JP2015218748A - Thrust conical roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thrust conical roller bearing which can reduce and save the power of a mechanism and a machine which are embedded by suppressing torque at a start and a low-speed operation.SOLUTION: In this thrust conical roller bearing, a plurality of conical rollers 3 are rollingly interposed while being aligned in a circumferential direction between mutually-opposing raceway surfaces 1a, 2a of a rotation-side raceway ring 1 and a fixed-side raceway ring 2 which oppose each other in a direction of a rotation axial core C. The rotation-side raceway ring 1 has a large flange 11 larger than the raceway surface 1a at a large diameter side. A flange part 32 in which a side face 32b being a roller face contacts with the large flange 11 is arranged at a large-diameter side end of the conical roller 3. A contact position A contacting with the large flange 11 at the side face 32b of the flange part 32 is arranged on an extension of a rolling face 3a.

Description

  The present invention relates to a thrust tapered roller bearing used in a rotating part having a low speed and a large load in a construction machine, a distribution machine, an industrial machine and the like.

  FIG. 6 shows a conventional general thrust tapered roller bearing. A thrust tapered roller bearing is formed between a raceway surface 1a, 2a facing each other of a rotation side raceway ring 1 attached to a rotating body (not shown) and a fixed side raceway ring 2 attached to a fixing member (not shown). A plurality of tapered rollers 3 are interposed in a circumferential direction so as to be freely rollable. In this example, the roller axis O is a type orthogonal to the rotation axis C. Large ridges 11 and 21 are formed on the large-diameter side of the rotation-side raceway 1 and the fixed-side raceway ring 2, respectively, and the large end surfaces 3 b of the tapered rollers 3 are in contact with the large ridges 11 and 21.

JP 2002-89568 A JP 2004-60767 A

  Thrust tapered roller bearings mainly support axial loads, but are often used at low speeds and large loads. Due to the large load, the torque at the time of start-up and low-speed operation is large, which is a problem in reducing the power and saving power of the mechanism and machine in which the bearing is incorporated. A dominant factor of the starting torque is a sliding frictional force between the large end surface 3b of the tapered roller 3 and the large flanges 11 and 21 of the race rings 1 and 2 (particularly, the large flange 11 of the rotating side race ring 1). That is, since the contact positions A and B between the large end surface 3b of the tapered roller 3 and the large flanges 11 and 21 are not located on the extension of the rolling surface 3a of the tapered roller 3, the tapered rollers are at the contact positions A and B. 3 has a peripheral speed difference between the large end surface 3b and the large flanges 11 and 21, and slip occurs.

  An object of the present invention is to provide a thrust tapered roller bearing that can reduce torque during start-up and low-speed operation and reduce the power and power saving of a built-in mechanism or machine.

  In the thrust tapered roller bearing of the present invention, a plurality of tapered rollers can roll in the circumferential direction between the mutually facing raceway surfaces of the rotating side raceway and the stationary side raceway facing each other in the direction of the rotation axis. In the thrust tapered roller bearing intervening side by side, the rotating side raceway ring has a large flange on the larger diameter side than the raceway surface, and a side surface serving as a roller end surface is located on the large diameter side end of the tapered roller. The flange part which contacts a collar is provided, The contact position with the said large collar on the said side surface of this flange part is arrange | positioned on the extension of the said rolling surface, It is characterized by the above-mentioned.

The peripheral speed at an arbitrary point on the side surface of the flange portion is a speed obtained by adding the peripheral speed due to the rotation of the tapered roller and the peripheral speed due to the revolution of the tapered roller around the rotation axis of the bearing. The rotational speed of rotation and revolution of the tapered roller is determined by the rotational speed of the rotating raceway because the tapered roller is caused by rolling the raceway of the raceway. Further, the rotation speed of the tapered roller varies depending on the geometric dimensions of each part. The peripheral speed at an arbitrary point of the main shaft of the rotation side raceway is the speed due to the rotation around the rotation axis.
As in this configuration, when the tapered portion is provided with a flange portion, and the contact position of the rotating side raceway ring on the side surface of the flange portion is arranged on the extension of the rolling surface, the side surface of the flange portion at the contact position is There is no difference in the peripheral speed between the rotating side race ring and the collar, and no slip occurs between the side surface of the flange, which is the end surface of the tapered roller, and the rotating side race ring. For this reason, the torque at the time of starting and a low speed driving | operation can be suppressed, and the motive power reduction and labor saving of the mechanism and machine in which this thrust tapered roller bearing is incorporated can be achieved.

