JP2012017064A - Wheel bearing and electric vehicle driving device - Google Patents

Abstract

An axial length of an electric vehicle driving device is shortened.
A wheel bearing 50 is fixed to a casing G and rolls on an outer ring 50a in which a first raceway 63a and a second raceway 63b are formed in a circumferential direction of an inner peripheral surface, and the first raceway 63a. A plurality of first rolling elements 60a, a plurality of second rolling elements 60b that roll on the second track 63b, a first retainer 61a that supports the first rolling elements 60a, and a second A third raceway 64 on which the first rolling element 60a rolls in the circumferential direction is formed in the second retainer 61b that supports the rolling element 60b and the outer peripheral surface 71, and an inner gear is provided on the inner peripheral surface. 34, a plurality of attachment points 68 for attaching the wheel, a wheel support portion 66 formed at an end of the first inner ring 50c, and an inner peripheral surface of the first inner ring 50c. The second rolling element 60 is in contact with the outer peripheral surface 71 of the 50c and circumferentially on the outer peripheral surface. There includes a second inner ring 50b the fourth raceway 70 rotating is formed, the.
[Selection] Figure 3-1

Description

  The present invention relates to a wheel bearing that supports an output shaft of a motor and an electric vehicle driving apparatus in which the wheel bearing is incorporated.

  Of the electric vehicle driving devices, those that drive the wheels are called in-wheel motors. An in-wheel motor is a drive device provided in the vicinity of a wheel provided in an electric vehicle. The in-wheel motor does not necessarily have to be stored inside the wheel. The in-wheel motor needs to be disposed inside the wheel or in the vicinity of the wheel. However, the interior of the wheel and the vicinity of the wheel are relatively narrow spaces. Therefore, the electric vehicle drive device used as an in-wheel motor is required to be downsized.

  As a bearing mechanism, Patent Document 1 discloses an internal bicycle transmission hub. In this bicycle internal transmission hub, an internal gear 51 is integrally formed on the inner peripheral surface of the drive body 22. In this transmission hub, the internal gear 51 of the drive body 22 is placed on the input side of the speed reducer.

  In Patent Document 2, an internal gear 40 c is formed on the inner diameter surface of the hub outer ring 46. In this hub, the hub outer ring 46 is bolted to the wheel 12 at the outer-diameter flange portion 46a, and the hub outer ring 46 rotates to drive the wheel.

Japanese Patent Laying-Open No. 2005-199904 (0025, FIG. 3) JP 2007-331476 A (FIG. 1)

  In designing an electric vehicle drive device, there are various options as to what machine elements are selected and how the selected machine elements are arranged. However, when the electric vehicle drive device is used as an in-wheel motor, there are various restrictions in order to reduce the size of the electric vehicle drive device. For example, a design in which a plurality of motors, a plurality of planetary gear mechanisms, and a wheel bearing are arranged on the same axis can be selected. However, this arrangement increases the axial length of the electric vehicle drive device. A design that reduces the thickness of the motor core or reduces the gear tooth width is effective in reducing the axial length of the electric vehicle drive device, but this design reduces the motor torque, Reduce the allowable transmission torque of the gear. In addition, when a certain arrangement of machine elements is selected, the machine elements of the conventional mode may not be used. For example, the bearing mechanism according to Patent Document 1 cannot be applied to the output side of the speed reducer. Further, the bearing mechanism according to Patent Document 2 is not applicable when the outer ring is fixed and the inner ring is rotated. In order to increase the degree of design freedom of the electric vehicle drive device used as an in-wheel motor, it can be applied to the output side of the reducer, and can also be applied to a mode in which the outer ring is fixed and the inner ring rotates, There is a need for a wheel bearing that can reduce the axial length of the electric vehicle drive device and reduce the size of the electric vehicle drive device. Furthermore, it is required to shorten the axial length of the electric vehicle drive device.

  The present invention has been made in view of the above, and can be applied to the output side of the speed reducer, and can also be applied to a mode in which the outer ring is fixed and the inner ring rotates, and the axial direction of the electric vehicle drive device Provided is a wheel bearing that can be reduced in length. Alternatively, the present invention provides an electric vehicle drive device having a reduced axial length.

  Therefore, a wheel bearing according to the present invention is fixed to a casing and has an outer ring in which a first raceway and a second raceway are formed in a circumferential direction of an inner peripheral surface, and a plurality of first wheels that roll on the first raceway. One rolling element, a plurality of second rolling elements that roll on the second track, a first retainer that supports the first rolling element, and a second support that supports the second rolling element. A second raceway in which the first rolling element rolls in the circumferential direction is formed on the outer circumferential surface, the first inner ring on which the inner gear is formed, and the wheel A plurality of attachment points are provided, a wheel support portion formed at an end portion of the first inner ring, an inner peripheral surface is in contact with an outer peripheral surface of the first inner ring, and the outer peripheral surface has a circumferential direction. And a second inner ring on which a fourth track on which the second rolling element rolls is formed.

