JPH0678652U - Differential gear - Google Patents

Abstract

(57) [Abstract] [Purpose] An assembly that has a differential limiting mechanism that limits the differential of both drive shafts by viscous coupling that transmits torque via viscous fluid, and that can easily assemble the drive shafts. Provided is a differential gear device having good properties. [Structure] The differential gear mechanism side end of the hub 124 with which the inner plate 28 of the viscous coupling 20 is engaged,
In addition to providing the receiving recessed portion 124b formed with an inner peripheral surface having a non-circular cross-sectional shape that is coaxial with the axis C, the side gear 11
The outer peripheral surface 116a of the boss portion 6 is formed in the same non-circular cross-sectional shape corresponding to the inner peripheral surface of the receiving recess 124b.
The 24 and the side gear 116 are integrally rotatably fitted together.
Further, the portion of the hub 124 facing the drive shaft 6 is configured as a cylindrical inner surface 124c coaxial with the axis C so as not to come into direct contact with the male spline 6a.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a differential gear device in which the differential between both drive shafts is automatically limited by a viscous coupling that transmits torque via a viscous fluid. More specifically, it is improved so that the drive shafts can be easily attached. Differential gear device.

[0002]

[Prior art]

 Conventionally, a differential gear device has been used for a drive shaft in order to absorb a difference between inner and outer wheels when a vehicle turns. However, the conventional differential gear device has a drawback that the drive force cannot be transmitted to the drive wheels when either of the left and right drive wheels begins to spin, for example, when it falls in the muddy or runs on ice or snow on the road surface. . For this reason, in recent years, so-called differential gears with viscous coupling have been used to perform differential limitation by viscous coupling that utilizes viscous resistance generated between many thin plates placed in a highly viscous fluid such as silicone oil. The device is becoming widely used.

FIG. 10 is a cross-sectional view showing an example of such a differential gear device with a viscous coupling. In this differential gear device 90, the case 11 of the differential gear mechanism 10 and one drive shaft are shown. A viscous coupling 20 which is a differential limiting mechanism is interposed between the drive shaft 6 and the drive shaft 6. The differential gear mechanism is configured to perform the differential limiting when relative rotation occurs between the case 11 and the drive shaft 6. ing.

In the differential gear device 90, the viscous coupling 20 is provided in the housing 21 separate from the case 11 of the differential gear mechanism 10, so that the viscous coupling 20 can be manufactured and assembled. The advantage is that it is easy and the case 11 of the differential gear mechanism 10 does not need to be manufactured separately for the case where the viscous coupling is attached and the case where it is not. Further, even if the viscous coupling 20 operates and the silicon oil filled in the working chamber 27 becomes hot and the pressure rises, the side gear 16 is not affected by the influence. Therefore, the side gear 16 does not move to the pinion gears 14a and 14b. There is no danger of it being strongly pressed against and impairing its durability. Furthermore, since this viscous coupling 20 is interposed between the case 11 of the differential gear mechanism 10 and the drive shaft 6, as compared with the case where the viscous coupling is interposed between the pair of drive shafts 5 and 6. Since the rotational interference between both drive shafts is weak, it is an optimal differential limiting device for use on the drive shaft of a front-wheel drive vehicle that drives the steered front wheels.

[0005]

[Problems to be solved by the device]

 By the way, in the above-described differential gear device 90, the hub 24 of the viscous coupling and the side gear 16 must rotate integrally with the drive shaft 6 due to the structure thereof. Therefore, as shown in FIG. 10, the drive shaft 6 on the side on which the viscous coupling 20 is arranged has both the hub 24 of the viscous coupling that is engaged with the drive shaft 6 and integrally rotated, and the side gear 16. Is splined to.

However, in most cases, the female spline 24c provided on the hub 24 and the female spline 16b provided on the side gear 16 are out of phase with each other in the rotational direction, so the drive shaft 6 is simply inserted. The male spline 6a cannot be fitted to the female splines 24c and 16b of both by only by itself. Therefore, first, after fitting the drive shaft 6 into the hub 24, the drive shaft 6 is manually rotated to match the phases of the male spline 6a of the drive shaft 6 and the female spline 16b of the side gear 16, and then drive The shaft 6 must be inserted and fitted into the side gear 16.