In this invention, the fixed-side raceway has a large flange that contacts the side surface of the flange portion of the tapered roller, and the contact position of the fixed-side track ring with the large flange on the side surface of the flange portion, You may arrange | position on the extension of the said rolling surface.
In this case, slip does not occur between the side surface of the flange portion, which is the end surface of the tapered roller, and the large flange of the fixed-side raceway, so that torque during startup and low-speed operation can be further suppressed.

In this invention, it is preferable that the flange portion has a truncated cone shape in which an outer peripheral surface extends from the maximum diameter portion of the rolling surface in a tapered shape with a larger inclination angle than the rolling surface.
In this case, since the diameter of the flange portion is the maximum at or near the side surface, the contact position with the large flange on the side surface of the flange portion should be on the extension of the rolling surface without increasing the diameter of the flange portion more than necessary. Can be arranged.

When the outer peripheral surface of the flange portion has a truncated cone shape, a stealing portion may be provided at a boundary portion between the rolling surface of the tapered roller and the outer peripheral surface of the flange portion.
Providing the stealing portion can prevent the flange portion from coming into contact with the raceway surfaces of the rotation side raceway and the stationary side raceway. Further, the stealing portion can be used as a lubricating oil reservoir.

In this invention, the roller diameter difference between the plurality of tapered rollers is within a range of 1 / 10,000 of the roller diameter, and the top three tapered rollers are circularly arranged in descending order of the roller diameter of the plurality of tapered rollers. It is good to arrange at equal intervals in the circumferential direction. The axial direction position of the roller diameter to be compared for obtaining the difference between the roller diameters is not particularly limited. For example, it is a center point between the maximum diameter position and the minimum diameter position.
By setting the difference in roller diameter between the plurality of tapered rollers to be within a range of 1 / 10,000 of the roller diameter, it is possible to support the rotation-side raceway with high precision and rotation with respect to the fixed-side raceway. In addition, when the top three tapered rollers are arranged equally in the circumferential direction in the descending order of the roller diameter among the plurality of tapered rollers that have determined the mutual roller diameter difference as described above, in the no-load state after the bearing is assembled, The upper three tapered rollers are preferentially rolled and guided. That is, it is possible to reduce the number of effective rollers that become rolling friction resistance, which is a dominant factor of operating torque. As a result, assembly adjustment is possible without increasing the torque.

In this invention, on the rolling surface of the tapered roller, a contact portion crowning portion that comes into contact with the raceway surface, and on the both sides in the roller axial direction of the contact portion crowning portion, the rotation side raceway and the fixed side raceway Forming a crowning portion composed of a non-contact portion crowning portion that is non-contact with each raceway surface, and each bus bar of the contact portion crowning portion and the non-contact portion crowning portion is expressed by a function different from each other and is smooth at a connection point. The curvature of the bus bar of the non-contact part crowning part may be smaller than the curvature of the bus bar of the contact part crowning part in the vicinity of the connection point. For example, a part or all of the generatrix of the contact portion crowning portion is a logarithmic crowning represented by a logarithmic curve.
The above “smoothly continuous” means continuous without generating a corner, and ideally, the bus bar of the contact portion crowning portion and the bus bar of the non-contact portion crowning portion are at the connection point of each other. Continue to have a common tangent. In other words, the bus is a function that can be continuously differentiated at the connection point.

