JP2009144891A - Final reduction gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a final reduction gear simplifying a support structure for the output gear of a final reduction gear device and a planetary gear. <P>SOLUTION: An angular ball bearing 18 as a radial bearing is used as a bearing member supporting a bevel ring bear 142 (a final gear device 14) and the planetary gear 16 (a bearing housing 15). The angular ball bearing has load capability with respect to a radial load and an axial load, and is formed with a flange portion 181a which is provided to an outer race 181 and is provided as a projecting portion extending toward the inner peripheral surface of the bevel ring gear 142 in order to be joined to the inner peripheral surface of the bevel ring gear 142. Further, the inner peripheral surface of the bevel ring gear 142 is formed with an engagement projecting portion 142c joined to one end surface of the flange portion 181a, and the bevel ring gear 142 and bearing housing 15 are connected and fixed to each other with both end surfaces of the flange portion 181a sandwiched between the engagement projecting portion 142c and the baring housing 15. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a final reduction gear, and more particularly to a final reduction gear including a final reduction gear device (final gear device), a differential gear device (differential gear device), and a planetary gear device.

  Conventionally, the final reduction gear is a final reduction gear that converts the rotation direction of the input shaft extending in the front-rear direction to transmit the driving force from the engine to the left and right drive wheels into the rotation direction of the left-right drive shaft extending in the left-right direction. Device (final gear device) and differential gear device (differential gear) that rotates the left and right drive shafts at different rotational speeds while turning the vehicle, while equally distributing the driving force that has passed through the final gear device to the left and right drive shafts (left and right drive wheels) Gear device).

  Although the hypoid gear which is one of orthogonal shaft gears has been used for the final gear device (see, for example, Patent Document 1), the hypoid gear offsets the pinion gear as compared with the bevel gear (including the spiral bevel gear), Although the vibration can be suppressed and the reduction ratio can be increased, the friction at the time of low load increases as the offset increases, and the final reduction gear increases in size.

  Therefore, in order to obtain a reduction ratio that is almost the same as when a bevel gear with an offset of 0 is used for the final gear device and a hypoid gear, a planetary gear device (reduction mechanism unit) is provided between the final gear device and the differential gear device. (See, for example, Patent Document 2), the applicant of the present application has already proposed that the efficiency of the final reduction gear is improved and the size reduction and the reduction of gear noise (gear noise) are attempted. (For example, see application number: Japanese Patent Application No. 2007-146986).

Japanese Patent Laying-Open No. 2007-40339 (FIG. 2) JP-A 64-65548 (FIG. 1)

  Incidentally, in the final reduction gear (11) previously proposed by the applicant of the present application, as shown in FIG. 4, the cylindrical roller bearing (20) and the bush (22) provided in the radial direction of the differential case (141). ) Supports the bevel ring gear (122), which is the output gear of the bevel gear (12), and the sun gear (131) of the planetary gear unit (13). However, the cylindrical roller bearing (20) and the bush (22) have a low load capacity with respect to an axial load. Therefore, in order to receive an axial load from the bevel ring gear (122) and the planetary gear unit (13) connected thereto, the differential case (141) and the sun gear (131) are arranged on the layout of the planetary gear unit (13). And two thrust bearings (21), (23), one each between the connecting member (123) connecting the bevel ring gear (122) and the sun gear (131) and the planetary carrier (134). Was necessary. In other words, four bearing members (20), (21), (22), (23) are required to support the bevel ring gear (122) and the planetary gear device (13), so the bevel ring gear (122) And the planetary gear unit (13) have a complicated support structure. And since the support structure of the bevel ring gear (122) and the planetary gear device (13) is complicated, the assembly accuracy of the bevel ring gear (122) and the planetary gear device (13) is increased, and the bevel ring gear (122) In addition, there is a possibility that deflection (shaking) occurs in the planetary gear unit (13) or gear noise occurs. Furthermore, there is a problem in that the manufacturing cost (parts and assembly cost) is increased and the assembly size of the planetary gear device (13) in the axial direction of the differential case (141) is increased.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a final reduction gear device that can simplify the support structure between the output gear and the planetary gear device of the final reduction gear device.

