JP2008215550A - Gear transmission mechanism and wheel drive device - Google Patents

Abstract

The present invention relates to a gear transmission mechanism and a wheel drive device, and is to make the configuration compact and simple while maintaining a high degree of freedom in setting a gear ratio.
A planetary carrier connected to a motor shaft and rotated by the rotation of the motor shaft, a planetary gear 30 revolved by the rotation of the planetary carrier, and a planetary gear on the center of the revolution axis of the planetary gear. A fixed gear 40 that meshes with and rotates the planetary gear 30 when the planetary gear 30 revolves, an output gear 44 that meshes with the planetary gear 30 on the revolving shaft center side of the planetary gear 30 and rotates by the revolution and rotation of the planetary gear, Is provided. The planetary gear 30 includes a first gear 36 that meshes with the fixed gear 40 and revolves and rotates integrally with each other, and a second gear 38 that meshes with the output gear 44. The diameter of 38 is made smaller than the diameter of the first gear 36.
[Selection] Figure 2

Description

  The present invention relates to a gear transmission mechanism and a wheel drive device, and is particularly suitable for transmitting a rotation of a motor shaft to an output gear on a wheel side at a predetermined gear ratio, for example, when rotating a wheel using an electric motor, for example. The present invention relates to a gear transmission mechanism and a wheel drive device.

2. Description of the Related Art Conventionally, there has been known a wheel drive device that decelerates rotational torque of a motor and transmits it to wheels of a vehicle (see, for example, Patent Document 1). In this wheel drive device, a planetary gear mechanism is used as a speed reducer that reduces the rotational speed of the motor. The planetary gear mechanism includes a sun gear provided on a shaft connected to a motor rotor, a planetary gear that meshes with the sun gear and revolves and rotates around the sun gear, a planet carrier that is connected to the planetary gear, and the planetary gear. And an internal gear meshing with the planetary gear on the outer peripheral side opposite to the center of the revolution axis. The internal gear is fixed to the case, and the planet carrier is connected to a wheel-side hub. According to this planetary gear mechanism, the degree of freedom in setting the reduction ratio can be made relatively large in order to transmit the rotation of the motor rotor to the hub with a relatively small configuration.
JP 2005-73364 A

  However, in the conventional wheel drive device described above, it is necessary to dispose an internal gear that meshes with the planetary gear on the outer peripheral side opposite to the center side of the revolution axis of the planetary gear. In this regard, in such a wheel drive device, since the outer diameter of the speed reducer is relatively large, it is difficult to place the speed reducer in the wheel of the wheel, or an attempt is made to place the speed reducer in the wheel. In this case, it is necessary to increase the outer diameter of the wheel. Further, since a part of the gear structure (specifically, a ring gear) is formed or joined to a wheel structural member such as a motor housing or a steering knuckle, the structure of the speed reducer becomes complicated or high assembly accuracy is required. Become.

  The present invention has been made in view of the above-described points, and provides a gear transmission mechanism and a wheel drive device capable of downsizing and simplifying the configuration while maintaining a high degree of freedom in setting a gear ratio. For the purpose.

  The object is to connect the planetary gear connected to the shaft and rotate by the rotation of the shaft, the planetary gear revolving by the rotation of the planetary carrier, and the planetary gear meshing with the planetary gear at the center of the revolution axis of the planetary gear, A gear transmission mechanism comprising: a fixed gear that rotates the planetary gear at the time of revolution of the planetary gear; and an output gear that meshes with the planetary gear on the center side of the revolution axis of the planetary gear and rotates by the revolution and rotation of the planetary gear. Is achieved.

  In the invention of this aspect, the planetary gear is revolved by the rotation of the planet carrier that rotates by the rotation of the shaft. The planetary gear is meshed with a fixed gear that rotates the planetary gear when the planetary gear revolves, and an output gear that rotates by the revolution and rotation of the planetary gear. According to such a configuration, it is not necessary to provide a gear that meshes with the planetary gear or the like on the outer peripheral side opposite to the center side of the revolution axis of the planetary gear, so that the outer diameter can be reduced and the configuration can be simplified. it can. Further, since the planetary gear, the fixed gear, and the output gear are interposed to transmit the rotational torque of the shaft to the output gear side, a high degree of freedom in setting the gear ratio can be maintained.