Therefore, in order to rotate the drive shaft 6, the hub 24 must be rotated against the large starting torque of the viscous coupling 20, which imposes a severe physical burden on the operator. There has been a strong demand for improvement over the past. That is, the object of the present invention is to solve the above-mentioned problems, and in addition to having a differential limiting mechanism for limiting the differential between both drive shafts by a viscous coupling that transmits torque through viscous fluid, It is an object of the present invention to provide a differential gear device which can be easily assembled with good assemblability.

[0008]

[Means for Solving the Problems]

 The above object of the present invention is to provide a differential gear case that rotates around an axis line of a pair of coaxial drive shafts, and a pinion shaft that is attached to the differential gear case so as to be orthogonal to the axis line. The pinion gear rotatably supported by the pinion shaft and the pinion gear are opposed to each other with the pinion shaft interposed therebetween and engage with the pinion gear to rotate about the axis and rotate integrally with the drive shafts. A differential gear mechanism that includes a pair of side gears that are rotatably engaged, a housing that rotates integrally with the differential gear case, and a housing that is supported by the housing and is integral with one of the drive shafts. A hub that rotates dynamically, a working chamber defined by the hub and the housing, in which a viscous fluid is enclosed, and an outer peripheral portion of the working chamber, which is disposed in the working chamber, includes the housing. A differential limiting mechanism including a plurality of outer plates that are rotatably engaged with each other, and a plurality of inner plates that are alternately arranged with the outer plates and that have an inner peripheral portion that is integrally rotatably engaged with the hub. And a hub that is integrally rotatably fitted to an adjacent side gear, and one drive shaft that is rotatably engaged integrally with the side gear is not engaged with the hub. It is achieved by a differential gear device characterized in that

As the fitting means for fitting the hub with the adjacent side gear so as to be able to rotate integrally, the outer peripheral surface of the boss portion of the side gear is formed into a non-circular cross-sectional shape and corresponds to the outer peripheral surface of the boss portion. A receiving recess provided with an inner peripheral surface having a non-circular cross-section is provided at the end of the hub on the side of the differential gear mechanism, and the boss is fitted into the receiving recess so that they can be integrally rotated. There is.

Further, as another fitting means for fitting the hub to the adjacent side gear so as to be able to rotate integrally, the outer peripheral surface of the boss portion of the side gear and the differential gear mechanism side end of the hub into which the boss portion is fitted. In some cases, a spline and a key member provided between the receiving recess and the inner peripheral surface of the receiving portion are integrally fitted so as to rotate the both. Further, as another fitting means for fitting the hub to the adjacent side gear so as to be able to rotate integrally therewith, a facing portion between the boss portion of the side gear and the end portion of the hub into which the boss portion is fitted is located on the differential gear mechanism side. There is a dog clutch that is installed on the front and rear wheels so that they can rotate together.

[0011]

[Action]

 According to the above configuration of the present invention, the hub, which is integrally rotatably fitted to the adjacent side gear, can rotate integrally with one of the drive shafts via the side gear, and directly with the drive shaft. No need to engage. Therefore, when assembling the drive shaft to the preassembled differential gear device, it is only necessary to fit the drive shaft to the side gear.

[0012]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same parts in each embodiment are designated by the same reference numerals to simplify the description. 1 is a vertical sectional view of a differential gear device 100 according to a first embodiment of the present invention, and FIG. 2 is a II-II sectional view of the differential gear device shown in FIG.

In the differential gear device 100, the differential gear mechanism 10 provided on the right side in FIG. 1 and the viscous coupling 20 provided on the left side in FIG. 1 are integrated, and the differential gear mechanism 10 is provided around the axis C of the drive shaft. It is supposed to rotate. The differential gear mechanism 10 is fitted in a bowl-shaped case 11 for housing the gear mechanism, and a through hole 11c formed in the case 11 so as to be orthogonal to the axis C and has a spring pin 12. And the pair of pinion gears 14a and 14b that are rotatably supported on both ends of the pinion shaft 13, and the pinion shaft 13 is opposed to each other with the pinion shaft 12 interposed therebetween. The side gear 116 on the side of the viscous coupling 20 and the side gear 15 on the opposite side are driven by being engaged with the pinion gears 14a and 14b and rotating around the axis C. The side gears 15 and 116 are fitted with the female splines 15b and 116b, respectively, to which the male splines 5a and 6a of the drive shafts 5 and 6 are fitted, respectively, and are prevented from coming off by the circlips 5c and 6c. , Are designed to rotate together.

