JP2016114161A - Lubrication structure of bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discharge a lubrication oil efficiently without causing increase in agitation resistance and the like in a bearing, in a CVT which use the lubrication oil leaked from an oil passage to a secondary pulley for lubrication of the bearing on the secondary pulley side and which discharges it from an oil hole to a primary pulley side.SOLUTION: On a bottom wall 11a of a bearing accommodation recess part 11 for accommodating an outer race of a bearing in a side cover of a transmission case, a first groove 15 which receives a shaft part end of a secondary pulley and a second groove 16 which continues to the outside of it and which the bearing faces are provided, and an oil hole 20 is set at a downstream side terminal end of the second groove 16 along the rotation direction of a shaft part. The width of the second groove 16 becomes wider toward the downstream side. A lubrication oil toward the outside by a centrifugal force is guided directly to the oil hole 20 along the second groove 16, and discharged. As a lower edge of the oil hole 20 is set at the same height as the lowermost position P of an end surface inner diameter edge of the outer race of the bearing, lubrication oil supply into the bearing is secured without excess or deficiency.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a bearing lubrication structure for supporting a rotating shaft in a transmission or the like.

  For example, in a continuously variable transmission (CVT) for a vehicle, a V belt is wound between a primary pulley and a secondary pulley to transmit a rotational driving force. Each pulley shaft is rotatably supported by a bearing. Conventionally, lubrication of the bearing has passed through a gap between the pulley shaft and the case side member from an oil passage that supplies hydraulic pressure to displace the pulley in the axial direction. There are many examples in which a leak is used as a lubricating oil supply source.

  And, for example, when the pulley shaft of the secondary pulley is higher than the pulley shaft of the primary pulley in the vehicle-mounted state of the CVT, the lubricating oil leaked from the oil passage to the secondary pulley is removed from the bearing on the secondary pulley side. In addition to being used for lubrication, the oil hole connected to the lower primary pulley is discharged and distributed to the bearing on the primary pulley side for use in lubrication. The oil hole opens in the peripheral wall of the oil sump surrounding the pulley shaft that the bearing faces.

  Here, the amount of lubricating oil to the bearing is determined by the degree of leakage. When the oil pressure to the secondary pulley is low or when the oil temperature is low, the amount of leakage is small. Since the hole opens in a direction transverse to the flow of the lubricating oil that rotates with the pulley shaft, it is difficult for the oil to be discharged from the oil hole, which may cause insufficient lubrication of the bearing on the primary pulley side. Further, even if the oil pressure and the oil temperature are high, if a large amount of lubricating oil stagnates due to the difficulty of being discharged into the oil hole, the stirring resistance of the bearing on the secondary pulley side will increase.

  As a measure for facilitating the discharge of the lubricating oil into the oil hole that opens in a direction transverse to the flow of the lubricating oil as described above, for example, Japanese Patent Laid-Open No. 11-257470 discloses an outlet of the lubricating oil introduction path in the oil reservoir. A technique has been proposed in which an opening is provided between the oil hole and the oil hole to gradually increase the volume and then gradually decrease the volume to reduce the pressure. As a result, it is expected that the lubricating oil is actively sucked into the oil reservoir by the pressure difference and pushed out from the oil hole.

JP-A-11-257470

  The above conventional technique is effective when the inflow position of the lubricating oil into the oil sump is clear as the outlet of the lubricating oil introduction path, but leaks through the gap between the pulley shaft and the case side member. When it is used as a supply source, the inflow position into the oil sump is unclear such as irregular locations, and even if this technology is applied, the expected effect is not always obtained.

  Therefore, in view of the above-mentioned conventional problems, the present invention provides a bearing lubrication structure in which lubricating oil is smoothly discharged into an oil hole regardless of whether the inflow position to the oil sump is clear or not. The purpose is to do.

  Therefore, the present invention provides a bearing lubrication structure in a device that supports a rotating member in a case via a bearing. The rotating member has a shaft portion to which the bearing is attached. The case includes a boss portion and a boss portion. A first groove that surrounds and receives the end of the shaft part, a second groove that continues to the outside of the first groove, and an oil hole that is disposed in the second groove are provided so that the bearing faces the second groove. The hole was set on the downstream side along the predetermined rotation direction of the shaft portion.