  In the gear transmission mechanism described above, the planetary gear includes a first gear that meshes with the fixed gear, and a second gear that meshes with the output gear, which revolve and rotate integrally with each other. Then, when the planetary gear rotates during the revolution by the meshing of the first gear and the fixed gear, the output gear meshed with the second gear can be rotated.

  In this case, if the diameter of the first gear and the diameter of the second gear are different from each other, the rotational torque of the shaft can be shifted and transmitted to the output gear side. In this case, if the diameter of the second gear is smaller than the diameter of the first gear, the rotational torque of the shaft can be reduced and transmitted to the output gear side.

  Furthermore, in the gear transmission mechanism described above, if the output gear is arranged coaxially with the fixed gear, the fixed gear that is rotationally fixed and the output gear that rotates at the rotational speed after the shift are mutually connected. It can be placed adjacent to the direction.

  By the way, if the gear transmission mechanism described above is provided with a pump that decelerates the rotational torque of the shaft and transmits it to the output gear and is driven by the rotation of the output gear, it is transmitted to the output gear. Since the pump can be driven at the rotational speed after deceleration, the rotational speed can be kept relatively low when the pump is driven.

  In this case, if the pump has a pump housing fixed to the fixed gear and a drive shaft connected to the output gear, the pump can be driven at a rotational speed after deceleration with a simple configuration. Can be realized.

  Further, if the gear transmission mechanism described above is applied to a wheel drive device that decelerates the rotational torque of the electric motor and transmits it to the wheel, the reduction ratio is set to transmit the rotational torque of the electric motor to the wheel. The wheel drive device can be made compact while maintaining a high degree of freedom.

  ADVANTAGE OF THE INVENTION According to this invention, a structure can be compactized and simplified, maintaining the setting freedom degree of a gear ratio highly.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall configuration diagram of a wheel drive device 12 including a gear transmission mechanism 10 according to an embodiment of the present invention. In addition, in FIG. 1, sectional drawing of the wheel drive device 12 is shown. The wheel drive device 12 of the present embodiment is a device provided on each drive wheel that is a wheel of the vehicle, and is a device applied to a so-called in-wheel motor type electric vehicle. In FIG. 1, the left side is the vehicle outer side, and the right side is the vehicle center side.

  The wheel drive device 12 includes an electric motor 14. The electric motor 14 is disposed on the center side of the vehicle in the disc wheel 16 of the drive wheel. The electric motor 14 includes a stator 18 and a rotor 20.

  The stator 18 has a structure in which a coil is wound around an iron core, and is attached and fixed to a steering knuckle on the vehicle body side or a motor housing 22 (hereinafter referred to as a housing side) fixed to the knuckle. The rotor 20 has a permanent magnet, and is disposed on the inner diameter side of the stator 18 so as to face the stator 18 via a predetermined air gap. The rotor 20 is integrally fixed to the outer periphery of a motor shaft 26 that is rotatably supported via a bearing 24 on the housing 22 side. The rotor 20 is rotated by an electromagnetic force acting between the rotor 16 and the stator 16 by energization of the stator coil from the in-vehicle power source. The motor shaft 26 is rotated by the rotation of the rotor 20.

  The wheel drive device 12 also includes a gear transmission mechanism 10. The gear transmission mechanism 10 is a speed reducer that reduces the rotational speed of the rotational torque generated by the electric motor 14 and transmits the rotational torque to the disk wheel 16 of the wheel. The gear speed change mechanism 10 is disposed outside the electric motor 14 in the drive wheel disc wheel 16 and adjacent to the electric motor 14. The gear transmission mechanism 10 includes a circular planetary gear 30 and a planet carrier 32 that connects the rotation axis centers of the planetary gear 30 as described later.

