JP2005029116A - Drive device for vehicles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a wheel hub of a drive device for vehicles to be easily fixed to or removed from the drive device. <P>SOLUTION: This drive device 1 for a vehicle comprises a wheel hub 3 supporting a vehicle wheel 2, and a drive shaft 6 for use in transmitting a rotating output of a motor to the wheel hub 3. A threadably engaging thread of a fixing bolt 11 is formed at the axial position of the extremity end of the drive shaft 6. The wheel hub 3 is formed with a shaft insertion hole into which the extremity end of the drive shaft 6 is inserted. The extremity end of the drive shaft 6 is inserted into the shaft insertion hole of the wheel hub 3 so as to cause the drive shaft 6 and the wheel hub 3 to be connected in spline. The fixing bolt 11 is threadably engaged with the extremity end of the drive shaft 6 from outside the wheel hub 3 and then the wheel hub 3 is fixed to the drive shaft 6. Fixing or removing work for the wheel hub 3 can be easily carried out only through removal and threadable engagement of the fixing bolt 11 from outside the wheel hub 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle drive device that rotationally drives a wheel hub that supports a wheel of a vehicle using a rotational output of a motor.

  Conventionally, a vehicle drive device that rotationally drives a wheel hub by reducing the rotational output of a motor by a spur gear reducer and a planetary gear reducer, and transmitting the reduced rotational output to a wheel hub via a drive shaft. There is. In this type of vehicle drive device, a spur gear reducer, a planetary gear reducer, and a drive shaft are generally housed in a housing, and a wheel hub is connected to the drive shaft from the inside of the housing. .

  The spur gear reducer has a pinion spur gear connected to the shaft of the motor and a large spur gear meshed with the pinion spur gear. The planetary gear speed reducer is a sun gear that rotates coaxially with the rotation shaft of the large spur gear according to the rotation of the large spur gear of the spur gear reducer, a planetary gear that revolves around the sun gear by the rotation of the sun gear, It has a planet carrier that rotates on the same axis as the rotation axis of the sun gear by the revolution of the planetary gear. A hub bearing is provided between the wheel hub and the housing.

  Such a vehicle drive device forms a wheel shaft integrally with the wheel hub, forms a shaft insertion hole in the shaft center portion of the drive shaft, and inserts the wheel shaft into the shaft insertion hole so that the wheel hub is connected to the drive shaft. (For example, refer to Patent Document 1 and Patent Document 2). In the devices described in Patent Document 1 and Patent Document 2, the wheel hub and the drive shaft are connected by spline coupling, and a nut is screwed into the tip of the wheel shaft from the inside of the wheel hub (that is, inside the housing). Thus, the wheel hub is prevented from being removed from the drive shaft. Further, the drive shaft is formed integrally with the planet carrier.

Further, the wheel hub and the drive shaft are connected in the same manner as in the devices described in Patent Document 1 and Patent Document 2, and a bolt is screwed from the inside of the wheel hub to the tip of the wheel shaft to prevent the wheel hub from being removed from the drive shaft. Such a configuration is also known.
DE4321699C1 USP 5,147,255

  However, in the above-described conventional vehicle drive device, the wheel hub is secured by screwing a nut or a bolt into the wheel shaft from the inside of the wheel hub. It is necessary to operate a nut or a bolt from the inside of the. For this reason, the work of attaching and detaching the wheel hub is complicated, and the maintenance of the hub bearing provided between the wheel hub and the housing is complicated.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicle drive device that allows a wheel hub to be easily attached and detached.

  In order to achieve the above object, a first aspect of the present invention provides a vehicle drive device that includes a wheel hub that supports a wheel of a vehicle, and that rotates the wheel hub using the rotation output of the prime mover. A drive shaft for transmitting to the hub is provided, the drive shaft has a screw for bolting at the wheel side tip of the drive shaft, and the wheel hub is a shaft insertion into which the wheel side tip of the drive shaft is inserted. A spline for connecting the drive shaft and the wheel hub is provided on the outer peripheral surface of the front end of the wheel side of the drive shaft and the inner peripheral surface of the shaft insertion hole of the wheel hub. The wheel hub is secured to the drive shaft by preventing the wheel hub from being pulled out of the drive shaft by screwing a fixing bolt into the screw.

  In this configuration, the wheel hub is removed by removing the fixing bolt from the drive shaft and removing the wheel hub from the drive shaft. The wheel hub is mounted by fitting the wheel hub into the drive shaft and screwing the fixing bolt into the drive shaft. The fixing bolt is removed and screwed from the outside of the wheel hub. In other words, the wheel hub can be easily attached and detached simply by removing and screwing the fixing bolt from the outside of the wheel hub.

