JP5613419B2 - Power transmission device - Google Patents

Description

  The present invention relates to a power transmission device applied to a vehicle.

  Conventionally, as a power transmission device having a casing that houses a power transmission mechanism including an input / output shaft and an input / output gear, a hollow shaft as an input shaft, a drive pinion as an output shaft, a hollow shaft and a drive pinion There has been known one provided with a bevel gear provided as an input / output gear and a transfer case accommodating each member (see, for example, Patent Document 1).

  In this power transmission device, the transfer case is composed of three divided members such as a transfer case that accommodates each member, a cover that closes the inside of the transfer case, and a cylindrical member that supports a bearing that supports the drive pinion. The cover and the cylindrical member are fixed to the transfer case by fixing means such as bolts.

  Further, as a power transmission device having a similar structure, a hollow shaft as an input shaft, a drive shaft as an output shaft, a ring gear and a drive pinion as input / output gears provided on the hollow shaft and the drive shaft, respectively, A device including a transfer case that accommodates a member is known (see, for example, Patent Document 2).

  Also in this power transmission device, the transfer case is divided into three parts such as a case main body that accommodates each member, a cover body that closes the inside of the case main body, and a bearing support body that supports the bearing that supports the drive shaft. The cover body and the bearing support body are fixed to the case main body by fixing means such as bolts.

Japanese Patent Laid-Open No. 2004-314796 JP 2009-115309 A

  By the way, in the power transmission devices such as Patent Documents 1 and 2, peripheral members such as a drive source such as an engine and a vehicle body frame are arranged on the outer diameter side of the transfer case, and considering interference with the peripheral members, Since there is a restriction on the outside diameter of the transfer case, it is necessary to set the shape of the transfer case so that the transfer case does not protrude further in the radial direction. And the ring gear had to be arranged with different axial positions.

  However, if the axial position of the fitting portion between the case body and the cover body and the ring gear is arranged differently, the transfer case overhangs in the axial direction, and the axial size of the device increases, Again, interference with peripheral members will be taken into account, and the mountability of the power transmission device will deteriorate. In addition, there is a size restriction on the outer diameter side of the transfer case, and if the shape is set in consideration of the allowable value of the driving torque of the vehicle, the size of the device cannot be easily reduced.

  Accordingly, an object of the present invention is to provide a power transmission device that can suppress an increase in the radial size, reduce the axial size, and improve the mountability on a vehicle.

According to the first aspect of the present invention, a first shaft that is formed in a hollow shape and is inserted into the shaft center so that the axle is relatively rotatable, and the shaft center is disposed so as to intersect the shaft center of the first shaft. Two shafts, a ring gear provided so as to rotate integrally with the first shaft, a pinion provided so as to rotate integrally with the second shaft and meshing with the ring gear, and the first shaft comprising the ring gear and the pinion. A bevel gear set capable of changing the direction of transmission of the driving force between the second shaft and a bevel gear set; and a casing for housing the first shaft, the second shaft and the bevel gear set, wherein the casing includes: A casing body that supports one end side of the first shaft, a cover body that is fitted and fixed to the casing body and supports the other end side of the first shaft, and is fitted and fixed to the casing body. And bearing support for supporting the second shaft A power transmission apparatus comprising a, on the back side of the gear of the ring gear is formed an annular recess, and the fitting portion is the concave portion of the outer diameter side and the casing body and the cover body of the recess The fitting portion is disposed to be opposed to the radial side surface of the recess, and the first shaft has a flange portion that fixes the ring gear, and the flange portion is It is integrally joined to the ring gear on the bottom surface side of the recess, and the joint between the ring gear and the first shaft is arranged on the inner side in the axial direction from the bearing that supports the first shaft.

The invention according to claim 2 is the power transmission device according to claim 1 , wherein a joint portion between the ring gear and the first shaft is provided on the inner diameter side of the fitting portion.

The invention according to claim 3 is the power transmission device according to claim 1 or 2 , wherein the side wall of the cover body has the bearing support portion that supports the bearing supporting the first shaft from the outer peripheral side of the bearing support portion. An inclined rib is provided on the fitting portion side.

The invention according to claim 4 is the power transmission device according to any one of claims 1 to 3 , wherein a plurality of bolts for fixing the casing body and the cover body are inserted into the casing body. A plurality of bolt fastening holes are provided, and an outer shape of the bearing support is located between the adjacent bolt fastening holes.

A fifth aspect of the present invention is the power transmission device according to any one of the first to fourth aspects, wherein the first shaft and the ring gear are welded, bolted, press-fitted, and splined. It is characterized by being integrally fixed by at least one of the fixing means.