  In the wheel bearing according to the present invention, since the internal gear is formed on the inner peripheral surface of the first inner ring, the axial length can be reduced as compared with the case where the internal gear and the bearing are separate members. . In the above configuration, the outer ring is fixed to the casing, and the first inner ring rotates together with the inner gear. Therefore, the wheel bearing according to the present invention can be applied to a mode in which the outer ring is fixed and the inner ring rotates. In addition, by dividing the inner ring into the first inner ring and the second inner ring, it is easy to apply an appropriate pressure to the wheel bearing.

  The wheel bearing according to the present invention is characterized in that a pitch circle diameter of the first rolling element is larger than a pitch circle diameter of the plurality of attachment points.

  Generally, the pitch circle diameter of the plurality of attachment points is limited to a certain range depending on the diameter of the wheel, and cannot be greatly increased. However, since the wheel bearing of the present invention has such a configuration, the space inside the wheel bearing, that is, the space inside the first inner ring can be widened. As a result, a mechanism of a size that has been difficult to store in the past, such as a planetary gear mechanism, can be stored in this inner space, and the axial length of the electric vehicle drive device can be shortened.

  In the wheel bearing according to the present invention, the center in the tooth width direction of the internal gear is between a surface including the centers of the plurality of first rolling elements and a surface including the centers of the plurality of second rolling elements. It is characterized by being.

  By disposing the center in the tooth width direction of the internal gear in this way, even when a load is applied to the wheel bearing and the shaft is inclined, the degree of displacement of the internal gear is reduced, and the load acting on the internal gear can be reduced. That is, it is possible to increase the rigidity of the wheel bearing with respect to the displacement in the moment direction when a moment acts on the shaft.

  The electric vehicle driving apparatus according to the present invention includes the wheel bearing, the first motor, the second motor, the first sun gear coupled to the first motor, and the first pinion gear meshing with the first sun gear. A first carrier holding the first pinion gear so that the first pinion gear can rotate and the first pinion gear can revolve around the first sun gear; and A clutch device capable of restricting rotation; meshed with the first pinion gear; and coupled to the second motor; a second sun gear coupled to the first motor; and a second gear coupled to the second sun gear. A second pinion gear, a second pinion gear, a third pinion gear that meshes with the inner gear of the first inner ring, the second pinion gear, and the front pinion gear. The second pinion gear and the third pinion gear are held so that the third pinion gear can rotate, and the second pinion gear and the third pinion gear can revolve around the second sun gear. And a second carrier coupled to the ring gear.

  The wheel bearing according to the present invention can be applied to the output side of the speed reducer, and can be applied to an aspect in which the outer ring is fixed and the inner ring rotates, and the axial length of the electric vehicle drive device can be shortened. Moreover, the electric vehicle drive device according to the present invention can reduce the axial length.

FIG. 1 is a front view of the electric vehicle driving apparatus according to the embodiment. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3A is a cross-sectional view of the wheel bearing included in the electric vehicle drive device according to the embodiment, taken along line AA in FIG. 1. FIG. 3-2 is an enlarged view of part B of FIG. 3-1. FIG. 4 is a diagram illustrating the configuration of the electric vehicle drive device according to the embodiment. FIG. 5 is an explanatory diagram illustrating a path through which the rotational force is transmitted when the electric vehicle drive device according to the embodiment is in the second speed change state. FIG. 6 is an explanatory diagram showing the electric vehicle drive device according to the embodiment in an exploded manner.

  Hereinafter, the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is not limited by the modes for carrying out the invention (hereinafter referred to as embodiments). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art and those that are substantially the same.

(Wheel bearing)
FIG. 1 is a front view of the electric vehicle driving apparatus according to the present embodiment. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3A is a cross-sectional view of the wheel bearing provided in the electric vehicle drive device according to the present embodiment, taken along line AA in FIG. FIG. 3-2 is an enlarged view of part B of FIG. 3-1. Electric vehicle drive device 10 includes a casing G, a first motor 11, a second motor 12, and a speed change mechanism 13. First, the wheel bearing 50 will be described in detail. The wheel bearing 50 included in the electric vehicle drive device 10 according to the present embodiment includes an outer ring 50a, a first inner ring 50c, a second inner ring 50b, a plurality of first rolling elements 60a, and a plurality of second wheels. It includes a rolling element 60b, a first holder 61a, and a second holder 61b. The internal gear 34 formed on the first inner ring 50c is a part of the second planetary gear mechanism 30 described in detail later.

