JP4698358B2 - Power transmission device - Google Patents

Description

  The present invention relates to a three-shaft power transmission device that changes the direction of a driving force of a prime mover and transmits it to a wheel side.

  Patent Document 1 describes a four-wheel drive device that is a transfer of a four-wheel drive vehicle.

FIG. 5 shows a power transmission device 501 having a configuration similar to that of the four-wheel drive device. The driving force of the engine is input from the input shaft 503, is transmitted to the intermediate shaft 507 via the gear transmission mechanism 505, is further transmitted to the output shaft 511 via the direction change gear set 509, and is sent to the wheel side.
JP 62-59130 A

  However, the power transmission device 501 used as a transfer is configured to be compact because other structural members such as a steering shaft are disposed around the power transmission device 501, but the meshing portion 513 of the direction change gear set 509 is the axis of the intermediate shaft 507. 515, when viewed in the opposite direction of the input shaft 503, that is, in the axial direction of the output shaft 511, since the output shaft 511 is behind the axis of the intermediate shaft 507, the size of the transfer becomes long, Packaging for vehicles is difficult.

  Accordingly, an object of the present invention is to provide a power transmission device that can be configured compactly.

The power transmission device according to claim 1, wherein the first shaft to which the driving force of the prime mover is input,
A second axis disposed parallel to the first axis;
A third axis arranged perpendicular to the second axis and outputting a driving force ;
A gear transmission mechanism that includes a first gear that rotates integrally with the first shaft and a second gear that rotates integrally with the second shaft, and transmits the rotation of the first shaft to the second shaft;
The first direction change gear that rotates integrally with the second shaft and the second direction change gear that rotates integrally with the third shaft, and the direction of rotation of the second shaft is changed and transmitted to the third shaft. the direction conversion gear set which,
A casing that houses the gear transmission mechanism and the direction change gear set ;
The meshing portion of the first direction change gear and the second direction change gear is disposed on the first axis side in the axial direction of the third axis from the axis of the second axis ,
A front end portion of the third shaft is supported by the casing via a first bearing, and the second direction change gear is disposed on the front end side;
The rear end portion of the third shaft is supported on the casing via a second bearing on the opposite side of the front end portion in the axial direction of the third shaft with respect to the axis of the second shaft. .

  Invention of Claim 2 is the power transmission device described in Claim 1, Comprising: As for the said 1st direction change gear, the gear part is arrange | positioned in the axial direction opposite direction with respect to the said 2nd gear. It is characterized by.

  According to a third aspect of the present invention, in the power transmission device according to the first aspect, the first direction change gear and the second gear are arranged adjacent to each other on the second shaft.

  The invention according to claim 4 is the power transmission device according to claim 1, wherein the first direction change gear and the second gear on the second shaft are shafts of a pair of bearings that support the first shaft. It is characterized by being arranged inside each direction.

  A fifth aspect of the invention is the power transmission device according to the first aspect, wherein the second shaft is rotatably supported on a fixed shaft supported on a fixed side.

The invention according to claim 6 is the power transmission device according to claim 5, wherein the fixed shaft has a support end on one side and a support end on the other side offset in a radial direction. Features .

  In the power transmission device according to claim 1, the meshing portion of the first direction change gear and the second direction change gear is disposed on the first axis side from the axis of the second axis along the axial direction of the third axis. Unlike the conventional example in which the meshing portion 513 of the direction change gear set 509 is located on the output shaft 511 side with respect to the axis of the intermediate shaft 507, it is possible to configure it in a compact manner, and packaging becomes much easier.

  In the power transmission device according to the second aspect, the gear portion of the first direction change gear is axially opposite to the second gear (the rear surface of the gear portion of the first direction change gear faces the gear portion of the second gear). ), The meshing portion of the direction change gear set can be arranged on the opposite side to the second gear with respect to the first direction change gear, and the axial length of the second shaft can be shortened.

  In the power transmission device according to claim 3, the first direction change gear and the second gear on the second shaft are arranged adjacent to each other (for example, arranged adjacent to each other), whereby the second shaft is shortened in the axial direction by that amount, Since the arrangement space for the third shaft and the second direction change gear is widened, the power transmission device can be made more compact, and packaging becomes easier.

  According to a fourth aspect of the present invention, the first direction change gear and the second gear on the second shaft are arranged on the inner side in the axial direction of the pair of bearings supporting the first shaft, thereby preventing interference with these bearings. To be released.

  The power transmission device according to the fifth aspect prevents the second shaft from protruding without extending the second shaft itself in the axial direction and supporting it by the casing, thereby avoiding interference with the third shaft.

