal,
A wheel drive device comprising an oil pan that receives a lubricant leaking from an arrangement position of the oil seal.   The wheel drive device according to claim 9, wherein the oil pan is supported by a member integrated with the fixing member. A pan support member that is integrated with the fixing member and supports the oil pan;
The oil pan and the pan support member are long members that are long in the running direction of the tire,
The wheel drive device according to claim 9 or 10, wherein the oil pan can be pulled out in a longitudinal direction of the pan support member.   The wheel drive device according to claim 11, wherein the oil pan is held by a magnetic force of a magnet with respect to the pan support member.   The wheel drive device according to claim 11 or 12, further comprising an inclined portion that is inclined upward toward an outer side in a longitudinal direction of the pan support member at an end portion in a longitudinal direction of the pan support member. In the oil pan,
A first oil pan extending in a running direction of the tire;
A second oil pan extending in the axial direction of the tire,
The wheel drive device according to any one of claims 9 to 13, wherein one of the first oil pan and the second oil pan is provided so that the received lubricant can be guided to the other oil pan. A rotating plate that rotates integrally with the rotating body, and includes a swing-off plate that shakes off the lubricant leaked from the location where the oil seal is disposed,
The wheel drive device according to any one of claims 9 to 14, wherein the oil pan is disposed vertically below an outer peripheral end portion of the swing plate.

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