  The planet carrier 32 is connected to and integrated with the motor shaft 26 described above, and rotates integrally with the motor shaft 26 when the motor shaft 26 rotates. The planet carrier 32 is formed so as to connect the centers of the rotation axes of the planetary gears 30, and has a function of revolving the planetary gears 30 on the axis thereof by rotation on the same axis as the motor shaft 26.

  A plurality of planetary gears 30 are provided at equal intervals around a revolution shaft (coaxial with the rotation shaft of the motor shaft 26 or the planetary carrier 32). Each planetary gear 30 is rotatably supported by a planetary gear shaft 34 (= rotation shaft) integrated with a planet carrier 32 via a bearing. The planetary gear 30 revolves around the revolution axis by the rotation of the planet carrier 32 and can rotate around the planetary gear axis 34.

  The planetary gear 30 includes a first gear 36 and a second gear 38. The first gear 36 and the second gear 38 are integrally formed coaxially with each other, revolve around the revolution axis and rotate around the planetary gear shaft 34 integrally. The first gear 36 is provided on the electric motor 14 side, that is, the vehicle center side, while the second gear 36 is provided on the vehicle outer side.

  The diameter of the first gear 36 and the diameter of the second gear 38 are different from each other, and the number of teeth of the first gear 36 and the number of teeth of the second gear 38 are different from each other. Specifically, the second gear 38 has a smaller diameter than that of the first gear 36 and has a smaller number of teeth than that of the first gear 36. Note that, between the planetary gears 30, the first gear 36 has the same diameter and the same number of teeth, and the second gear 38 has the same diameter and the same number of teeth.

  A circular fixed gear 40 whose rotation is prohibited is engaged with the first gear 36. Only one fixed gear 40 is provided for each planetary gear 30, and meshes with the first gear 36 of each planetary gear 30 on the center side of the revolution axis of the planetary gear 30. A fixed shaft 42 that extends in the axial direction on the rotation axis of the motor shaft 26 is fixedly attached to the housing side 22. The fixed shaft 42 is attached to the housing side 22 at an end portion on the vehicle center side, and supports the motor shaft 26 via a bearing 24 so as to be rotatable. The fixed gear 40 described above is fixed or formed integrally with the fixed shaft 42 on the outer periphery of the end portion of the fixed shaft 42 on the vehicle outer side, and is fixed to the housing side 22 by rotation. The fixed gear 40 has a function of rotating the planetary gear 30 around the planetary gear shaft 34 when the planetary gear 30 engaged with the planetary gear 30 revolves by the rotation of the planetary carrier 32.

  A circular output gear 44 that is allowed to rotate is meshed with the second gear 38. Only one output gear 44 is provided for each planetary gear 30, and meshes with the second gear 38 of each planetary gear 30 on the center side of the revolution axis of the planetary gear 30. An axle carrier 46 is attached and fixed to the housing side 22. An axle shaft 50 is rotatably supported on the axle carrier 46 via an axle bearing 48. The axle shaft 50 extends coaxially with the motor shaft 26 and the fixed shaft 42 and extends toward the outside of the vehicle in the axial direction adjacent to the shafts 26 and 42.

  The output gear 44 described above is fixed or formed integrally with the axle shaft 50 on the outer periphery of the end of the axle shaft 50 on the vehicle center side, and is coaxial with the fixed gear 40 and adjacent to the axial direction thereof. Are arranged. When the planetary gear 30 meshed with the output gear 44 revolves and rotates, the output gear 44 is integrated with the axle shaft 50 at a predetermined reduction ratio and rotates about its rotation axis.

  The diameter of the fixed gear 40 and the diameter of the output gear 44 are different from each other, and the number of teeth of the fixed gear 40 and the number of teeth of the output gear 44 are different from each other. Specifically, the output gear 44 has a larger diameter than that of the fixed gear 40 and has a larger number of teeth than that of the fixed gear 40. The distance between the center of the fixed gear 40 and the center of the planetary gear 30 and the distance between the center of the output gear 44 and the center of the planetary gear 30 are the same.