  According to the present invention, the lubricating oil traveling outward by centrifugal force is guided directly to the oil hole on the downstream side along the second groove, so that it is efficiently discharged.

It is a longitudinal cross-sectional view around the bearing of the secondary pulley concerning embodiment. It is an AA arrow line view in FIG. FIG. 3 is a cross-sectional view taken along the line BB in FIG. 2. It is CC sectional view taken on the line in FIG.

Hereinafter, an embodiment in which the present invention is applied around a bearing that supports one end of a pulley shaft of a secondary pulley in a CVT will be described.
FIG. 1 is a longitudinal sectional view around a bearing of a secondary pulley showing an embodiment.
The CVT 1 transmits the rotation by winding the V belt 4 between a primary pulley and a secondary pulley 30 (not shown).
The secondary pulley 30 forms a V-groove M sandwiching the V-belt 4 between the fixed pulley 31 and the movable pulley 32, and receives a secondary pressure from a hydraulic control circuit (not shown) in a secondary pressure chamber R described later attached to the movable pulley 32. Thus, the groove width of the V groove M is changed.
The primary pulley has the same configuration.

The fixed pulley 31 of the secondary pulley 30 extends a shaft portion 35 as a pulley shaft and a movable pulley support portion 36 in both directions integrally with a belt support portion 34 having a conical sheave surface. The movable pulley support 36 supports the movable pulley 32 having a sheave surface facing the sheave surface of the fixed pulley 31 so as to be movable in the axial direction.
A drum-shaped cylinder 37 extends from the movable pulley 32 in a direction opposite to the V-groove M formation side, and a disk-shaped piston 38 fixed to the movable pulley support portion 36 is disposed in the cylinder 37. The outer peripheral edge can slide relative to the inner wall of the cylinder 37 in the axial direction. A seal ring 39 is held on the outer peripheral edge of the piston 38, and an oil-tight secondary pressure chamber R is formed between the movable pulley 32 (cylinder 37) and the piston 38.

A bearing 45 (an inner race 46) is attached to the outer periphery of the shaft portion 35 as one end of the pulley shaft by a nut 6. The side cover 10 forming the transmission case is formed with a bearing receiving recess 11 for receiving and holding the bearing 45 (the outer race 47 thereof). The bearing 45 includes a ball 48 as a rolling element between the inner race 46 and the outer race 47.
In assembling the bearing 45, the bearing 45 is attached to the shaft portion 35 of the secondary pulley 30 with the nut 6, and the outer race 47 is inserted into the bearing housing recess 11 of the side cover 10 while being coupled to the secondary pulley 30. Thus, the secondary pulley 30 is supported by the transmission case (side cover 10) via the bearing 45.

When the bearing 45 is assembled, the bearing 45 is attached to the shaft portion 35 with the nut 6 in a state where the bearing support 8 is allowed to play between the belt support portion 34 of the secondary pulley 30 and is coupled to the secondary pulley 30. In this state, the outer race 47 is inserted into the bearing housing recess 11 of the side cover 10. Then, an unillustrated peripheral portion of the bearing support is pressed against and fixed to the inner wall of the side cover 10 around the bearing accommodating recess 11 with a bolt (not shown) penetrating the side cover 10. As a result, the bearing support 8 abuts against the outer race 47 of the bearing 45 to define the axial position thereof, thereby restricting the shift to the belt support portion 34 side.
Further, the gap between the outer race 47 and the belt support portion 34 is filled with the bearing support 8.

The side cover 10 further includes a boss portion 12 extending into a support hole 40 formed at the shaft end of the shaft portion 35, and the seal ring 13 is held on the outer periphery of the boss portion 12, so that the inner peripheral surface of the support hole 40. It is sealed between.
The side cover 10 is formed with an oil passage 14 that opens to the front end surface of the boss portion 12, and the oil passage 14 is connected to a hydraulic control circuit.

