JP2011089583A - Lubricating structure for vehicular continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently lubricate a radial bearing supporting a secondary shaft without forming a lubricating oil path in a housing, separately. <P>SOLUTION: An output gear 27 fixed to the shaft end of the secondary shaft 20 is put in direct engagement with a ring gear 31 of a differential device 30. The radial bearing 26 is provided for supporting the intermediate of the secondary shaft 20 on a transmission case 53, and the width dimension of an outer race 26b thereof is smaller than that of an inner case 26a. A predetermined clearance δ is formed between the outer race and a piston 22 of a secondary pulley 21 to pass oil therethrough. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a lubricating structure for a continuously variable transmission for a vehicle, and more particularly to a lubricating structure for a bearing that supports a secondary shaft.

Conventionally, in a continuously variable transmission for an FF type vehicle, an intermediate portion of a secondary shaft supporting a secondary pulley is supported by a radial bearing, and a piston portion of the secondary pulley is disposed on one side of the secondary shaft with the radial bearing in between. Is arranged, an output gear is arranged on the other side of the secondary shaft, and this output gear is meshed with a ring gear of a differential device (see Patent Document 1). In this case, the output gear and the radial bearing can be lubricated with the oil accumulated in the bottom of the housing by scooping it up with the ring gear of the differential device.

FIG. 5 shows a secondary shaft portion of the continuously variable transmission disclosed in Patent Document 1. An intermediate portion of the secondary shaft 100 is supported by the housing 102 via a radial bearing 101. A piston portion 103 of a secondary pulley is disposed on one side of the secondary shaft 100 with the radial bearing 101 therebetween, and an output gear 104 is fixed on the other side. The output gear 104 meshes with the ring gear 105 of the differential device. The inner race 101a of the radial bearing 101 is in contact with the back surface of the piston portion 103 of the secondary pulley. Since the piston part 103 may be bent by the action of the bias spring 106 and the hydraulic pressure disposed in the piston part, it is necessary to provide a gap so that the piston part 103 does not interfere with the outer race 101b. Further, in order to circulate the oil lubricated in the radial bearing 101, it is necessary to secure a passage for the lubricating oil that passes from the output gear side of the radial bearing 101 to the piston portion side.

Therefore, in Patent Document 1, a stepped portion 103 a is provided on the back surface of the piston portion 103 of the secondary pulley, and a gap δ is provided between the outer race 101 b and the back surface of the piston portion 103. However, in order to process the stepped portion 103a on the back surface of the piston portion 103, dimensional management is required and processing costs are also required. Further, when the stepped portion 103a is made high, the free length of the bias spring 106 disposed in the piston portion 103 is restricted, so that there is a problem that stress increases during operation.

JP 2009-222177 A

An object of the present invention is to provide a lubricating structure for a continuously variable transmission for a vehicle that can efficiently lubricate a radial bearing that supports a secondary shaft without forming a step portion in the piston portion, and can prevent interference between the outer race and the piston portion. It is to provide.

In order to achieve the above object, the present invention provides a primary pulley and a secondary pulley, a primary pulley and a secondary pulley that are supported by the primary shaft and the secondary shaft, respectively, and the belt winding diameter is variable by hydraulic pressure, and between the pulleys. A wound belt, an output gear fixed to one end portion of the secondary shaft, and an intermediate portion of the secondary shaft located between the piston portion of the secondary pulley and the output gear are rotatable with respect to the housing. In the continuously variable transmission for a vehicle, the inner ring of the radial bearing that is fitted to the secondary shaft includes: a radial bearing that is supported by a ring gear; and a differential device that has a ring gear that directly meshes with the output gear and that drives a wheel. The width dimension of the outer race of the radial bearing fitted to the housing with respect to the race Shortened, oil between the piston portion of the said outer race secondary pulley is characterized in that to form a predetermined gap can pass, to provide a lubrication structure for a vehicle continuously variable transmission.

The oil accumulated at the bottom of the housing is pumped up along with the rotation of the ring gear of the differential device, and the output gear is lubricated. Since the pumped-up oil is blocked at the meshing portion between the ring gear and the output gear, the oil is supplied to the side surface of the radial bearing disposed adjacent to the output gear, and sufficient lubricating oil can be supplied to the radial bearing.

In order to prevent interference between the outer race of the radial bearing and the piston portion of the secondary pulley, and to secure a passage of lubricating oil from the output gear side of the radial bearing to the piston portion side, in the present invention, the outer race with respect to the inner race of the radial bearing The gap dimension through which oil can pass is formed between the outer race and the piston portion of the secondary pulley. Therefore, the passage of the lubricating oil can be easily secured without forming a step portion in the piston portion, and interference between the piston portion and the outer race can be prevented. Furthermore, since the free length of the bias spring is not restricted, there is no concern that stress increases during operation.

As described above, according to the present invention, the oil pumped up by the ring gear of the differential device is supplied to one side surface of the radial bearing, and after the oil has passed through the radial bearing, it is between the outer race and the piston portion of the secondary pulley. Since it flows to the secondary pulley side through the gap, it can always be lubricated with fresh oil. Therefore, the durability of the radial bearing is improved, and interference between the piston portion and the outer race can be reliably prevented. In addition, the width of the outer race of the radial bearing is narrower than that of the inner race, so there is no need to form a step in the piston, reducing machining costs and restricting the free length of the bias spring placed inside the piston. Not receive.