According to this configuration, the crowning portion formed on the rolling surface of the tapered roller can reduce the surface pressure and the stress at the contact portion, thereby extending the life of the bearing. By providing the flange portion on the tapered roller, the effective length of the rolling surface is shortened with respect to the entire length of the tapered roller, but due to the effect of extending the rolling life by uniformizing the surface pressure of the crowning portion, the effective length of the tapered roller is reduced. Can compensate for the decrease. Therefore, even if it is the same cross-sectional shape as the conventional one, a load capacity equal to or higher than that can be obtained.
Furthermore, in the vicinity of the connection point between the contact part crowning part and the non-contact part crowning part, the curvature of the bus bar of the non-contact part crowning part is smaller than the curvature of the bus bar of the contact part crowning part. The amount of drop can be reduced. Therefore, for example, the amount of grinding can be suppressed as compared with that of a single arc crowning, the processing efficiency of the tapered roller can be improved, and the manufacturing cost can be reduced.

  In the thrust tapered roller bearing of the present invention, a plurality of tapered rollers can roll in the circumferential direction between the mutually facing raceway surfaces of the rotating side raceway and the stationary side raceway facing each other in the direction of the rotation axis. In the thrust tapered roller bearing intervening side by side, the rotating side raceway ring has a large flange on the larger diameter side than the raceway surface, and a side surface serving as a roller end surface is located on the large diameter side end of the tapered roller. Since the flange portion that contacts the flange is provided, and the contact position with the large flange on the side surface of the flange portion is arranged on the extension of the rolling surface, the torque is reduced during start-up and low-speed operation, and is incorporated. The power of the mechanism and machine can be reduced and labor can be saved.

It is a longitudinal cross-sectional view of the thrust tapered roller bearing which concerns on one Embodiment of this invention. It is the elements on larger scale of FIG. It is the top view which abbreviate | omitted the stationary side ring of the thrust tapered roller bearing. It is a longitudinal cross-sectional view of the thrust tapered roller bearing which concerns on different embodiment of this invention. It is a figure which shows the crowning shape of a tapered roller. It is a longitudinal cross-sectional view of the conventional thrust tapered roller bearing.

An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a thrust tapered roller bearing according to an embodiment of the present invention, and FIG. 2 is a partially enlarged view thereof. This thrust tapered roller bearing is rotatable between the rotating raceway 1 and the stationary raceway 2 facing each other in the direction of the rotation axis C, and the raceway surfaces 1a and 2a of the raceways 1 and 2 facing each other. A plurality of tapered rollers 3 interposed between the plurality of tapered rollers 3 and a retainer 4 that holds the plurality of tapered rollers 3. The rotation-side bearing ring 1 is attached to a rotating body (not shown) such as a shaft rotating around the rotation axis C, and the stationary-side bearing ring 2 is attached to a fixing member (not shown) of the housing. The rotation-side raceway 1 may be referred to as an inner ring, and the fixed-side raceway 2 may be referred to as an outer ring.

  The raceway surfaces 1a and 2a of the rotation-side raceway 1 and the fixed-side raceway ring 2 have buses L1 and L2 passing through the intersection P between the rotation axis C and the roller axis O of each tapered roller 3 around the rotation axis C. It is a truncated cone shape obtained by rotating it. In this embodiment, the rotational axis C and the axis O are orthogonal to each other, but the roller axis O may intersect the rotational axis C at an angle other than a right angle.

  The rotation-side bearing ring 1 is formed with an annular large collar 11 that protrudes greatly toward the fixed-side raceway 2 at the end on the large-diameter side, and slightly projects toward the fixed-side raceway 2 side at the end on the small-diameter side. An annular gavel 12 is formed. A portion between the raceway surface 1a and the large collar 11 on the surface facing the fixed side raceway ring 2 is an annular recess 1b that is recessed from the raceway surface 1a. Further, the fixed side raceway ring 2 is formed with an annular large collar 21 projecting greatly toward the rotation side raceway ring 1 at the end portion on the large diameter side, and slightly projecting toward the rotation raceway ring 1 side at the end portion on the small diameter side. The small gavel 22 is formed. A portion between the raceway surface 2a and the large collar 21 on the surface facing the rotation-side raceway ring 1 is an annular recess 2b that is recessed from the raceway surface 2a.