  The power transmission device according to claim 6 is an interference between the fixed shaft supporting the second shaft and the third shaft by offsetting the support end on one side of the fixed shaft and the support end on the other side in the radial direction. By avoiding this, the power transmission device can be made compact.

<First Embodiment>
The power transmission device 1 (first embodiment of the present invention) will be described with reference to FIGS. 1 and 2. In this embodiment, the power transmission device 1 is used as a transfer for a four-wheel drive vehicle. FIG. 1 is a cross-sectional view in the vehicle width direction, and the left and right directions are the four-wheel drive vehicle and the left and right directions in FIG. FIG. 2 is a partial cross-sectional view in the vehicle traveling direction, and the right side of FIG. 2 is the front of the four-wheel drive vehicle.

[Features of power transmission device 1]
The power transmission device 1 includes an input shaft 3 (first shaft) to which driving force of an engine (prime mover) is input, an intermediate shaft 5 (second shaft) arranged in parallel to the input shaft 3, and the intermediate shaft 5. Drive pinion shaft 7 (third axis: output shaft) arranged at right angles to the base 6 at one end in the axial direction of the first gear 9 and the intermediate shaft 5 formed on the input shaft 3 by welding. A gear transmission mechanism 13 that integrally transmits the rotation of the input shaft 3 together with the base portion 6 of the intermediate shaft 5; and a ring gear 15 (first direction change gear) formed on the intermediate shaft 5. And a pinion gear 17 (second direction change gear) splined to the drive pinion shaft 7, and a direction change gear set 19 for changing the direction of rotation of the intermediate shaft 5 and transmitting it to the drive pinion shaft 7.
The meshing portion 21 between the ring gear 15 and the pinion gear 17 is arranged closer to the input shaft 3 than the shaft core 22 of the intermediate shaft 5 in the axial direction 8 of the third shaft 7 as shown in FIG.
As shown in FIG. 1, the ring gear 15 has a gear portion 23 that is opposite to the second gear 11 in the axial direction so that the back surface 24 of the gear portion 23 of the ring gear 15 faces the second gear 11 in the axial direction. Further, a part of the gear part 23 is arranged to face a part of the bearing 29 in the rotation axis direction,
The intermediate shaft 5 is rotatably supported on a fixed shaft 27 supported by the casing 25 (fixed side),
In the intermediate shaft 5, the second gear 11 and the ring gear 15 are disposed adjacent to each other,
The ring gear 15 and the second gear 11 on the intermediate shaft 5 are arranged on the inner side in the axial direction of a pair of ball bearings 29 and 31 (bearings) that support the input shaft 3, respectively.
The intermediate shaft 5 is supported on the fixed shaft 27 by taper roller bearings 33 and 35, and
The meshing reaction force between the ring gear 15 and the second gear 11 on the intermediate shaft 5 is applied to the tapered roller bearings 33 and 35,
The power transmission device 1 is housed in a casing 25, and seals 37, 39, 41, 43 are provided at portions (openings) where the input shaft 3 (shaft) and the drive pinion shaft 7 (shaft) protrude from the casing 25. It is arranged and unitized.

[Configuration of power system of four-wheel drive vehicle]
In the four-wheel drive vehicle, the driving force of the engine is transmitted from the transmission to the front differential (a differential device that distributes the driving force of the engine to the left and right front wheels) and distributed from the front axle to the left and right front wheels. From the differential case to the input shaft 3 of the power transmission device 1 through the following hollow shaft and transmitted from the drive pinion shaft 7 to the power transmission system on the rear wheel side. This rear wheel side power transmission system includes a clutch mechanism that is actively or passively controlled intermittently according to the running state of the vehicle. When this clutch mechanism is connected, the driving force of the engine is the rear differential (the engine driving force is reduced). To the left and right rear wheels), and from the rear axle to the left and right rear wheels, the vehicle enters a four-wheel drive state. Further, when the clutch mechanism is disconnected, the vehicle enters a two-wheel drive state of front wheel drive.

[Structure of power transmission device 1]
Since the second gear 11 and the ring gear 15 of the intermediate shaft 5 are disposed adjacent to each other, they are disposed on the inner side in the axial direction of the ball bearings 29 and 31 as described above.

  The casing 25 is configured by fixing left and right casing members 45, 47 with bolts 49, and a cover 51 is fixed to the rear end portion of the casing member 45 with bolts 53. Also, transfer oil is sealed inside the casing 25. Before the casings 45, 47 are fixed with the bolts 53, the pressures of the bearings 33, 35 are controlled by the thickness-selectable shims 46, 48 that abut against the wall surfaces of the respective casings 45, 47 at both ends of the intermediate shaft 5. The axial position of the gear 23 is adjusted.