  In the power transmission device according to the first aspect, the annular recess is formed on the back side of the ring gear, and the fitting portion between the casing body and the cover body is located on the outer diameter side of the recess. While maintaining the directional size, the concave portion and the fitting portion of the ring gear can be arranged to overlap in the radial direction. For this reason, even if there is a restriction on the outer diameter side of the casing, the axial size of the casing can be reduced.

  Therefore, since the axial size of the casing can be reduced while maintaining the radial size of the casing, the increase in the radial size of the device can be suppressed and the axial size of the device can be reduced. , It is possible to improve the mountability to various vehicles.

Moreover, since the fitting part is arrange | positioned facing the radial direction side surface of a recessed part, the power transmission apparatus of Claim 1 arrange | positions a fitting part in a recessed part, and the axial direction position of a fitting part and a ring gear Can be disposed so as to overlap in the radial direction, and the axial size of the casing can be reduced while maintaining the radial size of the casing.

The power transmission device according to claim 1 has a flange portion in which the first shaft is fixed a ring gear, since the flange portion is joined to the ring gear integrally with the bottom portion side of the concave portion, the bottom portion of the recess Thus, the space portion can be formed in a portion directed outward in the radial direction, and the axial size of the casing can be reduced while maintaining the radial size of the casing. In addition, the degree of freedom in designing the fitting portion located on the outer diameter side of the recess can be improved.

In the power transmission device according to the second aspect , since the joint portion between the ring gear and the first shaft is provided on the inner diameter side of the fitting portion, the fitting portion and the joint portion are arranged so as to overlap in the radial direction. The axial size of the casing can be reduced while maintaining the radial size of the casing.

In the power transmission device according to the third aspect , since the inclined rib is provided from the outer peripheral portion side of the bearing support portion supporting the bearing supporting the first shaft to the fitting portion side on the side wall of the cover body, The thickness of the casing can be further reduced as much as possible while maintaining the outer diameter side of the bearing support portion of the cover body, and the axial size of the casing can be reduced.

In the power transmission device according to the fourth aspect , since the outer shape of the bearing support body is located between the adjacent bolt fastening holes, the outer shape of the bearing support body and the bolt fastening hole do not interfere with each other, and In order to secure the bolt fastening hole, the cover body can be prevented from protruding outward in the axial direction. Therefore, the positional relationship between the recess and the fitting portion can be appropriately maintained, and the axial size of the casing can be reduced.

In the power transmission device according to a fifth aspect , the first shaft and the ring gear are integrally fixed by at least one fixing means of welding, bolts, press-fitting, and splines. These show specific forms of the fixing means of the present invention.

It is the schematic which shows the motive power system of a vehicle. It is a perspective view of the casing of the power transmission device concerning a 1st embodiment of the present invention. It is sectional drawing of the power transmission device which concerns on 1st Embodiment of this invention. It is sectional drawing of the power transmission device which concerns on 1st Embodiment of this invention. It is a bottom view of the casing of the power transmission device according to the first embodiment of the present invention. It is sectional drawing of the power transmission device which concerns on 2nd Embodiment of this invention. It is sectional drawing of the power transmission device which concerns on 3rd Embodiment of this invention. It is sectional drawing of the power transmission device which concerns on 4th Embodiment of this invention.

  First, an example of a vehicle power system to which a power transmission device according to an embodiment of the present invention is applied will be described with reference to FIG. In addition, although it is set as the power system which applied the power transmission device 1 which concerns on 1st Embodiment here, the power transmission device which concerns on other embodiment may be applied similarly to the power transmission device 1 of 1st Embodiment. it can.

  As shown in FIG. 1, the power system of the vehicle includes a drive source such as an engine 401 and an electric motor 403, a planetary gear type transmission 405 as a speed change mechanism, and a front that allows differential of the left and right wheels on the front wheel side. A differential 407, front axles 409 and 411, front wheels 413 and 415, a power transmission device 1, a propeller shaft 417, and a coupling 419 that intermittently controls driving force transmitted from the front wheel side to the rear wheel side. The rear differential 421 that allows the differential of the left and right wheels on the rear wheel side, the rear axles 423 and 425, the rear wheels 427 and 429, and the like. In the vicinity of the transmission 405, an electric motor 431 for shifting and driving is connected to the transmission 405.

  The driving force of the driving source is transmitted from the transmission 405 to the pinion 435 via the differential case 433 of the front differential 407, and is connected to a pair of side gears 437 and 439, output shafts 443 and 445, constant velocity drive joints 447 and 449, front axles 409, 411, distributed from the constant velocity drive joints 451, 453 to the front wheels 413, 415, branched to the first shaft 3 connected to the differential case 433, and transmitted to the power transmission device 1.