  According to a second aspect of the present invention, in the vehicle drive device according to the first aspect, a planetary gear speed reducer for reducing the rotational output of the prime mover is further provided between the drive shaft and the prime mover. A sun gear that transmits the rotational output of the planetary gear, a planetary gear that meshes with the sun gear and revolves around the sun gear by the rotation of the sun gear, and a rotation axis of the sun gear that supports the planetary gear and revolves around the planetary gear. A planetary carrier that rotates on the same axis, the drive shaft is integral with the planetary carrier, the screw is provided at the axis of the drive shaft, and there is one fixing bolt. The wheel hub is fixed to the drive shaft by screwing the fixing bolts with the screws.

  In this configuration, since the drive shaft is integral with the planet carrier, the work of connecting and fixing the drive shaft and the planet carrier is unnecessary, and the assembling work is simplified. In addition, the strength of the drive shaft and the planet carrier is increased. Further, since one fixing bolt is attached to the drive shaft, the wheel hub can be easily attached and detached simply by removing and screwing one fixing bolt.

  According to the first aspect of the present invention, since the fixing bolt is screwed into the driving shaft tip from the outside of the wheel hub to prevent the wheel hub from being pulled out, only the fixing bolt is removed and screwed from the outside of the wheel hub. The wheel hub can be easily attached and removed, and the hub bearing can be easily maintained.

  According to the invention of claim 2, since the drive shaft is integral with the planet carrier, the assembling work can be simplified, the manufacturing cost can be reduced, the strength of the drive shaft and the planet carrier is increased, and the running performance is improved. In addition, since one fixing bolt is attached, the wheel hub can be attached and detached more easily, and the hub bearing can be maintained more easily. In addition, the present invention can be applied to a long and thin drive shaft, and the number of parts and screw processing are small, resulting in cost reduction.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. 1 and 2, a vehicle drive device 1 drives a wheel hub 3 that supports a vehicle wheel 2 by using a rotational output of a motor (only a motor shaft 10 is shown) as a prime mover. It is. The vehicle drive device 1 reduces the rotational output of the motor by the spur gear reducer 4 and the planetary gear reducer 5 and transmits the reduced rotational output to the wheel hub 3 via the drive shaft 6. The hub 3 is driven to rotate, and the rotation of the wheel hub 3 is braked by the wet disc brake 7. The spur gear reducer 4, the planetary gear reducer 5, the drive shaft 6, and the wet disc brake 7 are housed in the housing 8, and the wheel hub 3 is connected to the drive shaft 6 from the outside of the housing 8. . The housing 8 is covered with a housing cover 9.

  The spur gear reducer 4 decelerates the rotational output of the motor, and has a pinion spur gear 41 and a large spur gear 42. The pinion spur gear 41 transmits the rotational output of the motor to the large spur gear 42 and is connected to the motor shaft 10. The large spur gear 42 is meshed with the pinion spur gear 41 and rotates according to the rotation of the pinion spur gear 41. The rotational output of the large spur gear 42 is obtained by reducing the rotational output of the pinion spur gear 41 in accordance with the gear ratio between the pinion spur gear 41 and the large spur gear 42. In this large spur gear 42, a shaft portion 45 and a flange portion 46 are configured as separate members from the gear portion 47. Further, the flange portion 46 is provided with a stopper 48 against which a brake disk 71 described later is pressed. The gear portion 47 and the flange portion 46 are connected and fixed by bolts 49.

  The spur gear reducer 4 reduces the rotational output of the pinion spur gear 41 according to the gear ratio to the rotational output of the large spur gear 42, thereby reducing the rotational output of the motor shaft 10 transmitted to the pinion spur gear 41. To do.

  The planetary gear speed reducer 5 decelerates the rotational output of the large spur gear 42 (that is, the rotational output of the motor decelerated by the spur gear speed reducer 4). The sun gear 51, the planetary gear 52, the ring gear 53, And a planet carrier 54. The sun gear 51 transmits the rotational output of the large spur gear 42 to the planetary gear 52, and is formed integrally with the shaft portion 45 and the flange portion 46 of the large spur gear 42. It rotates on the same axis as the rotation axis of the gear 42.

  The planetary gear 52 is meshed with the sun gear 51 and the ring gear 53. The ring gear 53 is fixed to the housing 8. The planetary gear 52 revolves around the sun gear 51 in accordance with the rotation of the sun gear 51 by being engaged with the sun gear 51 and the ring gear 53. The revolution output of the planetary gear 52 is obtained by reducing the rotation output of the sun gear 51. The planetary carrier 54 has a structure in which the planetary gear 52 is supported so as to be able to revolve around the sun gear 51, and rotates on the same axis as the rotation axis of the sun gear 51 according to the revolution of the planetary gear 52. The rotation output of the planet carrier 54 is the same as the revolution direction of the planetary gear 52 (thus, the rotation output of the sun gear 51 is decelerated). A carrier bearing 59 is provided between the planet carrier 54 and the housing 8.

