JP2016061333A - Lubrication structure of differential gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure lubrication performance of a bearing supporting a differential case and a bearing supporting a transmission shaft while reducing stirring resistance of a lubricant caused by a final drive gear disposed on the differential case.SOLUTION: As the inside of a transmission case 11 is partitioned into a first space 42 at a side of a differential case 15 and a final driven gear 23, and a second space 43 outside of the first space 42 by a baffle plate 41, a lubricant scraped up by rotation of the differential case 15 and the final driven gear 23 inside of the first space 42, flows out to the second space 43, so that not only an oil level O1 of the lubricant in the first space 42 is lowered and stirring resistance by the rotation of the differential case 15 and the final driven gear 23 is reduced, but also an oil level O2 of the lubricant in the second space 43 is raised, and toughness of aeration of an oil pump 44 to inclination of an oil surface can be improved.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a differential gear lubrication structure that lubricates bearings with a differential case that rotates inside a transmission case and a lubricating oil that is swept up by a final driven gear.

  Lubricant supplied to the chamber from the oil pump through the oil cooler by forming a chamber in the upper part of the transmission case that rotatably supports the inboard part of the differential case via a bearing. Japanese Laid-Open Patent Publication No. 2004-228867 discloses that oil is guided to the bearing by a guide plate and forcedly lubricated.

JP 2008-138780 A

  By the way, the lubricating oil stored at the bottom of the transmission case is agitated by a final driven gear fixed to the outer periphery of the differential case, and the scraped-up lubricating oil is a bearing that supports the differential case in the transmission case, and the transmission shaft is attached to the transmission case. When lubricating by supplying to the bearing to support, if the final driven gear is deeply immersed under the surface of the lubricating oil, there is a problem that the agitation resistance of the lubricating oil increases, and in order to avoid this, the amount of lubricating oil is reduced If the oil level is lowered, there is a problem that when the oil level is inclined, the suction port of the lubricating oil arranged at the bottom of the transmission case is exposed on the oil level, and the oil pump that sucks up the lubricating oil causes aeration.

  The present invention has been made in view of the above-mentioned circumstances, and while ensuring the lubrication performance of the bearing that supports the differential case and the bearing that supports the transmission shaft while reducing the agitation resistance of the lubricating oil by the final drive gear provided in the differential case. The purpose is to do.

  To achieve the above object, according to the first aspect of the present invention, a differential case having a pair of inboard portions that support a pair of inboard shafts, a final driven gear attached to the differential case, and the differential case A transmission shaft and a transmission gear that are arranged above the transmission to transmit driving force to the final driven gear, an oil pump that is arranged above the differential case, and the differential case, the final driven gear, the transmission gear, and the oil pump are accommodated. And a differential gear lubrication structure comprising: a transmission case that stores lubricating oil at a bottom portion; and a pair of first bearings that rotatably support the pair of inboard portions inside the transmission case; By fixing a baffle plate inside the transmission case, the change is made. The interior of the machine case is partitioned into a first space on the differential case and final driven gear side, and a second space outside the first space, and the baffle plate is outside the rotation locus of the differential case and the final driven gear. Along the wall that partitions the first space and the second space, an opening that penetrates the upper portion of the wall and communicates the first space with the second space, and at least from the opening in the second space A lubricating oil guide groove for guiding lubricating oil to one of the first bearings, an arc-shaped first rib formed so as to surround an outer periphery of the final driven gear, and a second rib extending radially outward from the first rib And a lubricating oil suction passage provided radially outside the first rib, and a lubricating oil inlet at a lower end of the lubricating oil suction passage is in the vicinity of the bottom of the second space. Thus, a differential gear lubrication structure is proposed, which opens to a position surrounded by the first rib and the second rib, and a lubricating oil outlet at an upper end of the lubricating oil suction passage communicates with the oil pump. Is done.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, the transmission case includes a first case facing the first space and a second case facing the second space. The second case includes a partition wall that supports the transmission shaft via a second bearing, and a curved surface portion that guides lubricating oil toward the second bearing is provided on an upper portion of the baffle plate. A differential gear lubrication structure is proposed in which the partition wall is formed with a guide portion for guiding the lubricating oil guided by the curved surface portion to the second bearing.

  According to the invention described in claim 3, in addition to the configuration of claim 1 or claim 2, the protruding portion protruding in the axial direction from the baffle plate is fitted into the recess provided in the transmission case. Thus, the baffle plate is fixed to the transmission case, the lubricating oil outlet at the upper end of the lubricating oil suction passage is formed of a tubular member, and the protruding portion and the lubricating oil outlet are mutually sandwiched between the baffle plates. A differential gear lubrication structure is proposed which projects in the opposite direction.

