JP2009185936A - Power transmitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmitting device capable of being embodied in a small construction while its configuration allows the input rotation fed from a motor to be speed changed at two stages. <P>SOLUTION: The power transmitting device 1 includes a brake device 40 which can restrict the rotation of a ring gear 22 and a clutch device 50 which can uncouple a sun gear 21 from a carrier 24, whereby the input rotation fed to the sun gear 21 is decelerated. On the other hand, the input rotation fed to the sun gear 21 is transmitted with the speed kept equal, by admitting the rotation of the ring gear 22 by the brake device 40 and coupling the sun gear 21 with the carrier 24 through the clutch device 50. This enables the input rotation fed from the motor M to be speed changed at two stages, decelerative and at a constant speed, through one planetary gearing unit 1, so that the arrangement does not require two sets of planetary gearing units, and accordingly, the device can be constructed small. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power transmission device that is mounted on a vehicle using a motor as a power source and transmits the rotational force of the motor to the left and right wheels of the vehicle, and in particular, the input rotation input from the motor can be shifted in two stages. However, the present invention relates to a power transmission device that can reduce the size of the device.

  Conventionally, as a power transmission device that is mounted on a vehicle that uses a motor as a power source and that transmits the rotational force of the motor to the left and right wheels of the vehicle, for example, in Patent Document 1, the input rotation input from the motor is decelerated, An electric vehicle drive device that aims to amplify the rotational force is disclosed.

The electric vehicle drive device includes two sets of planetary gear trains, and restricts the rotation of any one of the speed change elements (sun gear, ring gear, and carrier) constituting each planetary gear train and allows the rotation. The input rotation input from the motor can be shifted in two stages depending on the combination of the speed change elements to be regulated.
Japanese Patent Laid-Open No. 5-116549

  However, the electric vehicle drive device disclosed in Patent Document 1 is configured to shift the input rotation input from the motor in two stages by two sets of planetary gear trains, and accordingly, a space is required. However, there was a problem that the size would be increased.

  The present invention has been made to solve the above-described problems, and is a power transmission device that can reduce the size of the device while being able to shift the input rotation input from the motor to two stages. The purpose is to provide.

  In order to achieve this object, a power transmission device according to claim 1 includes a motor that generates a rotational force, and a speed reducer that receives the rotational force of the motor and decelerates the input rotation. It is mounted on a vehicle as a source and transmits the rotational force of the motor to the left and right wheels of the vehicle via the speed reducer, and the speed reducer rotates around the rotation axis when the torque of the motor is input. A first sun gear, a first ring gear disposed on an outer periphery of the first sun gear and rotatable about the rotation shaft, and disposed between the first sun gear and the first ring gear. A planetary planetary gear comprising: a plurality of first planetary gears engaged with a sun gear and a first ring gear; and a first carrier that rotatably supports the plurality of first planetary gears and is rotatable about the rotation axis. A vehicle unit; a brake device that allows or restricts rotation of the first ring gear; and a clutch device that connects or releases the first sun gear and the first carrier. The brake device rotates the first ring gear. And the clutch device releases the connection between the first sun gear and the first carrier, so that the first planetary gear rotates while the first sun gear rotates, and the first sun gear and the first carrier rotate. It rolls between the ring gear and revolves around the rotation axis, and the first carrier rotates around the rotation axis along with the revolution of the first planetary gear, so that it is input to the first sun gear. The input rotation is decelerated and transmitted from the first carrier to the left and right wheels of the vehicle, while the brake device rotates the first ring gear. And by connecting the first sun gear and the first carrier by the clutch device, the first carrier rotates around the rotation axis as the first sun gear rotates. A transmission is provided for transmitting the input rotation input to the first sun gear from the first carrier to the left and right wheels of the vehicle at a constant speed.

  The power transmission device according to claim 2 is the power transmission device according to claim 1, wherein the speed reduction device includes a second sun gear that receives the rotational force of the motor and rotates around the rotation shaft, and the second sun gear. And a plurality of second planetary gears disposed between the second sun gear and the second ring gear and meshed with the second sun gear and the second ring gear. And a planetary gear unit that rotatably supports the plurality of second planetary gears and that can rotate about the rotation axis, and the second planetary gears according to the rotation of the second sun gear. Rolls between the second sun gear and the second ring gear while rotating and revolves around the rotation axis, and the second key rotates along with the revolution of the second planetary gear. By rear is rotated around the rotation axis, and a speed reduction unit for transmitting to said first sun gear from said second said decelerating the input rotation that is input to the sun gear second carrier.

  The power transmission device according to claim 3 is the power transmission device according to claim 1 or 2, wherein the rotational force of the first carrier is inputted and the third ring gear is rotated around the rotation shaft, and the third ring gear. A plurality of third sun gears disposed on an inner periphery of the first sun gear and rotatable about the rotation shaft, and disposed between the third ring gear and the third sun gear and meshed with the third ring gear and the third sun gear. A planetary gear unit comprising: a third planetary gear; and a third carrier that rotatably supports the plurality of third planetary gears and that can rotate about the rotation axis, and the rotation of the third ring gear. When the third planetary gear revolves around the rotation axis and the third sun gear rotates around the rotation axis, the input rotation input to the third ring gear is Transmission from the three sun gears and the third carrier to the left and right wheels of the vehicle, respectively, and the third planetary gear rolls between the third sun gear and the third ring gear while rotating to revolve around the rotation axis. And a differential device that absorbs the differential between the left and right wheels of the vehicle by generating a rotational difference between the rotation of the third sun gear and the rotation of the third carrier.

