JP2016033404A - Lubrication structure of differential gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubrication structure of a differential gear which can favorably supply a lubricant to the differential gear even at the high-speed rotation of a ring gear.SOLUTION: An oil catch part 37 is formed at an upper part of a space 32 in a position above a differential case 5 of a differential gear 3 being an upstream side of a rotating direction of a ring gear 21 with respect to a linear line L. The oil catch part 37 is formed as a recessed part which is recessed to a vehicle width direction by recessing an internal face 38 of a transaxle case 4. A first extension part 39, a second extension part 40, and a third extension part 41 which extend to the vehicle width direction from the internal face 38 of the transaxle case 4 are formed at the surroundings of the oil catch part 37.SELECTED DRAWING: Figure 2

Description

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

  FF (front engine / front drive) vehicles often employ so-called transaxles, in which a differential gear (differential device) is built in a transaxle case together with a transmission. In the on-vehicle state of the transaxle, the differential gear is usually disposed at a lower position than the transmission.

  The differential gear includes a ring gear to which driving force is transmitted from the transmission, and a differential case that rotates integrally with the ring gear. Oil (lubricating oil) is enclosed in the transaxle case, and the oil is stored at the bottom of the space that houses the differential gear. When the ring gear and the differential case rotate, the stored oil is scraped up by the ring gear and the differential case, and is sprayed to be supplied to a bearing that rotatably supports the differential case.

  If the amount of stored oil is large, the oil becomes the rotational resistance (stirring resistance) of the ring gear and differential case, resulting in deterioration of fuel consumption and heat generation due to torque loss. Therefore, it has been proposed to form an oil tank capable of storing oil scraped up by a ring gear (differential drive gear) and a guide for guiding oil to the oil tank in the transaxle case (for example, , See Patent Document 1). According to this proposed configuration, when the ring gear rotates, the oil scooped up by the ring gear flows into the oil tank along the guide, the oil level of the oil reservoir in which the ring gear is immersed is lowered, and the rotation resistance of the ring gear is reduced. Can be small.

Utility Model Registration No. 2584081

  However, when the vehicle is traveling at high speed, the oil is vigorously scooped up by the ring gear rotating at high speed, and most of the scooped up oil flows into the oil tank. Therefore, if the vehicle continues to travel at a high speed, the amount of oil in the oil pool in which the ring gear is immersed becomes insufficient, the lubrication of each part of the differential gear becomes poor, and the seizure of the gear may occur.

  An object of the present invention is to provide a differential gear lubrication structure capable of satisfactorily supplying lubricating oil to the differential gear even during high-speed rotation of the ring gear.

  In order to achieve the above-described object, a differential gear lubrication structure according to the present invention includes a differential case including a drive shaft inserted therein and a ring gear fixed to the differential case so as not to rotate relative to each other and to which a driving force is input from a transmission. A structure for lubricating the gear with oil, in which the oil is enclosed in the case that houses the differential gear, and the inner surface of the case is above and below the differential case and through the center of rotation of the ring gear in the vertical direction. A concave portion that is recessed in the axial direction of the ring gear is formed at a position upstream of the rotation direction of the ring gear with respect to a straight line that extends in the first direction, and a first extending portion that extends in the axial direction from the inner surface, An extension part and a third extension part are formed, and the first extension part is provided on the downstream side in the rotation direction with respect to the recess, The end is disposed at a position closer to the differential case than the recess, extends from the lower end in a direction away from the differential case, and the second extension portion is spaced from the lower end portion of the first extension portion on the differential case side with respect to the recess. The third extending part is provided between the first extending part and the second extending part, and the height from the inner surface of the case is increased. Is smaller than the first extension part and the second extension part.

  According to this configuration, the ring gear axis line is formed by denting the inner surface of the case at a position upstream of the differential case and upstream of the straight line extending in the vertical direction through the rotation center of the ring gear. A recess that is recessed in the direction is formed. And the 1st extension part extended in the direction away from a differential case from the lower end arrange | positioned in the position closer to a differential case than a recessed part is formed in the downstream of the rotation direction of the ring gear with respect to the recessed part.

  Therefore, when the ring gear rotates at a low speed, a part of the oil (lubricating oil) scooped up from the oil sump at the bottom of the case by the ring gear hits the first extension part and flows into the recess from the first extension part. While oil flows into the recess, the oil flows down from the recess due to its own weight. At this time, the amount of oil flowing into the recess is large and the amount exceeds the amount of oil flowing down from the recess, so that the oil is stored in the recess.

