JP2006132552A - Continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a continuously variable transmission with a fixed sheave and a ring gear supported with higher accuracy to suppress gear noises and wear. <P>SOLUTION: A boss portion 11a<SB>1</SB>protruded on the back face of the fixed sheave 11a of a driving pulley 11 is supported at its outer peripheral face on a transmission case 5 via a bearing 46, and an outer spline 11a<SB>3</SB>is formed on the outer peripheral face of an extension portion 11a<SB>2</SB>extending from the boss portion to the axial direction. A ring gear 42 of a forward/reverse change-over device is supported at one axial end by a disc supporting member 42a, and an inner spline 42b spline-fitted to the outer spline of the extension portion 11a<SB>2</SB>is formed on the inner periphery of the supporting member. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a continuously variable transmission, and more particularly to a power transmission structure from a forward / reverse switching device provided on an input shaft to a drive pulley.

Conventionally, a forward / reverse switching device having a planetary gear mechanism is disposed on the input shaft, the input shaft and the drive pulley are disposed in series in the axial direction, the output rotation element of the forward / reverse switching device and the fixed sheave of the drive pulley Is a continuously variable transmission in which a boss portion protruding from the back surface of the fixed sheave and the output rotating element are mechanically connected.

Patent Document 1 discloses a continuously variable transmission using a double pinion type planetary gear mechanism, in which a sun gear of the planetary gear mechanism is connected to an input shaft, and a carrier is connected to a fixed sheave of a drive pulley. The boss portion of the fixed sheave is spline-fitted to the inner periphery of the inner diameter portion of the carrier, and the outer peripheral surface of the inner diameter portion of the carrier is supported by a bearing.

Further, as in Patent Document 1, a double pinion type planetary gear mechanism is used in Patent Document 2, in which a sun gear of the planetary gear mechanism is connected to an input shaft, and a carrier is connected to a fixed sheave. In this case, the outer peripheral surface of the boss portion of the fixed sheave is supported by a bearing, and an extension portion is projected from the boss portion in the axial direction, and the inner diameter portion of the carrier is spline-fitted to the outer peripheral surface of the extension portion. It has a structure.

In the case of Patent Document 1, the carrier is directly supported by the bearing. However, since the fixed sheave is indirectly supported by the bearing through the spline fitting portion with the carrier, there is a problem that the support accuracy of the fixed sheave is lowered.
In the case of the forward / reverse switching device described in Patent Documents 1 and 2, both the sun gear input and the carrier output are used, and the ring gear is not stably supported by the input shaft or the like. Therefore, there is a problem that the position accuracy of the ring gear is lowered and gear noise and uneven wear are likely to occur.

In Patent Document 3, the forward / reverse switching device includes a single pinion planetary gear mechanism, the sun gear of the planetary gear mechanism is connected to the input side, the ring gear is connected to the output side, and the carrier is locked to the case. A continuously variable transmission including a reverse brake and a direct coupling clutch that couples a carrier and a sun gear is disclosed.

FIG. 6 shows the structure of the forward / reverse switching device described in Patent Document 3.
The sun gear 101 of the planetary gear mechanism 100 constituting the forward / reverse switching device is coupled to the input shaft 102, and the pinion gear 103 that meshes with the sun gear 101 is supported by the carrier 105 via the pinion shaft 104. A carrier plate 106 is fixed to the front side of the carrier 105 via a pinion shaft 104, and an inner diameter portion thereof is rotatably supported by the input shaft 102. A reverse brake 107 is provided between the carrier plate 106 and the transmission case 112, and a direct coupling clutch 108 is provided between the carrier plate 106 and the input shaft 102. An inner diameter portion 114a of the ring gear 114 that meshes with the pinion gear 103 is spline-fitted inside a boss portion 115a that protrudes from the back surface of the fixed sheave 115 of the drive pulley. The outer peripheral surface of the boss portion 115 a is supported by the transmission case 112 via a bearing 116.