  According to the power transmission device of the first aspect, the speed reducer includes a transmission unit having a planetary gear unit, a brake device, and a clutch device, the rotation of the first ring gear is restricted by the brake device, and the clutch device By releasing the connection between the first sun gear and the first carrier, as the first sun gear rotates, the first planetary gear rotates while rotating between the first sun gear and the first ring gear around the rotation axis. As the first planetary gear revolves, the first carrier rotates around the rotation axis, and the input rotation input to the first sun gear is decelerated and transmitted from the first carrier to the left and right wheels of the vehicle.

  On the other hand, by allowing the first ring gear to rotate by the brake device and connecting the first sun gear and the first carrier by the clutch device, the first carrier rotates about the rotation axis as the first sun gear rotates. As a result, the input rotation input to the first sun gear is transmitted from the first carrier to the left and right wheels of the vehicle at a constant speed.

  Therefore, the input rotation input to the first sun gear, that is, the input rotation input from the motor, can be shifted in two steps of reduction and constant speed by one planetary gear unit. No planetary gear unit is required and the apparatus can be reduced in size accordingly.

  As described above, according to the power transmission device of the present invention, the input rotation input from the motor can be shifted in two steps of deceleration and constant speed, so that the motor can be used efficiently in a wide vehicle speed range. There is an effect that can be.

  That is, the motor generally has a characteristic that the rotational force decreases as the rotational speed increases. Therefore, simply decelerating the input rotational speed causes the wheels to rotate when the rotational speed of the motor increases and the vehicle speed increases. The required rotational force may not be obtained sufficiently. For this reason, the motor must be enlarged to ensure the rotational force.

  On the other hand, according to the present invention, since the input rotation can be shifted in two stages, decelerating and constant speed, when the vehicle speed is high, the input rotation is transmitted to the wheels while maintaining the constant speed. The increase in the number can be suppressed. Thereby, there exists an effect that the rotational force of a motor can be obtained efficiently. As a result, the motor can be used efficiently in a wide vehicle speed range. Further, if the rotational force of the motor can be obtained efficiently, there is no need to increase the size of the motor, and there is an effect that the apparatus can be reduced in size accordingly.

  According to the power transmission device of the second aspect, in addition to the effect achieved by the power transmission device of the first aspect, the speed reduction device includes a speed reduction portion having a planetary gear unit, and the second sun gear rotates in accordance with the rotation of the second sun gear. While the planetary gear rotates, the outer periphery of the second sun gear revolves around the rotation axis, and the second carrier rotates around the rotation axis along with the revolution of the second planetary gear, so that the input rotation input to the second sun gear is Since the motor is decelerated and transmitted from the second carrier to the first sun gear, the input rotation input from the motor can be decelerated and then input to the transmission unit. Thereby, since the rotational force of the motor can be amplified, there is no need to increase the size of the motor, and there is an effect that the motor can be reduced in size accordingly.

  According to the power transmission device of the third aspect, in addition to the effect achieved by the power transmission device according to the first or second aspect, the power transmission device includes a differential device having a planetary gear unit, and the third ring gear is rotated along with the rotation of the third ring gear. As the planetary gear revolves around the rotation axis and the third sun gear rotates around the rotation axis, the input rotation input to the third ring gear is transmitted from the third sun gear and the third carrier to the left and right wheels of the vehicle, respectively.

  Further, the third planetary gear rotates while rotating between the third sun gear and the third ring gear and revolves around the rotation axis, so that the rotation difference between the rotation of the third sun gear and the rotation of the third carrier is achieved. Occurs and the differential between the left and right wheels of the vehicle is absorbed.

  Therefore, the rotational force input to the third ring gear, that is, the rotational force of the first carrier can be distributed and transmitted to the left and right wheels of the vehicle, and the rotational difference between the left and right wheels can be absorbed. As a result, the rotational force of the motor is distributed and transmitted to the left and right wheels of the vehicle, and the elements from the power source motor to the differential device are configured as one unit while absorbing the rotational difference between the left and right wheels. Therefore, there is an effect that the structure can be simplified.

  Further, according to the power transmission device of the present invention, since the differential device is constituted by a planetary gear unit, it is possible to shorten the length dimension in the direction of the rotation axis as compared with the case of using a bevel gear. Thus, the apparatus can be reduced in size.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. First, an overall configuration of a power transmission device 1 according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of the power transmission device 1, and FIG. 2 is a schematic diagram of the power transmission device 1 schematically showing the speed reduction device 2 and the differential device 3. FIG. 3 is an enlarged cross-sectional view of the power transmission device 1 in which the portion indicated by III in FIG. 1 is enlarged. In FIG. 1, a part of the power transmission device 1 is shown in an external view.

  As shown in FIG. 1, the power transmission device 1 includes a motor M that generates rotational force, a speed reduction device 2 that receives the rotational force of the motor M, and a differential that receives rotational force from the speed reduction device 2. And a transmission device that mainly transmits the rotational force of the motor M to the left and right wheels (not shown) of the vehicle via the speed reduction device 2 and the differential device 3, and reduces the input rotation input from the motor M to the speed reduction device. It is comprised so that it can decelerate by 2.

  The reduction gear 2 is a device that transmits the rotational force of the motor M to the differential device 3 and decelerates the input rotation input from the motor M. As shown in FIG. The speed reduction part 10 and the speed change part 20 to which rotational force is input from the speed reduction part 10 are provided.