The viscous coupling 20 has a housing 21 integrally attached to the case 11 of the differential gear mechanism 10, and the housing 21 includes an annular thick plate portion 21 a attached to a flange 11 a of the case 11. An outer rotary member 21b attached to the annular thick plate portion 21a and coaxial with the axis C, and an outer rotary member 21b attached to the outer rotary member 21b to rotatably support the differential gear device 100. The outer member 21c has a shaft portion 21d for The working chamber 27 in which the viscous fluid is enclosed is defined in the housing 21 in an annular shape coaxial with the axis C. Further, a hub 124, which is supported by the annular thick plate portion 21a and the outer member 21c and is rotatable around the axis C, forms an X ring (oil having an X-shaped cross section) in the working chamber 27. (Seal) 25 and 26 are sealed together.

Inside the working chamber 27, outer plates 29 and inner plates 28, which are thin plates punched out in an annular shape, are alternately arranged. The outer plate 29 has an outer peripheral portion inside the outer rotating member 21 b of the housing 21. The inner plate 28 is integrally rotatably engaged with the inner plate 28, and the inner peripheral portion of the inner plate 28 is integrally rotatably engaged with the outer peripheral surface of the hub 124 so as to be integrally rotated around the axis C. It has been done.

Then, the inside of the working chamber 27 is filled with a viscous fluid through a through hole provided in the housing 21, and then sealed by a ball 22 so as not to leak to the outside. As shown in FIG. 2, at the end of the hub 124 on the side of the differential gear mechanism, a receiving recess 124b having an inner peripheral surface of a non-circular cross-section that is coaxial with the axis C is provided. There is. The outer peripheral surface 116a of the boss portion of the side gear 116 is formed in the same non-circular cross-sectional shape corresponding to the inner peripheral surface of the receiving recess 124b. As a result, the receiving recess 124b of the hub 124 is externally fitted and engaged with the outer peripheral surface 116a of the boss portion of the side gear 116, so that they are integrally rotatably fitted around the axis C.

The portion of the hub 124 facing the drive shaft 6 is a cylindrical inner surface 124c coaxial with the axis C so as not to come into direct contact with the male spline 6a. 124 and the drive shaft 6 are disengaged. Accordingly, when the drive shaft 6 is attached to the differential gear device 100 of this embodiment, the male spline 6a of the drive shaft 6 only needs to be inserted and fitted into the female spline 116b of the side gear 116. , Easy to install.

That is, in the differential gear device 100 of this embodiment, the hub 124, with which the inner plate 28 of the viscous coupling 20 is engaged, is not directly spline-fitted to the drive shaft 6, but via the side gear 116. Since the drive shaft 6 is integrally rotatably engaged with the drive shaft 6, the male spline 6a provided at the tip of the drive shaft 6 is attached to the side gear 116 when the drive shaft 6 is attached to the differential gear device 100. Since it suffices to fit it to the female spline 116b provided at, it can be easily attached. Further, since the hub 124 rotates integrally with the drive shaft 6 via the side gear 116, the viscous coupling 20 can operate in the same manner as the conventional one.

The shape coupling portion forming the fitting means for integrally rotating the hub 124 and the side gear 116 is not limited to the non-circular cross-sectional shape as described above, and may have a polygonal cross-sectional shape. Next, the operation of the differential gear device 100 of the first embodiment will be described. First, a power transmission path of a vehicle to which the differential gear device 100 is applied is schematically described. This vehicle drives left and right front wheels 7R and 7L by an engine 1 mounted in front of a vehicle body. In a front-wheel drive vehicle, after the drive force generated by the engine 1 is changed by the transmission 2, the case 2 of the transmission 2 is rotatably supported by the bearings 4a and 4b in the case 11 of the differential gear mechanism 10. The differential gear mechanism 10 is driven and rotated by transmission to the spur gear 3 fixed to the. The left and right drive shafts 5 and 6 attached to the side gears of the differential gear mechanism 10 drive the left and right front wheels 7R and 7L.