  The driving force transmitted to the power transmission device 1 is a bevel gear set comprising a ring gear 7 that rotates integrally with the first shaft 3 through which the output shaft 445 penetrates the shaft center side, and a pinion 9 that rotates integrally with the second shaft 5. 11 is output from the first shaft 3 side to the second shaft 5 side through 11, and is transmitted to the coupling 419 through the propeller shaft 417. The driving force transmitted to the coupling 419 is transmitted to the rear differential 421 when the coupling 419 is connected, and is distributed from the rear axles 423 and 425 to the rear wheels 427 and 429 so that the four-wheel drive state of front and rear wheel driving is achieved. Become. When the connection of the coupling 419 is released, the vehicle enters a two-wheel drive state of front wheel drive. Hereinafter, the power transmission device will be described.

  A power transmission device according to an embodiment of the present invention will be described with reference to FIGS.

(First embodiment)
The first embodiment will be described with reference to FIGS.

  The power transmission device 1 according to the present embodiment includes a first shaft 3 that is formed in a hollow shape and into which an output shaft 445 (see FIG. 1) is inserted so as to be relatively rotatable, and an axis of the first shaft 3. The second shaft 5 is disposed so that the shaft centers intersect with each other, the ring gear 7 provided so as to be integrally rotatable with the first shaft 3, and the pinion provided so as to be integrally rotatable with the second shaft 5 and meshing with the ring gear 7 9, a bevel gear set 11 including a ring gear 7 and a pinion 9 and capable of changing the direction of driving force transmitted between the first shaft 3 and the second shaft 5, and the first shaft 3 and the second shaft 5. A casing 13 that houses the bevel gear set 11 is provided.

  The casing 13 includes a casing body 15 that supports one end side of the first shaft 3, a cover body 17 that is fitted and fixed to the casing body 15 and supports the other end side of the first shaft 3, It comprises a bearing support 19 that is fitted and fixed to the casing body 15 and supports the second shaft 5.

  An annular concave portion 21 is formed in the annular base portion 8 on the back side of the gear portion of the ring gear 7, and a fitting portion 23 between the casing body 15 and the cover body 17 is formed on the outer diameter side of the concave portion 21. Is located.

  Further, the fitting portion 23 is disposed to face the radial side surface 25 (the back surface of the base portion 8) of the recess 21.

  Further, the first shaft 3 has a flange portion 27 for fixing the ring gear 7, and the flange portion 27 is integrally joined to the ring gear 7 on the bottom surface portion 29 side of the recess 21.

  Further, on the inner diameter side of the fitting portion 23, joint portions 30 and 32 (the axial joint portion 30 and the radial joint portion 32) between the ring gear 7 and the flange portion 27 of the first shaft 3 are provided. .

  Furthermore, inclined ribs are provided on the side wall 31 of the cover body 17 from the outer peripheral portion side of the bearing support portion 35 that supports the bearing 33 that supports the first shaft 3 to the fitting portion 23 side.

  The casing body 15 is provided with a plurality of bolt fastening holes 39 into which a plurality of bolts 37 for fixing the casing body 15 and the cover body 17 are inserted, and a bearing support body is provided between the adjacent bolt fastening holes 39. 19 outlines 43 are located.

  Furthermore, the 1st axis | shaft 3 and the ring gear 7 are integrally fixed by welding joining, and have comprised the junction part 30. FIG.

  As shown in FIGS. 2 to 5, the first shaft 3 is formed in a hollow shape and is rotatably supported by the casing body 15 and the cover body 17 of the casing 13 via bearings 45 and 33. A spline-shaped connecting portion 47 is formed on the outer periphery of the first axial end portion of the first shaft 3. A differential case 433 (see FIG. 1) of the front differential 407 is coupled to the coupling portion 47 so as to be integrally rotatable, and a driving force is input to the first shaft 3. Further, on the inner peripheral side of the first shaft 3, an output shaft 445 (see FIG. 1) and a front gear 411 (see FIG. 1) that connect the side gear 439 (see FIG. 1) of the front differential 407 to be rotatable relative to the first shaft 3. 1) is inserted. The driving force input to the first shaft 3 is output to the second shaft 5.

  The second shaft 5 is disposed in a direction in which the shaft center intersects with the shaft center of the first shaft 3, specifically in a direction orthogonal thereto, and is rotatably supported by the bearing support 19 of the casing 13 via the bearing 49. Has been. A spline-shaped connecting portion 51 is formed on the outer periphery of one axial end portion of the second shaft 5, and the output member 53 is connected to the second shaft 5 so as to be integrally rotatable.

