JP2016164422A - Lubrication structure of release bearing, and transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubrication structure of a release bearing, which can prevent infiltration of water, and heating thereof, and can reduce rotational resistance.SOLUTION: A lubricant structure 10 of release bearing includes: a cylinder block 60 covering the base end side outer peripheral surface of an input shaft 31; a piston 63 arranged in a piston storage part 61 of the cylinder block 60; and a release bearing 70 disposed at the end part of a clutch connection/disconnection mechanism side of the piston 63, and configured to operate the clutch connection/disconnection mechanism. The cylinder block 60 has a lubricant system 80 passing through the clearance between the cylinder block 60 and the input shaft 31 and communicating with a mission chamber 6 through the release bearing 70.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a lubrication structure for a release bearing that operates a clutch connecting / disconnecting mechanism of a vehicle, and a transmission.

  In order to improve the fuel efficiency of a vehicle, coasting control is performed mainly for large vehicles, in which the clutch is disengaged while traveling. In a normal manual transmission, in order to connect and disconnect the clutch, a piston attached to a casing of the transmission is operated to operate a clutch connecting / disconnecting mechanism of the clutch. At this time, a rotation difference is generated between the fixed-side piston and the rotating-side clutch connecting / disconnecting mechanism. Therefore, a bearing called a release bearing is incorporated between the piston and the clutch-connecting / disconnecting mechanism.

  There is no problem with the durability of the release bearing if the time is as short as the speed change. However, in coasting control, the clutch is disengaged for a longer time than before, so that the load continues to be applied to the release bearing and the release bearing may be damaged.

  A conventional release bearing for a dry clutch is separated from a transmission main body, and the lubrication of the release bearing is performed by grease sealed in the release bearing (see Patent Document 1 below).

JP 2010-91043 A JP 2010-53984 A

  Incidentally, a release bearing is generally a grease-enclosed bearing. Also, the environment where the release bearing is placed is open to the atmosphere, and water may enter the release bearing. Therefore, if the release bearing is operated for a long time, the life is shortened due to generation of heat and rust.

  Therefore, conventionally, a dedicated seal is attached between the outer cylinder and the inner cylinder of the release bearing and sealed to prevent grease retention and water intrusion (see Patent Document 2). Since a dedicated seal is attached between the outer cylinder and the inner cylinder of the release bearing, if the release bearing is used for a long time, the bearing temperature rises and the wear of the release bearing is promoted. Therefore, it is not suitable for continuing to disengage the clutch for a long time as in coasting control. In addition, since grease has a high viscosity and seals are attached to both ends of the release bearing, there is a problem that rotational resistance increases.

  An object of the present invention is to provide a lubrication structure for a release bearing that can prevent water from entering the release bearing and heat generation from the release bearing and reduce rotational resistance, and a transmission including the lubrication structure. There is.

  In order to achieve the above-described object, a lubrication structure for a release bearing according to the present invention includes a cylinder block that covers an outer peripheral portion on the base end side of an input shaft, a piston that is disposed in a piston housing portion of the cylinder block, A release bearing that is disposed at an end of the clutch connecting / disconnecting mechanism and operates the clutch connecting / disconnecting mechanism, and the cylinder block passes through a gap between the cylinder block and the input shaft, and the release bearing And having a lubricating oil system communicating with the mission chamber.

  In the structure of the lubricating structure of the release bearing, it is preferable that the lubricating oil system is connected to an oil passage for a transmission mechanism.

  The transmission according to the present invention includes a release bearing in a transmission casing, and has a lubrication structure for the release bearing.

  According to the present invention, it is possible to prevent water from entering the release bearing and heat generation of the release bearing, and to reduce rotational resistance.

It is typical sectional drawing of the transmission which applies the lubrication structure of the release bearing which concerns on one Embodiment of this invention. It is typical sectional drawing of the lubrication structure of the release bearing which concerns on this embodiment.

  Hereinafter, a lubrication structure for a release bearing and a transmission according to an embodiment of the present invention will be described with reference to the accompanying drawings. The same parts are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  First, with reference to FIG. 1, the structure of the transmission 1 which applies the lubrication structure 10 of the release bearing which concerns on one Embodiment of this invention is demonstrated. FIG. 1 is a schematic sectional view of a transmission to which a release bearing lubrication structure according to an embodiment of the present invention is applied.