In order to achieve the above object, the invention according to claim 1 is an input that converts the rotation direction of the input shaft that transmits the driving force from the engine to the left and right drive wheels into the rotation direction of the left and right drive shafts orthogonal to the input shaft. A final reduction gear device having an output gear, a sun gear connected to the output gear via a connecting member joined to an inner peripheral surface of the output gear of the final reduction gear device, an internal gear is fixed, and the A planetary carrier that supports a sun gear and a pinion gear that meshes with the internal gear is used as an output, and a planetary gear device that reduces the rotational speed of the output gear that is input from the sun gear, and a differential case that is connected to the planetary carrier. While driving force is input and the input driving force is evenly distributed to the left and right drive shafts, A final reduction gear comprising: a differential gear device that rotates the drive shaft at different rotational speeds; and a bearing member that is provided in a radial direction of the differential case and rotatably supports the output gear via the connecting member. In
The bearing member is a radial bearing that has a load capacity for a radial load and an axial load, and a convex portion that extends toward the inner peripheral surface of the output gear. The outer peripheral surface of the output gear is provided on the outer race. Are provided with engaging projections joined to one end surface of the convex portion, and the output gear and the output gear in a state where the engaging projection portions and the connecting member are sandwiched between both end surfaces of the convex portion. The connecting member is fixedly coupled to the connecting member.

  In order to achieve the above object, according to a second aspect of the present invention, in the first aspect of the present invention, the convex portion is fitted to a flange portion integrally formed with the outer race or an outer peripheral surface of the outer race. The connecting member is a snap ring joined from the axial direction, and a washer disposed between opposing surfaces of the snap ring and the engaging protrusion.

  To achieve the above object, the invention according to claim 3 is the invention according to claim 1, wherein the radial bearing is an angular ball bearing of any one of a single row, a combination, and a double row. And

  According to the first to third aspects of the present invention, the radial bearing is capable of receiving the radial load and the axial load from the output gear of the final reduction gear device (final gear device) and the planetary gear device (including the connecting member). Angular contact ball bearings (single row, combination, double row) are used. In order to use an angular ball bearing, the angular ball bearing must be held with an output gear inner diameter larger than the maximum outer diameter of the differential case. Therefore, a convex portion extending toward the inner peripheral surface of the output gear, specifically a flange portion, or a snap ring and a retaining washer is provided on the outer race of the angular ball bearing. In addition, an engaging projection that is joined to one end face of the convex portion is provided on the inner peripheral surface of the output gear. Then, the output gear and the connecting member are coupled and fixed in a state where the connecting member and the engaging projection are sandwiched between the both end faces of the convex portion.

  Thus, the radial load from the output gear and the planetary gear device is input from the outer race of the angular ball bearing, and the axial load from the output gear and the planetary gear device is input from the convex portion to the outer race of the angular ball bearing. It will be. In other words, since the output gear and the planetary gear device can be supported by one angular ball bearing, two thrust bearings and bushes that have been conventionally required can be reduced, and the final reduction gear can be obtained. The support structure of the device and the planetary gear device can be simplified. Therefore, the assembly accuracy between the output gear of the final reduction gear device and the planetary gear device is improved, and the shaft shake and gear noise between the output gear of the final reduction gear device and the planetary gear device can be prevented. Become. Further, the manufacturing cost can be reduced, and the assembly dimension of the planetary gear device with respect to the axial direction of the differential case can be shortened.

  According to the final reduction gear device of the present invention, the output gear of the final reduction gear device (final gear device) and the planetary gear device are supported by the angular ball bearing, and the inner peripheral surface of the output gear is supported on the outer race of the angular ball bearing. And a convex portion that is sandwiched from the left and right sides by the output gear and the connecting member of the final reduction gear device. As a result, the radial load and the axial load from the output gear and the planetary gear unit can be received by one angular ball bearing, so that the final reduction gear unit and the planetary gear unit supporting structure for the final reduction unit can be simplified. The device is realized.

A final reduction gear according to an embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 is a cross-sectional view showing an embodiment of the final reduction gear, and FIG. 2 is a cross-sectional view taken along arrow AA in FIG.
1 is a front drive final reduction device connected to a longitudinal engine (not shown), the lower side in FIG. 1 is the front and the upper side in FIG. 1 is the rear.