It is a skeleton figure of an example of a continuously variable transmission provided with the lubrication structure concerning the present invention. FIG. 2 is a detailed cross-sectional view of a secondary shaft and a differential device shown in FIG. 1. It is a side view of the transmission case of the continuously variable transmission shown in FIG. FIG. 3 is an enlarged cross-sectional view of a secondary shaft portion of the continuously variable transmission shown in FIG. 2. It is an expanded sectional view of the secondary shaft part of the conventional continuously variable transmission.

1 to 4 show an example of a continuously variable transmission for a vehicle provided with a lubricating structure according to the present invention, and the continuously variable transmission is applied to an FF horizontal type vehicle. This continuously variable transmission includes an input shaft (turbine shaft) 3 driven by an engine output shaft 1 via a torque converter 2, and a forward / reverse switching device 4 that transmits the rotation of the input shaft 3 to the primary shaft 10 by switching forward and reverse. A continuously variable transmission 9 in which a V-belt 15 is wound between the primary pulley 11 and the secondary pulley 21, a differential device 30 that transmits the power of the secondary shaft 20 to the drive shafts 32 and 33, and the like are provided. The input shaft 3 and the primary shaft 10 are arranged on the same axis, and the secondary shaft 20 and the drive shafts 32 and 33 of the differential device 30 are arranged parallel to the input shaft 3 and non-coaxially. Therefore, this continuously variable transmission has a three-axis configuration as a whole.

Each component constituting the continuously variable transmission is accommodated in the housing 5. Here, the housing 5 is composed of three parts: a rear cover 51 on the rear side (non-engine side), a converter housing 52 on the front side (engine side), and an intermediate transmission case 53. The torque converter 2 is accommodated in the converter housing 52, the continuously variable transmission 9 is accommodated in a space between the rear cover 51 and the transmission case 53, and the output gear 27 and the differential device 30 are provided between the converter housing 52 and the transmission case 53. It is housed in the space between.

The forward / reverse switching device 4 includes a planetary gear mechanism 40, a forward brake 41, and a reverse clutch 42. When the reverse clutch 42 is released and the forward brake 41 is fastened, the forward drive state is established, and the forward / reverse switching device 4 is moved forward. When the brake 41 is released and the reverse clutch 42 is engaged, the reverse drive state is established. The forward / reverse switching device 4 is accommodated in a space between the transmission case 53 and the converter housing 52.

The primary pulley 11 of the continuously variable transmission 9 includes a fixed sheave 11a integrally formed on the primary shaft 10, a movable sheave 11b supported on the primary shaft 10 so as to be axially movable and integrally rotatable, And a cylinder 12 fixed to the shaft 10. An oil chamber 13 is formed between the movable sheave 11 b and the cylinder 12, and the shift control is performed by controlling the amount of oil supplied to the oil chamber 13. The secondary pulley 21 is fixed to the secondary shaft 20, a fixed sheave 21 a that is integrally formed on the secondary shaft 20, a movable sheave 21 b that is supported on the secondary shaft 20 so as to be axially movable and integrally rotatable. And a piston 22. An oil chamber 23 is formed between the movable sheave 21b and the piston 22, and the belt thrust necessary for torque transmission is given by controlling the hydraulic pressure supplied to the oil chamber 23. A bias spring 24 that provides an initial belt thrust is accommodated in the oil chamber 23. Note that one end of the bias spring 24 is supported by a spring receiving portion 22a of the piston 22, and the spring receiving portion 22a is not a stepped shape, so that the free length of the bias spring 24 is not restricted. The diameter of the bias spring 24 is substantially the same as the diameter of an outer race 26b of a radial bearing 26 described later, and the spring receiving portion 22a and the outer race 26b are substantially aligned in the axial direction.

The primary shaft 10 is rotatably supported by a rear cover 51 and a transmission case 53 via a pair of radial bearings (ball bearings) 14 and 16, and the secondary shaft 20 includes a pair of radial bearings (ball bearings) 25 and 26. Via the rear cover 51 and the transmission case 53. Further, the differential device 30 is also rotatably supported by the transmission case 53 and the converter housing 52 via a pair of radial bearings 36 and 37.

One end of the secondary shaft 20 extends through the transmission case 53 toward the engine side, and the output gear 27 is fixed to the free end. The secondary shaft 20 is terminated before the converter housing 52 and is not supported by the converter housing 52. The output gear 27 is spline-fitted to the outer periphery of the secondary shaft 20, and the inner race 26 a of the radial bearing 26 and the rotational speed detection are detected together with the output gear 27 by screwing a lock nut 28 to the end of the secondary shaft 20. The plate 34, the piston 22 of the secondary pulley 21, and the stopper member 29 are pressed in the axial direction, and are crimped and fixed to the stepped portion 20 a of the secondary shaft 20.