  A drive wheel disc wheel 16 is fixedly fastened to the axle shaft 50 by a plurality of bolts 52 at a flange portion extending in the radial direction. The disk wheel 16 rotates integrally with the axle shaft 50 as the axis center by the rotation of the axle shaft 50.

  The gear speed change mechanism 10 includes a gear pump 54. The gear pump 54 communicates with an oil reservoir through an oil passage. The gear pump 54 pumps oil from an oil reservoir through an oil passage to cool or lubricate each part (mainly the sliding part between the gears) when the gear transmission mechanism 10 is operated. 10 is an oil pump that delivers oil to each of the ten parts.

  The gear pump 54 is provided in an opening hole formed in the center portion of the vehicle outer end of the fixed gear 40, the pump housing 56 fixed to the vehicle outer end of the fixed gear 40 or the fixed shaft 42, and the output gear 44. Or it has the drive shaft 58 connected with the vehicle center side front end of the axle shaft 50. The drive shaft 58 is integrally rotated with the pump housing 56 by the same rotation as the output gear 44, that is, the axle shaft 50 is rotated. The gear pump 54 drives its drive shaft 58 by the rotation of the output gear 44, and sends the oil pumped up from the oil reservoir to each part.

  Next, with reference to FIG. 2, a specific operation of the wheel drive device 12 including the gear transmission mechanism 10 of the present embodiment will be described. FIG. 2 is a diagram showing the operating principle of the gear transmission mechanism 10 of this embodiment.

  In the wheel drive device 12 of the present embodiment, when the stator coil of the electric motor 14 is energized from the on-vehicle power supply, electromagnetic force acts between the stator 18 and the rotor 20 in accordance with the energized state, so that the rotor As the motor 20 rotates, the motor shaft 26 rotates. When the motor shaft 26 rotates, the rotational torque is transmitted to the planet carrier 32 constituting the gear transmission mechanism 10, and the planet carrier 32 rotates integrally with the motor shaft 26 on the same axis.

  When the planetary carrier 32 rotates, the planetary gears 30 constituting the gear transmission mechanism 10 revolve around a revolution axis coaxial with the rotation shaft of the motor shaft 26 or the planetary carrier 32. As described above, the first gear 36 of the planetary gear 30 meshes with the fixed gear 40 that is rotationally fixed. For this reason, when the planetary gear 30 is revolved by the rotation of the planet carrier 32 as described above, the planetary gear 30 rotates around the planetary gear shaft 34.

  The planetary gear 30 has a first gear 36 and a second gear 38 that is integrally formed with the first gear 36 on the same axis. The first gear 36 and the second gear 38 have different diameters and different numbers of teeth. The second gear 38 meshes with the output gear 44 that is allowed to rotate. Therefore, when the planetary gear 30 revolves as described above and rotates along with the revolution, the rotational torque of the motor shaft 26 and the planetary carrier 32 is meshed with the second gear 38 while its rotational speed is changed. By being transmitted to the gear 44, the output gear 44 rotates.

  The gear ratio between the rotation on the motor shaft 26 side and the rotation of the output gear 44 is the ratio of the diameter or the number of teeth of the first gear 36 and the second gear 38 (= the ratio between the output gear 44 and the fixed gear 40). It is a value determined by the ratio of the diameter and the number of teeth). In this embodiment, the second gear 38 has a smaller diameter and fewer teeth than that of the first gear 36, and the output gear 44 has a larger diameter and more teeth than that of the fixed gear 40. Therefore, when the rotational torque on the motor shaft 26 side is transmitted to the output gear 44, the rotational speed is decelerated at a predetermined reduction ratio corresponding to the diameter and the number of teeth.