  A transmission 1 illustrated in FIG. 1 is an FR (front engine / rear drive) vehicle, and is provided between an engine (not shown) and a differential (not shown). The transmission casing 2 of the transmission 1 has a deformed cylindrical shape in which the engine side (front side) is bent upward. The transmission casing 2 is partitioned by a first partition 3 on the engine side (front side) and a second partition 4 on the differential side (rear side). That is, the first partition 3 and the second partition 4 divide the transmission casing 2 into a front chamber 5, an intermediate chamber (mission chamber) 6, and a rear chamber 7.

  A main shaft 21 is pivotally supported on the second partition 4 via a roller bearing 20. The main shaft 21 penetrates the transmission casing 2 and projects rearward from the transmission 1 and is connected to a propeller shaft (not shown). The main shaft 21 is pivotally supported via a bearing (not shown) in the penetrating portion of the transmission casing 2.

  An input shaft 31 is pivotally supported on the first partition 3 via a roller bearing 30. A hollow portion 32 is formed at the rear end portion of the input shaft 31, and the front end portion of the main shaft 21 is inserted into the hollow portion 32. The input shaft 31 and the main shaft 21 are provided coaxially, but the input shaft 31 and the main shaft 21 are not connected.

  A counter shaft 41 is pivotally supported between the first partition 3 and the second partition 4 via roller bearings 42 and 43. The counter shaft 41 is pivotally supported in parallel with the main shaft 21 in the lower part of the mission chamber 6. A plurality of speed change gears (5th speed in this embodiment) 40 are provided on the outer periphery of the counter shaft 41. All the driving force from the input shaft 31 is transmitted to the counter shaft 41. Note that the torque increases as the diameter of the transmission gear 40 increases.

  A plurality of transmission gears 22 and sleeves 23 are arranged in a portion of the main shaft 21 in the mission chamber 6. When the shift lever (not shown) is neutral, the plurality of transmission gears 22 idle around the axis of the main shaft 21. A clutch hub (not shown) is provided under the sleeve 23.

  A fork shaft 51 is pivotally supported between the first partition 3 and the second partition 4 in the upper part of the mission chamber 6. The fork shaft 51 is pivotally supported in parallel with the main shaft 21. The fork shaft 51 is connected to a shift lever (not shown), and a shift fork 52 is provided. The shift fork 52 is engaged with the groove portion of the sleeve 23 to move the sleeve 23 in the axial direction. When the shift lever is put in each shift position, the transmission gear 22 and the clutch hub are connected via the sleeve 23.

  In addition, an oil pump P is provided in the transmission casing 2 for sucking transmission oil from the bottom and supplying it to a transmission mechanism such as the transmission gear 22. The oil pump P is driven by the rotation of the counter shaft 41. A transmission mechanism oil passage 100 for supplying transmission oil from the oil pump P to a transmission mechanism such as the transmission gear 22 is connected to the first pipe 101 connected to the discharge side of the oil pump P and the first pipe 101. A rear wall oil passage 102 formed in the rear wall 2a of the transmission casing 2 and a shaft oil passage 103 connected to the rear wall oil passage 102 and formed in the main shaft 21 are provided. A branch passage 102 a is formed in the rear wall oil passage 102. A bearing oil passage 104 for supplying transmission oil to a lubricating oil system 80 for a release bearing 70, which will be described later, is connected to the branch passage 102a. The bearing oil passage 104 includes a second pipe 105 connected to the branch passage 102 a and an intra-partition oil passage 106 connected to the second pipe 105 and formed in the first partition 3 of the transmission casing 2. The oil passage 106 in the partition wall is connected to a relief portion 69 of a cylinder block 60 (see FIG. 2), which will be described later, at a position above the roller bearing 30. The first pipe 101 and the second pipe 105 may be formed by providing a metal pipe or the like separate from the transmission casing 2 in the transmission casing 2 and forming a hole in the outer wall of the transmission casing 2 or the like. Then, it may be formed integrally with the transmission casing 2.

  Next, the lubrication structure 10 for the release bearing according to the present embodiment will be described. FIG. 2 is a schematic cross-sectional view of a release bearing lubrication structure according to the present embodiment.