An oil passage 41 that opens in the support hole 40 of the shaft portion 35 and extends in the axial direction over the movable pulley support portion 36 is formed on the pulley shaft of the secondary pulley 30, and the oil passage 41 is connected to the secondary pressure chamber R.
That is, the secondary pressure is supplied from the hydraulic control circuit to the secondary pressure chamber R through the oil passage 14 and the oil passage 41, the movable pulley 32 is moved by the control of the secondary pressure, and the groove width of the V groove M of the secondary pulley 30 is increased. Change.
The above configuration of the secondary pulley 30 is the same as that of a known conventional structure.
The

FIG. 2 is a view showing a side cover as viewed in the direction of arrows AA in FIG.
In FIG. 2, an end face inner diameter edge 47 a of the outer race 47 of the bearing 45 is indicated by a virtual line a for reference. Here, the inner diameter edge of the end surface of the outer race 47 refers to the inner diameter edge of the bank portion on both sides in the axial direction across the rolling path 47b. (See Figure 1)
In FIG. 2, for convenience of explanation, the portion of the second groove 16 is shown in white and other portions are hatched.
With reference to FIGS. 1 and 2, the side cover 10 is formed with a first groove 15 that surrounds the periphery of the boss portion 12 as a recess that is further recessed from the bottom wall 11 a of the bearing housing recess 11. The shaft portion 35 and the nut 6 face the first groove 15, and in particular, the outer diameter of the first groove 15 is set so as to leave a small gap with the nut 6.

In particular, as shown in FIG. 2, the second cover 16 is formed outside the first groove 15 in the side cover 10 in the present embodiment. The bottom wall 16 a of the second groove 16 is continuous with the bottom wall 15 a of the first groove 15.
The second groove 16 extends from the same height as the axial center of the boss portion 12 along the rotational direction of the secondary pulley 30 to the position at a predetermined angle α along the rotational direction of the secondary pulley 30 in the vehicle mounted state of the CVT 1. The rotation direction here is preferably the rotation direction during forward travel having a wide speed range from low speed to high speed.
The oil hole 20 of the oil passage 19 to the primary pulley side is opened at the terminal end of the second groove 16 with the same height as the axis of the boss part 12 as the starting end of the second groove 16.
The start and end of the second groove 16 are walls 18 a and 18 b that rise to the bottom wall 11 a of the bearing housing recess 11.
The sealing structure by the seal ring 13 between the support hole 40 of the shaft portion 35 and the boss portion 12 allows a predetermined lubricating oil leak, and the lubricating oil from the leaked oil passage 41 passes through the first groove 15. Then, it flows into the second groove 16 and lubricates the bearing 45, and the second groove 16 forms an oil sump Q for lubricating the bearing 45.
As a result, the lubricating oil heading outward is guided along the second groove 16 directly to the terminal oil hole 20 by the centrifugal force when the shaft portion 35 and the bearing 45 are rotated. Since the lubricating oil flowing to the end is blocked by the wall 18b, it is positively pushed out to the oil hole 20.

The peripheral wall of the second groove 16 substantially overlaps with the inner diameter edge of the outer surface 47 of the outer race 47 at the start end, and gradually expands outward toward the end to increase the radial groove width, and is substantially the same as the peripheral wall of the bearing housing recess 11 at the end. It has become.
Since the oil path 19 to the primary pulley side extends outward on a line crossing the second groove 16, if the flow direction changes suddenly at the oil hole 20 by flowing at a constant width, the oil path resistance is large. As the groove width becomes closer to 20, the oil hole 20 opens into a large-volume oil reservoir, and the oil path resistance is kept low.

The lower edge of the opening of the oil hole 20 is set to the same height as the lowest position P of the end surface inner diameter edge 47a of the outer race 47 of the bearing 45 in the vehicle mounted state.
As a result, if the oil level of the oil sump Q is equal to or greater than the lower edge of the oil hole 20, the supply of lubricating oil into the bearing 45 (rolling path 47b) is ensured and also supplied to the primary pulley side. Become.
If the lower edge of the oil hole 20 is lower than the lowest position P of the end face inner diameter edge 47a of the outer race 47, the lubricating oil in the oil sump Q is discharged from the oil hole 20 to the primary pulley before entering the bearing 45. If the bearing 45 is insufficiently lubricated and the lower edge of the oil hole 20 is higher than the lowest position P of the end face inner diameter edge 47a of the outer race 47, a large amount of lubricating oil enters the bearing 45 and the stirring resistance increases. It will be.