  The output member 53 is formed in a hollow shape, and the second shaft 5 is inserted through the inner periphery thereof, and is connected to the second shaft 5 via the connecting portion 51 so as to be integrally rotatable. The output member 53 is in contact with a nut 55 that is screwed to the end of the second shaft 5, so that the axial position with respect to the second shaft 5 is fixed. The output member 53 is connected to the propeller shaft 417 (see FIG. 1) side and outputs the driving force transmitted from the first shaft 3 to the propeller shaft 417 side.

  Such transmission of the driving force from the first shaft 3 side to the second shaft 5 side is transmitted by a bevel gear set 11 including a ring gear 7 and a pinion 9 provided on the first shaft 3 and the second shaft 5 respectively. Has been made.

  The ring gear 7 is formed in an annular shape, and is fixedly joined to a flange portion 27 formed on the outer periphery of the first shaft 3 via a welded portion 57 so as to be integrally rotatable. On the outer peripheral surface of the first shaft 3, the inner peripheral surface of the ring gear 7 is press-fitted and supported at the positions of the base portion 8 and the concave portion 21 of the ring gear 7 to form a joint portion 32. Therefore, the joint portion 30 is set at least on the inner diameter side of the fitting portion 23. Therefore, the fitting portion 23 and the joint portion 30 have a radial overlap relationship, but the joint portion 32 is also set so as to have a radial overlap relationship with the fitting portion 23. May be.

  Further, an annular recess 21 having an L-shaped cross section is formed on the back side of the gear portion of the ring gear 7 and the base portion 8. The ring gear 7 is fixed to the first shaft 3 so as to rotate together with the first shaft 3 via the flange portion 27 and the welded portion 57 on the bottom surface portion 29 side of the concave portion 21. The ring gear 7 meshes with the pinion 9 to form a bevel gear set 11.

  The pinion 9 is formed as one member continuous with the second shaft 5 at the other axial end of the second shaft 5. The pinion 9 meshes with the ring gear 7 and a driving force from the ring gear 7 side is input to the second shaft 5. This bevel gear set 11 changes the direction of the driving force from the first shaft 3 side and transmits it to the second shaft 5 side.

  The first shaft 3, the second shaft 5, and the bevel gear set 11 are accommodated in a casing 13, and the casing 13 includes a casing body 15, a cover body 17, and a bearing support body 19.

  The casing body 15 is formed with an accommodation space for accommodating accommodation members such as the first shaft 3, the second shaft 5, and the bevel gear set 11. One side of the casing body 15 is provided with an assembly portion 59 to be assembled to the transmission case 441 (see FIG. 1) of the transmission 405, and is fixed by fastening bolts to the plurality of bolt fastening holes 61. Note that the bolt fastening hole 61 shown in FIG. 2 is configured to be fastened by inserting a bolt from the casing 13 side to the transmission 405 side, and the bolt fastening hole 61 shown in FIG. The bolt is inserted and fastened. In this assembly portion 59, an O-ring 63 is disposed as a sealing means for partitioning the internal space and the external space of the casing 13. Further, on the other side of the casing body 15, a fitting portion 23 to which the cover body 17 is fitted is provided. A baffle plate 65 that protects a breather (not shown) that adjusts the pressure inside the casing 13 is fixed by a bolt 67 at a position facing the gear of the ring gear 7 in the axial direction.

  The cover body 17 is formed in a lid shape so as to close the other side of the casing body 15, is fitted to the casing body 15 by the fitting portion 23, and is fixed by a plurality of bolts 37. The fitting portion 23 is located on the outer diameter side of the concave portion 21 of the ring gear 7 and the joint portion 30, and is disposed to face the radial side surface 25 of the concave portion 21. That is, the axial position of the fitting portion 23 and the ring gear 7 is disposed so as to exceed the flange portion 27 in the axial direction and overlap in the radial direction, and the axial position between the fitting portion 23 and the joint portion 30. Are also arranged to overlap in the radial direction. Further, the fitting portion 23 is provided with an O-ring 69 as a sealing means that divides the internal space and the external space of the casing 13, and the axial positions of the O-ring 69 and the ring gear 7 as the sealing means are also set. It overlaps in the radial direction. In addition, inclined ribs are provided on the side wall 31 of the cover body 17 from the outer peripheral portion side of the bearing support portion 35 that supports the bearing 33 to the fitting portion 23 side. A plurality of bolts 37 for fixing the cover body 17 are inserted into a plurality of bolt fastening holes 39 and 41 respectively provided in the casing body 15 and the cover body 17. Between the adjacent bolt fastening holes 40 among the plurality of bolt fastening holes 39, the outer shape 43 of the fitting portion 71 of the bearing support 19 is located. Here, the outer peripheral side of the casing body 15 is indicated as the outer shape 43 of the bearing support body 19. However, since the outer shape 43 of the bearing support body 19 is located on the inner peripheral side of the casing main body 15, The outer peripheral side shall be indicated.