  The tapered roller 3 includes a roller main body portion 31 formed as a rolling surface 3 a having an outer periphery formed of a conical surface, and a flange portion 32 having a larger diameter than the roller main body portion 31. The flange portion 32 has a substantially truncated cone shape in which the outer peripheral surface 32a (FIG. 2) extends from the maximum diameter portion of the rolling surface 3a in a tapered shape with a larger inclination angle than the rolling surface 3a. It arrange | positions in each dent part 1b, 2b of the stationary side ring 2. Chamfers 33 and 34 are provided on the small-diameter end of the roller body 31 and the large-diameter end of the flange 32, respectively. Moreover, the side surface 32b of the flange part 32 used as a roller end surface is made into the convex surface shape which expanded so that it might go to the roller axis | shaft O side.

  In the assembled state of FIG. 1, the tapered roller 3 has a rolling surface 3 a that is in rolling contact with the raceway surfaces 1 a and 2 a of the rotation side raceway 1 and the stationary side raceway ring 2, and a side surface 32 b of the flange portion 32 is a rotation side raceway. The rings 1 and 21 are brought into contact with the large collars 11 and 21 of the fixed-side raceway ring 2. The outer peripheral surface 32 a of the flange portion 32 is not in contact with the recesses 1 b and 2 b of the rotation side raceway ring 1 and the fixed side raceway ring 2. The contact positions A and B with the large flanges 11 and 12 on the side surface 32b of the flange portion 32 are arranged on the extension of the rolling surface 3a. In order to arrange the contact positions A and B as described above, the cross-sectional shape of the inner diameter surface of the large flanges 11 and 21 is formed such that the locations where the contact positions A and B are swelled toward the rotation axis C.

  In order to support the rotation-side raceway ring 1 with respect to the fixed-side raceway ring 2 so as to be rotatable with high precision, the roller diameter difference between the tapered rollers 3 is set within a range of 1 / 10,000 of the roller diameter. The axial direction position of the roller diameter to be compared for obtaining the difference between the roller diameters is not particularly limited. For example, it is a center point between the maximum diameter position and the minimum diameter position. Further, as shown in FIG. 3, the upper three tapered rollers 3A, 3B, 3C are arranged equally in the circumferential direction in descending order of the diameter of the plurality of tapered rollers 3. That is, the angle between the roller axes O of the upper three tapered rollers 3A, 3B, 3C is 120 °. In FIG. 3, the rotation-side race 1 is not shown.

  Each tapered roller 3 is individually held in each pocket 4 a provided in the cage 4. The retainer 4 is assembled to the retainer body 41 formed with an incomplete pocket 4a having an open outer diameter side and the outer diameter side of the retainer body 41, thereby closing the opening portion of the incomplete pocket 4a. And a cage lid 42 that forms a complete pocket 4a. The cage body 41 and the cage lid 42 are fixed to each other by a plurality of pins 43.

  In this thrust tapered roller bearing, the peripheral speed at an arbitrary point on the side surface 32b of the flange portion 32 is that of the tapered roller 3 around the roller axis O and the tapered roller 3 centering on the rotational axis C of the bearing. This is the speed obtained by adding the peripheral speed due to revolution. The rotational speed of the tapered roller 3 during rotation and revolution is determined by the rotational speed of the rotating raceway ring 1 because the tapered roller 3 is caused by rolling the raceway surfaces 1 a and 2 a of the raceway rings 1 and 2. Further, the rotation speed of the tapered roller 3 varies depending on the geometric dimensions of each part. The peripheral speed at an arbitrary point of the large collar 11 of the rotation-side race 1 is a speed due to rotation around the rotation axis C.

