JP2017115912A - Lubrication structure for differential device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cool a bearing periphery of an input shaft member of a differential device without requiring any additional component.SOLUTION: A lubrication structure of a differential device according to the present invention comprises: a first oil hole 40 which has an opening part 40a at a gear part 12G of an input shaft member 12 meshing with a ring gear 16 and extends along an axis of the input shaft member 12; and a second oil hole 42 which communicates with the first oil hole and has an opening part 42a on an outer peripheral surface of the input shaft member. A spacer 36 arranged between a first bearing 28 and a second bearing 30 arranged side by side along the axis of the input shaft member to bear the input shaft member rotatably comprises a cut part 36a provided to communicate with the opening part 42a of the second oil hole 42.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lubricating structure for a differential device.

  Conventionally, a differential device is mounted on a vehicle in order to perform a differential operation with respect to the left and right wheels of the vehicle. In the differential device, a rotational driving force from a driving source (for example, an internal combustion engine) is transmitted to a drive pinion shaft that is an input shaft member. The rotational driving force is input to the ring gear that meshes with the drive pinion gear of the drive pinion shaft, and is further transmitted differentially to the left and right wheels via the drive shaft by the operation of the differential mechanism including the differential case, the side gear, and the pinion gear. Is done.

  In such a differential device, frictional heat is generated at each bearing portion of the input shaft member, and such heat may adversely affect the sealing performance of an oil seal provided at one end portion of the input shaft member, for example. Concerned. Accordingly, various cooling methods or cooling structures have been proposed to reduce or eliminate such adverse effects. For example, in Patent Document 1, a plurality of fins are provided in association with the input shaft member of the differential device, and the fins are rotated along with the rotation of the input shaft member, so that the differential device is blown and the temperature of the lubricating oil is appropriately adjusted. Disclose keeping things.

JP 2008-190582 A

  However, in the configuration of Patent Document 1, it is necessary to newly provide fins. Further, since such fins are rotated, it is necessary to newly secure a space for mounting them, and there is a problem in mountability.

  Therefore, an object of the present invention is to provide a lubrication structure for a differential device that can cool the periphery of a bearing of an input shaft member without requiring additional parts.

According to one aspect of the invention,
A differential gear lubrication structure in which a ring gear to which rotational driving force is input from an input shaft member and a differential mechanism including a differential case attached to the ring gear is housed in a differential carrier,
A first oil hole extending in the axial direction of the input shaft member, the first oil hole having an opening in a gear portion of the input shaft member meshing with the ring gear;
A second oil hole communicating with the first oil hole and having an opening on an outer peripheral surface of the input shaft member;
A spacer disposed between the first bearing and the second bearing that rotatably supports the input shaft member side by side in the axial direction of the input shaft member, the spacer being disposed in the opening of the second oil hole There is provided a lubricating structure for a differential device, including a spacer having a notch or a hole provided to communicate with each other.

  According to the lubrication structure of the differential device according to the one aspect of the present invention, inflow of the lubricating oil into the first oil hole of the input shaft member is promoted as the ring gear and the differential carrier rotate, and the second oil hole and Lubricating oil can be supplied between the first bearing and the second bearing through the notch or hole of the spacer. Therefore, according to one aspect of the present invention, an excellent effect is achieved that the periphery of the bearing of the input shaft member can be cooled without requiring additional components.

It is sectional drawing of the front differential apparatus with which the lubrication structure of the differential apparatus which concerns on one Embodiment of this invention was applied. FIG. 2 is a partial cross-sectional view of a drive pinion shaft in the front differential device of FIG. 1. It is sectional drawing of the spacer in the front differential apparatus of FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  A lubrication structure for a differential apparatus according to an embodiment of the present invention is applied to a front differential apparatus 10 that is a differential apparatus. The front differential device 10 can be used in, for example, a four-wheel drive vehicle. Hereinafter, the front differential apparatus 10 is demonstrated as what is employ | adopted as the four-wheel drive vehicle. However, the differential apparatus to which the present invention is applied is not limited to the front differential apparatus as shown in FIG. The present invention can be applied to various differential devices, and may be applied to a rear differential device.

  In the front differential device 10, first, rotational torque (rotational driving force) from a power source (not shown) (not shown) is transmitted to a drive pinion shaft 12, which is an input shaft member, via a propeller shaft (not shown). This rotational torque is input to the ring gear 16 that meshes with the drive pinion gear 14 via the drive pinion gear 14 located on the vehicle front end side of the drive pinion shaft 12. The front differential device 10 includes a differential case 18, and a ring gear 16 is attached to the differential case 18. In the differential case 18, a pair of side gears (bevel gears) 20a and 20b and a pair of pinion gears 22a and 22b are rotatably supported, respectively, and the side gears 20a and 20b are engaged with the pinion gears 22a and 22b. 23 is configured. Although not shown, rotational torque is transmitted from the front differential device 10 to the left and right front wheels through the left and right drive shafts so as to be differentially rotatable.