  Further, in each of the embodiments, the outer shape 43 of the bearing support body 19 shows the outer shape of the outer race of the bearing. However, as another possible configuration, a cylindrical bearing support body that supports the outer race of the bearing is provided as a separate member. The outer shape of the fitting portion for fitting and fixing the separate bearing support to the casing body can also be defined as the “outer shape” of the present invention.

  The bearing support 19 is fixed by fitting the outer shape 43 described above with the fitting portion 71 on the casing body 15 on the side where the second shaft 5 of the casing body 15 is disposed. Is functioning as The bearing 49 is a double angular type bearing composed of an outer race as the bearing support 19, an inner race, and a pair of balls. A shim 73 for adjusting the meshing of the bevel gear set 11 is provided between the inner race of the bearing 49 and the pinion 9 in the axial direction. In addition, a seal 75 is disposed at the axial end of the bearing 49, and a dust cover 77 is provided on the outer periphery of the output member 53 to abut against the lip of the seal 75 to prevent entry of dust or muddy water into the casing 13. Is arranged. Further, a flange portion 79 is provided at the end portion of the bearing support body 19, and the bearing support body 19 is fixed to the bolt fastening hole 82 of the casing body 15 through the plurality of bolts 81 at the fitting portion 71. Yes.

  A plurality of sealing means for partitioning the inside and the outside of the casing 13 are disposed in the casing 13 that accommodates such members. Specifically, in addition to the O-rings 63 and 69, the seal 75, and the dust cover 77, seals 83 and 85 are disposed between the casing body 15 and both axial ends of the first shaft 3. Further, a seal 87 is disposed between the first shaft 3 and the axle.

  Here, the seal 83 is composed of two seal members arranged back to back, and each separates the lubricating oil on the transmission 405 side and the lubricating oil enclosed in the casing 13. The seal 83 is located on the inner side of the casing 13 with respect to the assembly portion 59 of the casing body 15 with the transmission case 441. For this reason, the radial size of the seal 83 does not affect the assembling portion 59, and the degree of design freedom such as the radial and axial dimensions of the assembling portion 59 can be improved. The seal 83 is inserted and assembled from the opening on the fitting portion 23 side before the cover body 17 is assembled to the casing body 15. The seal 83 has two members adjacent to each other. However, only the member that partitions the lubricating oil sealed in the casing 13 can be disposed between the casing body 15 and the first shaft 3. In this case, a member that partitions the lubricating oil on the transmission 405 side may be disposed on the transmission 405 side.

  Further, a vent hole 84 is provided on the outer peripheral side between the two seals from the casing body 15 toward the outside atmosphere side, and the fluctuating pressure generated in the space on both sides in the axial direction in the sliding portion of each seal is relieved. And the sealing performance is improved.

  Further, in the vicinity of the fitting portion 71 of the casing body 15 with the bearing support 19, a filler hole 89 is provided in the casing 13 for enclosing lubricating oil for lubricating and cooling the gear meshing portion and the sliding portion. The filler hole 89 is closed by a filler plug 91. An oil groove 93 is provided in the fitting portion 71 of the casing body 15 in the portion where the filler hole 89 is provided.

  The oil groove 93 is formed on the inner peripheral surface of the fitting portion 71 with the bearing support 19 of the casing body 15 by cutting using a lathe. The oil groove 93 is set in a tunnel shape having a crescent cross section and a predetermined length in the axial direction so that the lubricating oil scraped up by the rotation of the ring gear 7 and the pinion 9 can be easily introduced. The oil groove 93 is provided in communication with the filler hole 89, and the lubricating oil is introduced into the oil groove 93 more easily by introducing the lubricating oil from the filler hole 89. Further, the bearing support 19 is provided with a plurality of oil holes 95 communicating with the oil groove 93 to reliably lubricate the bearing 49 that supports the second shaft 5 and the sliding portion on the second shaft 5 side. be able to. By providing the oil groove 93 and the oil hole 95 in this manner, the lubricating oil can be reliably supplied to the sliding portion with a simple configuration.

  In such power transmission of the power transmission device 1, the driving force from the differential case 433 is transmitted to the ring gear 7 via the first shaft 3, and the direction is changed by the bevel gear set 11 including the ring gear 7 and the pinion 9. Then, the driving force transmitted to the pinion 9 is transmitted to the output member 53 via the second shaft 5 and output to the propeller shaft 417 side.