As shown in FIG. 4, the inner race 26 a of the radial bearing 26 is fitted to the outer periphery of the secondary shaft 20, and the outer race 26 b is fitted to the bearing hole 53 d of the transmission case 53. The axial width of the outer race 26b of the radial bearing 26 is shorter than that of the inner race 26a. Therefore, a gap δ through which oil can pass is provided between the outer race 26b and the rotation speed detection plate 34 adjacent thereto. The gap δ can prevent interference between the rotating rotation speed detection plate 34 and the stationary outer race 26b, and can form a lubricating oil passage.

The rotation speed detection plate 34 is made of a magnetic metal plate having a disc-shaped portion and a cylindrical portion, and an appropriate number of detection holes 34a are formed in the cylindrical portion at intervals in the circumferential direction. A magnetic rotation sensor 35 is fixed to the wall portion of the transmission case 53 so that the sensing portion faces the cylindrical portion of the rotation speed detection plate 34. The rotation speed of the secondary shaft 20 can be detected. The rotation speed detection plate 34 is fitted to the secondary shaft 20 together with the piston 22 and is integrally fixed to the secondary shaft 20 by the fastening force of the lock nut 28 as described above. The rotation speed detection plate 34 has a function of reinforcing the spring receiving portion 22 a of the piston 22 and suppressing the bending of the spring receiving portion 22 a due to the hydraulic pressure or the bias spring 24. The rotation speed detection plate 34 can be omitted, and in this case, a predetermined gap δ is formed between the outer race 26 b and the piston 22.

The output gear 27 meshes with a ring gear 31 of a differential device 30 disposed below the output gear 27, and power is transmitted from the differential device 30 to drive shafts 32 and 33 extending left and right to drive the wheels.

Here, the lubrication method of the radial bearing 26 will be described in detail with reference to FIGS. The differential device 30 is a space between the converter housing 52 and the transmission case 53 as described above, and is accommodated in the lowermost portion thereof. Therefore, the lower end of the ring gear 31 is immersed in the oil (indicated by OIL in FIG. 2) stored at the bottom of this space. As shown in FIG. 3, an arcuate inner wall 53 a that is close to the outer periphery of the ring gear 31 is formed in the lower part of the transmission case 53 and the converter housing 52, so that the rotation of the ring gear 31 (the rotational direction during forward movement) The oil OIL is efficiently pumped up by the arrow A). The pumped up oil rises along the inclined inner wall surface 53b of the transmission case 53, and collides with the output gear 27, the rib 53c protruding from the inner wall of the transmission case 53, and the like. Since the output gear 27 meshes directly with the ring gear 31 and the rotation direction is opposite to the rotation direction of the ring gear 31, the oil rising along the peripheral surface of the ring gear 31 is blocked at the meshing portion with the output gear 27. Spatter around. Therefore, a large amount of oil can be supplied to the side surface of the radial bearing 26 adjacent to the output gear 27 by the oil pumped up by the ring gear 31 or the scattered oil. Part of the oil supplied to the side surface of the radial bearing 26 passes between the inner race 26a and the outer race 26b and flows into the space in which the pulley is accommodated. At this time, the width dimension of the outer race 26b is shorter than that of the inner race 26a, and a gap δ is formed between the outer race 26b and the rotation speed detection plate 34. Therefore, a lubricating oil passage can be secured and the space in which the pulley is accommodated can be secured. It can flow smoothly. Therefore, fresh oil always passes through the radial bearing 26, and the durability of the radial bearing 26 can be improved.

In the above embodiment, the ball bearing is used as the radial bearing 26, but a roller bearing may be used. Moreover, although the example which the one end part which provided the output gear 27 of the secondary axis | shaft 20 was a free end was shown, even if the one end part of the secondary axis | shaft 20 is extended and it supports with the converter housing 52 via another radial bearing. Good.

DESCRIPTION OF SYMBOLS 1 Engine output shaft 3 Input shaft 4 Forward / reverse switching device 5 Housing 10 Primary shaft 11 Primary pulley 15 Belt 20 Secondary shaft 21 Secondary pulley 22 Piston 22a Spring receiving portion 24 Bias spring 26 Radial bearing 26a Inner race 26b Outer race 27 Output gear 30 Differential Device 31 Ring gear 32, 33 Drive shaft 51 Rear cover 52 Converter housing 53 Transmission case

Claims (1)

A primary shaft and a secondary shaft, a primary pulley and a secondary pulley that are supported by the primary shaft and the secondary shaft, respectively, and the belt winding diameter is variable by hydraulic pressure, a belt wound between both pulleys, and the secondary shaft An output gear fixed to one end, a radial bearing that rotatably supports an intermediate portion of the secondary shaft located between the piston portion of the secondary pulley and the output gear, and the output gear; In a continuously variable transmission for a vehicle having a ring gear having a directly meshing ring gear and driving a wheel,
A width dimension of an outer race of the radial bearing fitted to the housing is shortened with respect to an inner race of the radial bearing fitted to the secondary shaft, and oil is provided between the outer race and the piston portion of the secondary pulley. A lubricating structure for a continuously variable transmission for a vehicle, wherein a predetermined gap through which the vehicle can pass is formed.

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