  On the other hand, when the ring gear rotates at high speed, most of the oil that is scraped from the oil sump at the bottom of the case by the ring gear scatters above the first extension, for example, in the transmission housed in the case together with the differential gear. Supplied. At this time, the amount of oil flowing into the recess is small, the amount is less than the amount of oil flowing down from the recess, and the amount of oil in the recess gradually decreases.

  On the differential case side with respect to the concave portion, the second extending portion is provided with a space from the lower end portion of the first extending portion. The second extending portion is inclined so as to approach the rotation center of the ring gear toward the lower end. In addition, a third extension portion is provided between the first extension portion and the second extension portion. The third extending portion has a height from the inner surface of the case that is smaller than the height from the inner surfaces of the first extending portion and the second extending portion. Therefore, the oil flowing down from the concave portion flows on the third extending portion, and flows down from the tip of the third extending portion through between the first extending portion and the second extending portion. Since the second extending portion is inclined so as to approach the rotation center of the ring gear, the oil flowing down from the tip of the second extending portion is guided to the second extending portion and directed toward the rotation center of the ring gear. , Poured into the differential case. As a result, the supply of oil to the differential gear can be ensured, and the oil can be supplied to the shaft and pinion accommodated in the differential case.

  Therefore, when the ring gear rotates, the oil level (oil amount) of the oil pool in which the ring gear is immersed can be reduced to reduce the rotational resistance of the ring gear, while oil is applied to the differential gear even during high-speed rotation of the ring gear. It can supply satisfactorily and can wet each part of the differential gear well.

  In the case, an oil receiver capable of storing oil and an oil guide for guiding the oil scattered from the ring gear to the oil receiver when the ring gear rotates are formed above the recess, and the recess side with respect to the first extension portion An oil return path through which oil returned from the oil receiver side to the differential gear side may be formed on the opposite side.

  According to this structure, the oil which splashes above the 1st extension part can be received with an oil receiver. Further, oil flowing from the oil receiver to the differential gear side and oil flowing down without being received by the oil receiver can be supplied to the differential gear through the oil return path. As a result, the amount of oil supplied to the differential gear can be increased, and each part of the differential gear can be wetted well.

  According to the present invention, when the ring gear is rotated, the oil level of the oil reservoir in which the ring gear is immersed can be lowered to reduce the rotational resistance of the ring gear, and the differential gear can be lubricated with the differential gear even when the ring gear rotates at high speed. Can be supplied satisfactorily, and each part of the differential gear can be wetted well.

It is sectional drawing which shows a part of transaxle to which the oil storage structure which concerns on one Embodiment of this invention was applied. It is an illustration sectional view of a transaxle case.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view showing a part of a transaxle 1 to which an oil storage structure according to an embodiment of the present invention is applied.

  The transaxle 1 has a transmission 2 and a differential gear 3 built in a transaxle case 4.

  The transmission 2 is, for example, a manual transmission (manual transmission).

  The differential gear 3 includes a differential case 5. A gear housing space 6 and shaft insertion spaces 7 and 8 are formed inside the differential case 5. The shaft insertion spaces 7 and 8 are respectively formed on one side and the other side of the gear housing space 6 in the vehicle width direction and communicate with the gear housing space 6.

  A shaft 9 extending in a direction orthogonal to the vehicle width direction passes through the gear housing space 6. Both ends of the shaft 9 are fixedly supported by the differential case 5. Two pinion gears 10 and 11 are rotatably supported on the shaft 9. The pinion gears 10 and 11 are bevel gears. Further, two side gears 12 and 13 are accommodated in the gear accommodating space 6. The side gears 12 and 13 are bevel gears, are arranged apart from each other in the vehicle width direction, and mesh with both the pinion gears 10 and 11.

  Drive shafts 14 and 15 are inserted into the shaft insertion spaces 7 and 8, respectively. The drive shafts 14 and 15 are connected to the side gears 12 and 13, respectively.

  The differential case 5 has cylindrical portions 16 and 17 that respectively surround the shaft insertion spaces 7 and 8 (providing the shaft insertion spaces 7 and 8 therein). Since the cylindrical portions 16 and 17 are held by the transaxle case 4 via bearings 18 and 19, respectively, the differential case 5 is supported so as to be rotatable around the same rotation center line as the drive shafts 14 and 15.

  In the differential case 5, a flange portion 20 is formed between the one cylindrical portion 16 and the shaft 9 so as to project radially from the outer peripheral surface thereof. A ring gear 21 is fixed to the flange portion 20 so as not to be relatively rotatable. Ring gear 21 meshes with output gear 22 of transmission 2. When the driving force is transmitted from the output gear 22 to the ring gear 21, the differential case 5 and the ring gear 21 rotate integrally.