  When the rotational torque on the motor shaft 26 side is transmitted to the output gear 44 and the output gear 44 rotates, the axle shaft 50 rotates integrally with the output gear 44. When the axle shaft 50 is rotated, the disk wheel 16 is integrally rotated about the axle shaft 50 as an axis by the rotation. When the rotation direction of the motor shaft 26 by the electric motor 14 is a specific one direction, the disc wheel 16 rotates to advance the vehicle, while the rotation direction of the motor shaft 26 is a specific other direction. Rotates to retract the vehicle.

  Thus, in the wheel drive device 12 of the present embodiment, the rotational torque generated by the electric motor 14 can be transmitted to the disc wheel 16 of the wheel through the gear transmission mechanism 10 at a predetermined reduction ratio. Accordingly, the drive wheel including the disc wheel 16 and the brake disc can be rotated around the axle shaft 50 at a predetermined reduction ratio by driving the electric motor 14, so that the wheel is driven to rotate using a so-called in-foil motor. Can be realized.

  In the wheel drive device 12 of the present embodiment, the gear transmission mechanism 10 includes the planetary carrier 32 that rotates by the rotation of the motor shaft 26 and the planetary gear 30 that revolves by the rotation of the planetary carrier 32 as described above. ing. The planetary gear 30 meshes with a fixed gear 40 that rotates the planetary gear 30 at the time of revolution and a first gear 36 that meshes with the center side of the revolution shaft, and an output gear 44 that rotates by the revolution and rotation with the center side of the revolution shaft. And a second gear 38. That is, in the configuration of the gear transmission mechanism 10 according to the present embodiment, the planetary gear 30 on the outer peripheral side opposite to the center side of the revolution shaft of the planetary gear 30 is used to reduce the rotational torque generated by the electric motor 14 and transmit it to the wheels. It is not necessary to provide a gear that meshes with the gear 30 (for example, an internal gear (ring gear) of a normal planetary gear mechanism).

  In the configuration of a gear transmission mechanism (hereinafter referred to as a first contrast configuration) in which an internal gear that meshes with the planetary gear 30 is provided on the outer peripheral side opposite to the center side of the revolution shaft of the planetary gear 30, the housing side 22 Since it is necessary to directly form the internal gear or to join a separate internal gear, the overall outer diameter of the gear transmission mechanism becomes large, the structure becomes complicated, the housing side 22 and the gear transmission A high assembling accuracy is required on the mechanism side, and inconvenience that the assembling itself becomes difficult occurs.

  On the other hand, according to the gear transmission mechanism 10 of the present embodiment, as described above, it is not necessary to provide a gear that meshes with the planetary gear 30 on the outer peripheral side opposite to the revolution shaft center side of the planetary gear 30. Therefore, the outer diameter is reduced and the configuration is simplified as compared with the first contrast configuration described above, and high assembly accuracy with the housing side 22 is not required. It becomes possible to improve the property.

  Further, the gear transmission mechanism 10 of this embodiment includes a first gear 36 and a second gear 38 of the planetary gear 30, a fixed gear 40, and an output gear 44, and reduces the rotational torque generated by the electric motor 14. These four gears are interposed for transmission to the wheels. For this reason, the reduction ratio of the rotation speed from the electric motor 14 side to the wheel side can be set with a high degree of freedom.

  Specifically, in the gear transmission 10, as described above, the second gear 38 has a smaller diameter and a smaller number of teeth than that of the first gear 36, and the output gear 44 is a fixed gear. It has a larger diameter and a larger number of teeth than 40. In this regard, for example, as the diameter of the second gear 38 is larger and closer to the diameter of the first gear 36 (that is, the diameter of the output gear 44 is smaller and closer to the diameter of the fixed gear 40), the reduction ratio becomes infinite. The rotational speed of the wheel is smaller than the rotational speed of the motor shaft 26. On the other hand, the smaller the diameter of the second gear 38 (that is, the larger the diameter of the output gear 44), the closer the reduction ratio becomes “1”, and the rotational speed of the wheel becomes closer to the rotational speed of the motor shaft 26. In this regard, when the rotational torque generated by the electric motor 14 is decelerated and transmitted to the wheels, it is possible to maintain a high degree of freedom in setting the speed reduction ratio.