  As shown in FIG. 1, a final reduction gear 10 according to the present invention includes an input shaft 11, left and right drive shafts 12, 13, a final gear device 14 as a final reduction gear device, a bearing housing 15 as a connecting member, and a planetary gear device. 16, a differential device 17 as a differential gear device, and a radial bearing 18 as a bearing member.

  The input shaft 11 is a power transmission shaft that extends in the front-rear direction so as to transmit the driving force of the engine output from a vertical engine and a transmission (not shown) to the left and right drive shafts 12 and 13. The output side (final gear device side) of the input shaft 11 includes two single-row angular ball bearings 20, 21 disposed between left and right support portions 19 a, 19 b in the transmission case 19 that forms the outer shell of the final reduction gear 10. It is supported so that it can rotate through. The axial direction of the input shaft 11 and the axial direction of the left and right drive shafts 12 and 13 are orthogonal to each other, and the output side of the input shaft 11 is disposed close to the left drive shaft 12.

  The left and right drive shafts 12 and 13 are supported so as to be rotatable relative to the differential case 171 in a differential case 171 that forms an outer shell of a differential gear device 17 described later. Wheels are connected to shaft end portions of the left and right drive shafts 12 and 13 projecting from the differential case 171 toward the left and right sides via a drive shaft (not shown).

  The final gear device 14 uses a bevel gear with an offset of 0, and is provided integrally with the input shaft 11 as an input / output gear that converts the rotational direction of the input shaft 11 into the rotational direction of the left and right drive shafts 12 and 13. A bevel pinion gear 141 and a bevel ring gear 142 (an output gear of the final reduction gear device) disposed in the radial direction of the differential case 171 so as to mesh with the bevel pinion gear 141 are provided. A screw hole 142b into which a fixing bolt 22 for fastening and fixing the bearing housing 15 is screwed is formed in the back surface portion 142a of the bevel ring gear 142. Further, as will be described in detail later, an engagement protrusion 142c that is joined from the axial direction to a flange 181a as a protrusion provided on the bearing member 18 is provided on the inner peripheral surface of the bevel ring gear 142. .

The bearing housing 15 includes a back plate portion 15a extending in the radial direction of the differential case 171 so as to be connected to the back surface portion 142a of the bevel ring gear 142, and a base end portion of the back plate portion 15a. After extending along the axial direction of the differential case 171 so as to be joined to the surface, the main body 15b is formed to bend so as to extend in the radial direction of the differential case 171, and the sun gear 161 of the planetary gear device 16 is formed from the main body 15b. A projecting portion 15c projecting along the axial direction of the differential case 171 is provided so as to be connected to the inner peripheral surface without being joined to the differential case 171. The back plate portion 15a is formed with a plurality of uniform holes 15a1 through which the fixing bolts 22 are inserted (however, only one is shown in FIG. 1).
Thereby, the bearing housing 15 can be regarded as a part of the planetary gear device 16.

  As shown in FIGS. 1 and 2, the planetary gear device 16 is a single pinion type planetary gear device, which is integrally connected to the bevel ring gear 142 via the bearing housing 15 and is arranged in the radial direction of the differential case 171. The disposed sun gear 161, the internal gear 162 fixed to the transmission case 19, the pinion gear 163 meshing with the sun gear 161 and the internal gear 162, and the pinion gear 163 are rotatably supported and are provided on the outer peripheral surface of the differential case 171. And a planetary carrier 164 fitted with a spline.

In other words, in the planetary gear device 16, the sun gear 161 connected to the bevel ring gear 142 is input, the internal gear 162 is fixed, and the planetary carrier 164 connected to the differential case 171 is assigned to the output. The planetary gear device 16 decelerates the rotational speed input from the sun gear 161 by a reduction ratio (a + c) / a set by the number of teeth a of the sun gear 161 and the number of teeth c of the internal gear 162. This is transmitted to the differential case 171.
The planetary gear device 16 is not limited to a single pinion type planetary gear device, and a double pinion type planetary gear device may be used.