  The outer ring 50a has a cylindrical shape, and a flange portion 62 is formed on the outer periphery near the end on the wheel side. The flange portion 62 is fixed to the casing G by bolt fastening. Therefore, the outer ring 50a cannot be rotated.

  Two rows of tracks are formed in the circumferential direction on the inner circumferential surface of the outer ring 50a. The outer diameter of the both ends of the outer ring 50a is smaller than the central portion. A curved surface is formed in the circumferential direction at the boundary between the central portion and both end portions. The first rolling element 60a contacts the curved surface on the wheel side, and the second rolling element 60b contacts the curved surface on the vehicle body side of the electric vehicle. The curved surface on the wheel side in contact with the first rolling element 60a is the first track 63a, and the curved surface on the vehicle body side in contact with the second rolling element is the second track 63b.

  Both the first rolling element 60a and the second rolling element 60b are spheres. The 1st rolling element 60a and the 2nd rolling element 60b are separated by the thick part of the center part of the outer ring | wheel 50a, and are arrange | positioned at a fixed space | interval in the axial direction. The first cage 61a holds the first rolling element 60a, and the first rolling element 60a revolves along the first track 63a while rotating. The second cage 61b holds the second rolling element 60b, and the second rolling element 60b revolves along the second track 63b while rotating.

  The outer peripheral surface 71 of the first inner ring 50c faces the inner peripheral surface of the outer ring 50a across the first rolling element 60a and the second rolling element 60b. The outer diameter of the first inner ring 50c decreases in three stages from the wheel side toward the vehicle body side. When the outer peripheral surface is a reference outer diameter surface 69a, a first step outer diameter surface 69b, a second step outer diameter surface 69c, and a minimum outer diameter surface 69d from the wheel side to the vehicle body side, the reference outer diameter surface 69a and the first step A curved surface is formed in the circumferential direction at the boundary with the outer diameter surface 69b, and the first rolling element 60a contacts the curved surface. This curved surface is the third track 64.

  It has a plurality of teeth protruding from the inner peripheral surface of the first inner ring 50c. This tooth is an internal gear 34. The shaft of the electric vehicle drive device 10 shown in FIGS. 1 and 2 is formed by integrally forming the internal gear 34 on the inner peripheral surface of the first inner ring 50c, compared with the case where the bearing and the gear are configured separately. The direction length can be shortened. In addition, by configuring the first inner ring 50c and the internal gear 34 as one unit rather than as separate bodies, the strength of the first inner ring 50c can be improved and the dimensional accuracy can be improved. Moreover, since the number of parts of the wheel bearing 50 can be reduced, the manufacturing cost of the wheel bearing 50 can be reduced. Furthermore, the wheel bearing 50 can be reduced in size and weight.

  The tooth width direction center 65 of the internal gear 34 is located between a surface S1 including the centers of the plurality of first rolling elements 60a and a surface S2 including the centers of the plurality of second rolling elements 60b. By arranging the tooth width direction center 65 of the internal gear 34 in this way, even when a load is applied to the wheel bearing 50 and the shaft is inclined, the degree of displacement of the internal gear 34 is reduced and acts on the internal gear 34. The load can be reduced. That is, the rigidity of the wheel bearing 50 against the displacement in the moment direction when a moment is applied to the shaft can be increased.

  A wheel support portion 66 extending toward the rotation axis R of the first inner ring 50c is formed at the end of the first inner ring 50c on the wheel side. In the present embodiment, the wheel support portion 66 has a shape that closes the wheel side of the first inner ring 50c. A plurality of bolt holes 67 are formed in the wheel support portion 66. The center of the bolt hole 67 is an attachment point 68 with the wheel formed in the wheel support portion 66. The wheel is provided with the same number of bolt holes as the wheel support portion 66. The bolt hole 67 of the wheel support portion 66 and the bolt hole of the wheel are overlapped, and the stud bolt 51 is inserted and fastened with a nut. In this embodiment, a bolt hole 67 is formed in the wheel support portion 66, and the stud bolt 51 is inserted into the bolt hole 67. However, even if the wheel support portion 66 and the stud bolt 51 are integrally formed. Good. In this case, the center position of the stud bolt 51 is an attachment point with the wheel formed on the wheel support portion 66.