  In such a power transmission device 1, the annular recess 21 is formed in the annular base portion 8 on the back side of the gear portion of the ring gear 7, and the casing body 15 and the cover body 17 are formed on the outer diameter side of the recess 21. Since the fitting part 23 is located, the ring gear 7 and the fitting part 23 can be arranged to overlap in the radial direction while maintaining the radial size of the casing 13. For this reason, even if there is a restriction on the outer diameter side of the casing 13, the axial size of the casing 13 can be reduced.

  Therefore, since the axial size of the casing 13 can be reduced while maintaining the radial size of the casing 13, the increase in the radial size of the device can be suppressed and the axial size of the device can be reduced. The power transmission device of the present invention can be mounted on various vehicles. In addition, by reducing the axial size of the apparatus, the allowable range of the axial arrangement space of the constant velocity drive joint 449 (see FIG. 1) between the output shaft 445 and the axle 441 can be expanded, Therefore, the degree of freedom of arrangement of the dense mounting layout around the power transmission device can be greatly improved.

  Moreover, since the fitting part 23 is arrange | positioned facing the radial direction side surface 25 of the recessed part 21, the fitting part 23 is arrange | positioned in the recessed part 21, and the axial direction position of the fitting part 23 and the ring gear 7 is a diameter. The casing 13 can be arranged in an overlapping manner, and the axial size of the casing 13 can be reduced while maintaining the radial size of the casing 13.

  Furthermore, since the first shaft 3 has a flange portion 27 for fixing the ring gear 7, and this flange portion 27 is integrally joined to the ring gear 7 on the bottom surface portion 29 side of the recess 21, Thus, the space portion can be formed in a portion directed outward in the radial direction, and the axial size of the casing 13 can be reduced while maintaining the radial size of the casing 13. In addition, the degree of freedom in designing the fitting portion 23 located on the outer diameter side of the recess 21 can be improved.

  Further, since the joint portion 30 between the ring gear 7 and the first shaft 3 is provided on the inner diameter side of the fitting portion 23, the fitting portion 23 and the joint portion 30 are arranged so as to overlap in the radial direction. The axial size of the casing 13 can be reduced while maintaining the radial size of the casing 13.

  Furthermore, since the inclined rib is provided on the side wall 31 of the cover body 17 from the outer peripheral portion side of the bearing support portion 35 that supports the bearing 33 that supports the first shaft 3 to the fitting portion 23 side, the rigidity of the cover body 17 is increased. The outer diameter side of the bearing support portion 35 of the cover body 17 can be reduced in size, and the casing 13 can be further reduced in size.

  Further, since the outer shape 43 of the bearing support 19 is positioned between the adjacent bolt fastening holes 39, the outer shape 43 of the bearing support 19 and the bolt fastening holes 39 do not interfere with each other, and the bearing support 19 and the bolts are not interfered with each other. The axial size of the casing 13 can be reduced without changing the setting of the fastening hole 39.

  Further, since the first shaft 3 and the ring gear 7 are integrally fixed by welding (welded portion 57), the first shaft 3 and the ring gear 7 can be fixed integrally by simple fixing means. And the ring gear 7 can be simplified.

(Second Embodiment)
A second embodiment will be described with reference to FIG.

  In the power transmission device 101 according to the present embodiment, the first shaft 3 and the ring gear 7 are integrally fixed by a bolt 103. In addition, although the same code | symbol is described to the structure same as 1st Embodiment, description is abbreviate | omitted, but since it is the same structure as 1st Embodiment, a structure and functional description refer to 1st Embodiment. Although omitted, the obtained effects are the same.

  As shown in FIG. 6, the base portion 8 of the ring gear 7 is fixed to the flange portion 105 of the first shaft 3 by a bolt 103 so as to be integrally rotatable with the first shaft 3. Further, an axial joint portion 30 is formed by fastening with a bolt 103 between the radial wall surface on the back side of the base portion 8 and the radial wall surface of the flange portion 105. Further, a radial joint portion 32 is formed between the inner peripheral surface of the base portion 8 and the outer peripheral surface of the first shaft 3. An annular recess 107 having an L-shaped cross section is formed in the base portion 8 on the back side of the gear portion of the ring gear 7. A fitting portion 23 between the casing body 15 and the cover body 17 is located on the outer diameter side of the concave portion 107 so as to extend beyond the outer peripheral portion of the flange portion 105 to the inner side in the axial direction (in the axial direction of the ring gear 7). The portion 23 is disposed to face the radial side surface 109 of the recess 107. For this reason, even when the 1st axis | shaft 3 and the ring gear 7 are integrally fixed with the volt | bolt 103, the axial direction position of the fitting part 23 and the ring gear 7 can be arrange | positioned overlapping in a radial direction.