  The planetary gear speed reducer 5 revolves the planetary gear 52 using the rotation output of the sun gear 51 and reduces the rotation output of the sun gear 51 by using the revolution output of the planetary gear 52 as the rotation output of the planet carrier 54. Thus, the rotation output of the planetary carrier 54 is set, and thereby the rotation output of the large spur gear 42 transmitted to the sun gear 51 (that is, the rotation output of the motor decelerated by the spur gear reducer 4) is decelerated.

  The drive shaft 6 transmits the rotation output of the planet carrier 54 (that is, the rotation output of the motor decelerated by the planetary gear speed reducer 5) to the wheel hub 3. The drive shaft 6 is formed integrally with the planet carrier 54. The wheel hub 3 and the drive shaft 6 are connected and fixed using a fixing bolt 11 and a retainer plate 12. The details of the connection structure between the wheel hub 3 and the drive shaft 6 will be described later. A bolt cap 13 is attached to the retainer plate 12 so as to cover the head of the fixing bolt 11. A hub bearing 15 is provided between the wheel hub 3 and the housing 8. The wheel hub 3 is rotationally driven by the rotation of the drive shaft 6 to rotate the wheel 2 and the tire 16.

  The wet disc brake 7 brakes the rotation of the wheel hub 3 and is disposed inside the large spur gear 42 of the spur gear reducer 4 and has a plurality of brake discs 71 and a pressure plate 72. ing. The plurality of brake discs 71 are composed of a plurality of inner brake discs 73 and a plurality of outer brake discs 74, and each of the inner brake discs 73 and the outer brake discs 74 is a rotating shaft of the large spur gear 42. They are superposed alternately in the direction and arranged at positions adjacent to the stopper 48. The stopper 48 is provided on the flange portion 46 of the large spur gear 42 as described above.

  The inner brake disc 73 is supported by a disc support member 75 fixed to the housing cover 9, and the outer brake disc 74 is supported on the inner peripheral surface of the gear portion 47 of the large spur gear 42. The inner brake disc 73 does not rotate, and the outer brake disc 74 rotates with the large spur gear 42. Both the inner brake disc 73 and the outer brake disc 74 are supported so as to be movable in the direction of the rotation axis of the large spur gear 42, and oil is interposed between each inner brake disc 73 and the outer brake disc 74. . The disk support member 75 is fixed to the housing cover 9 by bolts 76, and a spur gear bearing 77 is provided between the disk support member 75 and the shaft portion 45 of the large spur gear 42.

  The pressure plate 72 presses the brake disc 71 against the stopper 48. The pressure plate 72 is moved toward the stopper 48 by being pressed from the outside of the housing cover 9 by the pre-piston 85, and presses the brake disk 71 against the stopper 48. A projecting member 81 formed integrally with the housing cover 9 is inserted into a hole 82 formed in the pressure plate 72, so that the pressure plate 72 is supported so as to be movable in the rotational axis direction of the large spur gear 42. In addition, the rotation of the pressure plate 72 is restricted.

  When the pressure plate 72 is pressed by the pre-piston 85, the wet disk brake 7 presses the brake disk 71 against the stopper 48 by the pressure plate 72, thereby causing friction between each inner brake disk 73 and the outer brake disk 74. Force is generated, and the rotation of the large spur gear 42 is decelerated by this frictional force, and the rotation of the wheel hub 3 is braked.

  Next, a connection structure between the wheel hub 3 and the drive shaft 6 will be described with reference to FIG. The wheel hub 3 has a shaft insertion hole 31 formed in the center thereof, and a plurality of engagement grooves (spline grooves) for spline coupling the tip of the drive shaft 6 to the inner peripheral surface of the shaft insertion hole 31. 32 is formed. Each engagement groove 32 extends in the insertion direction of the drive shaft 6. On the other hand, the drive shaft 6 is formed with bolts 61 for screwing at the axial center of the tip, and a plurality of engaging projections (for spline coupling with the wheel hub 3) are formed on the outer peripheral surface of the tip. Spline) 62 is formed. Each engaging projection 62 extends in the axial direction of the drive shaft 6.