  The front differential device 10 includes a differential case 24 that is a differential carrier that accommodates the ring gear 16, the differential mechanism 23, and the like, and a bearing case 26 that is integrally provided in the differential case 24. A pair of tapered roller bearings 28 and 30 are provided. The drive pinion shaft 12 is supported by the pair of tapered roller bearings 28 and 30 so as to be rotatable around the rotation axis 12C. Note that the rotation axis of the ring gear 16 rotatably supported by the differential case 24 and the rotation axis of the drive pinion shaft 12 cross each other in three dimensions. Hereinafter, of the pair of tapered roller bearings 28 and 30, the tapered roller bearing 28 closer to the ring gear 16 is referred to as a first bearing, and the other tapered roller bearing 30 is referred to as a second bearing 30.

  The first bearing 28 includes an outer ring 28a, an inner ring 28b, and a tapered roller 28c. The second bearing 30 includes an outer ring 30a, an inner ring 30b, and a tapered roller 30c.

  The drive pinion gear 14 that meshes with the ring gear 16 is formed at one end of the drive pinion shaft 12 on the ring gear 16 side, and a flange joint 32 is fixed to the other end of the drive pinion shaft 12 via a nut 34. On the outer peripheral surface of the drive pinion shaft 12, a spacer (spacer) 36 formed by plastic working is fitted (arranged) between the inner ring 28b of the first bearing 28 and the inner ring 30b of the second bearing 30. ). The stepped portion 12a of the drive pinion shaft 12 is in contact with the end surface of the inner ring 28b of the first bearing 28 on the ring gear 16 side, and the spacer 36 is in contact with each end surface between the inner rings 28b and 30b of both the bearings 28 and 30. The flange joint 32 abuts on the end surface of the inner ring 30b of the two bearings 30 opposite to the ring gear 16, and the preload applied to the first and second bearings 28 and 30 can be adjusted by the tightening degree of the nut 34. Yes. An oil seal 38 is fitted and fixed at a position opposite to the ring gear 16 of the second bearing 30. The oil seal 38 is in sliding contact with the outer peripheral surface of the flange joint 32.

  The configuration described above is the same in the conventional front differential apparatus. Furthermore, the front differential apparatus 10 of the present embodiment has a characteristic configuration.

  First, as shown in FIGS. 1 and 2, the drive pinion shaft 12 is provided with a first oil hole 40 extending in the direction of the rotation axis 12C (axial direction). The first oil hole 40 has an opening 40a in an end portion including the drive pinion gear 14 that meshes with the ring gear 16 (hereinafter, gear portion 12G). The opening 40a is located on the rotation axis 12C of the drive pinion shaft 12, and has a circular shape centered around the rotation axis 12C.

  Further, the drive pinion shaft 12 is provided with a second oil hole 42 as shown in FIGS. 1 and 2. The second oil hole 42 communicates with the first oil hole 40 of the drive pinion shaft 12 and extends in the radial direction about the rotation axis 12C. The second oil hole 42 has an opening 42 a on the outer peripheral surface of the drive pinion shaft 12. In the front differential device 10 of the present embodiment, as shown in FIG. 1, the opening 42 a of the second oil hole 42 is located directly inside the second bearing 30 and directly below the second bearing 30.

  Further, as clearly shown in FIG. 2, a groove 44 is formed in the outer peripheral surface of the drive pinion shaft 12. The groove 44 extends in the axial direction of the drive pinion shaft 12, and in particular, one end thereof extends to the opening 42 a of the second oil hole 42. Thus, the groove 44 is formed so that the fluid from the second oil hole 42, that is, the lubricating oil can flow. While this groove 44 reaches the opening 42a of the second oil hole 42, it extends toward the gear portion 12G in the axial direction of the drive pinion shaft 12 up to a predetermined position. In the front differential device 10 of the present embodiment, this predetermined position is a position beyond the ring gear side end surface of the second bearing 30 in the axial direction of the drive pinion shaft 12. That is, this predetermined position is determined so that oil can be supplied to the second bearing 30 from the ring gear side, as will be more apparent from the description to be described later.

  A cutout portion 36 a is provided in the substantially cylindrical spacer 36 so as to correspond to a predetermined position of the groove 44. The notch 36a is positioned so as to be located substantially radially outside the ring gear side end of the groove 44 located at the predetermined position in the assembled state of the front differential device 10 of FIG. That is, the notch 36 a is provided so as to communicate with the opening 42 a of the second oil hole 42 through the groove 44. However, this notch portion 36a is not provided at the axial center portion 36b that receives a relatively large force (load), but is provided at the end portion thereof, particularly at the end portion opposite to the ring gear 16 side. ing.