  In addition, a vehicle speed detection rotor 23 is fitted on the other cylindrical portion 17 at a position closer to the shaft 9 than the bearing 19. The vehicle speed detecting rotor 23 is fixed to the differential case 5 and is provided so as to be rotatable integrally with the differential case 5.

  A vehicle speed sensor 24 is held in the differential case 5. The vehicle speed sensor 24 is composed of an electromagnetic pickup, and is arranged so that a tip portion in which a magnetic pole (not shown) is built is opposed to the outer periphery of the vehicle speed detection rotor 23 in the radial direction.

  FIG. 2 is a schematic cross-sectional view of the transaxle case 4.

  The transaxle case 4 is formed with spaces 31 and 32 for accommodating the transmission 2 and the differential gear 3, respectively.

  By accommodating the transmission 2 and the differential gear 3 in the spaces 31 and 32, respectively, the transmission 2 and the differential gear 3 are arranged side by side in the longitudinal direction of the vehicle.

  In the transaxle case 4, oil guides 33 and 34 are formed at portions extending over the spaces 31 and 32. The oil guides 33 and 34 have a thin plate shape having a width in the axial direction (vehicle width direction) of the ring gear 21 of the differential gear 3. One oil guide 33 extends obliquely upward from the straight line L extending in the vertical direction through the rotation center C of the ring gear 21 of the differential gear 3 toward the space 31 side. The other oil guide 34 extends substantially parallel to the oil guide 33 with an interval in a direction perpendicular to the direction of inclination of the one oil guide 33.

  An oil receiver 35 is provided in the upper part of the space 31. The oil receiver 35 extends in the front-rear direction and the vehicle width direction.

  A differential portion oil guide 36 is formed in the upper portion of the space 32. The differential portion oil guide 36 has a thin plate shape having a width in the axial direction of the ring gear 21, and the upper end is connected to the lower end of the oil guide 34 and extends toward the rotation center C of the ring gear 21.

  Further, in the upper part of the space 32, above the differential case 5 of the differential gear 3, on the side opposite to the space 31 side with respect to the straight line L, in other words, on the upstream side in the rotation direction of the ring gear 21 with respect to the straight line L. An oil catch portion 37 is formed at the position. The oil catch portion 37 is formed as a recess that is recessed in the vehicle width direction by recessing the inner surface 38 of the transaxle case 4.

  Around the oil catch portion 37, a first extension portion 39, a second extension portion 40, and a third extension portion 41 extending in the vehicle width direction from the inner surface 38 of the transaxle case 4 are formed.

  The first extending portion 39 is provided on the space 31 side with respect to the oil catch portion 37. The first extending portion 39 has an upper end connected to the lower end of one of the oil guides 33, and extends so as to be inclined with respect to the straight line L to the side opposite to the space 31. The lower end of the first extension portion 39 is disposed at a position closer to the differential case 5 than the oil catch portion 37.

  The second extending portion 40 is provided below the oil catch portion 37 (on the differential case 5 side) at a distance from the lower end portion of the first extending portion 39 on the side opposite to the space 31 side. The second extending portion 40 is inclined from the lower end edge of the oil catch portion 37 toward the rotation center C.

  The third extending portion 41 is provided between the first extending portion 39 and the second extending portion 40. The third extending portion 41 is smaller in height from the inner surface 38 of the transaxle case 4 than the first extending portion 39 and the second extending portion 40, and the tip 9 is supported by the differential case 5. (See FIG. 1).

  In the transaxle case 4, oil (lubricating oil) for lubricating each part is sealed, and an oil pool is generated at the bottom of the space 32 that houses the differential gear 3. In a state where the rotation of the ring gear 21 is stopped, about half of the differential case 5 and the ring gear 21 are immersed in the oil reservoir.

  When driving force is transmitted from the output gear 22 (see FIG. 1) to the ring gear 21 and the differential case 5 and the ring gear 21 rotate, the oil stored in the bottom of the space 32 is scraped up by the differential case 5 and the ring gear 21. It becomes splash and spreads around it.

  Therefore, when the differential case 5 and the ring gear 21 rotate, the oil level (amount) of oil stored in the bottom of the space 32 can be reduced. As a result, the rotational resistance (stirring resistance) of the differential case 5 and the ring gear 21 can be reduced.