  Therefore, according to the gear transmission mechanism 10 of the present embodiment, the configuration can be made compact and simplified while maintaining a high degree of freedom in setting the transmission ratio (reduction ratio), and the housing can be simplified. It is possible to avoid the requirement for high assembling accuracy between the side 22 and improve the assembling property. For this reason, according to the wheel drive device 12 provided with the gear transmission mechanism 10 of the present embodiment, the degree of freedom in setting the reduction ratio is kept high when the rotational torque is transmitted from the electric motor 14 to the wheel. It is possible to reduce the size and improve the assembly.

  Next, the operation of the gear pump 54 in the gear transmission mechanism 10 of the present embodiment will be described with reference to FIG. FIG. 3 is a diagram showing the operating principle of the gear pump 54 in the gear transmission mechanism 10 of this embodiment.

  In the gear transmission mechanism 10 of the present embodiment, the gear pump 54 includes the pump housing 56 fixed to the vehicle outer end of the fixed gear 40 or the fixed shaft 42 and the vehicle gear center end of the output gear 44 or the axle shaft 50 as described above. And a drive shaft 58 connected to each other. In this regard, the gear pump 54 is a pump in which the drive shaft 58 is driven with respect to the pump housing 56 by the rotation of the output gear 44.

  In the wheel drive device 12 described above, when the rotational torque by the electric motor 14 is decelerated by the operation of the gear transmission mechanism 10 and transmitted to the wheel side, the output gear 44 is at a rotational speed that is decelerated from the rotational speed of the electric motor 14. Rotate. When the output gear 44 rotates, the drive shaft 58 of the gear pump 54 is rotationally driven. At this time, the gear pump 54 pumps up the oil from the oil reservoir through the oil passage, and sends the pumped up oil to each part of the gear transmission mechanism 10.

  Thus, in the wheel drive device 12 of the present embodiment, when the gear transmission mechanism 10 is operated, that is, when the rotational torque by the electric motor 14 is transmitted to the wheel side through the gear transmission mechanism 10, the rotation of the output gear 44 is performed. Thus, the gear pump 54 can be rotationally driven. Therefore, according to the present embodiment, when the gear transmission mechanism 10 is operated, each part of the gear transmission mechanism 10 to be operated can be cooled or lubricated by the oil sent from the gear pump 54.

  In the present embodiment, the gear pump 54 is rotationally driven by the rotation of the output gear 44 while being fixed to the fixed gear 40 or the fixed shaft 42 provided with the fixed gear 40. Rotational torque generated by the electric motor 14 is reduced and transmitted to the output gear 44. In this regard, in the gear transmission mechanism 10 of the present embodiment, the gear pump 54 is rotationally driven at the rotational speed after deceleration by transmitting torque from the electric motor 14 to the output gear 44.

  In the configuration in which the gear pump is rotationally driven by the rotation of the motor shaft 26 before deceleration by the gear transmission mechanism 10 (hereinafter referred to as the second comparison configuration), the rotational driving of the gear pump is performed at a relatively high speed. The gear pump itself tends to vibrate, which may cause inconvenience that the efficiency of cooling and lubrication deteriorates.

  On the other hand, according to the gear transmission mechanism 10 of the present embodiment, as described above, the gear pump 54 transmits torque from the electric motor 14 to the output gear 44 instead of the number of rotations by the electric motor 14 (before deceleration). Therefore, the rotation speed of the gear pump 54 is compared when the gear pump 54 is driven as compared with the above-described second comparison configuration. Thus, vibration generated in the gear pump 54 itself can be suppressed, and reduction in cooling and lubrication efficiency can be suppressed.