  As shown in FIGS. 1 and 3, the speed reduction unit 10 mainly includes a speed reduction sun gear 11, a speed reduction ring gear 12, a speed reduction planetary gear 13, and a speed reduction carrier 14, and is configured by a so-called planetary gear train.

  The reduction sun gear 11 constitutes a sun gear of a planetary gear train, and is connected to a rotor (not shown) of the motor M. Therefore, the reduction sun gear 11 is rotated around the rotation axis O by the rotational force of the motor M when the rotational force of the motor M is input through the rotor.

  The reduction ring gear 12 constitutes an internal gear of the planetary gear train, and is fixed to a case C that forms an outer shell of the power transmission device 1. Therefore, the rotation of the reduction ring gear 12 is restricted by the case C.

  The reduction planetary gear 13 constitutes a planetary gear of a planetary gear train. The reduction planetary gear 13 is engaged with the reduction sun gear 11 and the reduction ring gear 12 and supported by the reduction carrier 14 by the shaft 15. Accordingly, the speed reduction planetary gear 13 rolls between the speed reduction sun gear 11 and the speed reduction ring gear 12 while rotating about the shaft 15 as the speed reduction sun gear 11 rotates as the speed reduction sun gear 11 rotates about the rotation axis O. And revolves around the rotation axis O.

  1 and 3, the reduction planetary gear 13 includes a large-diameter planetary gear 13a meshed with the reduction sun gear 11 and a small-diameter planetary gear 13b meshed with the reduction ring gear 12, and these large-diameter planetary gear 13a and The small diameter planetary gear 13b is integrally connected. Therefore, the large-diameter planetary gear 13 a and the small-diameter planetary gear 13 b rotate integrally with the rotation of the reduction sun gear 11 as the reduction sun gear 11 rotates around the rotation axis O.

  In the present embodiment, the speed reduction unit 10 is provided with three speed reduction planetary gears 13, and the three speed reduction planetary gears 13 are arranged at equal intervals (interval of central angle 120 °).

  The speed reduction carrier 14 constitutes a planetary frame of the planetary gear train. As described above, the speed reduction planetary gear 13 is supported by the shaft 15 and supported by the case C via the bearing 16. Accordingly, the reduction carrier 14 rotates around the rotation axis O as the reduction planetary gear 13 revolves as the reduction planetary gear 13 rolls between the reduction sun gear 11 and the reduction ring gear 12 and revolves around the rotation axis O. To do. The support structure of the shaft 15 by the deceleration carrier 14 will be described later with reference to FIGS. 3 and 4A.

  As described above, the speed reduction unit 10 constituted by the planetary gear train plays the role of the speed reduction sun gear 11 as an input element, the speed reduction ring gear 12 as a reaction force element, and the speed reduction carrier 14 as an output element. As a result, the reduction unit 10 can output the rotational force of the motor M input to the reduction sun gear 11 from the reduction carrier 14 via the reduction planetary gear 13.

  Further, as shown in FIG. 2, the speed reduction unit 10 is configured such that the pitch circle radius R1 of the reduction sun gear 11 is smaller than the pitch circle radius R2 of the reduction ring gear 12 (R1 <R2). Thereby, in the deceleration part 10, rotation of the reduction sun gear 11, ie, the input rotation input from the motor M, can be decelerated.

  Further, the reduction planetary gear 13 is configured such that the pitch circle radius R3 of the large diameter planetary gear 13a is larger than the pitch circle radius R4 of the small diameter planetary gear 13b (R3> R4). Thereby, in the reduction part 10, the rotation of the reduction sun gear 11, that is, the input rotation input from the motor M can be reduced by the reduction planetary gear 13. Therefore, the input rotation input from the motor M can be decelerated with a larger reduction ratio.

  As shown in FIGS. 1 and 3, the transmission unit 20 mainly includes a transmission sun gear 21, a transmission ring gear 22, a transmission planetary gear 23, and a transmission carrier 24. The transmission unit 20 includes a so-called planetary gear train and a brake. A device 40 and a clutch device 50 are provided.

  The transmission sun gear 21 constitutes a sun gear of a planetary gear train, and is connected to the reduction carrier 14. Therefore, the transmission sun gear 21 is rotated about the rotation axis O by the rotational force of the speed reduction unit 10 when the rotational force is input from the speed reduction unit 10 via the speed reduction carrier 14.

  The transmission ring gear 22 constitutes an internal gear of the planetary gear train, and is supported by the case C via a bearing 26. Therefore, the transmission ring gear 22 rotates as the transmission planetary gear 23 revolves as the transmission planetary gear 23 rolls between the transmission sun gear 21 and the transmission ring gear 22 and revolves around the rotation axis O, as will be described later. Rotate around axis O.

  The transmission planetary gear 23 constitutes a planetary gear of a planetary gear train. The transmission planetary gear 23 is engaged with the transmission sun gear 21 and the transmission ring gear 22 and supported by the transmission carrier 24 by the shaft 25. Therefore, the transmission planetary gear 23 rolls between the transmission sun gear 21 and the transmission ring gear 22 while rotating around the shaft 25 as the transmission sun gear 21 rotates as the transmission sun gear 21 rotates about the rotation axis O. And revolves around the rotation axis O.

  In the present embodiment, the transmission unit 20 is provided with three transmission planetary gears 23, and these three transmission planetary gears 23 are arranged at equal intervals (intervals of the central angle of 120 °).