  The lubricating oil guide grooves 13e and 13f and the lubricating oil guide wall 13g of the embodiment correspond to the guide portion of the present invention, and the first ball bearings 16L and 16R of the embodiment correspond to the first bearing of the present invention. The second ball bearings 36 and 37 of the embodiment correspond to the second bearing of the present invention, and the cylindrical portion 41a and the first flat plate portion 41b of the embodiment correspond to the wall portion of the present invention.

  According to the configuration of the first aspect, by fixing the baffle plate inside the transmission case, the transmission case is divided into the first space on the differential case and final driven gear side, and the second space outside the first space. As the differential case and the final driven gear rotate in the first space and the lubricating oil swirled up flows into the second space, the oil level of the lubricating oil in the first space decreases and the differential case and final Not only the stirring resistance due to the rotation of the driven gear is reduced, but also the oil level of the lubricating oil in the second space is increased, so that the toughness of the aeration of the oil pump with respect to the oil surface inclination in the second space is improved.

  In particular, an arc-shaped first rib formed so as to surround the outer periphery of the final driven gear, a second rib extending radially outward from the first rib, and a lubricating oil suction passage provided radially outward of the first rib And a lubricating oil inlet at the lower end of the lubricating oil suction passage opens near the bottom of the second space and is surrounded by the first rib and the second rib, and a lubricating oil outlet at the upper end of the lubricating oil suction passage. Since it communicates with the oil pump, the aeration of the oil pump can be more effectively prevented by suppressing the first oil and the second rib from preventing the oil from leaking near the oil inlet at the lower end of the oil intake passage. be able to.

  In addition, the baffle plate includes at least one of a wall portion along the outside of the rotation locus of the differential case and the final driven gear, an opening that penetrates the upper portion of the wall portion and communicates the first space with the second space, and at least one of the openings in the second space. Since the lubricating oil guide groove that guides the lubricating oil to the first bearing is provided, the lubricating oil scraped up by the differential case and the final driven gear in the first space can be efficiently supplied to the first bearing for lubrication.

  According to the second aspect of the present invention, the transmission case is configured by joining the first case facing the first space and the second case facing the second space at the dividing surface, and the second case has the transmission shaft. A partition wall supported via the second bearing is provided, and a curved surface portion is formed on the upper portion of the baffle plate to guide the lubricating oil toward the second bearing, and the lubricant oil guided by the curved surface portion is provided on the partition wall to the second bearing. Since the guiding part is formed, the differential oil and the final driven gear are supplied with the lubricating oil scraped up inside the baffle plate to the second bearing through the curved part and the guiding part, thereby efficiently lubricating the second bearing. Can do.

  According to the third aspect of the present invention, the baffle plate is fixed to the transmission case by fitting the protruding portion protruding in the axial direction from the baffle plate into the recess provided in the transmission case, and the lubricating oil intake passage The lubricating oil outlet at the upper end is formed of a tubular member, and the protruding portion and the lubricating oil outlet protrude in opposite directions with the baffle plate interposed therebetween. Therefore, the load input to the lubricating oil outlet is passed through the protruding portion of the transmission case. By transmitting directly to the recess and supporting it, the rigidity of the lubricating oil suction passage can be increased and positioning can be performed with high accuracy.

Sectional drawing of the differential gear part of the transmission of a motor vehicle. (Sectional view taken along line 1-1 in FIG. 2) The 2-2 line arrow directional view of FIG. 1 which shows the inside of the 2nd case of a transmission case. The figure which shows the state which removed the baffle plate from FIG. The perspective view of a baffle plate. FIG. 5 is a view in the direction of arrows 5 in FIG. 4. FIG. 6 is a view in the direction of arrows 6 in FIG. 5. FIG. 7 is a view in the direction of arrow 7 in FIG. 5.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, a transmission case 11 of a front engine / front drive automobile is configured by connecting a first case 12 and a second case 13 at split surfaces 12 a and 13 a, and a bottom portion of the transmission case 11. The differential gear 14 is arranged in The differential case 15 constituting the outer casing of the differential gear 14 includes left and right inboard portions 15a and 15b. The left inboard portion 15a is rotatably supported by the first case 12 via a first ball bearing 16L. The right inboard portion 15b is rotatably supported by the second case 13 via the first ball bearing 16R.