  The inner peripheral surface of the second inner ring 50b is in contact with the outer peripheral surface 71 of the first inner ring 50c. The second inner ring 50b is in contact with the second outer diameter surface 69c of the outer peripheral surface 71 of the first inner ring 50c. On the outer peripheral surface of the second inner ring 50b, a concave curved surface that is smoothly connected to the first step outer diameter surface 69b of the first inner ring 50c is formed in the circumferential direction, and the second rolling element 60b is formed on the concave curved surface. Contact. The concave curved surface with which the second rolling element 60 b comes into contact is the fourth track 70.

  The second inner ring 50b is applied with a force toward the wheel side by a lock nut 57, whereby an appropriate pressure is applied to the wheel bearing 50 and the rigidity of the wheel bearing 50 is increased. Since the inner ring is not a single part but two parts of the first inner ring 50c and the second inner ring 50b, it is easy to apply an appropriate pressure to the wheel bearing 50.

  The plurality of first rolling elements 60a have a pitch circle diameter D1 larger than the pitch circle diameter D2 of the plurality of attachment points 68 formed on the wheel support portion 66. In general, the pitch circle diameter D2 of the plurality of attachment points 68 is limited to a certain range depending on the diameter of the wheel, and cannot be significantly increased. However, by making the pitch circle diameter D1 of the plurality of first rolling elements 60a larger than the pitch circle diameter D2 of the plurality of attachment points 68 formed in the wheel support portion 66, the space inside the wheel bearing 50, That is, the space inside the first inner ring 50c can be widened. As a result, a mechanism of a size that has been difficult to store in the past, such as a planetary gear mechanism, can be stored in this inner space, and the axial length of the electric vehicle drive device 10 can be shortened.

(Electric vehicle drive device)
The wheel bearing 50 included in the electric vehicle drive device 10 has been described in detail above. Next, other configurations will be described in detail. FIG. 4 is a diagram illustrating the configuration of the electric vehicle drive device according to the present embodiment. Please refer to FIG. 2 as appropriate.

  As shown in FIG. 2 or FIG. 4, the electric vehicle drive device 10 includes a casing G, a first motor 11, a second motor 12, and a speed change mechanism 13. The casing G houses the first motor 11, the second motor 12, and the speed change mechanism 13. The first motor 11 can output the first rotational force TA. The second motor 12 can output the second rotational force TB. The speed change mechanism 13 is connected to the first motor 11. Thereby, when the 1st motor 11 act | operates, the 1st rotational force TA will be transmitted to the transmission mechanism 13 (input). The operation of the motor here means that electric power is supplied to the motor and the output shaft rotates. The transmission mechanism 13 is connected to the second motor 12. Thereby, when the 2nd motor 12 act | operates, the 2nd rotational force TB will be transmitted to the transmission mechanism 13 (input). The internal gear 34 of the wheel bearing 50, which is a part of the speed change mechanism 13, is integrated with the first inner ring 50c, and the shifted rotational force is attached to the first inner ring 50c through the first inner ring 50c. Is transmitted (output) to the wheel H of the electric vehicle.

  The speed change mechanism 13 includes a first planetary gear mechanism 20, a second planetary gear mechanism 30, and a clutch device 40. The first planetary gear mechanism 20 is a single pinion type planetary gear mechanism. The first planetary gear mechanism 20 includes a first sun gear 21, a first pinion gear 22, a first carrier 23, and a ring gear 24. The second planetary gear mechanism 30 is a double pinion planetary gear mechanism. The second planetary gear mechanism 30 includes a second sun gear 31, a second pinion gear 32 a, a third pinion gear 32 b, a second carrier 33, and an internal gear 34 of the wheel bearing 50.

  The first sun gear 21 is supported in the casing G so as to be able to rotate (spin) about the rotation axis R. The first sun gear 21 is connected to the first motor 11. Therefore, the first sun gear 21 receives the first rotational force TA when the first motor 11 is operated. As a result, the first sun gear 21 rotates about the rotation axis R when the first motor 11 is operated. The first pinion gear 22 meshes with the first sun gear 21. The first carrier 23 holds the first pinion gear 22 so that the first pinion gear 22 can rotate (rotate) about the first pinion rotation axis Rp1. The first pinion rotation axis Rp1 is, for example, parallel to the rotation axis R.

  The first carrier 23 is supported in the casing G so that it can rotate (rotate) about the rotation axis R. Thereby, the first carrier 23 holds the first pinion gear 22 so that the first pinion gear 22 can revolve around the first sun gear 21, that is, around the rotation axis R. The ring gear 24 can rotate (spin) about the rotation axis R. The ring gear 24 meshes with the first pinion gear 22. The ring gear 24 is connected to the second motor 12. Therefore, the second rotational force TB is transmitted to the ring gear 24 when the second motor 12 is operated. As a result, when the second motor 12 is operated, the ring gear 24 rotates (spins) about the rotation axis R.