The oil path 19 to the primary pulley side extends within the wall thickness of the side cover 10, but is set as close to the inner wall surface as possible so as to prevent the bulge from interfering with an adjacent member outside the transmission case. Is higher by a predetermined amount in the axial direction than the bottom wall 15a of the first groove 15 and is closer to the bearing 45.
Correspondingly, as shown in FIG. 3, the bottom wall 16a of the second groove 16 is gradually increased in the axial direction from the same level as the bottom wall 15a of the first groove 15 outward in the radial direction. The step immediately before the opening is eliminated by connecting to the opening edge of the oil hole 20 at the end portion.
Also, as shown in FIG. 4, it is preferable that the bottom wall 16a of the second groove 16 is gradually raised in the axial direction and connected to the opening edge of the oil hole 20 in the same manner toward the downstream side in the circumferential direction. .

With the above configuration, the bearing 45, in particular, the opening between the inner race 46 and the outer race 47 directly faces the oil sump Q only in the substantially lower half where the second groove 16 is formed, and in the remaining substantially upper half, the bearing is accommodated. Since it opposes the wall part which consists of the inward extension part of the bottom wall 11a of the recessed part 11, an oil sump is only through the outer peripheral surface of the axial part 35 (specifically nut 6) and the bent micro clearance gap along the end surface of the inner race 46. Communicate with Q.
Note that, in the above-described substantially upper half portion, the wall portion facing the opening of the bearing 45 first has an outer periphery that is substantially along the inner edge of the outer race end surface of the imaginary line a, that is, equivalent to the starting end of the second groove 16. It is also possible to form a ring groove having a width of 1 mm on the entire circumference (see the phantom line in FIG. 1) and then apply a new member padding to the substantially upper half of the ring groove.
Thereby, the flow of the lubricating oil from the oil reservoir Q to the substantially upper half of the bearing 45 is suppressed, and the lubricating oil is guided to the second groove 16 having the oil holes 20.

Further, while the bearing support 8 abuts against the outer race 47 of the bearing 45, the lower half part slightly overlaps the opening between the outer race 47 and the inner race 46 and is substantially open, but in the upper half part, the inner edge is formed on the inner race 46. It extends inward to the vicinity of the outer edge of the end surface of the inner surface, and covers an opening between the outer race 47 and the inner race 46 in a larger area than the lower half.
Thereby, the lubricating oil from above inside the transmission case such as dripping down the inner wall of the side cover 10 is suppressed from entering the bearing 45.
Since the opening in the lower half is substantially open, the lubricating oil that has entered the bearing 45 can be smoothly discharged downward.

In the present embodiment, the side cover 10 forming the transmission case corresponds to the case in the invention, and the secondary pulley 30 corresponds to the rotating member.
Further, the ball 48 corresponds to a rolling element.

The embodiment is configured as described above. In the CVT 1 for a vehicle that supports the secondary pulley 30 through the bearing 45 in the transmission case, the secondary pulley 30 has a shaft portion 35 to which the bearing 45 is attached. The side cover 10 that forms the machine case includes a boss portion 12, a first groove 15 that surrounds the boss portion 12 and receives the end of the shaft portion 35, and a second groove 16 that continues to the outside of the first groove 15. The oil hole 20 disposed in the second groove 16 is provided, the bearing 45 faces the second groove 16, and the oil hole 20 is set on the downstream side along the rotation direction of the shaft portion 35 when the vehicle moves forward. Therefore, the lubricating oil that is directed outward by centrifugal force is guided directly to the terminal oil hole 20 along the second groove 16, and the oil hole 20 can be efficiently produced regardless of where the lubricating oil is introduced from around the boss portion 12. Discharged from.
(Effects corresponding to claim 1)

And since the lower edge of the oil hole 20 is set at the same height as the lowest position P of the end face inner diameter edge 47a of the outer race 47 of the bearing 45, the stirring resistance is not increased and the lubrication is insufficient. Thus, the lubricating oil supply into the bearing 45 is ensured.
(Effect corresponding to claim 7)

In particular, since the width of the second groove 16 increases toward the downstream side, an increase in oil path resistance due to a rapid change in the flow direction at the oil hole 20 by flowing at a constant width can be avoided. (Effects corresponding to claim 2)
Further, the second groove 16 ends at the position where the oil hole 20 is provided, and the wall 18b rises immediately adjacent to the downstream side of the oil hole 20 so that the lubricating oil can be easily prevented from flowing. Led to. (Effects corresponding to claim 3)