  The speed change carrier 24 constitutes a planetary frame of the planetary gear train. As described above, the speed change planetary gear 23 is pivotally supported by the shaft 25 and is configured to be rotatable around the rotation axis O. Therefore, the transmission carrier 24 rotates around the rotation axis O as the transmission planetary gear 23 revolves as the transmission planetary gear 23 rolls between the transmission sun gear 21 and the transmission ring gear 22 and revolves around the rotation axis O. To do. The support structure of the shaft 25 by the speed change carrier 24 will be described later with reference to FIGS. 3 and 4B.

  As described above, the speed change unit 20 configured by the planetary gear train plays the role of the speed change sun gear 21 as an input element and the speed change carrier 24 as an output element. Thereby, the transmission unit 20 can output the rotational force of the reduction unit 10 input to the transmission sun gear 21 from the transmission carrier 24.

  The brake device 40 is for permitting or restricting the rotation of the transmission ring gear 22, and as shown in FIGS. 1 and 3, a plurality of (in this embodiment, five) pressing plates 41, and the plurality of the pressing plates 41. A plurality of (four in this embodiment) friction plates 42 interposed between the pressing plates 41 and a piston 43 are mainly provided.

  The pressing plate 41 is a disk-like plate-like member, and is spline-fitted to the transmission ring gear 22 by a spline joint 44 formed between the inner periphery thereof and the outer peripheral surface of the transmission ring gear 22. Therefore, the pressure plate 41 rotates about the rotation axis O together with the transmission ring gear 22 as the transmission ring gear 22 rotates as the transmission ring gear 22 rotates about the rotation axis O.

  The friction plate 42 is a disk-shaped plate member having a friction material affixed on the surface thereof, and is spline-fitted to the case C by a spline joint 45 formed between the outer periphery of the friction plate 42 and the case C. Accordingly, the rotation of the friction plate 42 is restricted by the case C.

  Thus, the pressing plate 41 and the friction plate 42 are configured to be operable in the extending direction of the spline joints 44 and 45 (the left-right direction in FIG. 1) by being spline-fitted to the transmission ring gear 22 or the case C. Yes.

  The piston 43 is a disk-shaped member having a substantially L-shaped cross section, and is disposed in a piston chamber P1 in which an oil passage L1 formed in the case C is communicated with a protruding portion directed toward the pressing plate 41. Therefore, the piston 43 presses the pressing plate 41 by the pressure of the oil supplied to the piston chamber P1 when oil is supplied from the oil pump 60 described later to the piston chamber P1 through the oil passage L1.

  As a result, the gap between the pressing plate 41 and the friction plate 42 is closed, and the transmission ring gear 22 is fixed to the case C by the frictional force generated between the pressing plate 41 and the friction plate 42, and the rotation of the transmission ring gear 22 is restricted. Is done. As a result, in the transmission unit 20 configured by the planetary gear train, the transmission ring gear 22 can be given a role as a reaction force element.

  On the other hand, in a state where oil is not supplied to the piston chamber P1, the piston 43 is urged by the return spring 46 in a direction opposite to the pressing direction of the pressing plate 41 (right side in FIG. 1). Thereby, a clearance is secured between the pressing plate 41 and the friction plate 42, and the rotation of the transmission ring gear 22 is allowed.

  The clutch device 50 is for connecting or releasing the transmission sun gear 21 and the transmission carrier 24. As shown in FIGS. 1 and 3, a plurality of (seven in this embodiment) pressing plates 51, A plurality of (six in this embodiment) friction plates 52 interposed between the plurality of pressing plates 51 and a piston 53 are mainly provided.

  The pressing plate 51 is a disk-like plate-like member, and is splined to the transmission sun gear 21 by a spline joint 54 formed between the inner periphery thereof and the outer peripheral surface of the transmission sun gear 21. Therefore, the pressure plate 51 rotates around the rotation axis O together with the transmission sun gear 21 as the transmission sun gear 21 rotates as the transmission sun gear 21 rotates around the rotation axis O.

  The friction plate 52 is a disk-shaped plate member having a friction material affixed to the surface thereof, and is spline-fitted to the transmission carrier 24 by a spline joint 55 formed between the outer periphery thereof and the transmission carrier 24. Therefore, the friction plate 52 rotates around the rotation axis O together with the transmission carrier 24 as the transmission carrier 24 rotates as the transmission carrier 24 rotates around the rotation axis O.

  As described above, the pressing plate 51 and the friction plate 52 are configured to be operable in the extending direction of the spline joints 54 and 55 (the left-right direction in FIG. 1) by being spline-fitted to the transmission sun gear 21 or the transmission carrier 24. ing.

  The piston 53 is a disk-shaped member having a substantially L-shaped cross section, and the protrusion is disposed toward the pressing plate 51. Further, the piston 53 is provided close to the sub piston 57 disposed in the piston chamber P2 through which an oil passage L2 formed in the case C communicates. Therefore, the piston 53 presses the pressing plate 51 via the sub piston 57 by the pressure of the oil supplied to the piston chamber P2 when oil is supplied to the piston chamber P2 from the oil pump 60 described later through the oil passage L2. To do.

  As a result, the gap between the pressing plate 51 and the friction plate 52 is closed, and the transmission sun gear 21 and the transmission carrier 24 are connected by the frictional force generated between the pressing plate 51 and the friction plate 52. As a result, the transmission sun gear 21 and the transmission carrier 24 can be rotated together.