  The clutch device 40 can regulate the rotation of the first carrier 23. Specifically, the clutch device 40 can switch between restricting (braking) the rotation of the first carrier 23 around the rotation axis R and allowing the rotation. Hereinafter, in the clutch device 40, a state where the rotation is restricted (braking) is referred to as an engaged state, and a state where the rotation is allowed is referred to as a non-engaged state.

  The clutch device 40 is a one-way clutch device. The one-way clutch device transmits only the rotational force in the first direction, and does not transmit the rotational force in the second direction that is opposite to the first direction. The one-way clutch device is, for example, a cam clutch device or a roller clutch device.

  The second sun gear 31 is supported in the casing G so as to rotate (spin) around the rotation axis R. The second sun gear 31 is connected to the first motor 11 via the first sun gear 21. Specifically, the first sun gear 21 and the second sun gear 31 are formed integrally with the sun gear shaft 14 so as to be rotatable on the same axis (rotation axis R). The sun gear shaft 14 is connected to the first motor 11. Thus, the second sun gear 31 rotates about the rotation axis R when the second motor 12 is operated.

  The second pinion gear 32 a meshes with the second sun gear 31. The third pinion gear 32b meshes with the second pinion gear 32a. The second carrier 33 holds the second pinion gear 32a so that the second pinion gear 32a can rotate (spin) about the second pinion rotation axis Rp2. The second carrier 33 holds the third pinion gear 32b so that the third pinion gear 32b can rotate (rotate) about the third pinion rotation axis Rp3. The second pinion rotation axis Rp2 and the third pinion rotation axis Rp3 are parallel to the rotation axis R, for example.

  The second carrier 33 is supported in the casing G so that it can rotate (rotate) about the rotation axis R. As a result, the second carrier 33 has the second pinion gear 32a and the third pinion gear 32a so that the second pinion gear 32a and the third pinion gear 32b can revolve around the second sun gear 31, that is, around the rotation axis R. 32b is held. The second carrier 33 is connected to the ring gear 24. As a result, the second carrier 33 rotates (spins) about the rotation axis R when the ring gear 24 rotates (spins). The internal gear 34 can rotate (rotate) about the rotation axis R. The internal gear 34 meshes with the third pinion gear 32b. The internal gear 34 is integral with the first inner ring 50c. Thereby, when the internal gear 34 rotates (autorotates), the first inner ring 50c of the wheel bearing 50 rotates. Next, the transmission path of the rotational force in the electric vehicle drive device 10 will be described.

  The electric vehicle drive device 10 can realize two shift states, a first shift state and a second shift state. First, a description will be given of a case where the electric vehicle driving device 10 realizes a first shift state, that is, a so-called low gear state used when the electric vehicle starts or climbs (when climbing a hill). In the first speed change state, the first motor 11 operates. The rotational force output by the first motor 11 during the first speed change state is defined as a first rotational force T1. In the first speed change state, the second motor 12 does not operate, that is, idles. The clutch device 40 is in an engaged state. That is, in the first speed change state, the first pinion gear 22 cannot revolve with respect to the casing G. Note that the rotational forces of the first rotational force T1, the circulating rotational force T3, the combined rotational force T4, the first distributed rotational force T5, and the second distributed rotational force T6 shown in FIG. The unit is Nm. The combined rotational force T5 indicates the torque transmitted to the bearing mechanism 80. The bearing mechanism 80 includes an outer ring 50a of the wheel bearing 50, a first inner ring 50c, a second inner ring 50b, a plurality of first and second rolling elements 60a and 60b, and a first and a second. It is comprised including the holder | retainers 61a and 61b.

  The first rotational force T <b> 1 output from the first motor 11 is input to the first sun gear 21. Then, the first rotational force T1 merges with the circulating rotational force T3 at the first sun gear 21. The circulating rotational force T3 is a rotational force transmitted from the ring gear 24 to the first sun gear 21. Details of the circulating rotational force T3 will be described later. Thereby, the second sun gear 31 is transmitted with a combined rotational force T4 obtained by combining the first rotational force T1 and the circulating rotational force T3. The combined rotational force T4 is amplified by the second planetary gear mechanism 30. The combined rotational force T4 is distributed by the second planetary gear mechanism 30 to the first distributed rotational force T5 and the second distributed rotational force T6. The first distributed rotational force T5 is a rotational force distributed to the internal gear 34. The second distributed rotational force T6 is a rotational force distributed to the second carrier 33.

