JP2019132333A - Differential device - Google Patents

Abstract

To provide a differential device capable of securing strength of a differential case and reducing the thickness of the differential case, and further capable of sufficiently spreading lubricant into the differential case.SOLUTION: A differential device has oil grooves 32 and 34 extending in an axial direction of drive shafts 14 and 14 formed on the inner peripheral surfaces of shaft insertion parts 52 and 54 forming a differential case 18. Also, the differential case 18 has ribs 36 and 38 and ribs 40 and 42 formed so as to reach an outer peripheral side of a differential pinion gear 20 from the end parts of the oil grooves 32 and 34. The ribs 36 and 38 and the ribs 40 and 42 are formed so as to reach pinion shaft mounting parts 28 and 30 from the end parts of the oil grooves 32 and 34.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a differential device mounted on a vehicle such as an automobile.

  Generally, in a differential device mounted on a vehicle such as an automobile, the lubricant is injected into the differential case by injecting the lubricant toward the center of the differential mechanism as in the differential device disclosed in Patent Document 1. Some are configured to supply. Further, in the differential device, the lubricating oil supplied into the casing is lifted up by a ring gear and supplied to a portion requiring lubrication such as a bearing.

  Specifically, the lubricating oil supplied into the differential case includes a portion where the left and right differential side gears and the differential pinion gear slide, a portion where the drive shaft and the differential case slide, a portion where a differential side seal is provided, etc. Has been supplied to.

JP 59-208267 A

  Here, in the conventional differential device, a heavy case having a large plate pressure is used as a differential case for accommodating the differential gear mechanism. From the viewpoint of improving the fuel efficiency of the vehicle, the differential device is also required to be lighter, but in the prior art, there is a problem that it is difficult to reduce the thickness of the differential case in order to ensure strength.

  Further, in the conventional differential device, the lubricating oil can be introduced into the differential case via an oil groove formed along the drive shaft. However, most of the lubricating oil introduced into the differential case cannot reach each part in the differential case, such as the part provided with the differential pinion gear, and is only used for lubricating the back side of the differential side gear. was there. For this reason, in the conventional differential device, there is a concern that the lubricating oil does not spread in the differential case and seizure occurs depending on the use environment.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a differential device capable of sufficiently distributing lubricating oil in a differential case while ensuring the strength and thinning of the differential case.

  The differential device of the present invention provided to solve the above-described problem includes a differential gear mechanism and a differential case having a housing space for housing the differential gear mechanism, and the differential gear mechanism is driven. A differential side gear connected to one end of a drive shaft that transmits power to the wheel, and a differential pinion gear meshed with the differential side gear, wherein the differential case communicates with the accommodating space, and A drive shaft insertion portion that supports the drive shaft inserted into the space so as to be able to rotate while sliding, and either or both of the inner peripheral surface of the shaft insertion portion and the drive shaft An oil groove extending in the axial direction of the drive shaft is provided so as to reach the outer peripheral side of the differential pinion gear from the end of the oil groove. Formed ribs, is characterized in that characterized in that provided in the differential case.

  By providing the differential case with ribs as in the present invention, the strength of the differential case can be improved. Therefore, the strength of the differential case can be ensured even if the thickness of the differential case is reduced. Therefore, according to this invention, the differential apparatus provided with the differential case which has light weight and sufficient intensity | strength can be provided.

  Moreover, in the differential apparatus of this invention, it forms so that a rib may reach | attain to the outer peripheral side (back side) of a differential pinion gear from the edge part of an oil groove. Therefore, the lubricating oil supplied via the oil groove can reach the outer peripheral side of the differential pinion gear via the rib, and the seizure of the differential gear mechanism can be further suppressed.

  In the differential device of the present invention described above, the differential gear mechanism includes a differential pinion shaft that supports the differential pinion gear so that the differential pinion gear can rotate, and the differential case includes a pinion shaft into which the differential pinion shaft is inserted. It is preferable that a mounting portion is provided, and that the rib is formed so as to reach the pinion shaft mounting portion from an end portion of the oil groove.

  According to such a configuration, it is possible to make the lubricating oil reach the outer peripheral side (back side) of the differential pinion gear more reliably and suppress the seizure of the differential gear mechanism.

  The differential apparatus of the present invention described above has a flow path between ribs formed by arranging the ribs so as to make a pair with a predetermined interval, and the flow path between the ribs follows the oil groove. It is preferable that it is formed.

  According to such a configuration, the lubricating oil supplied via the oil groove can be reliably supplied via the inter-rib channel.