  The input shaft 3 is formed in a hollow shape. A hollow shaft is connected to the spline portion 55 at the left end, and the driving force of the engine is input through the hollow shaft and the differential case of the front differential. A front axle 57 that distributes the driving force from the front differential to the left front wheel passes through the hollow shaft and the input shaft 3.

  Both ends of the fixed shaft 27 are supported by casing members 45 and 47. A key groove 59 is formed in the fixed shaft 27, and the fixed shaft 27 is prevented from rotating by a key 61 mounted between the key groove 59 and the casing member 45. Further, the key groove 59 is an oil groove partially extending to an intermediate portion between the tapered roller bearings 33 and 35, and guides the oil repelled by the rotation of the ring gear 15 and the pinion gear 17 to taper the roller. Lubricate and cool the bearings 33 and 35.

  The pinion gear 17 is splined to the front end portion of the drive pinion shaft 7, and the tip end portion is in contact with a collar portion formed on the shaft 7 and is axially positioned by a bolt 63. The drive pinion shaft 7 is supported by the casing member 45 at the front end portion via the pinion gear 17 and the taper roller bearing 65 and at the rear end portion via the taper roller bearing 67. An output shaft 69 constituting a part of the rear wheel side power transmission system is splined to the rear end portion of the drive pinion shaft 7. A small diameter portion 71 is formed in the drive pinion shaft 7, and this small diameter portion 71 serves as a clearance for the intermediate shaft 5 (fixed shaft 27) that is orthogonal to the drive pinion shaft 7.

  The seal 37 prevents transfer oil and transmission oil from mixing between the input shaft 3 and the casing member 45, the seal 39 is between the input shaft 3 and the casing member 47, and the seal 41 is between the input shaft 3 and the front axle. 57, the seal 43 prevents oil leakage and foreign matter from entering between the output shaft 69 and the cover 51, respectively.

  Further, shims 66 and 68 capable of selecting thicknesses for adjusting the axial position of the pinion gear 17 are disposed between the outer races of the bearings 65 and 67, the casing 45, and the cover 51, respectively. 48, the meshing tooth contact of the direction changing gear portion 19 can be obtained with high accuracy.

[Effect of power transmission device 1]
The power transmission device 1 has the following effects.

  Since the meshing portion 21 between the ring gear 15 and the pinion gear 17 is arranged in the direction of the input shaft 3 from the shaft core 22 of the intermediate shaft 5, it is possible to make it compact, and packaging becomes easier.

  Further, as the meshing portion 21 of the direction change gear set 19 is arranged in the direction of the input shaft 3, it becomes possible to widen the support span of the drive pinion shaft 7 (the interval between the tapered roller bearings 65 and 67). Thus, the drive pinion shaft 7 can be firmly supported.

  Further, since the gear portion 23 of the ring gear 15 is disposed in the opposite direction to the axial direction of the second gear 11, the meshing portion of the gear set 19 may be disposed on the opposite side of the second gear 11 with respect to the gear 23. And the axial length of the second axis can be shortened. As shown in FIG. 2, when the input shaft 3 is rotated in the direction of the arrow 81 by the driving force of the engine, the rotation direction of the drive pinion shaft 7 as the output shaft is right as shown by the arrow 83, contrary to the conventional example. Rotation and compatibility with a normal final drive unit (FDU) is maintained. Therefore, it is not necessary to provide a mechanism for reversing the rotation, and an increase in cost associated with this can be avoided.

  In addition, since the drive pinion shaft 7 is formed with the small diameter portion 71 that is a clearance for the fixed shaft 27, the fixed shaft 27 and the drive pinion shaft 7 can be arranged orthogonally (easily), and the power transmission device 1 Is even more compact.

  Further, since a part of the key groove 59 for preventing rotation formed on the fixed shaft 27 is used as the oil groove, the tapered roller bearings 33 and 35 that can reduce part of the processing time of the oil groove are sufficient oil. Lubricated and cooled by

  Further, since the ring gear 15 and the second gear 11 on the intermediate shaft 5 are arranged close to each other, the intermediate shaft 5 is shortened in the axial direction, and a space 73 for arranging the drive pinion shaft 7 and the pinion gear 17 as shown in FIG. Therefore, the power transmission device 1 can be made more compact, and packaging becomes easier.