Since this forward / reverse switching device is a single pinion type, the structure can be simplified and the inner diameter portion 114a of the ring gear 114 is spline-fitted with the boss portion 115a of the fixed sheave 115 supported by the bearing 116. Further, not only the support accuracy of the fixed sheave 115 but also the support accuracy of the ring gear 114 is expected.
However, since it is necessary to form the spline groove of the fixed sheave 115 on the inner peripheral surface of the boss portion 115a, the spline groove is formed by cold forging and the dimensional accuracy cannot be increased. Therefore, the improvement of the support accuracy of the ring gear 114 cannot be expected so much, and there is a problem that gear noise is generated due to poor spline contact.
JP-A-10-281246 JP-A-7-186747 JP 2002-327828 A

SUMMARY OF THE INVENTION An object of the present invention is to provide a continuously variable transmission capable of increasing the support accuracy of a fixed sheave and a ring gear and suppressing gear noise and wear.

In order to achieve the above object, the invention according to claim 1 is characterized in that a forward / reverse switching device having a planetary gear mechanism is disposed on the input shaft, the input shaft and the drive pulley are disposed in series in the axial direction, A continuously variable transmission in which an output rotation element of a forward switching device and a fixed sheave of a drive pulley are arranged close to each other, and a boss portion projecting from the back surface of the fixed sheave and the output rotation element are mechanically coupled The outer surface of the boss portion of the fixed sheave is supported by a stationary member such as a transmission case via a bearing, and an outer spline is formed on the outer surface of the extension portion extending in the axial direction from the boss portion. The output rotation element is a ring gear of a planetary gear mechanism, and one end portion in the axial direction of the ring gear is supported by a disk-like support member, and the outer spline of the extension portion is spline fitted to the inner peripheral portion of the support member. Providing CVT, characterized in that splines are formed.

In the present invention, since the outer peripheral surface of the boss portion protruding from the back surface of the fixed sheave of the drive pulley is supported by the bearing, the support accuracy of the fixed sheave is improved.
In addition, an extension part is further projected in the axial direction from the boss part of the fixed sheave, and an external spline is formed on this extension part, so that the fixed sheave has high precision such as cutting without performing cold forging. The outer spline can be processed by the processing method, and the generation of gear noise due to poor tooth contact with the inner spline of the ring gear can be prevented.
Furthermore, since the ring gear is supported by the support member and the inner peripheral portion of the support member is spline-fitted to the extension of the boss portion, the positional accuracy of the ring gear is also improved along with the improvement of the processing accuracy of the outer spline. There is an advantage that gear wear can be prevented.

The sun gear of the planetary gear mechanism is integrally formed or fixed to the input shaft as in claim 2, and the carrier of the planetary gear mechanism is rotatably supported on the shaft end of the input shaft, and the support member for the sun gear, the carrier, and the ring gear It is good to set it as the structure arrange | positioned in order in an axial direction.
Thus, by arranging the sun gear, the carrier, and the support member for the ring gear in this order in the axial direction, the structure of each component can be simplified and the axial dimension can be shortened.

As described above, according to the present invention, the outer peripheral surface of the boss portion of the fixed sheave is supported by the bearing, and the inner spline of the support member that supports the ring gear is supported by the outer spline of the extension portion that extends in the axial direction from the boss portion. Since the mating is designed to improve the support accuracy of the fixed sheave, the outer spline can be machined with a high-precision machining method such as cutting, so the gear due to poor tooth contact with the inner spline of the ring gear. Generation of sound can be prevented. Further, since the inner peripheral portion of the support member of the ring gear is spline-fitted with the extension portion of the boss portion, there is an advantage that the positional accuracy of the ring gear is improved and gear wear and the like can be prevented.

Embodiments of the present invention will be described below with reference to examples.

1 to 3 show an example of a continuously variable transmission according to the present invention.
The continuously variable transmission of this embodiment is an FF horizontal type automotive transmission, which is roughly switched between forward and reverse rotation of the input shaft 3 driven by the engine output shaft 1 via the torque converter 2 and the input shaft 3. The forward / reverse switching device 4 that transmits to the drive shaft 10, the continuously variable transmission A comprising the drive pulley 11, the driven pulley 21, and the V belt 15 wound between both pulleys, the power of the driven shaft 20 is output shaft 32. And a differential device 30 that transmits to the terminal. The input shaft 3 and the drive shaft 10 are arranged on the same axis, and the driven shaft 20 and the output shaft 32 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.
The V belt 15 used in this embodiment is a known metal belt composed of a pair of endless tension bands and a large number of blocks supported by these tension bands.