  Further, as described above, the gear pump 54 is rotationally driven by the rotation of the output gear 44 while being fixed to the fixed gear 40 or the fixed shaft 42 provided with the fixed gear 40. The fixed shaft 42 is fixedly attached to the housing side 22 and extends in the axial direction on the rotation shaft of the motor shaft 26 while rotatably supporting the motor shaft 26 via the bearing 24. Further, the fixed shaft 42 and the axle shaft 50 provided with the output gear 44 are coaxially adjacent to each other and extend in the axial direction.

  According to the existing positional relationship between the fixed shaft 42 and the axle shaft 50, the fixed gear 40 and the output gear 44 can be arranged coaxially adjacent to each other in the axial direction, and the pump of the gear pump 54 The portion where the housing 56 is fixed and the portion where the rotational torque after deceleration to which the drive shaft 58 of the gear pump 54 should be connected can be brought close to each other.

  In this regard, according to the gear transmission mechanism 10 of the present embodiment, the gear pump 54 to be driven to rotate at the rotational speed after deceleration is relatively fixed in the axial direction and relatively fixed to each other. 42 and the output gear 44 and the axle shaft 50 can be set and arranged. For this reason, the gear pump 54 can be easily arranged in the vicinity of the portion that is rotationally driven at the rotational speed of the deceleration, and the rotational driving of the gear pump 54 can be realized with a simple configuration. Therefore, when the gear pump 54 is rotationally driven at the rotational speed after deceleration, it is possible to avoid a complicated structure or an increase in cost.

  In the above embodiment, the motor shaft 26 corresponds to the “shaft” recited in the claims, and the gear pump 54 corresponds to the “pump” recited in the claims.

  By the way, in the above embodiment, the electric motor 14 is arranged on the vehicle center side and the gear transmission mechanism 10 is arranged on the vehicle outer side in the disk wheel 16 of the driving wheel, but the present invention is limited to this. On the contrary, as shown in FIG. 4, the electric motor 14 may be disposed outside the vehicle and the gear transmission mechanism 10 may be disposed on the vehicle center side.

  Further, in the above-described embodiment, the fixed shaft 42 that is attached and fixed to the housing side 22 and rotatably supports the motor shaft 26 via the bearing 24 is provided, and the fixed shaft 42 rotates around the outer periphery of the end portion of the vehicle. Although the fixed fixed gear 40 is provided, the present invention is not limited to this. As shown in FIG. 5, the axle carrier attached and fixed to the housing side 22 without providing the fixed shaft 42 described above. It is good also as providing the rotation fixed stationary gear 40 which meshes with the 1st gearwheel 36 integrally fixed to the outer periphery of the axial part of 46, or is formed. In this case, the first gear 36 is provided on the outside of the vehicle, while the second gear 36 is provided on the electric motor 14 side, that is, the vehicle center side, and the axle shaft 50 rotates the motor shaft 26 via the bearing 24. Support as possible. The gear pump 54 has a pump housing 56 fixed directly to the housing side 22 and a drive shaft 58 connected to the output gear 44 or the axle shaft 50 at the vehicle center side front end. According to such a configuration, the pump housing 56 of the gear pump 54 can be directly attached and fixed to the housing side 22, so that it is not necessary to provide the fixed shaft 42, and it is possible to improve assembly and simplify the configuration.

  In the above embodiment, the wheel driving device 12 has a so-called inner ring rotating structure that rotates the hub inner ring to drive the wheel, but the present invention is not limited to this, and the wheel is driven. Further, the present invention may be applied to a so-called outer ring rotating structure for rotating the hub outer ring. In this case, as shown in FIG. 6, the electric motor 14 may be arranged in the center of the vehicle and the gear transmission mechanism 10 may be arranged outside the vehicle in the disk wheel 16 of the driving wheel. Also, as shown in FIG. The electric motor 14 may be disposed outside the vehicle, and the gear transmission mechanism 10 may be disposed on the vehicle center side. Further, as shown in FIG. 7, without providing the fixed shaft 42, the first gear 36 meshes with the first gear 36 that is integrally fixed or formed on the outer periphery of the shaft portion of the member 60 that is attached and fixed to the housing side 22. It is good also as providing the fixed gear 40 of rotation fixation.