  Effects of the front differential device 10 having the above-described configuration will be described.

  When the front differential device 10 is operating, the drive pinion shaft 12, the ring gear 16, the differential case 18 and the like are rotating. At this time, the lubricating oil that has been scooped up or sprung up by the rotation of the differential case 18 or the like faces the gear portion 12G of the drive pinion shaft 12, and enters the first oil hole 40 from the opening 40a of the drive pinion shaft 12. Lubricant oil flows (see arrow a11 in FIG. 1). The lubricating oil in the first oil hole 40 is supplied to the second oil hole 42 by the centrifugal force as the drive pinion shaft 12 rotates (see arrow a12 in FIG. 1). The lubricating oil flows toward the outer side in the radial direction through the second oil hole 42 and reaches the outer peripheral surface of the drive pinion shaft 12. First, the lubricating oil reaches the inner side in the radial direction of the second bearing 30 to directly move the second bearing 30. Can be cooled to. Further, the lubricating oil that has exited the opening 42a of the second oil hole 42 flows through the groove 44 (see arrow a13 in FIG. 1), reaches the inside in the radial direction of the spacer 36, and reaches the spacer 36 through the notch 36a. It flows out radially outward (see arrow a14 in FIG. 1). Thereby, the 2nd bearing 30 can be cooled further.

  On the other hand, as schematically shown by arrows a21, a22, a23, and a24 in FIG. 1, the lubricating oil is supplied to the first bearing 28 and the second bearing 30 by the lifting action of the lubricating oil by the ring gear 16 and the like. They are cooled and then returned to the oil sump below the ring gear 16. The lubricating oil that reaches the periphery of the second bearing 30 through the notch 36a of the spacer 36 so as to merge with the flow of the lubricating oil can also return to the oil reservoir and be circulated appropriately. .

  Since the lubricating oil is supplied to the periphery of the second bearing 30 in this way and the periphery of the second bearing can be suitably cooled, heat transfer to the oil seal 38 located near the second bearing 30 is suppressed. can do. Therefore, damage due to heat of the oil seal can be suppressed.

  As described above, in the front differential device 10 of the present embodiment, the drive pinion shaft 12 is provided with the first oil hole 40, the second oil hole 42, and the groove 44 as a new configuration, and the spacer 36 is further cut. Since only the notch portion 36a is provided, there is no need for an additional member and there is no connection with a special design change. Therefore, the above-described configuration according to the embodiment of the present invention can be easily applied to various differential devices. In addition, since only the holes are formed in this way, the drive pinion shaft 12 and the spacer 36 can be reduced in weight.

  In the above embodiment, the second oil hole is formed so as to have an opening portion on the radially inner side of the second bearing, but the formation position of the second oil hole is not limited to this. For example, the second oil hole may be provided so as to have an opening at an arbitrary position between the first bearing and the second bearing in the axial direction of the drive pinion shaft 12. Then, instead of the notch portion of the spacer, a hole (a hole such as a circle, an ellipse, or a square) may be provided in the spacer. Further, the first bearing may be positively cooled with lubricating oil reaching the outer side in the radial direction of the spacer via the drive pinion shaft and the spacer. However, preferably, as in the above embodiment, the second oil hole and the notch (or hole) of the spacer are preferably formed so as to suitably cool the periphery of the second bearing.

  Embodiments of the present invention are not limited to the embodiments described above. All modifications, applications, and equivalents included in the spirit of the present invention defined by the claims are included in the present invention.

DESCRIPTION OF SYMBOLS 10 Front differential apparatus 12 Drive pinion shaft 12G Gear part 14 Drive pinion gear 16 Ring gear 18 Differential case 20a, 20b Side gear 22a, 22b Pinion gear 24 Differential case (Differential carrier)
28, 30 Tapered roller bearing 36 Spacer 36a Notch 38 Oil seal 40 First oil hole 42 Second oil hole 44 Groove

Claims (1)

A differential gear lubrication structure in which a ring gear to which rotational driving force is input from an input shaft member and a differential mechanism including a differential case attached to the ring gear is housed in a differential carrier,
A first oil hole extending in the axial direction of the input shaft member, the first oil hole having an opening in a gear portion of the input shaft member meshing with the ring gear;
A second oil hole communicating with the first oil hole and having an opening on an outer peripheral surface of the input shaft member;
A spacer disposed between the first bearing and the second bearing that rotatably supports the input shaft member side by side in the axial direction of the input shaft member, the spacer being disposed in the opening of the second oil hole A lubricating structure for a differential device, comprising a spacer having a notch or a hole provided so as to communicate with each other.

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