  When the ring gear 21 rotates at a low speed, a part of the oil scooped up from the oil sump at the bottom of the space 32 by the ring gear 21 hits the first extension part 39 and flows into the oil catch part 37 from the first extension part 39. While the oil flows into the oil catch portion 37, the oil flows down from the oil catch portion 37 by its own weight. At this time, the amount of oil flowing into the oil catch portion 37 is large and the amount exceeds the amount of oil flowing down from the oil catch portion 37, so that the oil catch portion 37 is in a state where oil is stored.

  On the other hand, when the ring gear 21 rotates at high speed, most of the oil scooped up by the ring gear 21 passes above the first extension 39 and scatters toward the oil receiver 35 above the oil guide 33. Part of the oil scattered above the oil guide 33 is returned to the space 32 through the oil guides 33, 34 and between the first extending portion 39 and the differential portion oil guide 36. That is, between the oil guides 33 and 34 and between the first extension part 39 and the differential part oil guide 36, an oil return path 42 through which oil returned from the oil receiver 35 side to the differential gear 3 side flows is formed. . The remainder of the oil scattered above the oil guide 33 is received by the oil receiver 35 and supplied to each part of the transmission 2 accommodated in the space 31.

  Further, when the ring gear 21 rotates at a high speed, the amount of oil flowing into the oil catch portion 37 is small, the amount is less than the amount of oil flowing down from the oil catch portion 37, and the amount of oil in the oil catch portion 37 gradually decreases. To do.

  The second extending portion 40 is inclined so as to approach the rotation center of the ring gear 21 toward the lower end. The tip of the third extension 41 is located above the shaft 9 (see FIG. 1) supported by the differential case 5. The oil flowing down from the oil catch portion 37 flows on the third extending portion 41 and flows between the first extending portion 39 and the third extending portion 41 from the tip of the third extending portion 41. . The oil flowing down from the tip of the third extending portion 41 flows toward the rotation center of the ring gear 21 by being guided by the second extending portion 40, and reaches the portion where the shaft 9 of the differential case 5 is provided. Pour down. As a result, the supply of oil to the differential gear 3 can be ensured, and the oil can be supplied to the shaft 9 and the pinion gears 10 and 11 accommodated in the differential case 5.

  Therefore, when the ring gear 21 is rotated, the oil level (oil amount) of the oil reservoir in which the ring gear 21 is immersed can be reduced to reduce the rotational resistance of the ring gear 21. Oil can be supplied satisfactorily to the gear 3, and each part of the differential gear 3 can be wetted well.

  Further, the oil flowing from the oil receiver 35 toward the space 32 and the oil flowing down without being received by the oil receiver 35 can be supplied to the differential gear 3 through the oil return path 42. As a result, the amount of oil supplied to the differential gear 3 can be increased, and each part of the differential gear 3 can be wetted better.

  As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  The transmission 2 is, for example, a manual transmission, but may be an automatic transmission (automatic transmission) or a CVT (continuously variable transmission).

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

2 Transmission 3 Differential gear 4 Transaxle case 5 Differential case 33 Oil guide 35 Oil receiver 37 Oil catch (recess)
38 inner surface 39 first extending portion 40 second extending portion 41 third extending portion 42 oil return path C rotation center L straight line

Claims (2)

A differential gear comprising a differential case through which a drive shaft is inserted and a ring gear fixed to the differential case so as not to rotate relative to the drive shaft and receiving a driving force from a transmission is lubricated with oil,
Oil is enclosed in the case that houses the differential gear,
A recess recessed in the axial direction of the ring gear is formed on the inner surface of the case at a position upstream of the differential case and upstream of the straight line extending in the vertical direction through the center of rotation of the ring gear. Has been
Around the recess, a first extension, a second extension, and a third extension extending from the inner surface in the axial direction are formed,
The first extending portion is provided on the downstream side in the rotation direction with respect to the concave portion, the lower end is disposed at a position closer to the differential case than the concave portion, and extends from the lower end in a direction away from the differential case,
The second extending part is provided on the differential case side with respect to the concave part with a space from the lower end part of the first extending part, and the lower end is inclined to approach the rotation center,
The third extension portion is provided between the first extension portion and the second extension portion, and the height from the inner surface is higher than that of the first extension portion and the second extension portion. Small, differential gear lubrication structure. In the case, an oil receiver capable of storing oil and an oil guide for guiding oil scattered from the ring gear when the ring gear rotates to the oil receiver are formed above the recess.
2. The differential gear according to claim 1, wherein an oil return path through which oil returned from the oil receiver side to the differential gear side flows is formed on a side opposite to the concave portion side with respect to the first extension portion. Lubrication structure.

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