  Further, since the axially joined portion 30 and the radially joined portion 32 are both disposed on the inner diameter side of the fitting portion 23, the fitting portion 23 and the joined portions 30, 32 are overlapped in the radial direction. The axial size can be reduced while maintaining the radial size of the casing 13.

  In such a power transmission device 101, since the first shaft 3 and the ring gear 7 are integrally fixed by the bolt 103, the first shaft 3 and the ring gear 7 can be fixed integrally by a simple fixing means. The integral structure of the single shaft 3 and the ring gear 7 can be simplified.

(Third embodiment)
A third embodiment will be described with reference to FIG.

  In the power transmission device 201 according to the present embodiment, the first shaft 3 and the ring gear 7 are integrally fixed by press-fitting. In addition, although the same code | symbol is described to the structure same as 1st Embodiment, description is abbreviate | omitted, but since it is the same structure as 1st Embodiment, a structure and functional description refer to 1st Embodiment. Although omitted, the obtained effects are the same.

  As shown in FIG. 7, the ring gear 7 is fixed so as to be integrally rotatable with the first shaft 3 by press-fitting into a press-fitting portion 203 formed between the outer periphery of the first shaft 3 and the inner periphery of the ring gear 7. Yes. The press-fitting portion 203 forms a radial joint portion 32, and a space between the radial wall surface of the flange portion 205 of the first shaft 3 and the radial wall surface on the inner diameter side of the base portion 8 of the ring gear 7 is a mutual axis. It is a positioning portion for positioning the direction position, that is, the axial joint portion 30, and a fixing member 207 such as a snap ring is fixed to the first shaft 3 on the opposite side of the flange portion 205 with the ring gear 7 sandwiched in the axial direction. The position of the ring gear 7 in the axial direction is fixed. An annular recess 209 having an L-shaped cross section is formed in the base portion 8 on the back side of the gear portion of the ring gear 7. A fitting portion 23 between the casing main body 15 and the cover body 17 is positioned on the outer diameter side of the recess 209, and the fitting portion 23 is disposed to face the radial side surface 211 of the recess 209. For this reason, even when the 1st axis | shaft 3 and the ring gear 7 are integrally fixed by the press-fit part 203, the axial direction position of the fitting part 23 and the ring gear 7 can be arrange | positioned overlapping in radial direction. .

  In addition, since the joint portion 30 in the axial direction and the joint portion 32 in the radial direction are both disposed on the inner diameter side of the fitting portion 23, the fitting portion 23 and the joint portions 30, 32 are overlaid in the radial direction. The axial size can be reduced while wrapping and maintaining the radial size of the casing 13.

  In such a power transmission device 201, since the first shaft 3 and the ring gear 7 are integrally fixed by press-fitting (press-fit portion 203), the first shaft 3 and the ring gear 7 are fixed integrally by simple fixing means. Thus, the integrated structure of the first shaft 3 and the ring gear 7 can be simplified.

(Fourth embodiment)
A fourth embodiment will be described with reference to FIG.

  In the power transmission device 301 according to the present embodiment, the first shaft 3 and the ring gear 7 are integrally fixed by a spline. In addition, although the same code | symbol is described to the structure same as 1st Embodiment, description is abbreviate | omitted, but since it is the same structure as 1st Embodiment, a structure and functional description refer to 1st Embodiment. Although omitted, the obtained effects are the same.

  As shown in FIG. 8, the ring gear 7 is fixed so as to be integrally rotatable with the first shaft 3 by spline coupling to a spline coupling portion 303 formed between the outer periphery of the first shaft 3 and the inner periphery of the ring gear 7. Has been. The spline connecting portion 303 forms a radial joint portion 32, and the radial wall surface of the flange portion 305 of the first shaft 3 and the radial wall surface of the inner diameter side of the base portion 8 of the ring gear 7 are axially connected to each other. A positioning portion for positioning the position, that is, an axial joint portion 30, and a fixing member 307 such as a snap ring is fixed to the first shaft 3 on the opposite side of the flange portion 305 with the ring gear 7 sandwiched in the axial direction. The axial position of the ring gear 7 is fixed. An annular recess 309 having an L-shaped cross section is formed in the base portion 8 on the back side of the gear portion of the ring gear 7. A fitting portion 23 between the casing main body 15 and the cover body 17 is positioned on the outer diameter side of the recess 309, and the fitting portion 23 is disposed to face the radial side surface 311 of the recess 309. For this reason, even when the first shaft 3 and the ring gear 7 are integrally fixed by the spline connecting portion 303, the axial position of the fitting portion 23 and the ring gear 7 can be arranged so as to overlap in the radial direction. it can.