  The differential device 17 includes a hollow differential case 171 in which a planetary carrier 164 is integrally connected and is rotatably supported by a transmission case 19 via single-row angular ball bearings 23 and 24, and a laterally straight in the differential case 171. A vertically installed pinion shaft 173 that is secured by a pin 172, a pair of differential bevel pinions 174 and 174 as differential small gears rotatably supported at both ends of the pinion shaft 173, and these differential bevel pinions 174 and 174 and a pair of left and right differential bevel gears 175 and 175 as differential large gears connected to the left and right drive shafts 12 and 13. The differential device 17 distributes the driving force input via the differential case 171 connected to the planetary carrier 164 equally to the left and right drive shafts 12 and 13 while differentiating the left and right drive shafts 12 and 13 when the vehicle turns. It is designed to rotate at the number of rotations.

The radial bearing 18 is disposed in the radial direction of the differential case 171 and may be rephrased as the bevel ring gear 142 and the planetary gear device 16 (the planetary gear device 16 may be referred to as the sun gear 161. Further, as described above, the planetary gear device 16 is also a planet. The gear device 16 includes a bearing housing 15) and has a load capacity for radial load and axial load, and extends toward the inner peripheral surface of the bevel ring gear 142 so as to be joined to the inner peripheral surface of the bevel ring gear 142. An angular ball bearing (single row, combination, double row) is used as a radial bearing in which the flange portion 181a as the convex portion is integrally provided in the radial direction of the outer race 181.
In the figure, a double-row angular contact ball bearing is illustrated, but the present invention is not limited to this, and a combination angular contact ball bearing in which two single-row angular contact ball bearings are combined may be used. Moreover, you may use the other radial bearing with the load capability with respect to a radial load and a thrust load.

  A flange portion 181a of a radial bearing (hereinafter referred to as an angular ball bearing) 18 is provided so as to go around the outer periphery of the outer race 181 so that the side view is annular, and the front end portion of the flange portion 181a. Are joined to the inner peripheral surface of the bevel ring gear 142. Further, an engagement protrusion 142c provided on the inner peripheral surface of the bevel ring gear 142 is joined to the left end surface of the flange portion 181a, and the main body portion of the bearing housing 15 is connected to the right end surface of the flange portion 181a. 15b is joined.

Further, the left end face of the outer race 181 of the angular ball bearing 18 and the differential case 171 are not joined, and the right end face of the outer race and the bearing housing 15 are not joined.
On the other hand, the differential case 171 is joined to the left end surface of the inner race 182 of the angular ball bearing 18, and the snap ring 25 fitted to the outer peripheral surface of the differential case 171 is joined to the right end surface. Yes.

  Then, the flange portion 181a provided on the outer race 181 of the angular ball bearing 18 is sandwiched from the left and right sides (in the axial direction of the differential case 171) by the engagement protrusion 142c of the bevel ring gear 142 and the main body 15b of the bearing housing 15. In this state, the bevel ring gear 142 and the bearing housing 15 are fastened and fixed by fixing bolts 22 that are inserted through the equal distribution holes 15a1 and screwed into the screw holes 142b. As a result, when the angular ball bearing 18 is used, even if the bevel ring gear 142 has an inner diameter larger than the maximum diameter expansion portion of the differential case 171 so as not to interfere with the differential case 17, the angular ball bearing 18 Can be reliably held.

  As described above, according to the final reduction gear device 10 of the present invention, the radial load from the bevel ring gear 142 and the planetary gear device 16 (bearing housing 15) is input to the angular ball bearing 18 from the outer peripheral surface of the outer race 181. Further, the axial load from the bevel ring gear 142 is input to the angular ball bearing 18 from the flange portion 181a. On the other hand, an axial load from the bearing housing 15 (sun gear 161) is also input to the angular ball bearing 18 from the flange portion 181a.

  That is, the bevel ring gear 142 and the planetary gear device 16 (bearing housing 15) can be supported by one angular ball bearing 18, so that two thrust bearings and bushes that have been conventionally required are reduced. Will be able to. As a result, the support structure for the final gear device 14 and the planetary gear device 16 can be simplified. Therefore, the assembly accuracy of the final gear device 14 and the planetary gear device 16 is improved, and the shaft shake and gear noise of the final gear device 14 and the planetary gear device 16 can be prevented. Further, the manufacturing cost can be reduced, and the assembly dimension of the planetary gear device 16 with respect to the axial direction of the differential case 171 can be shortened.

  In the configuration described above, the flange portion 181a as a convex portion provided on the outer race 181 of the angular ball bearing 18 is formed integrally with the outer race 181. However, as shown in FIG. 181 may be formed separately. FIG. 3 is a cross-sectional view showing another embodiment of the final reduction gear.