  In the above embodiment, the gear pump 54 is used as an oil pump for sending oil to each part of the gear transmission mechanism 10. However, the present invention is not limited to this, and the output gear 44, that is, the axle is used. Any rotary pump that is rotationally driven by the rotation of the shaft 50 may be used, and a vane pump may be used.

  In the above embodiment, the gear pump 54 is an oil pump that pumps up oil from the oil reservoir and sends it to each part of the gear transmission mechanism 10. However, the pump may pump up fluid such as water other than oil. Moreover, the pump which sends out fluid to parts other than the gear transmission mechanism 10 may be sufficient.

  In the above-described embodiment, the wheel drive device 12 that rotates the drive wheels of the vehicle using the electric motor 10 is used as the device including the gear transmission mechanism 10. However, the present invention is not limited to this. Instead of this, a device that rotates the drive wheels by driving a drive source other than the electric motor 14 may be used, or a device that rotationally drives a drive target other than the vehicle may be used.

  In the above embodiment, the gear transmission mechanism 10 is used as a speed reducer that reduces the rotational torque and transmits it to the drive target. However, the present invention is not limited to this, and the rotational torque is not limited to this. It is good also as what is applied to what is used as a gearbox which accelerates and transmits to a drive object.

It is a whole lineblock diagram of a wheel drive device provided with a gear transmission mechanism of one example of the present invention. It is a figure showing the principle of operation of the gear transmission mechanism of a present Example. It is a figure showing the principle of operation of the gear pump in the gear transmission mechanism of a present Example. It is a whole block diagram of a wheel drive device provided with the gear transmission mechanism which is a modification of this invention. It is a whole block diagram of a wheel drive device provided with the gear transmission mechanism which is a modification of this invention. It is a whole block diagram of a wheel drive device provided with the gear transmission mechanism which is a modification of this invention. It is a whole block diagram of a wheel drive device provided with the gear transmission mechanism which is a modification of this invention. It is a whole block diagram of a wheel drive device provided with the gear transmission mechanism which is a modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Gear transmission mechanism 12 Wheel drive device 14 Electric motor 26 Motor shaft 30 Planetary gear 32 Planet carrier 36 1st gear 38 2nd gear 40 Fixed gear 44 Output gear 54 Gear pump 56 Pump housing 58 Drive shaft

Claims (8)

A planet carrier coupled to the shaft and rotating by rotation of the shaft;
Planetary gears revolving by rotation of the planet carrier;
A fixed gear that meshes with the planetary gear at the center of the revolution axis of the planetary gear, and rotates the planetary gear when the planetary gear revolves;
An output gear that meshes with the planetary gear on the center side of the revolution axis of the planetary gear and rotates by the revolution and rotation of the planetary gear;
A gear transmission mechanism comprising:   The said planetary gear consists of a 1st gear meshing with the said fixed gear and the 2nd gear meshing with the said output gear which revolve and rotate integrally with each other, The said 1st gear is characterized by the above-mentioned. Gear transmission mechanism.   The gear transmission mechanism according to claim 2, wherein the diameter of the first gear and the diameter of the second gear are different from each other.   The gear transmission mechanism according to claim 3, wherein the diameter of the second gear is smaller than the diameter of the first gear.   The gear transmission mechanism according to claim 1, wherein the output gear is arranged coaxially with the fixed gear. Reducing the rotational torque of the shaft and transmitting it to the output gear; and
The gear transmission mechanism according to any one of claims 1 to 5, further comprising a pump driven by rotation of the output gear.   The gear transmission mechanism according to claim 6, wherein the pump includes a pump housing fixed to the fixed gear, and a drive shaft connected to the output gear.   A wheel drive device that decelerates the rotational torque of the electric motor by the gear transmission mechanism according to any one of claims 1 to 7 and transmits the reduced torque to the wheels.

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