As described above, in the differential gear device 100, the viscous coupling 20 as a differential limiting mechanism is interposed between the case 11 of the differential gear mechanism 10 and the drive shaft 6. There is. Therefore, when the left-right rotation difference is small, such as during low-speed turning, the differential limiting torque due to the viscous coupling 20 is small, so the differential function of the differential device operates and smooth turning is possible.

Then, for example, when the right drive wheel 7R gets stuck in muddy water or runs on ice and snow on the road surface and spins idle, relative rotation occurs between the case 11 of the differential gear mechanism 10 and the drive shaft 6. . As a result, as shown in FIG. 1, the outer plate 29 engaged with the housing 21 of the viscous coupling 20 integrated with the case 11 and the side gear 116 with which the drive shaft 6 is spline-fitted are integrated. The inner plate 28 that engages with the hub 124 that is designed to rotate relative to each other rotates relatively in the high-viscosity silicone oil enclosed in the working chamber 27 to generate viscous resistance. 6 is limited to the case 11, the driving force can be transmitted to the left drive wheel 7L which is not idling, and high drivability is obtained.

FIG. 3 is a vertical sectional view of a differential gear device 200 according to a second embodiment of the present invention, and FIG. 4 is a sectional view of the differential gear device shown in FIG. . The differential gear device 200 is configured such that the hub 224 of the viscous coupling 20 is spline-fitted to the side gear 216 so that the two are integrally rotatably engaged with each other, and the other portions are the same as those of the first embodiment described above. It has the same structure as the differential gear device 100.

That is, the female spline 224b is formed on the inner peripheral surface of the receiving recess coaxial with the axis C of the hub 224 in the second embodiment, and the male spline is formed on the outer peripheral surface of the boss portion of the side gear 216. 216a is engraved, and the two are engaged with each other via the spline so as to be integrally rotatable. The portion of the hub 214 facing the male spline 6a of the drive shaft 6 is a cylindrical inner surface 224c coaxial with the axis C and having an inner diameter larger than the outer diameter of the male spline 6a, and is in direct contact with the spline 6a. It is supposed to never happen.

Therefore, by spline-fitting the hub 224 to the side gear 216, both of them rotate integrally around the axis C, and the hub 224 can rotate integrally with the drive shaft 6. The viscous coupling 20 can operate in the same manner as the conventional one, and the drive shaft 6 can be easily attached to the differential gear device 200.

FIG. 5 is a vertical sectional view of a differential gear unit 300 according to a third embodiment of the present invention, and FIG. 6 is a sectional view of the differential gear unit shown in FIG. . The differential gear device 300 is one in which the hub 324 of the viscous coupling 20 is engaged with the side gear 316 via a dog clutch, and the other parts are the same as those of the differential gear device 100 of the first embodiment described above. The structure is exactly the same.

That is, the dog clutch teeth 316a protruding toward the viscous coupling 20 along the axis C direction are equally distributed in the circumferential direction on the end surface of the boss portion of the side gear 316 in the third embodiment. The dog clutch tooth 324b that is provided and protrudes toward the side gear 316 corresponding to the portion of the receiving recess of the hub 324 into which the boss portion of the side gear 316 is inserted and that faces the dog clutch tooth 316a. Are engraved, and both are fitted so as to be integrally rotatable via this dog clutch. The portion of the hub 324 facing the male spline 6a of the drive shaft 6 is a cylindrical inner surface 324c coaxial with the axis C and having an inner diameter larger than the outer diameter of the male spline 6a, and is in direct contact with the male spline 6a. It is supposed to never happen.

Therefore, by fitting the hub 324 to the side gear 316 via the dog clutch, both of them rotate integrally around the axis C, and the hub 324 rotates integrally with the drive shaft 6. Therefore, the viscous coupling 20 can operate in exactly the same manner as the conventional one, and the drive shaft 6 can be easily attached to the differential gear device 300.

FIG. 7 is a vertical sectional view of a differential gear device 400 according to a fourth embodiment of the present invention, and FIG. 8 is a sectional view of the differential gear device shown in FIG. . The differential gear device 400 is one in which the hub 424 of the viscous coupling 20 is engaged with the side gear 416 via the round key 23, and the other parts are the same as those of the differential gear device 100 of the first embodiment described above. The structure is exactly the same.