  The first distributed rotational force T5 is transmitted from the internal gear 34 to the wheel H through the first inner ring 50c of the wheel bearing 50. Thereby, the wheel H rotates and the electric vehicle travels. The second distributed rotational force T6 is input to the first planetary gear mechanism 20. Specifically, the second distributed rotational force T6 is transmitted to the ring gear 24. The second distributed rotational force T6 is reduced by the first planetary gear mechanism 20. Specifically, the second distributed rotational force T6 is reduced by shifting when transmitted from the ring gear 24 to the first sun gear 21 via the first pinion gear 22. Further, when the second distributed rotational force T6 is transmitted from the ring gear 24 to the first sun gear 21 via the first pinion gear 22, the rotational direction of itself (second distributed rotational force T6) is reversed. Thus, the second distributed rotational force T6 is transmitted to the first sun gear 21 as a circulating rotational force T3.

  Thus, the first rotational force T1 input from the first motor 11 to the first sun gear 21 is amplified, and a part of the amplified rotational force is output as the first distributed rotational force T5. The remaining rotational force of the amplified rotational force is transmitted from the second carrier 33 to the first sun gear 21 through the ring gear 24 and the first pinion gear 22 as the circulating rotational force T3. The circulating rotational force T3 transmitted to the first sun gear 21 merges with the first rotational force T1 to become a combined rotational force T4 and is transmitted to the second sun gear 31.

  As described above, in the electric vehicle drive device 10, a part of the rotational force circulates between the first planetary gear mechanism 20 and the second planetary gear mechanism 30. Thereby, electric vehicle drive device 10 can realize a larger gear ratio. That is, the electric vehicle drive device 10 can transmit a larger rotational force to the wheel H in the first speed change state.

  FIG. 5 is an explanatory diagram illustrating a path through which the rotational force is transmitted when the electric vehicle drive device according to the embodiment is in the second speed change state. In the second speed change state, the first motor 11 operates. The rotational force output by the first motor 11 during the second speed change state is defined as a first rotational force T7. In the second speed change state, the second motor 12 operates. The rotational force output by the second motor 12 during the second speed change state is defined as a second rotational force T8. The clutch device 40 is in a non-engaged state. That is, in the second speed change state, the first pinion gear 22 can rotate with respect to the casing G. Thus, in the second speed change state, the circulation of the rotational force between the first planetary gear mechanism 20 and the second planetary gear mechanism 30 is interrupted. Further, in the second speed change state, since the first carrier 23 can freely revolve (rotate), the first sun gear 21 and the ring gear 24 can relatively freely rotate (spin). The combined rotational force T9 shown in FIG. 5 indicates the torque transmitted to the bearing mechanism 80, and its unit is Nm.

  In the second speed change state, the ratio between the first rotational force T7 and the second rotational force T8 is determined by the ratio between the number of teeth Z1 of the second sun gear 31 and the number of teeth Z4 of the internal gear 34. The first rotational force T7 merges with the second rotational force T8 at the second carrier 33. As a result, the combined rotational force T9 is transmitted to the internal gear 34.

  Here, since the first sun gear 21 and the ring gear 24 rotate (rotate) in opposite directions, the second sun gear 31 and the second carrier 33 also rotate (rotate) in opposite directions. When the angular velocity of the second sun gear 31 is constant, the angular velocity of the internal gear 34 decreases as the angular velocity of the second carrier 33 increases. Further, the angular velocity of the internal gear 34 increases as the angular velocity of the second carrier 33 decreases. As described above, the angular velocity of the internal gear 34 continuously changes depending on the angular velocity of the second sun gear 31 and the angular velocity of the second carrier 33. That is, the electric vehicle drive device 10 can continuously change the gear ratio by changing the angular velocity of the second rotational force T8 output from the second motor 12.

  Further, when the electric vehicle driving device 10 tries to make the angular speed of the internal gear 34 constant, the angular speed of the first rotational force T7 output from the first motor 11 and the second rotational force output from the second motor 12 are set. There are a plurality of combinations with the angular velocity of T8. That is, the angular velocity of the internal gear 34 is kept constant even if the angular velocity of the first rotational force T7 output from the first motor 11 changes due to the change in the angular velocity of the second rotational force T8 output from the second motor 12. Can be maintained. Thereby, the electric vehicle drive device 10 can reduce the amount of change in the angular velocity of the internal gear 34 when switching from the first shift state to the second shift state. As a result, the electric vehicle drive device 10 can reduce the shift shock.