  In addition, the second gear 11 and the ring gear 15 on the intermediate shaft 5 are disposed on the inner side in the axial direction of the ball bearings 29 and 31 that support the input shaft 3, so that they are free from interference with these, and on the generated space Can be used to increase the diameters of the second gear 11 and the ring gear 15, or can be used to further reduce the size of the power transmission device 1.

  Further, since the tapered roller bearings 33 and 35 receive the meshing reaction force of the ring gear 15 that is a bevel gear, the meshing state, the power transmission function, and the direction conversion function of the direction change gear set 19 are maintained normally for a long time.

  Further, the power transmission device 1 is housed in the casing 25, and the seals 37, 39, 41, 43 are arranged as a unit by projecting (opening) the shafts 3, 57, 69 from the casing 25. This further facilitates packaging into the vehicle.

Second Embodiment
The power transmission device 101 (second embodiment of the present invention) will be described with reference to FIGS. The power transmission device 101 is used in place of the power transmission device 1 in the four-wheel drive vehicle in which the power transmission device 1 is used. Hereinafter, differences from the power transmission device 1 will be mainly described. FIG. 3 is a cross-sectional view in the vehicle width direction, and the left and right directions are the four-wheel drive vehicle and the left and right directions in FIG. 4 is a partial cross-sectional view in the vehicle traveling direction, and the right side of FIG. 4 is the front of the four-wheel drive vehicle. In addition, about the member which has the same function as 1st Embodiment, the same code | symbol is provided and the description which overlaps is also omitted.

[Features of power transmission device 101]
The power transmission device 101 has an input shaft 3 (first shaft) to which driving force of the engine (prime mover) is input, an intermediate shaft 5 (second shaft) arranged in parallel to the input shaft 3, and the intermediate shaft 5. Drive pinion shaft 7 (third axis: output shaft) arranged at right angles with each other: first gear 9 formed on input shaft 3, and second gear 11 welded to intermediate shaft 5. A gear transmission mechanism 13 for transmitting the rotation of the motor to the intermediate shaft 5: a ring gear 15 (first direction change gear) formed on the intermediate shaft 5, and a pinion gear 17 (second direction) splined to the drive pinion shaft 7 A direction change gear set 19 that changes the direction of rotation of the intermediate shaft 5 and transmits the change to the drive pinion shaft 7.
The meshing portion 21 between the ring gear 15 and the pinion gear 17 is arranged in the direction of the input shaft 3 from the shaft core 22 of the intermediate shaft 5 as shown in FIG.
As shown in FIG. 3, the ring gear 15 has a gear portion 23 disposed in the axially opposite direction with respect to the second gear 11.
The intermediate shaft 5 is rotatably supported on a fixed shaft 27 supported by the casing 25 (fixed side),
In the intermediate shaft 5, the second gear 11 and the ring gear 15 are disposed adjacent to each other,
The fixed shaft 27 has a left side (one side) support end portion 103 and a right side (other side) support end portion 105 offset in the radial direction.

The ring gear 15 and the second gear 11 on the intermediate shaft 5 are arranged on the inner side in the axial direction of a pair of ball bearings 29 and 31 (bearings) that support the input shaft 3, respectively.
The intermediate shaft 5 is supported on the fixed shaft 27 by taper roller bearings 33 and 35, and
The meshing reaction force between the ring gear 15 and the second gear 11 on the intermediate shaft 5 is applied to the tapered roller bearings 33 and 35,
The power transmission device 101 is housed in the casing 25, and seals 37, 39, 41, 43 are provided at portions (openings) where the input shaft 3 (shaft) and the drive pinion shaft 7 (shaft) protrude from the casing 25. It is arranged and unitized.

[Structure of power transmission device 101]
The fixed shaft 27 has a left support end 103 supported by the casing member 45 and a right support end 105 supported by the casing member 47, and the support end 103 and the support end 105 are radially separated by a distance 107. The rotation is prevented by offsetting.

  Further, the drive pinion shaft 7 is formed with a small-diameter portion 109, which is a clearance for the orthogonal fixed shaft 27. Further, the small diameter portion 109 is not as small as the small diameter portion 71 in the power transmission device 1.

  Further, the second gear 11 and the ring gear 15 on the intermediate shaft 5 are adjacent to each other such that their side surfaces come into contact with each other, and are arranged back to back.

[Effect of power transmission device 101]
The power transmission device 101 has the following effects.

  By offsetting the support end portion 103 and the support end portion 105 of the fixed shaft 27, the generated space 111 becomes a clearance for the drive pinion shaft 7 as shown in FIG. 7 is possible (easily), and the power transmission device 101 is further compact.