Each component constituting the continuously variable transmission is accommodated in a transmission case 5. An oil pump 6 is disposed between the torque converter 2 and the forward / reverse switching device 4. As shown in FIG. 3, the oil pump includes an oil pump body 7 fixed to the transmission case 5, an oil pump cover 8 fixed to the oil pump body 7, an oil pump body 7, and an oil pump cover. 8 and the pump gear 9 accommodated between the two. The pump gear 9 is driven by the pump impeller 2 a of the torque converter 2. The turbine runner 2 b of the torque converter 2 is connected to the input shaft 3.

As shown in FIG. 3, the forward / reverse switching device 4 includes a planetary gear mechanism 40, a forward brake 50, and a reverse clutch 51, and a sun gear 41 of the planetary gear mechanism 40 is connected to an input shaft 3 as an input member. The ring gear 42 is coupled to the fixed sheave 11a of the drive pulley 11 as an output member. The planetary gear mechanism 40 is a single pinion system, the forward brake 50 is provided between the carrier 44 and the transmission case 5 that support the pinion gear 43 via the pinion shaft 45, and the reverse clutch 51 is provided with the carrier 44 and the sun gear. 41. When the reverse clutch 51 is released and the forward brake 50 is engaged, the rotation of the input shaft 3 is reversed, decelerated, and transmitted to the drive shaft 10. Conversely, when the forward brake 50 is released and the reverse clutch 51 is engaged, the carrier 44 and the sun gear 41 of the planetary gear mechanism 40 rotate together, so that the input shaft 3 and the drive shaft 10 are directly connected.

The structure of the forward / reverse switching device 4 will be specifically described. The carrier 44 is provided with a cylindrical portion 44a that doubles as a hub of the forward brake 50 and a drum of the reverse clutch 51, and this cylindrical portion 44a protrudes toward the engine side. Between the outer periphery of the cylindrical portion 44a and the transmission case 5, a brake plate (brake disc and brake plate) 50a of the forward brake 50 is disposed. The piston 50b of the forward brake 50 is operated by the hydraulic pressure supplied to the hydraulic chamber 50c formed in the transmission case 5, and the brake plate 50a is fastened by the piston 50b. A cylindrical cylinder portion 8a is integrally projected from an oil pump cover 8 that is a stationary member as a reaction force member that supports the end portion of the brake plate 50a that is pressed by the pressure of the piston 50b.

A cylindrical portion 41 a serving as a clutch hub of the reverse clutch 51 is integrally projected on the side of the sun gear 41 on the engine side, and between the outer periphery of the cylindrical portion 41 a and the inner periphery of the cylindrical portion 44 a of the carrier 44. Further, a clutch plate (clutch disk and clutch plate) 51a of the reverse clutch 51 is disposed. As will be described later, the reverse clutch 51 is a stationary cylinder type clutch device. A concave hydraulic chamber 51b is formed on the side face of the oil pump cover 8 facing the forward / reverse switching device 4, and the piston 51c is operated by the hydraulic pressure supplied to the hydraulic chamber 51b, and the reverse clutch 51 is fastened. The piston 51c has a U-shaped cross section, and a thrust bearing 52 that allows relative rotation is disposed on the side surface of the piston 51c that faces the clutch plate 51a. Therefore, the thrust of the piston 51c is effectively transmitted to the clutch plate 51a, and the piston 51c is prevented from rotating with the clutch plate 51a of the reverse clutch 51. Since the carrier 44 is disposed behind the clutch plate 51a, the end portion of the clutch plate 51a pressed by the pressure of the piston 51c can be supported by the end surface of the carrier 44.

The drive pulley 11 of the continuously variable transmission A is integrally movable with a fixed sheave 11a integrally formed on a drive shaft (pulley shaft) 10 and axially movable on the drive shaft 10 via a roller spline portion 13. The movable sheave 11b is rotatably supported, and the hydraulic servo 12 is provided behind the movable sheave 11b. A piston portion 12a extending to the back side is integrally formed on the outer peripheral portion of the movable sheave 11b, and the outer peripheral portion of the piston portion 12a is in sliding contact with the inner peripheral portion of the cylinder 12b fixed to the drive shaft 10. A hydraulic oil chamber 12c of the hydraulic servo 12 is formed between the movable sheave 11b and the cylinder 12b, and the shift control is performed by controlling the hydraulic pressure to the hydraulic oil chamber 12c.