  On the other hand, in a state where oil is not supplied to the piston chamber P2, the piston 53 is urged by the return spring 56 in a direction opposite to the pressing direction of the pressing plate 51 (right side in FIG. 1). Thereby, a clearance is secured between the pressing plate 51 and the friction plate 52, and the connection between the transmission sun gear 21 and the transmission carrier 24 is released. As a result, the transmission sun gear 21 and the transmission carrier 24 can be rotated separately.

  As described above, in the transmission unit 20, the rotation of the transmission ring gear 22 is restricted by the brake device 40, and the coupling between the transmission sun gear 21 and the transmission carrier 24 is released by the clutch device 50, thereby inputting the transmission sun gear 21. The rotational force of the deceleration unit 10 can be output from the transmission carrier 24 via the transmission planetary gear 23 and transmitted to the differential device 3.

  Further, as shown in FIG. 2, the transmission unit 20 is configured such that the pitch circle radius R5 of the transmission sun gear 21 is smaller than the pitch circle radius R6 of the transmission ring gear 22 (R5 <R6). Thereby, the transmission unit 20 can decelerate and output the rotation of the transmission sun gear 21, that is, the input rotation input from the reduction unit 10.

  On the other hand, the brake device 40 allows the transmission ring gear 22 to rotate, and the clutch device 50 connects the transmission sun gear 21 and the transmission carrier 24 so that the rotational force of the speed reduction unit 10 input to the transmission sun gear 21 is changed to the transmission planetary gear. It is possible to directly output from the speed change carrier 24 without passing through the terminal 23. As a result, the rotation of the transmission sun gear 21, that is, the input rotation input from the speed reduction unit 10 can be output at a constant speed.

  The differential device 3 is a device for transmitting the input rotation input from the reduction gear 2 to the left and right wheels of the vehicle. As shown in FIG. 1, the differential sun gear 31, the differential ring gear 32, and the differential The planetary gear 33 and the differential carrier 34 are mainly provided and constituted by a so-called planetary gear train.

  The differential sun gear 31 constitutes a sun gear of a planetary gear train, and is connected to a drive shaft (not shown) that supports one of the left and right wheels of the vehicle. As will be described later, the differential sun gear 31 is engaged with a differential planetary gear 33 that is meshed with the differential ring gear 32, so that the differential ring gear 32 rotates around the rotation axis O, thereby the differential ring gear 32. Rotates around the rotation axis O.

  The differential ring gear 32 constitutes an internal gear of the planetary gear train and is connected to the transmission carrier 24. Accordingly, the differential ring gear 32 is rotated about the rotation axis O by the rotational force of the transmission unit 20 when the rotational force is input from the transmission unit 20 via the transmission carrier 24.

  Further, as shown in FIG. 1, a pump drive shaft 36 is coupled to the differential ring gear 32, and the pump drive shaft 36 is supported by the case C via a bearing 37. Accordingly, the pump drive shaft 36 rotates around the rotation axis O as the differential ring gear 32 rotates as the differential ring gear 32 rotates around the rotation axis O.

  The differential planetary gear 33 constitutes a planetary gear of a planetary gear train. The differential planetary gear 33 is engaged with the differential sun gear 31 and the differential ring gear 32 and is supported by a differential carrier 34 by a shaft 35. Accordingly, the differential planetary gear 33 revolves around the rotation axis O as the differential ring gear 32 rotates as the differential ring gear 32 rotates around the rotation axis O.

  Further, as shown in FIG. 1, the differential planetary gear 33 includes an inner planetary gear 33a meshed with the differential sun gear 31, and an outer planetary gear 33b meshed with the differential ring gear 32. The inner planetary gear 33a and the outer planetary gear are provided. 33b is meshed. Accordingly, the inner planetary gear 33a and the outer planetary gear 33b rotate in the opposite directions.

  In the present embodiment, the differential device 3 is provided with three pairs of differential planetary gears 33 (that is, each of the three inner planetary gears 33a and the outer planetary gears 33b). They are arranged at equal intervals (center angle intervals of 120 °).

  The differential carrier 34 constitutes a planetary frame of the planetary gear train. As described above, the differential planetary gear 33 is pivotally supported by the shaft 35 and is configured to be rotatable around the rotation axis O. . Accordingly, the differential carrier 34 rotates around the rotation axis O as the differential planetary gear 33 revolves as the differential planetary gear 33 revolves around the rotation axis O.

  Further, as shown in FIG. 1, an output shaft 38 connected to a drive shaft (not shown) that supports one of the left and right wheels of the vehicle is connected to the differential carrier 34.

  As described above, the differential device 3 constituted by the planetary gear train plays the role of the differential ring gear 32 as an input element and the differential sun gear 31 and the differential carrier 34 as output elements. Thereby, in the differential device 3, the rotational force of the speed reducer 2 input to the differential ring gear 32 can be transmitted from the differential sun gear 31 and the differential carrier 34 while being distributed to the left and right wheels of the vehicle. .

  Further, the differential device 3 rotates between the differential sun gear 31 and the differential ring gear 32 and revolves around the rotation axis O while the differential planetary gear 33 rotates, thereby rotating the differential sun gear 31. A difference in rotation between the differential carrier 34 and the rotation of the differential carrier 34 can be produced to absorb the differential between the left and right wheels of the vehicle.

  Next, the support structure of the shaft 15 by the speed reduction carrier 14 and the support structure of the shaft 25 by the speed change carrier 24 will be described with reference to FIGS. 4A is a front view of the speed reduction carrier 14 as viewed in the direction of IVa in FIG. 3, and FIG. 4B is a front view of the speed change carrier 24 as viewed in the direction of IVb in FIG.