  A flange portion 32 having a diameter larger than the maximum diameter portion of the rolling surface 3 a is provided on the tapered roller 3, and contact positions A and B of the race rings 1 and 2 with the large collars 11 and 21 on the side surface 32 b of the flange portion 32 are set. By disposing on the extension of the rolling surface 3a, the peripheral speed difference between the side surface 32b of the tapered roller 3 and the large flanges 11 and 21 at the contact positions A and B is eliminated. That is, at the rotation side contact position A, the circumferential speed due to the rotation of the tapered roller 3 and the circumferential speed due to the revolution are in the same direction, and the speed obtained by adding these is equal to the circumferential speed of the large cage 11 of the rotation side raceway ring 1. Become. At the contact position B on the fixed side, the peripheral speed due to the rotation of the tapered roller 3 and the peripheral speed due to the revolution are opposite to each other, and the sum of these becomes zero. Thus, the circumferential speed difference between the side surface 32b of the tapered roller 3 and the large flanges 11 and 21 is eliminated, so that the gap between the side surface 32b of the tapered roller 3 and the large flanges 11 and 21 of the raceway rings 1 and 21 is eliminated. No slip occurs. For this reason, the torque at the time of starting and a low speed driving | operation can be suppressed, and the motive power reduction and labor saving of the mechanism and machine in which this thrust tapered roller bearing is incorporated can be achieved.

  Since the flange portion 32 has a truncated cone shape in which the outer peripheral surface 32a is tapered from the maximum diameter portion of the rolling surface 3a, the diameter of the flange portion 32 is maximized in the vicinity of the side surface 32b where the chamfer 34 starts. The diameter of 32b can be taken large. Therefore, the contact positions A and B with the large flanges 11 and 21 on the side surface 32b of the flange portion 32 can be arranged on the extension of the rolling surface 3a without increasing the diameter of the flange portion 32 more than necessary.

  Further, in this thrust tapered roller bearing, since the upper three tapered rollers 3A, 3B, 3C are arranged in the circumferential direction in the descending order of the diameter of the plurality of tapered rollers 3, the bearings are incorporated. In the no-load state, the top three tapered rollers 3A, 3B, 3C are preferentially rolled and guided. That is, it is possible to reduce the number of effective rollers that become rolling friction resistance, which is a dominant factor of operating torque. As a result, assembly adjustment is possible without increasing the torque.

  FIG. 4 shows a different embodiment of the invention. This thrust tapered roller bearing is provided with a stealing portion 51 at a boundary portion between the rolling surface 3a of the tapered roller 3 and the outer peripheral surface 32a of the flange portion 32 with respect to the thrust tapered roller bearing of FIG. Providing the stealing portion 51 can prevent the flange portion 32 from coming into contact with the raceway surfaces 1 a and 2 a of the rotation side raceway ring 1 and the fixed side raceway ring 2. Further, the stealing portion 51 can be used as a lubricating oil reservoir.

  In each of the above-described embodiments, the contact positions A and B of the side surface 32b of the flange portion 32 with respect to the large collars 11 and 21 of the rotation side raceway ring 1 and the fixed side raceway ring 2 are arranged on the extension of the rolling surface 3a. However, you may arrange | position only the contact position A of the side surface 32b of the flange part 32 with respect to the large collar 11 of the rotation side bearing ring 1 on extension of the rolling surface 3a. The reason for this is that the dominant factor of the starting torque is mainly the sliding frictional force between the end surface 3b of the tapered roller 3 and the large flange 11 of the rotating side race 1, so that only the contact position A of the rolling surface 3a. The torque at the time of start-up and low-speed operation can be sufficiently suppressed only by arranging the extension.

  A crowning portion 52 may be formed on the rolling surface 3a of the tapered roller 3 as shown in FIG. Specifically, the crowning portion 52 is located at the center portion in the roller axis direction and contacts with the contact portion crowning portion 53 in contact with the raceway surfaces 1a and 2a (FIG. 1) of the rotation side raceway 1 and the fixed side raceway ring. Located on both sides of the crowning portion 53, the track surfaces 1a, 2a and non-contact non-contact portion crowning portions 54, 55 are formed.

  The buses that constitute the contact portion crowning portion 53 and the non-contact portion crowning portions 54 and 55 are lines that are expressed by different functions and smoothly connect to each other at the connection points Q1 and Q2. In the vicinity of the connection points Q1, Q2, the curvatures R2, R3 of the bus bars of the non-contact portion crowning portions 54, 55 are set smaller than the curvature R1 of the bus portion of the contact portion crowning portion 53. For example, the contact portion crowning portion 53 is a logarithmic crowning formed by a generatrix curve. The buses of the non-contact portion crowning portions 54 and 55 may be arcs.