  The left inboard shaft 17L rotatably supported by the left inboard portion 15a penetrates the first case 12 from the inside to the outside through the seal member 18L and is inserted into the differential case 15. A differential side gear 19L is fixed to the right end. The right inboard shaft 17R rotatably supported by the right inboard portion 15b penetrates the second case 13 from the inside to the outside via the seal member 18R and is inserted into the differential case 15. A differential side gear 19R is fixed to the left end. A pair of differential pinions 22 and 22 meshing with the left and right differential side gears 19L and 19R are rotatably supported by a pinion shaft 21 that passes through the differential case 15 in the radial direction and is fixed by a pin 20. A final driven gear 23 is fixed to the outer periphery of the differential case 15 with bolts 24... And the rotation surface of the final driven gear 23 is located on the split surfaces 12 a and 13 a of the first case 12 and the second case 13.

  FIG. 2 is a view of the inside of the transmission case 11 as viewed from the split surface 13a side of the second case 13, and above the differential gear 14, a plurality of transmission shafts 30 to 30 having a plurality of transmission gears 25 to 29 on the outer periphery. 33 is rotatably supported by the partition wall 13b of the second case 13 via second ball bearings 34 to 37, respectively. The transmission gear 28 of the transmission shaft 32 is a final drive gear, and the final drive gear meshes with the final driven gear 23 of the differential case 15.

  As shown in FIGS. 2 and 4 to 7, a synthetic resin baffle plate 41 is attached to the lower portion of the transmission case 11 so as to cover the side surfaces of the differential case 15 and the final driven gear 23 on the second case 13 side. . The baffle plate 41 includes a tapered two-step cylindrical cylindrical portion 41 a that covers the outer side of the rotation locus of the right half of the differential case 15, and extends radially outward from the left end of the cylindrical portion 41 a and extends to the right side of the final driven gear 23. An annular first flat plate portion 41b covering the outer side of the rotation trajectory of the surface, a partial arc-shaped first rib 41c protruding in the axial direction from a part of the outer periphery of the first flat plate portion 41b, and the first flat plate portion 41b. A second flat plate portion 41d extending outward in the radial direction from the part of the outer periphery beyond the first rib 41c. The first rib 41 c is disposed so as to cover a part of the outer peripheral surface of the final driven gear 23.

  The lower portion of the transmission case 11 is partitioned by the baffle plate 41 into a first space 42 on the first case 12 side and a second space 43 on the second case 13 side, and the differential case 15 and the final driven gear 23 are in the first space. 42 (see FIG. 1).

  Three projecting portions 41e... Project from the first flat plate portion 41b toward the second case 13, and one projecting portion 41f projects from the second flat plate portion 41d toward the second case 13. These protrusions 41e..., 41f are respectively fitted into a total of four recesses 13c... 13d (see FIG. 3) formed in the second case 13, so that the baffle plate 41 is supported by the second case 13. .

  A rectangular opening 41g passes through the upper portion of the first flat plate portion 41b, and trough-like lubricating oil extends in the axial direction from the vicinity of the opening 41g along the upper surface of the cylindrical portion 41a toward the second case 13 side. A guide groove 41h is formed. The tip of the lubricating oil guide groove 41h that is inclined obliquely downward from the vicinity of the opening 41g faces the ball bearing 16R that supports the right inboard portion 15b on the second case 13.

  A square cylindrical lubricating oil suction passage 41i is integrally formed on the side surface of the second flat plate portion 41d on the second case 13 side, and the lubricating oil inlet 41j at the lower end of the lubricating oil suction passage 41i is the bottom of the transmission case 11. It faces the approximate center. A rectangular second rib 41k protrudes radially outward from the radially outer surface of the first rib 41c, and the lubricating oil inlet 41j is formed on the bottom wall of the transmission case 11, the first rib 41c, and the second rib 41k. Open in the enclosed position. A lubricating oil outlet 41m at the upper end of the lubricating oil suction passage 41i is a pipe-shaped member extending toward the first case 12, and is coaxial with one protruding portion 41f and opposite to each other across the second flat plate portion 41d. Protrusively.

  A lubricating oil outlet 41m of the lubricating oil suction passage 41i of the baffle plate 41 is connected to an oil pump 44 (see FIG. 2) disposed above the differential gear 14 via a lubricating oil suction passage (not shown).

  A triangular protrusion 41n protrudes from the end of the first rib 41c near the lubricating oil outlet 41m toward the first case 12, and a triangular protrusion protrudes from the radially outer end of the first flat plate portion 41b near the opening 41g. The portion 41o protrudes toward the first case 12 side. These convex portions 41n and 41o are in contact with the inner surface of the first case 12, and prevent the four protruding portions 41e..., 41f from coming out of the four concave portions 13c. Position in the case 11.