  As shown in FIGS. 3 and 4A, the speed reduction carrier 14 has a shaft hole 14a into which the shaft 15 is inserted, and a snap ring S1 is engaged with the inner surface of the shaft hole 14a. A snap ring groove 14b that can be stopped is recessed.

  Therefore, the shaft 15 can be held in the shaft hole 14a by locking the snap ring S1 in the snap ring groove 14b in a state where the shaft 15 is inserted into the shaft hole 14a. On the other hand, the shaft 15 can be extracted from the shaft hole 14a by removing the snap ring S1 from the snap ring groove 14b.

  As described above, since the shaft 15 is held by the snap ring S1, the assembly work can be simplified as compared with the case where the shaft 15 is held by press-fitting, caulking, or the like. It is possible to simplify disassembly and maintenance.

  Further, a pin groove 14c that can engage with a pin P1 projecting from the outer peripheral surface of the shaft 15 is formed in the inner surface of the shaft hole 14a. Therefore, by engaging the pin P1 with the pin groove 14c and inserting the shaft 15 into the shaft hole 14a, the rotation of the shaft 15 in the shaft hole 14a can be restricted.

  Thus, since it is the structure which regulates rotation of the shaft 15 with the pin P1, the lubricating oil supplied through the oil path 15a formed in the shaft 15 can be supplied toward a desired part, for example.

  Similarly, as shown in FIGS. 3 and 4B, the speed reduction carrier 24 has a shaft hole 24a into which the shaft 25 is inserted, and a snap ring is formed on the inner surface of the shaft hole 24a. A snap ring groove 24b capable of locking S2 is recessed.

  Therefore, the shaft 25 can be held in the shaft hole 24a by locking the snap ring S2 in the snap ring groove 24b in a state where the shaft 24 is inserted into the shaft hole 24a. On the other hand, the shaft 25 can be extracted from the shaft hole 24a by removing the snap ring S2 from the snap ring groove 24b.

  As described above, since the shaft 25 is held by the snap ring S2, the assembling work can be simplified as compared with the case where the shaft 25 is held by press-fitting or caulking, and the shaft 25 can be attached and detached. It is possible to simplify disassembly and maintenance.

  Further, a pin groove 24c that can engage with a pin P2 protruding from the outer peripheral surface of the shaft 25 is formed in the inner surface of the shaft hole 24a. Therefore, by engaging the pin P2 with the pin groove 24c and inserting the shaft 25 into the shaft hole 24a, the rotation of the shaft 25 in the shaft hole 24a can be restricted.

  Thus, since it is the structure which regulates rotation of the shaft 25 by the pin P2, for example, the lubricating oil supplied through the oil path 25a formed in the shaft 25 can be supplied toward a desired part.

  Next, a detailed configuration of the oil pump 60 will be described with reference to FIG. FIG. 5 is a cross-sectional view of the oil pump 60 taken along line VV in FIG. The oil pump 60 supplies lubricating oil to each part of the speed reducer 2 and the differential device 3 and supplies hydraulic oil to the pistons 43 and 53. As shown in FIG. A pump gear 62 disposed in the housing 61 is mainly provided.

  The housing 61 forms an outline of the oil pump 60, and includes a suction oil passage 61a that communicates with the internal space of the case C (see FIG. 1), a suction oil passage 61a, and the speed reducer 2 and Oil passages (for example, oil passages 15a and 25a, see FIG. 3) for supplying lubricating oil to each part of the differential device 3 and oil passages (for example, oil passages L1 and L2) for supplying hydraulic oil to the pistons 43 and 53 , Refer to FIG. 1).

  The pump gear 62 rotates to suck the oil stored in the case C into the housing 61 through the suction oil passage 61a, and the sucked oil through the supply oil passage 61b to each part of the speed reducer 2 and the differential device 3. And a gear for pressure-feeding to the pistons 43 and 53, and is splined to the pump drive shaft 36. Accordingly, the pump gear 62 is rotated about the rotation axis O by the rotational force of the differential device 3 when the rotational force of the differential device 3 is input via the pump drive shaft 36.

  As described above, the oil pump 60 lubricates the parts of the reduction gear 2 and the differential device 3 and the pistons 43 and 53 by the rotation of the pump gear 62 by the rotational force of the differential device 3, that is, the rotational force of the motor M. Supply hydraulic fluid. As a result, when the motor M generates a rotational force, that is, when the vehicle travels and lubricating oil is required for each part of the speed reduction device 2 and the differential device 3, or when the hydraulic oil is applied to the pistons 43 and 53, When required, lubricating oil or hydraulic oil can be reliably supplied.

  On the other hand, when the motor M does not generate a rotational force, that is, when the vehicle stops and no lubricating oil is required for each part of the speed reduction device 2 and the differential device 3, or when no hydraulic oil is required for the pistons 43 and 53. In this case, the supply of lubricating oil or hydraulic oil can be stopped to save energy.

  As described above, according to the power transmission device 1 in the present embodiment, the reduction gear 2 includes the transmission unit 20 including the planetary gear unit, the brake device 40, and the clutch device 50, and the transmission ring gear 22 is provided by the brake device 40. , And the clutch device 50 releases the connection between the transmission sun gear 21 and the transmission carrier 24, so that the transmission planetary gear 23 rotates while the transmission sun gear 21 rotates, and the transmission sun gear 21 and the transmission ring gear 22 are rotated. , And revolves around the rotation axis O, and the transmission carrier 24 rotates around the rotation axis O as the transmission planetary gear 23 revolves, so that the input rotation input to the transmission sun gear 21 is decelerated. Then, it is transmitted from the shift carrier 24 to the left and right wheels of the vehicle.