  The wheel hub 3 is fitted into the drive shaft 6 in a state where the engagement groove 32 is engaged with the engagement convex portion 62 of the drive shaft 6, and is connected to the drive shaft 6. The wheel hub 3 and the drive shaft 6 become spline coupling in which mutual rotation around the axis is restricted by the engagement of the engagement groove 32 and the engagement projection 62.

  The wheel hub 3 is in a state of being prevented from being removed from the drive shaft 6 when the fixing bolt 11 is screwed onto the bolt 61 for screwing the drive shaft 6 via the retainer plate 12. The bolt cap 13 is attached to the retainer plate 12 so as to cover the head of the fixing bolt (bolt with seat) 11, and the fixing bolt 11 is prevented from being loosened or damaged. The bolt cap 13 is made of metal or plastic and is fitted to the retainer plate 12 by elastic force. With such a connection structure of the wheel hub 3 and the drive shaft 6, when the drive shaft 6 rotates, the rotation output is transmitted to the wheel hub 3 and the wheel hub 3 rotates together with the drive shaft 6.

  According to the vehicle drive device 1 having such a configuration, the wheel hub 3 is removed by removing the bolt cap 13 and removing the fixing bolt 11 from the outside of the wheel hub 3 (that is, from the outside of the housing 8). 3 is extracted from the drive shaft 6. The wheel hub 3 is mounted by fitting the wheel hub 3 into the drive shaft 6, screwing the fixing bolt 11 from the outside of the wheel hub 3, and attaching the bolt cap 13. Thus, the detaching operation of the wheel hub 3 is easily performed by removing and screwing the fixing bolt 11 from the outside of the wheel hub 3.

  Further, since one fixing bolt 11 is attached to the drive shaft 6, the wheel hub 3 can be easily attached and detached simply by removing and screwing the one fixing bolt 11. Further, since the drive shaft 6 is integral with the planet carrier 54, the assembling work is simplified and the strength of the drive shaft 6 and the planet carrier 54 is increased.

  In addition, this invention is not restricted to the structure of the said embodiment, A various deformation | transformation is possible. For example, in the above embodiment, the wheel hub 3 and the drive shaft 6 may be spline-coupled by serration instead of the spline. Further, the wheel hub 3 may be prevented from being pulled out by screwing a plurality of fixing bolts 11 around the axis of the drive shaft 6. The drive shaft 6 is not limited to being integral with the planet carrier 54 but may be a member separate from the planet carrier 54.

1 is a cross-sectional view showing a schematic configuration of a vehicle drive device according to an embodiment of the present invention. The perspective view which fractured | ruptured partially which shows the structure of the drive device for vehicles. The disassembled perspective view which shows the connection structure of the wheel hub and drive shaft of the drive device for vehicles.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle drive device 2 Wheel 3 Wheel hub 4 Spur gear reducer 5 Planetary gear reducer 6 Drive shaft 7 Wet disk brake 8 Housing 9 Housing cover 10 Motor shaft 11 Fixing bolt 12 Retainer plate 13 Bolt cap 15 Hub bearing 16 Tire 31 Shaft insertion hole 32 Engagement groove 51 Sun gear 52 Planetary gear 54 Planetary carrier 61 Bolt screw screw 62 Engaging projection

Claims (2)

In a vehicle drive device that includes a wheel hub that supports a wheel of a vehicle, and that drives the wheel hub to rotate using a rotational output of a prime mover.
A drive shaft for transmitting the rotational output of the prime mover to the wheel hub;
The drive shaft has a screw for bolting at the wheel side tip of the drive shaft,
The wheel hub has a shaft insertion hole into which a wheel side tip of the drive shaft is inserted,
A spline for connecting the drive shaft and the wheel hub is provided on the outer peripheral surface of the wheel side tip of the drive shaft and the inner peripheral surface of the shaft insertion hole of the wheel hub,
A vehicle drive device characterized in that a fixing bolt is screwed onto the screw from the outside of the wheel hub to prevent the wheel hub from being removed from the drive shaft and fixed to the drive shaft. A planetary gear reducer for reducing the rotational output of the prime mover is further provided between the drive shaft and the prime mover, the planetary gear reducer being connected to the sun gear to which the rotational output of the prime mover is transmitted, and the sun gear. A planetary gear that is meshed and revolves around the sun gear by the rotation of the sun gear, and a planet carrier that supports the planetary gear and revolves coaxially with the rotation axis of the sun gear by the revolution of the planetary gear. Comprising
The drive shaft is integral with the planet carrier;
The screw is provided on an axis of the drive shaft;
The vehicle drive device according to claim 1, wherein the number of the fixing bolts is one, and the wheel hub is fixed to the driving shaft by screwing the one fixing bolt into the screw.

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