  In the above-described differential device of the present invention, the differential case rotates about the axis of the drive shaft, the rib is at least on the extension line of the oil groove, and the differential case is on the front side in the rotational direction. It is preferable that it is provided at this position.

  In such a configuration, the lubricating oil flowing from the oil groove toward the rib flows along the rib without being separated from the rib due to the influence of centrifugal force acting on the lubricating oil as the differential case rotates. . Therefore, according to the differential device of the present invention, the lubricating oil can be caused to reach the outer peripheral side (back side) of the differential pinion gear from the end of the oil groove to prevent the seizure of the differential gear mechanism.

  ADVANTAGE OF THE INVENTION According to this invention, the differential apparatus which can suppress the burning of a differential gear mechanism more reliably can be provided, aiming at weight reduction of a differential case.

It is sectional drawing which shows the differential apparatus connected to the output shaft of the transmission. (A), (b) is sectional drawing which shows the differential case which comprises the differential apparatus of FIG. 3, respectively. It is a perspective view which shows the differential case shown in FIG.

  A differential apparatus 10 according to an embodiment of the present invention will be described in detail with reference to the drawings. The differential device 10 operates by receiving power from an output shaft 2 of a transmission (not shown) such as a belt type continuously variable transmission (CVT). Specifically, as shown in FIG. 1, the differential device 10 includes an output gear 4 provided at an end portion of the output shaft 2 of the transmission and a diff ring gear 12 provided at the outer peripheral portion of the differential device 10. Meshed. The differential device 10 transmits the power transmitted via the output gear 4 and the differential ring gear 12 to the drive shafts 14 and 14 via the differential gear mechanism 16 provided in the differential case 18 to drive the wheels. be able to. Hereinafter, the differential apparatus 10 will be described in more detail.

  As shown in FIG. 1, the differential device 10 includes a differential gear mechanism 16, a differential case 18 that accommodates the differential gear mechanism 16, and a differential housing 60 that accommodates the differential case 18 while being rotatably supported. It has. The differential gear mechanism 16 has a pair of differential side gears 17 and 17 connected to the left and right drive shafts 14 and 14. The drive shafts 14 and 14 and the differential side gears 17 and 17 are integrated by spline fitting.

  Further, the differential gear mechanism 16 has a pair of differential pinion gears 20, 20 arranged vertically. The differential pinion gears 20, 20 mesh with differential side gears 17, 17 that are disposed opposite to each other in the illustrated state. The differential pinion gears 20 and 20 are connected to both ends of the differential pinion shaft 22 and are arranged between the differential side gears 17 and 17.

  The differential housing 60 is obtained by integrating a left housing portion 62 and a right housing portion 64 with a fastener such as a bolt. Boss portions 66 and 68 are formed in the left housing portion 62 and the right housing portion 64.

  As shown in FIGS. 1-3, the differential case 18 integrates the left case part 18a and the right case part 18b. As shown in FIG. 1, the differential case 18 is a bearing provided between the boss portions 24 and 26 formed on the left case portion 18a and the right case portion 18b and the boss portions 66 and 68 of the differential housing 60 described above. 48a and 48b are supported so as to be freely rotatable. Further, in the differential case 18, the differential ring gear 12 is attached at a position displaced toward the left case portion 18a. The diffring gear 12 meshes with the output gear 4 attached to one end portion of the output shaft 2 of the transmission as described above. Therefore, the differential case 18 can rotate in the differential housing 60 by receiving power from the continuously variable transmission.

  As shown in FIG. 1, the above-described differential pinion shaft 22 is sandwiched between the left case portion 18 a and the right case portion 18 b. Specifically, by integrating the left case portion 18a and the right case portion 18b, pinion shaft mounting portions 28 and 30 each having a substantially circular through hole are formed at a boundary portion therebetween. The differential pinion shaft 22 is sandwiched and held between the pinion shaft mounting portions 28 and 30. Therefore, the differential pinion shaft 22 rotates in conjunction with the rotation of the differential case 18. A housing space 50 for housing the above-described differential gear mechanism 16 is formed inside the differential case 18.

  Moreover, as shown in FIG. 1 etc., the differential case 18 has shaft insertion parts 52 and 54 in the left case part 18a and the right case part 18b. The shaft insertion portions 52 and 54 are portions into which the drive shafts 14 and 14 are inserted, respectively, and communicate with the accommodation space 50. The shaft insertion portions 52 and 54 can support the drive shafts 14 and 14 inserted from the outside of the differential case 18 toward the inside of the accommodation space 50 so as to be rotatable while sliding.