That is, the round key 23 is housed on the inner peripheral surface of the receiving recess 424b coaxial with the axis C of the hub 424 of the fourth embodiment and the outer peripheral surface of the boss portion 416a of the side gear 416. Each groove having a semicircular cross section is formed so as to extend in parallel with the axis C. The portion of the hub 424 facing the male spline 6a of the drive shaft 6 is a cylindrical inner surface 424c coaxial with the axis C and having an inner diameter larger than the outer diameter of the male spline 6a, and is in direct contact with the male spline 6a. There is no such thing.

Therefore, by fitting the hub 424 to the side gear 416 via a dog clutch, both of them rotate integrally around the axis C, and the hub 424 rotates integrally with the drive shaft 6. Therefore, the viscous coupling 20 can operate in exactly the same manner as the conventional one, and the drive shaft 6 can be easily attached to the differential gear device 400.

Although the circular key is used in the fourth embodiment, the shape of the key does not have to be limited to this, and a key having another shape may be used.

[0032]

[Effect of device]

 According to the differential gear device of the present invention, the hub with which the inner plate of the viscous coupling, which is the differential limiting mechanism, engages is rotatably fitted to the adjacent side gear, and one hub is driven through the side gear. Since it can rotate integrally with the shaft, it is not necessary to directly engage with the drive shaft. Therefore, when assembling the drive shaft to the preassembled differential gear device, it is only necessary to fit the drive shaft to the side gear.

Therefore, like a conventional differential gear device with a viscous coupling, first, the drive shaft is spline-fitted to the hub, and then the operator manually rotates the drive shaft while resisting the starting torque of the viscous coupling. Since it is not necessary to match the phases of the drive shaft spline and the side gear spline, the drive shaft can be easily attached.

Therefore, the viscous coupling for transmitting the torque via the viscous fluid has a differential limiting mechanism for limiting the differential between the driving shafts, and the drive shaft can be easily assembled. A good differential gear device can be provided.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a differential gear device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II of the differential gear device shown in FIG.

FIG. 3 is a vertical sectional view of a differential gear device according to a second embodiment of the present invention.

FIG. 4 is a sectional view of the differential gear unit shown in FIG. 3, taken along the line IV-IV.

FIG. 5 is a vertical sectional view of a differential gear device according to a third embodiment of the present invention.

6 is a sectional view of the differential gear device shown in FIG. 5, taken along the line VI-VI.

FIG. 7 is a vertical sectional view of a differential gear device according to a fourth embodiment of the present invention.

8 is a cross-sectional view taken along the line VIII-VIII of the differential gear device shown in FIG.

FIG. 9 is an explanatory diagram showing a power transmission system of a vehicle to which the differential gear device of the present invention is applied.

FIG. 10 is a vertical cross-sectional view of a conventional differential gear device.

[Explanation of symbols]

 5 Drive shaft 6 Drive shaft 10 Differential gear mechanism 11 Case of differential gear mechanism 12 Spring pin 13 Pinion shaft 14a Pinion gear 14b Pinion gear 15 Side gear 20 Viscous coupling 25 X ring 26 X ring 27 Working chamber 28 Inner plate 29 Outer plate 100 Differential gear device 116 Side gear 116a Boss outer peripheral surface 116b Female spline 124 Hub 124b Receiving recess 124c Cylindrical inner surface 216 Side gear

Claims (1)

[Scope of utility model registration request] 1. A differential gear case that rotates around axes of a pair of coaxial drive shafts, a pinion shaft that is attached to the differential gear case so as to be orthogonal to the axis, and a pinion. A pinion gear that is rotatably supported by a shaft, and a pinion gear that are opposed to each other with the pinion shaft interposed therebetween and that engages with the pinion gear to rotate about the axis and engage with the drive shafts. A differential gear mechanism including a pair of side gears, a housing that rotates integrally with the differential gear case, a hub that is supported by the housing and rotates integrally with one of the drive shafts, A working chamber defined by a hub and the housing, in which a viscous fluid is sealed, and an outer peripheral portion of the working chamber, which is disposed in the working chamber and is rotatable integrally with the housing. A differential limiting mechanism including a plurality of outer plates engaged with each other, and a plurality of inner plates alternately arranged with the outer plates and having inner peripheral portions engaged with the hub so as to rotate integrally with the hub. A gear device, wherein the hub is integrally rotatably fitted to an adjacent side gear, and one drive shaft engaged with the side gear rotatably is disengaged from the hub. A differential gear device characterized in that