The driven pulley 21 is supported by a fixed sheave 21a integrally formed on the driven shaft (pulley shaft) 20 and on the driven shaft 20 via a roller spline portion 23 so as to be axially movable and integrally rotatable. A movable sheave 21b and a hydraulic servo 22 provided behind the movable sheave 21b are provided. The structure of the roller spline portion 23 is the same as that of the roller spline portion 13 of the drive pulley 11. A cylinder portion 22a extending to the back side is integrally formed on the outer peripheral portion of the movable sheave 21b, and a piston 22b fixed to the driven shaft 20 is in sliding contact with the inner peripheral portion of the cylinder portion 22a. A hydraulic oil chamber 22c of the hydraulic servo 22 is formed between the movable sheave 21b and the piston 22b. By controlling the hydraulic pressure of the hydraulic oil chamber 22c, a belt thrust necessary for torque transmission is given. Note that a spring 24 for applying an initial thrust is disposed in the hydraulic oil chamber 22c.

One end portion of the driven shaft 20 extends toward the engine side, and an output gear 27a is fixed to this one end portion. The output gear 27a meshes with the ring gear 31 of the differential device 30, and power is transmitted from the differential device 30 to the output shaft 32 extending left and right to drive the wheels.

Here, the transmission mechanism portion from the forward / reverse switching device 4 to the drive pulley 11 will be described with reference to FIGS.
A sun gear 41 that is an input rotation element of the forward / reverse switching device 4 is spline-fitted with the input shaft 3. An axial rear end portion of the ring gear 42 as an output rotating element is supported by a disk-like support member 42a, and an inner spline 42b is formed on the inner peripheral portion of the support member 42a.

A boss portion 11 a ₁ protrudes from the back surface of the fixed sheave 11 a of the drive pulley 11, and the outer peripheral surface of the boss portion 11 a ₁ is supported by the transmission case 5 via a bearing 46. Therefore, the fixed sheave 11a is supported with high accuracy. A cylindrical extension portion 11a ₂ extending forward in the axial direction is projected from the front end portion of the boss portion 11a ₁ , and an outer spline 11a ₃ is formed on the outer peripheral surface of the extension portion 11a ₂ . Internal splines 42b of the support member 42a of the ring gear 42 is splined to the outer spline 11a _3. As described above, since the support member 42a is supported on the extended portion 11a ₂ having high support accuracy, the position accuracy of the ring gear 42 is also increased. A hollow portion 11a ₅ is formed in the back shaft center portion of the fixed sheave 11a.

The sun gear 41, the carrier 44, and the support member 42a of the ring gear 42 of the forward / reverse switching device 4 are arranged side by side in the axial direction. The rear surface of the support member 42 a is in contact with the step surface 11 a ₄ between the boss portion 11 a ₁ and the extension portion 11 a ₂ of the fixed sheave 11 a, and the front surface of the sun gear 41 is in contact with the flange portion 3 a formed on the input shaft 3. It touches. Further, thrust bearings 48 and 49 are disposed between the support member 42a and the carrier 44 and between the carrier 44 and the sun gear 41, respectively. Therefore, the three members of the support member 42a of the ring gear 42, the carrier 44, and the sun gear 41 are supported so as to be relatively rotatable and free from backlash in the axial direction. As a result, the meshing between the sun gear 41 and the pinion gear 43 and the meshing between the pinion gear 43 and the ring gear 42 are stabilized.

A lubrication hole 3b is formed in the shaft center portion of the input shaft 3, and opens to the shaft end portion 3c. The inner diameter portion of the carrier 44 is rotatably supported by the shaft end portion 3 c of the input shaft 3 via the bush 47. A diameter-expanded portion 44b that is expanded in the axial direction is formed on the inner diameter portion of the carrier 44, and a closing member 39 that closes the diameter-expanded portion 44b is fitted. In addition, a plurality of inflow grooves 44 c are formed in the inner diameter portion of the carrier 44 and in contact with the outer peripheral surface of the bush 47 at intervals in the circumferential direction. These inflow grooves 44 c are formed inside the carrier 44. It communicates with the radial communication hole 44d formed in the. Incidentally, the enlarged diameter portion 44b of the carrier 44 is inserted into the inside of the extension 11a ₂ of the boss portion 11a _1.