  On the other hand, the transmission ring gear 22 is allowed to rotate by the brake device 40, and the transmission sun gear 21 and the transmission carrier 24 are connected by the clutch device 50, so that the transmission carrier 24 rotates on the rotation axis O as the transmission sun gear 21 rotates. By rotating around, the input rotation input to the transmission sun gear 21 is transmitted from the transmission carrier 24 to the left and right wheels of the vehicle at a constant speed.

  Therefore, the input rotation input to the speed change sun gear 21, that is, the input rotation input from the motor M, can be shifted to two stages of speed reduction and constant speed by one planetary gear unit. A pair of planetary gear units is not required, and the apparatus can be miniaturized accordingly.

  As described above, according to the power transmission device 1 in the present embodiment, the input rotation input from the motor M can be shifted in two stages, ie, deceleration and constant speed, so that the motor M can be operated in a wide vehicle speed range. It can be used efficiently.

  That is, the motor M generally has a characteristic that the rotational force decreases as the rotational speed increases. Therefore, simply decelerating the input rotation causes the wheels to rotate when the rotational speed of the motor M increases and the vehicle speed increases. For this reason, the rotational force necessary for this may not be sufficiently obtained. For this reason, the motor M must be enlarged to ensure a rotational force.

  On the other hand, according to the power transmission device 1 in the present embodiment, the input rotation can be shifted in two stages, that is, deceleration and constant speed. Therefore, in a state where the vehicle speed is high, the input rotation remains constant at the wheels. By transmitting to, an increase in the rotational speed can be suppressed. Thereby, the rotational force of the motor M can be obtained efficiently. As a result, the motor M can be used efficiently in a wide vehicle speed range. Further, if the rotational force of the motor M can be obtained efficiently, the motor M need not be increased in size, and the apparatus can be reduced in size accordingly.

  Further, according to the power transmission device 1 in the present embodiment, the speed reduction device 2 includes the speed reduction unit 10 having a planetary gear unit, and the speed reduction sun gear 11 rotates while the speed reduction planetary gear 13 rotates with the rotation of the speed reduction sun gear 11. Rolls between the reduction ring gear 12 and revolves around the rotation axis O, and the deceleration carrier 14 rotates around the rotation axis O as the reduction planetary gear 13 revolves. The rotation is decelerated and transmitted from the deceleration carrier 14 to the transmission sun gear 21.

  Therefore, the input rotation input from the motor M can be input to the transmission unit 20 after being decelerated. Thereby, since the rotational force of the motor M can be amplified, it is not necessary to increase the size of the motor M, and the size of the motor M can be reduced accordingly.

  Furthermore, according to the power transmission device 1 in the present embodiment, the differential device 3 having the planetary gear unit is provided, and the differential planetary gear 33 revolves around the rotation axis O along with the rotation of the differential ring gear 32 and the difference. As the dynamic sun gear 31 rotates about the rotation axis O, the input rotation input to the differential ring gear 32 is transmitted from the differential sun gear 31 and the differential carrier 34 to the left and right wheels of the vehicle, respectively.

  Further, the differential planetary gear 33 rotates and rotates between the differential sun gear 31 and the differential ring gear 32 and revolves around the rotation axis O, whereby the rotation of the differential sun gear 31 and the rotation of the differential carrier 34 are performed. A difference in rotation occurs between the left and right wheels to absorb the differential between the left and right wheels of the vehicle.

  Therefore, the rotational force input to the differential ring gear 32, that is, the rotational force of the transmission carrier 24 can be distributed and transmitted to the left and right wheels of the vehicle, and the rotational difference between the left and right wheels can be absorbed. As a result, the rotational force of the motor M is distributed and transmitted to the left and right wheels of the vehicle, and the elements from the motor M to the differential device 3 as a power source are combined into one while absorbing the rotational difference between the left and right wheels. Since it can be configured as a unit, the structure can be simplified.

  Further, according to the power transmission device 1 in the present embodiment, since the differential device 3 is constituted by a planetary gear unit, the length dimension in the direction of the rotation axis O is compared with the case where it is constituted by using a bevel gear. Can be shortened, and the size of the apparatus can be reduced.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed.

  For example, the numerical values (such as the quantity of each component) given in the above embodiment are merely examples, and other numerical values can naturally be adopted.

  In the above-described embodiment, the case where the speed reduction device 2 is configured to include the speed reduction unit 10 and the transmission unit 20 has been described. However, the present invention is not necessarily limited thereto, and may be configured to include only the transmission unit 20. good.

  In the above-described embodiment, the case where the large-diameter planetary gear 13a and the small-diameter planetary gear 13b of the reduction planetary gear 13 are configured with different pitch circle radii has been described. 13b may be configured with the same pitch circle radius. That is, the large-diameter planetary gear 13a and the small-diameter planetary gear 13b may be constituted by one gear.

  Although the case where the differential device 3 is configured by a planetary gear train has been described in the above embodiment, the present invention is not necessarily limited thereto, and may be configured by another gear mechanism. Examples of the other gear mechanism include a bevel gear.