  As described above, the input shaft 31 is pivotally supported on the first partition 3 via the roller bearing 30. As shown in FIG. 2, a cylindrical cylinder block 60 is provided in the front chamber 5 of the transmission casing 2 so as to cover the periphery of the base end side of the input shaft 31. The cylinder block 60 includes an outer cylindrical portion 66 that is coaxially attached to the first partition 3 and the input shaft 31, a bottom plate portion 67 that is formed to extend radially inward from the rear end of the outer cylindrical portion 66, and a bottom plate portion 67, and an inner cylinder portion 68 that extends forward from the inner peripheral side of 67 and through which the input shaft 31 is inserted. In an annular groove-shaped space surrounded by the inner peripheral surface of the outer cylindrical portion 66, the front surface of the bottom plate portion 67, and the outer peripheral surface of the inner cylindrical portion 68, a piston 63 (to be described later) is movably accommodated. A piston accommodating portion 61 is formed. The bottom plate portion 67 is formed with a concave relief portion 69 for avoiding contact with the roller bearing 30 and for receiving transmission oil from the bearing oil passage 104. The inner cylinder portion 68 is formed with an inner diameter larger than the outer diameter of the input shaft 31, and transmission oil flows between the inner cylinder portion 68 and the input shaft 31. The outer diameter of the cylinder block 60 is sequentially reduced toward the front. A piston 63 for connecting and disconnecting a clutch (not shown) is provided in the piston housing 61 so as to be movable in the front-rear direction. The cylinder block 60 has a through hole 62 for supplying air A into the cylinder chamber C formed between the piston 63 and the bottom plate portion 67.

  The piston 63 is formed in a substantially cylindrical shape. Air seals 65 a and 65 b that are in contact with the inner cylindrical portion 68 and the outer cylindrical portion 66 are provided on the inner peripheral portion and the outer peripheral portion of the piston 63, and the piston 63 is caused by the pressure of the air A supplied from the through hole 62. It is designed to be driven. The piston 63 is formed to extend forward so as to always extend forward from the cylinder block 60. Furthermore, the piston 63 is formed with an inner diameter enlarged portion 63a that expands radially outward in multiple steps toward the front, so as to face the front end of the inner cylinder portion 68, and between the inner cylinder portion 68 and the input shaft 31. Transmission oil that has flowed forward through the gap enters the inner diameter enlarged portion 63a. A release bearing 70 for transmitting an axial force from the piston 63 to the clutch side is incorporated in the front end portion of the inner diameter enlarged portion 63a so as to be positioned on the radially inner side. The release bearing 70 is supplied with transmission oil in the inner diameter enlarged portion 63a.

  The release bearing 70 includes an outer ring 70a, an inner ring 70b, and a ball 70c interposed between the outer ring 70a and the inner ring 70b, and the inner ring 70b is rotatable with respect to the outer ring 70a that rotates integrally with the piston 63. Has been. A cylindrical seal support member 71 that rotates integrally with the inner ring 70 b is provided on the inner peripheral portion of the release bearing 70 so as to extend forward. A dust seal 72 for preventing dust from entering between the seal support member 71 and the input shaft 31 is provided at the front part of the inner periphery of the seal support member 71, and at the rear part of the inner periphery of the seal support member 71. A first oil seal 73 is provided for preventing transmission oil from leaking between the seal support member 71 and the input shaft 31. The cylinder block 60 is provided with a cover 90 for preventing transmission oil supplied to the release bearing 70 from leaking into the front chamber 5.

  The cover 90 includes an outer periphery covering portion 91 that covers the outer periphery of the piston 63 and a front end covering portion 92 that is formed to extend radially inward from the front end of the outer periphery covering portion 91 to the vicinity of the seal support member 71. The outer periphery covering portion 91 is formed to have the same inner diameter as the outer cylinder portion 66, and the rear end is fastened to the front end of the cylinder block 60 in a liquid-tight manner. A second oil seal 93 that seals between the cover 90 and the seal support member 71 is provided at the inner peripheral end of the front end covering portion 92.