  As shown in FIG. 2 and the like, oil grooves 32 and 34 are formed on the inner peripheral surfaces of the shaft insertion portions 52 and 54. The oil grooves 32 and 34 are formed so as to communicate from one end side (accommodating space 50 side) of the shaft insertion portions 52 and 54 toward the other end side (outside). The oil grooves 32 and 34 extend in the axial direction of the drive shafts 14 and 14 inserted in the shaft insertion portions 52 and 54. Although only one oil groove 32, 34 may be provided in the shaft insertion portions 52, 54, the oil grooves 32, 34 are provided at substantially equal intervals at a plurality of circumferential positions (for example, four locations) of the shaft insertion portions 52, 54. It is desirable.

  The differential case 18 includes ribs 36 and 38 and ribs 40 and 42 in the accommodation space 50. The ribs 36 and 38 are formed so as to reach from the end of the oil groove 32 on the shaft insertion portion 52 side to the outer peripheral side (rear side) of the differential pinion gears 20 and 20 disposed in the substantially central portion of the accommodation space 50. Has been. The ribs 36 and 38 reach the pinion shaft mounting portion 28. The ribs 36 and 38 are arranged to make a pair with a predetermined interval. Specifically, the ribs 36 and 38 are spaced at the same interval as the width of the oil groove 32. An inter-rib channel 44 is formed between the ribs 36 and 38. The inter-rib channel 44 is formed to continue to the oil groove 32. Therefore, the lubricating oil that has flowed through the oil groove 32 can be received by the inter-rib channel 44 and reach the pinion shaft mounting portion 28 on the outer peripheral side (back side) of the differential pinion gears 20 and 20.

  The ribs 40 and 42 are configured similarly to the ribs 36 and 38. Specifically, the ribs 40 and 42 are formed so as to reach from the end of the oil groove 34 on the shaft insertion portion 54 side to the pinion shaft mounting portion 30 on the outer peripheral side (back side) of the differential pinion gears 20 and 20. Has been. The ribs 40 and 42 are arranged so as to form a pair with an interval approximately equal to the width of the oil groove 34. An inter-rib channel 46 is formed between the ribs 40 and 42. The inter-rib channel 46 is formed to follow the oil groove 34. Therefore, the lubricating oil that has flowed through the oil groove 34 can be received in the inter-rib flow path 46 and reach the pinion shaft mounting portion 30 on the outer peripheral side (back side) of the differential pinion gears 20, 20.

  As described above, the differential device 10 of the present embodiment is provided with the ribs 36 and 38 and the ribs 40 and 42 in the differential case 18 to increase the strength of the differential case 18. Therefore, the differential apparatus 10 can ensure the strength of the differential case 18 even if the thickness of the differential case 18 is made thinner than that of the prior art. Therefore, the differential device 10 can ensure strength while reducing the weight of the differential case 18.

  Further, as described above, in the differential device 10, the ribs 36 and 38 and the ribs 40 and 42 are formed so as to reach the outer peripheral side (back side) of the differential pinion gear 20 from the end portions of the oil grooves 32 and 34. . Therefore, the lubricating oil supplied through the oil grooves 32 and 34 is made to reach the outer peripheral side of the differential pinion gear 20 through the oil grooves 32 and 34 formed between the ribs 36 and 38 and the ribs 40 and 42. be able to. Therefore, according to the differential device 10 of the present embodiment, the seizure of the differential gear mechanism 16 can be more reliably suppressed.

  As described above, the differential device 10 of the present embodiment is formed such that the ribs 36 and 38 and the ribs 40 and 42 reach the pinion shaft mounting portions 28 and 30 from the end portions of the oil grooves 32 and 34. . Therefore, the lubricating oil can surely reach the outer peripheral side (back side) of the differential pinion gear 20. In the present embodiment, the ribs 36 and 38 and the ribs 40 and 42 are all shown to reach the pinion shaft mounting portions 28 and 30. However, if the lubricating oil can be distributed to the respective portions, these It is good also as a structure which does not reach | attain the pinion shaft mounting parts 28 and 30 about one part or all. Specifically, although some or all of the ribs 36 and 38 and the ribs 40 and 42 do not reach the pinion shaft mounting portions 28 and 30, the lubricating oil reaches the outer peripheral side (back side) of the differential pinion gear 20. In order to achieve this, a structure in which a sufficient position is formed may be used.