  That is, as shown in FIG. 3, a snap ring 183 in which the convex portion is fitted to the outer peripheral surface of the outer race 181 of the angular ball bearing 18 and the main body 15b of the bearing housing 15 is joined from the axial direction, and the snap ring 183 and the washer 184 disposed between the opposing surfaces of the main body portion 15b of the bearing housing 15 and the engaging protrusion 142c. Thereby, the radial load from the bevel ring gear 142 and the bearing housing 15 is input to the angular ball bearing 18 from the outer peripheral surface of the outer race 181. Further, the axial load from the bevel ring gear 142 is input to the angular ball bearing 18 from the washer 184 through the snap ring 183. On the other hand, the axial load from the bearing housing 15 (sun gear 161) is input from the snap ring 183 to the angular ball bearing 18.

  As described above, the bevel ring gear 142 and the planetary gear device 16 (bearing housing 15) can be supported by the single angular ball bearing 18, so that it is possible to obtain substantially the same operational effects as the above-described configuration. In addition, the manufacturing cost can be kept low because the convex portions are not integrally formed.

In the present embodiment, a bevel gear with an offset of 0 is used for the final gear device 14, but the present invention is not limited to this, and a hypoid gear with an offset close to 0 may be used.
Further, the present embodiment can be applied not only to a final reduction gear using orthogonal shaft gears but also to a final reduction gear using parallel shaft gears. It can also be applied to a rear differential device.

It is sectional drawing which showed one Embodiment of this final reduction gear. It is AA arrow sectional drawing in FIG. It is sectional drawing which showed other embodiment of this final reduction gear. It is a closed sectional view of the conventional final reduction gear.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Final reduction gear 11 ... Input shaft 12 ... Left drive shaft 13 ... Right drive shaft 14 ... Final gear device (final reduction gear device)
141 ... Bevel pinion gear (input gear)
142 ... Bevel ring gear (output gear)
142c ... engaging protrusion 15 ... bearing housing (connecting member)
15b ... Main body 16 ... Planetary gear device 161 ... Sun gear 162 ... Internal gear 163 ... Pinion gear 164 ... Planetary carrier 17 ... Differential device (differential gear device)
171 ... Differential case 18 ... Angular contact ball bearing (bearing member)
181 ... Outer race 181a ... Flange (convex)
183 ... Snap ring (convex part)
184 ... Washer (convex part)
22 ... Fixing bolt

Claims (3)

A final reduction gear device including an input / output gear that converts the rotation direction of the input shaft that transmits the driving force from the engine to the left and right drive wheels into the rotation direction of the left and right drive shafts orthogonal to the input shaft;
A sun gear connected to the output gear is input via a connecting member joined to the inner peripheral surface of the output gear of the final reduction gear device, and the internal gear is fixed, and the sun gear and the pinion gear that meshes with the internal gear are supported. A planetary gear unit that reduces the rotational speed of the output gear input from the sun gear,
A driving force is input through a differential case connected to the planetary carrier, and the left and right drive shafts are rotated at different rotational speeds when the vehicle is turning while the input driving force is equally distributed to the left and right drive shafts. A differential gear unit;
A bearing member provided in a radial direction of the differential case, and rotatably supporting the output gear via the coupling member;
In the final speed reducer with
The bearing member is a radial bearing that has a load capacity for a radial load and an axial load, and a convex portion that extends toward the inner peripheral surface of the output gear. The outer peripheral surface of the output gear is provided on the outer race. Are provided with engaging projections joined to one end surface of the convex portion, and the output gear and the output gear in a state where the both end surfaces of the convex portion are sandwiched between the connecting member and the engaging projection portion. A final reduction device, wherein the connecting member is fixedly coupled to the connecting member.   The convex portion is a flange portion integrally formed with the outer race, or a snap ring that is fitted to an outer peripheral surface of the outer race and the connecting member is joined from the axial direction, and the snap ring and the engaging protrusion portion The final reduction device according to claim 1, wherein the final reduction device is a washer disposed between surfaces facing each other.   2. The final reduction gear according to claim 1, wherein the radial bearing is an angular ball bearing of any one of a single row, a combination, and a double row.

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