  Thus, by forming the crowning on the rolling surface 3a of the tapered roller 3, the surface pressure and the stress at the contact portion can be reduced, and the life of the bearing can be extended. Further, by providing the tapered portion 3 with the flange portion 32, the effective length of the rolling surface 3a is shortened with respect to the entire length of the tapered roller 3, but due to the effect of extending the rolling life due to uniform surface pressure of the crowning portion. , The decrease in the effective length can be compensated. Therefore, even if it is the same cross-sectional shape as the conventional one, a load capacity equal to or higher than that can be obtained.

  Further, in the vicinity of the connection points Q1 and Q2 between the contact portion crowning portion 53 and the non-contact portion crowning portions 54 and 55, the curvatures R2 and R3 of the bus bars of the non-contact portion crowning portions 54 and 55 are Since it is smaller than the curvature R1 of the busbar, it is possible to reduce the drop amount at both ends of the tapered roller body 31. Therefore, for example, the amount of grinding can be suppressed as compared with that of a single arc crowning, the processing efficiency of the tapered roller can be improved, and the manufacturing cost can be reduced.

DESCRIPTION OF SYMBOLS 1 ... Rotation side race ring 1a ... Raceway surface 2 ... Fixed side race ring 2a ... Raceway surface 3 ... Tapered roller 3a ... Rolling surface 11 ... Large collar 21 ... Large collar 32 ... Flange part 32a ... Outer peripheral surface 32b ... Side surface 51 ... Stealing part 52 ... crowning part 53 ... contact part crowning part 54, 55 ... non-contact part crowning part A, B ... contact position C ... rotational axis

Claims (6)

In a thrust tapered roller bearing in which a plurality of tapered rollers are rotatably arranged side by side in the circumferential direction between the mutually facing raceway surfaces of the rotating side raceway and the stationary side raceway facing each other in the direction of the rotation axis. ,
The rotation-side raceway has a large flange on the larger diameter side than the raceway surface, and a flange portion is provided on the large-diameter side end of the tapered roller so that a side surface serving as a roller end surface is in contact with the large collar. A thrust tapered roller bearing characterized in that a contact position with the large flange on the side surface of the flange portion is arranged on an extension of the rolling surface.   2. The thrust tapered roller bearing according to claim 1, wherein the fixed-side raceway has a large flange that contacts a side surface of the flange portion of the tapered roller, and the fixed-side raceway of the fixed-side raceway on the side surface of the flange portion. A thrust tapered roller bearing in which the position of contact with the main shaft is arranged on an extension of the rolling surface.   3. The thrust tapered roller bearing according to claim 1, wherein the flange portion has a truncated cone shape in which an outer peripheral surface extends in a tapered shape from a maximum diameter portion of the rolling surface with a larger inclination angle than the rolling surface. Is a thrust tapered roller bearing.   The thrust tapered roller bearing according to claim 3, wherein a tapered portion is provided at a boundary portion between the rolling surface of the tapered roller and an outer peripheral surface of the flange portion.   5. The thrust tapered roller bearing according to claim 1, wherein a difference in roller diameter between the plurality of tapered rollers is within a range of 1 / 10,000 of a roller diameter, and the plurality of tapered rollers. A thrust tapered roller bearing in which the top three tapered rollers are arranged equally in the circumferential direction in descending order of the roller diameter.   The thrust tapered roller bearing according to any one of claims 1 to 5, wherein a contact portion crowning portion that contacts the raceway surface and a roller of the contact portion crowning portion are provided on the rolling surface of the tapered roller. Forming a crowning portion on both sides in the axial direction and comprising a non-contact portion crowning portion that is in non-contact with each raceway surface of the rotation-side raceway and the fixed-side raceway, the contact portion crowning portion and the non-contact portion crowning portion Are each expressed by a function different from each other and smoothly connected to each other at a connection point, and in the vicinity of the connection point, the curvature of the bus bar of the non-contact portion crowning portion is a bus line of the contact portion crowning portion. A thrust cone in which a part or all of the generatrix of the contact portion crowning portion is represented by logarithmic crowning. Roller bearings.

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