  A curved surface portion 41p (see FIGS. 2, 4 and 5) whose diameter gradually increases from the cylindrical portion 41a toward the first flat plate portion 41b is formed on the upper portion of the baffle plate 41. The second ball bearings 36 and 37 of the transmission shafts 32 and 33 are located on the radially outer side. Lubricating oil guide grooves 13e,..., 13f extend radially outward from the second ball bearings 36, 37 of the transmission shafts 32, 33 in the partition wall 13b of the second case 13. A lubricating oil guide wall 13g protrudes along the upper portion of the lubricating oil guide groove 13f facing the second ball bearing 37 of the transmission shaft 33.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  A first space 42 on the left side that covers the differential case 15 and the final driven gear 23 and a second space 43 on the right side thereof are partitioned by a baffle plate 41 disposed at the bottom of the transmission case 11 (see FIG. 1). Since the baffle plate 41 includes the lubricating oil inlet 41j facing the bottom of the second space 43, when the oil pump 44 disposed inside the transmission case 11 is operated, the lubricating oil at the bottom of the second space 43 is moved to the lubricating oil inlet. 41j, the lubricating oil suction passage 41i, the lubricating oil outlet 41m, and a strainer (not shown) are sucked into the oil pump 44, supplied from the oil pump 44 to each lubricated portion in the transmission case 11, and rotate. As the differential case 15 and the final driven gear 23 scoop up the lubricant stored in the bottom of the first space 42, the differential case 15 and the final driven gear 23 are scattered. The lubricated section of the vicinity of the differential gear 14 are lubricated by the lubricating oil.

  Since the lubricating oil in the first space 42 is scattered by the differential case 15 and the final driven gear 23 and flows out into the second space 43, the oil level O1 in the first space 42 is lower than the oil level O2 in the second space 43 (FIG. 1). This not only reduces the stirring resistance at which the differential case 15 and the final driven gear 23 rotating in the first space 42 stir the lubricating oil, but also increases the oil level O2 in the second space 43 where the lubricating oil inlet 41j exists. When the oil level of the lubricating oil stored in the second space 43 is inclined, the lubricating oil inlet 41j is difficult to be exposed on the oil level, and the aeration of the oil pump 44 is not particularly increased without increasing the amount of the lubricating oil. Is prevented, and the function of supplying lubricating oil is ensured.

  Moreover, the baffle plate 41 includes an arc-shaped first rib 41c formed so as to surround the outer periphery of the final driven gear 23, and a second rib 41k extending radially outward from the first rib 41c, and includes a lubricating oil suction passage 41i. Since the lubricating oil inlet 41j at the lower end of the opening opens near the bottom of the second space 43 and is surrounded by the first ribs 41c and the second ribs 41k, By suppressing with the 1 rib 41c and the 2nd rib 41k, the aeration of the oil pump 44 can be prevented more effectively.

  Further, part of the lubricating oil scraped up by the differential case 15 and the final driven gear 23 in the first space 42 passes through the opening of the first flat plate portion 41b of the baffle plate 41 toward the second space 43, and from there, the lubricating oil guide groove 41h The first ball bearing 16R, which flows down due to gravity and is supplied to the first ball bearing 16R on the right side and is difficult to reach the lubricating oil because it is in the deep position of the second case 13, can be efficiently lubricated. .

  A part of the lubricating oil scraped up by the differential case 15 and the final driven gear 23 in the first space 42 is transferred to the second case 13 by the curved surface portion 41p (FIGS. 2, 4 and 5) of the cylindrical portion 41a of the baffle plate 41. Guided by the partition wall 13b and supplied to the second ball bearing 36 of the transmission shaft 32 via the lubricant guide groove 13e formed in the partition wall 13b, and the lubricant guide groove 13f and the lubricant guide formed in the partition wall 13b. It is supplied to the second ball bearing 37 of the transmission shaft 33 through the wall 13g, and the second ball bearings 36 and 37 can be efficiently lubricated.

  The baffle plate 41 is fixed by fitting four protrusions 41e..., 41f into four recesses 13c... 13d formed in the partition wall 13b of the second case 13, one of which is a protrusion. Since the portion 41f and the lubricating oil outlet 41m of the lubricating oil intake passage 41i protrude in the same direction and opposite to each other across the second flat plate portion 41d of the baffle plate 41, the load input to the lubricating oil outlet 41m By directly transmitting and supporting the concave portion 13d of the second case 13 through the protruding portion 41f, the rigidity of the lubricating oil suction passage 41i can be increased and positioned with high accuracy.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the first bearing of the present invention is not limited to the first ball bearings 16L and 16R of the embodiment, and may be another type of bearing such as a roller bearing.