  Here, the operation of the clutch device 40 which is a one-way clutch device will be described. The clutch device 40, which is a one-way clutch device, is in the first speed change state, that is, the state in which the second motor 12 is not operated, and the first motor 11 outputs a rotational force to advance the electric vehicle. The engaged state is established. When the second motor 12 is operated, the rotation direction of the second carrier 33 is reversed from the first speed change state. As a result, the clutch device 40 is in the disengaged state when in the second speed change state, that is, when the second motor 12 operates and the first motor 11 outputs a rotational force to advance the electric vehicle. Become. As described above, the clutch device 40 can follow the engagement state and the disengagement state depending on whether or not the second motor 12 is operated. Since the clutch device 40 does not require an actuator for driving, the structure of the electric vehicle drive device 10 can be simplified, and the electric vehicle drive device 10 can be downsized. Next, an example of the structure of the electric vehicle drive device 10 will be described.

  FIG. 6 is an explanatory view showing the electric vehicle drive device 10 according to the embodiment in an exploded manner. Please refer to FIG. 2 as appropriate. Hereinafter, the overlapping description is omitted about the component demonstrated above, and it shows with the same code | symbol in a figure. As shown in FIG. 2, the casing G includes a first casing G1, a second casing G2, a third casing G3, and a fourth casing G4. The first casing G1, the second casing G2, and the fourth casing G4 are cylindrical members. The second casing G2 is provided closer to the wheel than the first casing G1. The first casing G1 and the second casing G2 are fastened with, for example, four bolts.

  The third casing G3 is provided at the opening end opposite to the second casing G2 of the two opening ends of the first casing G1, that is, the opening end of the first casing G1 on the vehicle body side of the electric vehicle. The first casing G1 and the third casing G3 are fastened with, for example, four bolts. Accordingly, the third casing G3 closes the opening of the first casing G1. The fourth casing G4 is provided inside the first casing G1. The first casing G1 and the fourth casing G4 are fastened with, for example, eight bolts.

  As shown in FIGS. 2 and 6, the first motor 11 includes a first stator core 11a, a first coil 11b, a first insulator 11c, a first rotor 11d, a first motor output shaft 11e, And a resolver 11f. The first stator core 11a is a cylindrical member. As shown in FIG. 2, the first stator core 11a is sandwiched and positioned (fixed) between the first casing G1 and the third casing G3. The first coil 11b is provided at a plurality of locations of the first stator core 11a. The first coil 11b is wound around the first stator core 11a via the first insulator 11c.

  The first rotor 11d is disposed on the radially inner side of the first stator core 11a. The first rotor 11d includes a first rotor core 11d1 and a first magnet 11d2. The first rotor core 11d1 is a cylindrical member. A plurality of first magnets 11d2 are provided on the outer periphery of the first rotor core 11d1. The first motor output shaft 11e is a rod-shaped member. The first motor output shaft 11e is connected to the first rotor core 11d1. The first resolver 11f is provided on the first rotor core 11d1. The first resolver 11f detects the rotation angle of the first rotor core 11d1.

  The second motor 12 includes a second stator core 12a, a second coil 12b, a second insulator 12c, a second rotor 12d, and a second resolver 12f. The second stator core 12a is a cylindrical member. The second stator core 12a is sandwiched and positioned (fixed) between the first casing G1 and the second casing G2. The second coil 12b is provided at a plurality of locations of the second stator core 12a. The second coil 12b is wound around the second stator core 12a via the second insulator 12c.

  The second rotor 12d is provided on the radially inner side of the second stator core 12a. The second rotor 12d is supported by the fourth casing G4 together with the clutch device 40 so as to be able to rotate around the rotation axis R. The second rotor 12d includes a second rotor core 12d1 and a second magnet 12d2. The second rotor core 12d1 is a cylindrical member. A plurality of second magnets 12d2 are provided on the outer periphery of the second rotor core 12d1. The second resolver 12f is provided on the second rotor core 12d1. The second resolver 12f detects the rotation angle of the second rotor core 12d1.

  The electric vehicle drive device 10 further includes a stud bolt 51 shown in FIGS. 1, 2, 3-1 and 6, a bolt 52 shown in FIGS. 1 and 2, a shock absorber mounting portion 53, and FIG. 2. A first serration 54 shown in FIG. 6, a waterproof panel connector 55 shown in FIG. 1, a second serration 56 shown in FIG. 2, and a lock nut 57 are included. As shown in FIG. 1, the wheel bearing 50 is fastened to the second casing G2 by, for example, eight bolts 52. The waterproof panel connector 55 is provided in the first casing G1. The waterproof panel connector 55 is electrically connected to a power source to supply power to the first motor 11 and the second motor 12 provided in the casing G.