  In the differential device 10 of the present embodiment described above, the inter-rib flow paths 44 and 46 formed between the ribs 36 and 38 and the ribs 40 and 42 are formed so as to follow the oil grooves 32 and 34. Therefore, the lubricating oil supplied via the oil grooves 32 and 34 can be reliably supplied via the inter-rib passages 44 and 46. In the present embodiment, the example in which the inter-rib passages 44 and 46 are formed so as to be continuous with the oil grooves 32 and 34 is shown, but the present invention is not limited to this. Specifically, the differential device 10 may be a device in which discontinuous portions are provided between the inter-rib flow paths 44 and 46 and the oil grooves 32 and 34. Even in such a configuration, the lubricating oil supplied through the oil grooves 32 and 34 can be received by the inter-rib passages 44 and 46, so that the lubricating oil can be distributed to the outer peripheral side of the differential pinion gear 20 and seized. It is possible to alleviate the concerns.

  In the differential device 10 described above, the differential case 18 rotates around the axis of the drive shafts 14 and 14. Therefore, it is assumed that centrifugal force acts on the lubricating oil introduced through the oil grooves 32 and 34 when the differential device 10 is operated. Accordingly, the differential device 10 is only the rib 36, 38 and the ribs 40, 42 that are provided at the position on the front side in the rotational direction of the differential case 18, or those that are provided at the position on the rear side in the rotational direction. The height may be lowered. Also in the case of such a configuration, the outer peripheral side (rear side) of the differential pinion gear 20 along the ribs 36 and 40 or the ribs 38 and 42 without separating the lubricating oil supplied via the oil grooves 32 and 34. And the seizure of the differential gear mechanism 16 can be prevented.

  In the present embodiment, the configuration in which the oil grooves 32 and 34 are provided on the inner peripheral surfaces of the shaft insertion portions 52 and 54 is illustrated, but the present invention is not limited to this. Specifically, what corresponds to the oil grooves 32 and 34 may be formed on the outer peripheral surfaces of the drive shafts 14 and 14, and the inner peripheral surfaces of the shaft insertion portions 52 and 54 may be smooth. In addition, oil grooves 32 and 34 may be provided on the inner peripheral surfaces of the shaft insertion portions 52 and 54, and grooves corresponding to the oil grooves 32 and 34 may be formed on the outer peripheral surfaces of the drive shafts 14 and 14. By adopting these configurations, the same effects as those shown in the present embodiment can be obtained.

  In the present embodiment, the configuration in which the oil grooves 32 and 34 are provided on the inner peripheral surfaces of the shaft insertion portions 52 and 54 is illustrated, but the present invention is not limited to this. Specifically, what corresponds to the oil grooves 32 and 34 may be formed on the outer peripheral surfaces of the drive shafts 14 and 14, and the inner peripheral surfaces of the shaft insertion portions 52 and 54 may be smooth. In addition, oil grooves 32 and 34 may be provided on the inner peripheral surfaces of the shaft insertion portions 52 and 54, and grooves corresponding to the oil grooves 32 and 34 may be formed on the outer peripheral surfaces of the drive shafts 14 and 14. By adopting these configurations, the same effects as those shown in the present embodiment can be obtained.

  The present invention is not limited to the embodiments described above and those shown as modifications of each embodiment, and there may be other embodiments from the teaching and spirit thereof without departing from the scope of the claims. This will be easily understood by those skilled in the art.

  The present invention can be applied to, for example, a differential device mounted on an automobile.

10: Differential device 14: Drive shaft 16: Differential gear mechanism 17: Differential side gear 18: Differential case 20: Differential pinion gear 22: Differential pinion shaft 28, 30: Pinion shaft mounting portion 32, 34: Oil groove 36, 38: Rib 40, 42: Rib 44, 46: Channel between ribs 50: Storage space 52, 54: Shaft insertion part

Claims (1)

A differential gear mechanism;
A differential case having an accommodating space for accommodating the differential gear mechanism;
The differential gear mechanism is
A differential side gear connected to one end of a drive shaft that transmits power to the drive wheels;
A differential pinion gear meshed with the differential side gear,
The differential case is
A drive shaft insertion portion that communicates with the accommodation space and supports the drive shaft inserted into the accommodation space so as to be rotatable while sliding;
An oil groove extending in the axial direction of the drive shaft is provided on one or both of the inner peripheral surface of the drive shaft insertion portion and the drive shaft,
A differential device, wherein a rib formed so as to reach an outer peripheral side of the differential pinion gear from an end portion of the oil groove is provided in the differential case.

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