  The second bearing of the present invention is not limited to the second ball bearings 36 and 37 of the embodiment, and may be another type of bearing such as a roller bearing.

11 Transmission case 12 First case 12a Split surface 13 Second case 13a Split surface 13b Partition wall 13c Recess 13d Recess 13e Lubricating oil guide groove (guide portion)
13f Lubricating oil guide groove (guide part)
13g Lubricating oil guide wall (guide part)
15 Differential case 15a Inboard part 15b Inboard part 16L First ball bearing (first bearing)
16R First ball bearing (first bearing)
17L Inboard shaft 17R Inboard shaft 23 Final driven gear 28 Transmission gear 29 Transmission gear 32 Transmission shaft 33 Transmission shaft 36 Second ball bearing (second bearing)
37 Second ball bearing (second bearing)
41 Baffle plate 41a Cylindrical part (wall part)
41b 1st flat plate part (wall part)
41c First rib 41e Protruding part 41f Protruding part 41g Opening 41h Lubricating oil guide groove 41i Lubricating oil intake passage 41j Lubricating oil inlet 41k Second rib 41m Lubricating oil outlet 41p Curved part 42 First space 43 Second space 44 Oil pump

Claims (3)

A differential case (15) having a pair of inboard portions (15a, 15b) for supporting the pair of inboard shafts (17L, 17R);
A final driven gear (23) attached to the differential case (15);
A transmission shaft (32, 33) and a transmission gear (28, 29) disposed above the differential case (15) and transmitting a driving force to the final driven gear (23);
An oil pump (44) disposed above the differential case (15);
A transmission case (11) that houses the differential case (15), the final driven gear (23), the transmission gears (28, 29), and the oil pump (44) and stores lubricating oil at the bottom;
A differential gear lubrication structure comprising a pair of first bearings (16L, 16R) rotatably supporting the pair of inboard portions (15a, 15b) inside the transmission case (11);
By fixing a baffle plate (41) inside the transmission case (11), the inside of the transmission case (11) is placed in a first space (on the differential case (15) and final driven gear (23) side) ( 42) and a second space (43) outside the first space (42),
The baffle plate (41) includes wall portions (41a, 41a, 41b) that partition the first space (42) and the second space (43) along the outside of the rotation locus of the differential case (15) and the final driven gear (23). 41b), an opening (41g) passing through the upper part of the wall (41a, 41b) and communicating the first space (42) with the second space (43), and the second space (43). A lubricating oil guide groove (41h) for guiding lubricating oil from the opening (41g) to at least one of the first bearings (16R) and a circular arc-shaped first formed so as to surround the outer periphery of the final driven gear (23). A rib (41c), a second rib (41k) extending radially outward from the first rib (41c), and a lubricating oil suction passage (41) provided radially outward of the first rib (41c) ) And equipped with a,
A lubricating oil inlet (41j) at the lower end of the lubricating oil intake passage (41i) is near the bottom of the second space (43) and is surrounded by the first rib (41c) and the second rib (41k). The differential gear lubrication structure is characterized in that the lubricating oil outlet (41m) at the upper end of the lubricating oil suction passage (41i) communicates with the oil pump (44).   The transmission case (11) includes a first case (12) that faces the first space (42) and a second case (13) that faces the second space (43) on a split surface (12a, 13a). The second case (13) includes a partition wall (13b) that supports the transmission shaft (32, 33) via a second bearing (36, 37), and the baffle plate (41) A curved surface portion (41p) for guiding the lubricating oil toward the second bearing (36, 37) is formed on the upper portion, and the lubricating oil guided by the curved surface portion (41p) is formed on the partition wall (13b). The differential gear lubrication structure according to claim 1, characterized in that a guide portion (13e, 13f, 13g) leading to the two bearings (36, 37) is formed.   By fitting protrusions (41e, 41f) protruding in the axial direction from the baffle plate (41) into recesses (13c, 13d) provided in the transmission case (11), the baffle plate (41) is The lubricating oil outlet (41m) fixed to the transmission case (11) and at the upper end of the lubricating oil suction passage (41i) is formed of a tubular member, and the protruding portion (41f) and the lubricating oil outlet (41m) The differential gear lubricating structure according to claim 1 or 2, characterized in that they protrude in opposite directions with respect to the baffle plate (41).

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