  The shock absorber mounting portion 53 is provided in the first casing G1. Specifically, the shock absorber attachment portion 53 is provided in a portion of the first casing G1 that is on the upper side in the vertical direction when the electric vehicle drive device 10 is attached to the vehicle body of the electric vehicle. The shock absorber mounting portion 53 includes a first bolt hole 53a and a second bolt hole 53b. Bolts are inserted into the first bolt holes 53a and the second bolt holes 53b, and nuts are screwed into the bolts, whereby the electric vehicle drive device 10 is fastened to the vehicle body of the electric vehicle.

  The first serration 54 is formed on the second carrier 33. Specifically, it is formed on the outer peripheral portion of the end portion on the vehicle body side of the electric vehicle among the both end portions of the second carrier 33. The first serration 54 is fitted with the serration formed in the second rotor 12 d of the second motor 12. Thereby, the rotational force of the second rotor 12 d is coupled to the second carrier 33. In the second carrier 33, the ring gear 24 is formed on the inner periphery of the portion where the first serration 54 is provided. The second serration 56 is formed at the end of the sun gear shaft 14 on the first motor output shaft 11e side. The second serration 56 is fitted with the first motor output shaft 11e. Thereby, the sun gear shaft 14 is connected to the first motor 11.

  With the above configuration, the electric vehicle driving apparatus 10 can drive the electric vehicle by holding the wheel and transmitting the rotational force output from the first motor 11 and the second motor 12 to the wheel. .

  As described above, the wheel bearing according to the present invention is useful for application to an in-wheel motor, and the electric vehicle drive device incorporating the wheel bearing is useful as an in-wheel motor.

DESCRIPTION OF SYMBOLS 10 Electric vehicle drive device 11 1st motor 12 2nd motor 13 Transmission mechanism 14 Sun gear shaft 20 1st planetary gear mechanism 21 1st sun gear 22 1st pinion gear 23 1st carrier 24 Ring gear 30 2nd planetary gear mechanism 31 2nd Sun gear 32a Second pinion gear 32b Third pinion gear 33 Second carrier 34 Internal gear 40 Clutch device 50 Wheel bearing 50a Outer ring 50b Second inner ring 50c First inner ring 57 Lock nut 60a First rolling element 60b Second rolling Moving body 61a First cage 61b Second cage 62 Flange portion 63a First track 63b Second track 64 Third track 65 Center in the tooth width direction 66 Wheel support portion 70 Fourth track 71 Outer surface G Casing H Wheel R Rotating shaft

Claims (4)

An outer ring fixed to the casing and having a first track and a second track formed in the circumferential direction of the inner peripheral surface;
A plurality of first rolling elements rolling on the first track;
A plurality of second rolling elements rolling on the second track;
A first cage for supporting the first rolling element;
A second cage for supporting the second rolling element;
A third raceway on which the first rolling element rolls in the circumferential direction is formed on the outer peripheral surface, and a first inner ring on which an internal gear is formed on the inner peripheral surface;
A plurality of attachment points for attaching the wheel, and a wheel support portion formed at an end of the first inner ring;
An inner peripheral surface is in contact with the outer peripheral surface of the first inner ring, and the outer peripheral surface includes a second inner ring on which a fourth track on which the second rolling element rolls in the circumferential direction is formed. Wheel bearing characterized by.   2. The wheel bearing according to claim 1, wherein a pitch circle diameter of the first rolling element is larger than a pitch circle diameter of the plurality of attachment points.   The tooth width direction center of the internal gear is between a plane including the centers of the plurality of first rolling elements and a plane including the centers of the plurality of second rolling elements. Or the wheel bearing of 2. The wheel bearing according to any one of claims 1 to 3,
A first motor;
A second motor;
A first sun gear coupled to the first motor;
A first pinion gear meshing with the first sun gear;
A first carrier that holds the first pinion gear so that the first pinion gear can rotate and the first pinion gear can revolve around the first sun gear;
A clutch device capable of regulating rotation of the first carrier;
A ring gear meshing with the first pinion gear and coupled to the second motor;
A second sun gear coupled to the first motor;
A second pinion gear meshing with the second sun gear;
A third pinion gear meshing with the second pinion gear and meshing with the internal gear of the first inner ring;
The second pinion gear and the third pinion gear can rotate around the second pinion gear and the third pinion gear so that the second pinion gear and the third pinion gear can revolve around the second sun gear, respectively. A second carrier holding the third pinion gear and coupled to the ring gear;
The electric vehicle drive device characterized by including.

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