  Further, by offsetting the fixed shaft 27, the drive pinion shaft 7 makes the small-diameter portion 109 larger than the small-diameter portion 71 of the power transmission device 1 and maintains sufficient strength while maintaining sufficient strength. A bill can be provided.

  Further, the fixed shaft 27 having an offset configuration does not require a detent means, and the cost is reduced accordingly.

  Further, since the second gear 11 and the ring gear 15 are arranged adjacent to each other so as to come into contact with each other (back-to-back arrangement), the distance between the ball bearings 29 and 31 of the input shaft 3, in particular, as shown in FIG. The distance 113 between the bearing 29 and the bearing 29 is narrower than that at the same position of the power transmission device 1, and the power transmission device 101 is made more compact in the axial direction.

  Further, the intermediate shaft 5 is shortened in the axial direction by the contact arrangement of the second gear 11 and the ring gear 15, and the space 115 for arranging the drive pinion shaft 7 and the pinion gear 17 as shown in FIG. Therefore, if this is utilized for compactness, the power transmission device 101 can be further compacted, and packaging can be further facilitated.

  In addition, the power transmission device 101 can obtain the same effects as the power transmission device 1.

[Other Embodiments Included within the Scope of the Present Invention]
1. The “first axis”, “second axis”, and “third axis” in the present invention are defined as rotating members.

  2. The term “integral” in the present invention is defined as one that functions as a unit including one that combines two or more members that are joined by various joining means.

  3. The first member may be a front differential case. The second member may be a part of the center differential.

It is sectional drawing which cut | disconnected the power transmission device 1 of 1st Embodiment in the vehicle width direction. It is A arrow directional view of FIG. It is sectional drawing which cut | disconnected the power transmission device 101 of 2nd Embodiment in the vehicle width direction. FIG. 4 is a view taken in the direction of arrow B in FIG. 3. It is sectional drawing of a prior art example.

Explanation of symbols

1 Power transmission device 3 Input shaft (first shaft)
5 Intermediate shaft (second shaft)
7 Drive pinion shaft (third axis)
9 First gear 11 Second gear 13 Gear transmission mechanism 15 Ring gear (first direction change gear)
17 Pinion gear (second direction change gear)
DESCRIPTION OF SYMBOLS 19 Direction change gear set 21 Meshing part of direction change gear set 19 22 Shaft core of intermediate shaft 5 23 Gear part of 1st direction change gear 25 Casing (fixed side)
27 Fixed shafts 29, 31 A pair of ball bearings (bearings) for supporting the input shaft 3
33, 35 Tapered roller bearings 37, 39, 41, 43 for supporting the intermediate shaft 5 on the fixed shaft 27 Seal 101 Power transmission devices 103, 105 One side support end and the other side support end of the fixed shaft 27 that are offset

Claims (6)

A first shaft to which the driving force of the prime mover is input;
A second axis disposed parallel to the first axis;
A third axis arranged perpendicular to the second axis and outputting a driving force ;
A gear transmission mechanism that includes a first gear that rotates integrally with the first shaft and a second gear that rotates integrally with the second shaft, and transmits the rotation of the first shaft to the second shaft;
The first direction change gear that rotates integrally with the second shaft and the second direction change gear that rotates integrally with the third shaft, and the direction of rotation of the second shaft is changed and transmitted to the third shaft. the direction conversion gear set which,
A casing that houses the gear transmission mechanism and the direction change gear set ;
The meshing portion of the first direction change gear and the second direction change gear is disposed on the first axis side in the axial direction of the third axis from the axis of the second axis ,
A front end portion of the third shaft is supported by the casing via a first bearing, and the second direction change gear is disposed on the front end side;
The rear end portion of the third shaft is supported on the casing via a second bearing on the opposite side of the front end portion in the axial direction of the third shaft with respect to the axis of the second shaft. Power transmission device. The invention according to claim 1,
The power transmission device according to claim 1, wherein the first direction change gear has a gear portion disposed in an axially opposite direction with respect to the second gear. The invention according to claim 1,
In the second shaft, the first direction change gear and the second gear are arranged adjacent to each other. The invention according to claim 1,
The power transmission device according to claim 1, wherein the first direction changing gear and the second gear on the second shaft are respectively arranged on the inner sides in the axial direction of a pair of bearings supporting the first shaft. The invention according to claim 1,
The power transmission device, wherein the second shaft is rotatably supported on a fixed shaft supported on a fixed side. The invention according to claim 5,
The power transmission device according to claim 1, wherein the fixed shaft has a support end on one side and a support end on the other side offset in a radial direction.

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