  The cylinder block 60 is formed with a lubricating oil system 80 that passes through the gap between the cylinder block 60 and the input shaft 31 and communicates with the transmission chamber 6 via the release bearing 70. Specifically, the lubricating oil system 80 is a first supply oil that is formed between the bottom plate portion 67 of the cylinder block 60 and the roller bearing 30 and guides transmission oil from the bearing oil passage 104 to the input shaft 31. A second supply oil passage 82 formed between the passage 81, the inner cylinder portion 68 of the cylinder block 60 and the input shaft 31 for guiding transmission oil from the first supply oil passage 81 forward, and the cylinder block 60. A third supply oil passage 83 formed between the inner cylinder portion 68 and the seal support member 71 for guiding transmission oil from the second supply oil passage 82 to the release bearing 70, and a release formed in the cover 90. The transmission oil that has passed through the bearing 70 is caused to flow downward and guided to the cylinder block 60. The first return oil passage 84, the second return oil passage 85 formed in the cylinder block 60 for guiding transmission oil from the first return oil passage 84 to the first partition 3, and the first partition 3. And a third return oil passage 86 for returning transmission oil from the second return oil passage 85 into the rear mission chamber 6. The second return oil passage 85 is formed in the lower part of the cylinder block 60 with a hole that penetrates in the front-rear direction and inclines so as to descend toward the rear. The third return oil passage 86 is formed by forming a hole penetrating the first partition wall 3 in the front-rear direction. The lubricating oil system 80 is branched and connected to the transmission mechanism oil passage 100 via the bearing oil passage 104. Therefore, the same transmission oil as that of the transmission mechanism oil passage 100 flows through the lubricating oil system 80.

  Next, with reference to FIG.1 and FIG.2, the effect of the lubrication structure 10 and the transmission 1 of the release bearing which concerns on this embodiment is demonstrated.

  A conventional release bearing slides on the front cover, and has a positioning with a release fork and a rotation stopper on the back, and receives a thrust force by a grease lubrication system. The sliding portion with the front cover is grease lubricated, and when the grease is cut, the sliding becomes worse and the clutch pedal becomes heavy. When the grease on the release bearing is cut, abnormal noise is generated.

  In addition, the environment in which the conventional release bearing is placed is open to the atmosphere, and there is a possibility of water intrusion into the release bearing. If the release bearing is operated for a long time, the life is shortened due to generation of heat and rust. Become.

  On the other hand, the transmission 1 and release bearing lubrication structure 10 according to the present embodiment includes a release bearing 70 in the front chamber 5 of the transmission casing 2. By incorporating the release bearing 70 in the transmission casing 2, it is possible to prevent water from entering the release bearing 70.

  In addition, since the release bearing 70 is incorporated in the transmission 1, the release bearing 70 can be forcibly lubricated with transmission oil, and the release bearing 70 can be lubricated and cooled. Furthermore, since the lubricating oil is used instead of the conventional grease lubrication, the rotational resistance of the release bearing 70 can be reduced.

  As described above, according to the transmission 1 and the release bearing lubrication structure 10 according to the present embodiment, it is possible to prevent water from entering the release bearing 70 and heat generation of the release bearing 70 and to reduce rotational resistance. Demonstrate the excellent effect of being able to. Thereby, improvement in durability of the release bearing 70 and reduction in fuel consumption can be expected.

  In addition, this invention is not limited to the above-mentioned embodiment, In the range which does not deviate from the meaning of this invention, it can change suitably and can implement.

  Although the said embodiment illustrated and demonstrated the transmission 1 of FR vehicle, it is not limited to this, It can apply also to FF vehicle. Further, the transmission 1 and the release bearing lubrication structure 10 according to the present embodiment can be applied to both a pull clutch and a push clutch.

DESCRIPTION OF SYMBOLS 1 Transmission 3 1st partition 6 Mission chamber 10 Release bearing lubrication structure 31 Input shaft 60 Cylinder block 63 Piston 70 Release bearing 80 Lubricating oil system

Claims (3)

A cylinder block that covers the outer peripheral portion of the proximal end of the input shaft;
A piston disposed in a piston housing portion of the cylinder block;
A release bearing disposed at an end of the piston on the clutch connecting / disconnecting mechanism side to operate the clutch connecting / disconnecting mechanism;
With
The lubrication structure for a release bearing, wherein the cylinder block has a lubricating oil system that passes through a gap between the cylinder block and the input shaft and communicates with the transmission chamber via the release bearing. The lubrication structure for a release bearing according to claim 1, wherein the lubricating oil system is branched and connected to an oil passage for a transmission mechanism.   A transmission comprising a release bearing in a transmission casing and having a lubrication structure for the release bearing.

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