  In the above embodiment, the case where the oil pump 60 supplies the lubricating oil or the working oil to the parts of the speed reduction device 2 and the differential device 3 and the pistons 43 and 53 using the rotational force of the motor M has been described. However, the present invention is not limited to this. For example, another motor or the like is provided in addition to the motor M, and the pump gear 62 is rotated by the rotational force of the motor, whereby each part of the speed reduction device 2 and the differential device 3 and the pistons 43 and 53. It may be configured to supply lubricating oil or hydraulic oil.

It is sectional drawing of a power transmission device. It is a schematic diagram of a power transmission device schematically showing a reduction gear and a differential device. It is an expanded sectional view of the power transmission device which expanded the part shown by III of FIG. (A) is a front view of the deceleration carrier in the direction of IVa in FIG. 3, and (b) is a front view of the speed change carrier in the direction of IVb in FIG. It is sectional drawing of the oil pump in the VV line | wire of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power transmission device 2 Reduction device 3 Differential device 10 Reduction part 11 Reduction sun gear (2nd sun gear)
12 Reduction ring gear (second ring gear)
13 Deceleration planetary gear (second planetary gear)
13a Large diameter planetary gear (part of the second planetary gear)
13b Small diameter planetary gear (part of the second planetary gear)
14 Deceleration carrier (second carrier)
20 Transmission 21 Shifting sun gear (first sun gear)
22 Transmission ring gear (first ring gear)
23 Shifting planetary gear (first planetary gear)
24 Shifting carrier (first carrier)
31 Differential sun gear (3rd sun gear)
32 Differential ring gear (3rd ring gear)
33 Differential planetary gear (3rd planetary gear)
34 Differential carrier (third carrier)
40 Brake device 41 Press plate (part of the brake device)
42 Friction plate (part of brake device)
43 Piston (part of brake device)
46 Return spring (part of brake device)
50 Clutch device 51 Press plate (part of clutch device)
52 Friction plate (part of clutch device)
53 Piston (part of clutch device)
56 Return spring (part of clutch device)
57 Sub-piston (part of clutch device)
M Motor O Rotating shaft

Claims (3)

A motor that generates a rotational force; and a speed reducer that receives the rotational force of the motor and decelerates the input rotation, and is mounted on a vehicle that uses the motor as a power source. In the power transmission device that transmits the rotational force to the left and right wheels of the vehicle,
The speed reducer is
A first sun gear that receives the rotational force of the motor and is rotated about a rotation axis; a first ring gear that is disposed on an outer periphery of the first sun gear and is rotatable about the rotation axis; and the first sun gear; A plurality of first planetary gears arranged between the first ring gear and meshed with the first sun gear and the first ring gear, and rotatably supporting the plurality of first planetary gears and rotating about the rotation axis A planetary gear unit comprising a first carrier,
A brake device that allows or restricts rotation of the first ring gear;
A clutch device for connecting or releasing the first sun gear and the first carrier;
By restricting the rotation of the first ring gear by the brake device and releasing the connection between the first sun gear and the first carrier by the clutch device, the first planetary gear is accompanied with the rotation of the first sun gear. Rolls between the first sun gear and the first ring gear while rotating, revolving around the rotation axis, and the first carrier rotates around the rotation axis as the first planetary gear revolves. Thus, the input rotation input to the first sun gear is decelerated and transmitted from the first carrier to the left and right wheels of the vehicle, while the brake device allows the rotation of the first ring gear and the clutch. By connecting the first sun gear and the first carrier by an apparatus, the first carrier rotates as the first sun gear rotates. By rotating around the power transmission device, characterized in that it comprises a transmission unit for transmitting from the first carrier the input rotation that is input to the first sun gear at a constant speed to the left and right wheels of the vehicle. The speed reducer is
A second sun gear that receives the rotational force of the motor and rotates about the rotation axis; a second ring gear that is disposed on an outer periphery of the second sun gear and whose rotation is restricted; the second sun gear; A plurality of second planetary gears disposed between the ring gear and meshed with the second sun gear and the second ring gear; and a plurality of second planetary gears rotatably supported and rotatable about the rotation axis. A planetary gear unit comprising two carriers,
As the second sun gear rotates, the second planetary gear rotates while rotating between the second sun gear and the second ring gear and revolves around the rotation axis, and as the second planetary gear revolves. The second carrier is provided with a speed reduction unit that decelerates the input rotation input to the second sun gear and transmits the rotation from the second carrier to the first sun gear as the second carrier rotates about the rotation axis. The power transmission device according to claim 1. A third ring gear that receives the rotational force of the first carrier and is rotated about the rotation axis; a third sun gear that is disposed on the inner periphery of the third ring gear and is rotatable about the rotation axis; A plurality of third planetary gears disposed between a third ring gear and a third sun gear and meshed with the third ring gear and the third sun gear, and rotatably supporting the plurality of third planetary gears and the rotating shaft A planetary gear unit comprising a third carrier rotatable around the planetary gear unit;
With the rotation of the third ring gear, the third planetary gear revolves around the rotation axis and the third sun gear rotates around the rotation axis, whereby the input rotation input to the third ring gear is changed to the first rotation. Transmission from the three sun gears and the third carrier to the left and right wheels of the vehicle, respectively, and the third planetary gear rolls between the third sun gear and the third ring gear while rotating to revolve around the rotation axis. And a differential device for absorbing a differential between the left and right wheels of the vehicle by generating a rotational difference between the rotation of the third sun gear and the rotation of the third carrier. Or the power transmission device of 2.

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