Since the second groove 16 is provided below the boss portion 21 starting from the same height as the center of the boss portion 12, it is easy to collect lubricating oil as an oil sump Q for the bearing 45. (Effects corresponding to claim 4)
The outer diameter of the first groove 15 is set so as to leave a small gap with the shaft portion 35 (nut 6), and the opening of the bearing 45 is an oil reservoir in a substantially upper half other than the second groove 16. Since it does not directly face Q, the flow of lubricating oil to the substantially upper half is suppressed. As a result, an increase in stirring resistance is prevented and the lubricating oil is guided to the second groove 16 having the oil holes 20. (Effects corresponding to claim 5)

The oil hole 20 opens at a position higher in the axial direction than the bottom wall 15a of the first groove 15, and the second groove 16 becomes higher as the bottom wall 16a moves toward the oil hole 20, so that a steep step is eliminated. The lubricating oil is guided to the oil hole 20 without increasing the oil path resistance.
(Effect corresponding to claim 6)

Further, the bearing support 8 that abuts the axial end surface of the outer race 47 on the side opposite to the side facing the first groove 15 and the second groove 16 of the bearing 45 is formed with respect to the opening between the outer race 47 and the inner race 46 of the bearing 45. Since the upper half portion has a larger overlapping area than the lower half portion, the lubricating oil from above in the transmission case is prevented from entering the bearing 45 and the stirring resistance is prevented from increasing. The
(Effect corresponding to claim 8)

In the embodiment, the bearing 45 includes the ball 48 as a rolling element, but a bearing including a roller or a needle may be used.
The embodiment shows an example in which the present invention is applied around a bearing that supports the pulley shaft of the secondary pulley in the CVT. However, the pulley shaft of the primary pulley is higher than the pulley shaft of the secondary pulley in the vehicle mounted state. In this case, the present invention can be applied around the bearing that supports the pulley shaft of the primary pulley.
Moreover, it is not limited to CVT, It can apply also about the bearing of the various apparatuses which support a rotation member in a case via a bearing.

1 CVT
4 V belt 6 Nut 8 Bearing support 10 Side cover 11 Bearing receiving recess 11a Bottom wall 12 Boss portion 13 Seal ring 14, 41 Oil passage 15 First groove 15a, 16a Bottom wall 16 Second groove 18a, 18b Wall 19 Oil passage 20 Oil hole 30 Secondary pulley 31 Fixed pulley 32 Movable pulley 34 Belt support part 35 Shaft part 36 Movable pulley support part 37 Cylinder 38 Piston 39 Seal ring 40 Support hole 45 Bearing 46 Inner race 47 Outer race 47a End surface inner diameter edge 47b Rolling path 48 Ball MV groove Q Oil sump R Secondary pressure chamber

Claims (8)

In a bearing lubrication structure in a device that supports a rotating member in a case via a bearing provided with rolling elements between an inner race and an outer race,
The rotating member has a shaft portion to which the bearing is attached,
The case includes a boss portion, a first groove that surrounds the boss portion and receives the end of the shaft portion, a second groove that continues to the outside of the first groove, and an oil disposed in the second groove. A hole is provided so that the bearing faces the second groove,
A bearing lubrication structure, wherein the oil hole is set on a downstream side of the shaft portion along a predetermined rotation direction. 2. The bearing lubrication structure according to claim 1, wherein a width of the second groove increases toward the downstream side. 3. The bearing lubrication structure according to claim 1, wherein the second groove has a position where the oil hole is provided as a terminal, and a wall rises immediately adjacent to the downstream side of the oil hole. 4. The bearing lubrication structure according to claim 3, wherein the second groove is provided below the boss portion starting from the same height as the center of the boss portion. The bearing lubricating structure according to claim 4, wherein an outer diameter of the first groove is set so as to leave a small gap between the first groove and the shaft portion. The oil hole opens at a position higher in the axial direction than the bottom wall of the first groove,
The bearing lubrication structure according to any one of claims 1 to 5, wherein the second groove has a bottom wall that becomes higher toward the oil hole. 7. The bearing according to claim 1, wherein a lower edge of the oil hole is set at the same height as a lowermost position of an inner diameter edge of an end surface of the outer race of the bearing. Lubrication structure. A bearing support that abuts against an axial end surface of the outer race on a side opposite to the side facing the first groove and the second groove of the bearing is a lower half portion with respect to an opening between the outer race and the inner race of the bearing. The bearing lubrication structure according to any one of claims 1 to 7, wherein the upper half portion has a larger overlapping area.

Images