Since the forward brake 50 is engaged in the forward range, the carrier 44 is stationary. Therefore, the lubricating oil cannot be supplied to the pinion gear 43 using centrifugal force, and problems such as wear of the pinion gear 43 and seizure of the needle bearing 37 disposed between the pinion gear 43 and the pinion shaft 45 occur. there is a possibility. In this embodiment, since the lubricating oil sent through the lubricating hole 3b of the input shaft 3 is prevented from flowing out in the axial direction by the plugging member 39, an oil reservoir 36 is formed inside the enlarged diameter portion 44b. The Therefore, the lubricating oil is fed into the communication hole 44d through the inflow groove 44c by the lubricating pressure of the oil reservoir 36. A pin 38 for fixing the pinion shaft 45 to the carrier 44 is press-fitted into the outer peripheral end of the communication hole 44d, and oil leakage from the radial hole 45a of the pinion shaft 45 is prevented. Lubricating oil supplied from the communication hole 44d can pass through the axial lubrication hole 45b of the pinion shaft 45 and lubricate the needle bearing 37 and the pinion gear 43. Thus, even if the carrier 44 is stationary during the forward range, the needle bearing 37 and the pinion gear 43 can be forcibly lubricated, so that wear and seizure thereof can be effectively prevented.

A small hole 39a is formed in the axial center portion of the closing member 39, and a part of the lubricating oil stored in the oil reservoir 36 passes through the small hole 39a and flows into the hollow portion 11a ₅ on the back surface of the fixed sheave 11a. It has become. The lubricating oil flows in the outer diameter direction by centrifugal force, and can lubricate the thrust bearing 48 and the splines 11a ₃ and 42b.

It is an expanded sectional view of an example of a continuously variable transmission concerning the present invention. FIG. 2 is a skeleton diagram of the continuously variable transmission shown in FIG. 1. It is sectional drawing of the forward / reverse switching device of the continuously variable transmission shown in FIG. FIG. 4 is a detailed cross-sectional view of a connecting portion between a forward / reverse switching device and a drive pulley shown in FIG. 3. FIG. 5 is a partially enlarged view of FIG. 4. It is sectional drawing of an example of the conventional forward / reverse switching apparatus.

Explanation of symbols

3 Input shaft 4 Forward / reverse switching device 5 Transmission case (stationary member)
11 Drive pulley 11a Fixed sheave 11a ₁ Boss part 11a ₂ Extension part 11a ₃ Outer spline 40 Planetary gear mechanism 41 Sun gear 42 Ring gear 42a Support member 42b Inner spline 43 Pinion gear 44 Carrier 45 Pinion shaft 46 Bearing 50 Forward brake 51 Reverse clutch

Claims (2)

A forward / reverse switching device having a planetary gear mechanism is arranged on the input shaft, the input shaft and the drive pulley are arranged in series in the axial direction, and the output rotating element of the forward / reverse switching device and the fixed sheave of the drive pulley are close to each other In the continuously variable transmission in which the boss portion projecting from the back surface of the fixed sheave and the output rotating element are mechanically coupled,
The outer peripheral surface of the boss portion of the fixed sheave is supported by a stationary member such as a transmission case via a bearing,
An outer spline is formed on the outer peripheral surface of the extended portion extending in the axial direction from the boss portion,
The output rotation element is a ring gear of a planetary gear mechanism, and one end portion in the axial direction of the ring gear is supported by a disk-like support member, and the outer spline of the extension portion is spline fitted to the inner peripheral portion of the support member. A continuously variable transmission, wherein an inner spline is formed. The sun gear of the planetary gear mechanism is integrally formed or fixed to the input shaft,
A carrier of the planetary gear mechanism is rotatably supported on the shaft end of the input shaft,
The continuously variable transmission according to claim 1, wherein the sun gear, the carrier, and a support member for the ring gear are sequentially arranged in the axial direction.

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