  In addition, since the joint portion 30 in the axial direction and the joint portion 32 in the radial direction are both disposed on the inner diameter side of the fitting portion 23, the fitting portion 23 and the joint portions 30, 32 are overlaid in the radial direction. The axial size can be reduced while wrapping and maintaining the radial size of the casing 13.

  In such a power transmission device 301, the first shaft 3 and the ring gear 7 are integrally fixed by a spline (spline connecting portion 303). Therefore, the first shaft 3 and the ring gear 7 are integrally fixed by simple fixing means. Therefore, the integrated structure of the first shaft 3 and the ring gear 7 can be simplified.

  In the power transmission device according to the embodiment of the present invention, the ring gear as the input gear is provided on the first shaft to which the driving force is directly input from the differential case, but the driving force is transmitted through a mechanism such as a speed change mechanism. May be provided on the input shaft to which is input, and the mechanism in which the input gear is provided may be any power mechanism.

  In addition, the first axis is the input side and the second axis is the output side. However, the first axis is the output side, the second axis is the input side, and the like. The input / output relationship may be any form as long as power can be transmitted to each other.

  Furthermore, the ring gear and the first shaft are integrally fixed by providing a flange portion on the first shaft. For example, the ring gear for the first shaft is welded between the inner periphery of the ring gear and the outer periphery of the first shaft. In the case of a structure in which the axial position can be securely fixed, it is not necessary to provide a flange portion.

  In addition, as for the shape of the concave portion, even if the cross section is not L-shaped, it is only necessary that the fitting portion has a shape that can be overlapped in the radial direction. It is.

DESCRIPTION OF SYMBOLS 1,101,201,301 ... Power transmission device 3 ... 1st shaft 5 ... 2nd shaft 7 ... Ring gear 9 ... Pinion 11 ... Bevel gear set 13 ... Casing 15 ... Casing main body 17 ... Cover body 19 ... Bearing support body 21, 107, 209, 309 ... concave portion 23 ... fitting portion 25, 109, 211, 311 ... radial side surface 27, 105, 205, 305 ... flange portion 29 ... bottom surface portion 31 ... side wall 33 ... bearing 35 ... bearing support portion 37 ... Bolt 39 ... Bolt fastening hole 43 ... External shape 103 ... Bolt (fixing means)
203 ... Press-fit part (fixing means)
303 ... Spline connecting part (fixing means)

Claims (5)

A first shaft that is formed in a hollow shape so that an axle is inserted into the shaft center so as to be relatively rotatable, a second shaft that is disposed so that the shaft center intersects the shaft center of the first shaft, and the first shaft A ring gear provided so as to be integrally rotatable, a pinion provided so as to be integrally rotatable with the second shaft and meshing with the ring gear, and the ring gear and the pinion between the first shaft and the second shaft. A bevel gear set capable of changing the direction of transmission of the driving force and a casing for housing the first shaft, the second shaft, and the bevel gear set, wherein the casing has one end side of the first shaft. A supporting casing body, a cover body that is fitted and fixed to the casing body and that supports the other end of the first shaft, a fitting body that is fixed and fitted to the casing body, and the second shaft. Power transmission device comprising a bearing support to support There is,
An annular recess is formed on the back side of the gear of the ring gear, and a fitting portion between the casing body and the cover body is positioned on the outer diameter side of the recess so as to overlap the recess in the radial direction .
The fitting portion is disposed to face the radial side surface of the recess,
The first shaft has a flange portion for fixing the ring gear, and the flange portion is integrally joined with the ring gear on the bottom surface side of the recess,
The joint between the ring gear and the first shaft is disposed on the inner side in the axial direction from a bearing that supports the first shaft. The power transmission device according to claim 1,
A power transmission device , wherein a joint portion between the ring gear and the first shaft is provided on an inner diameter side of the fitting portion . The power transmission device according to claim 1 or 2,
The power transmission device according to claim 1, wherein an inclined rib is provided on a side wall of the cover body from an outer peripheral portion side of the bearing support portion supporting the bearing supporting the first shaft to the fitting portion side . The power transmission device according to any one of claims 1 to 3,
The casing body is provided with a plurality of bolt fastening holes into which a plurality of bolts for fixing the casing body and the cover body are inserted, and the outer shape of the bearing support is between the adjacent bolt fastening holes. A power transmission device characterized by being positioned . The power transmission device according to any one of claims 1 to 4,
The power transmission device, wherein the first shaft and the ring gear are integrally fixed by at least one fixing means of welding, bolts, press-fitting, and splines .

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