JPH07117131B2 - Pulley for V-belt transmission - Google Patents

Description

TECHNICAL FIELD The present invention relates to a V-belt transmission pulley, and more particularly to a pulley structure suitable for a V-belt type continuously variable transmission that pulls and drives a V-belt without lubrication.

[Conventional technology]

In the V-belt type continuously variable transmission in which the V-belt is tension-driven without lubrication, the applicant has provided a cylinder behind the movable sheave, which is movably supported on the rotating shaft in the axial direction, and is provided in the cylinder. Fix the fixed piston in contact with the rotary shaft, install the diaphragm between the cylinder and the rotary shaft, form the hydraulic oil chamber between the movable sheave and the fixed piston, and correct the centrifugal hydraulic pressure between the fixed piston and the diaphragm. Proposed a seal structure in which a sub-chamber is formed (Japanese Patent Laid-Open No. 61-6595).
No. 3 bulletin).

[Problems to be Solved by the Invention]

In the above V-belt transmission pulley, a ball spline is provided between the rotary shaft and the boss portion of the movable sheave in order to guide the movable sheave movably only in the axial direction. The ball spline is a widely used means for guiding the rotating member in the axial direction, but in the V-belt continuously variable transmission of the type in which the V-belt is tension-driven without lubrication, the following serious problems occur. May invite.

That is, since the ball spline has a structure in which a spline groove is formed on the surface facing the rotary shaft and the boss portion of the movable sheave, and the ball is rotatably arranged between them, the ball spline directly contacts the hydraulic fluid chamber. If this happens, a drop in operating hydraulic pressure due to oil leakage cannot be avoided, and oil will leak to the belt drive surface of the pulley, significantly reducing the transmission efficiency between the V-belt and the pulley. Therefore, there is no choice but to adopt a complicated seal structure in which sub chambers are formed on both sides of the hydraulic oil chamber as in the above publication, which causes a problem that the structure of the pulley itself is large and complicated. Further, since the ball spline takes a space in the radial direction, the inner diameter of the movable sheave and the shaft diameter of the rotary shaft are increased. This results in that the pressure receiving area of the hydraulic oil chamber provided at the back of the movable sheave must be reduced when the outer diameter of the movable sheave is restricted.

The present invention has been made in view of the above problems, and an object thereof is to prevent a decrease in a hydraulic oil chamber and oil leakage with a simple seal structure, and to increase an inner diameter dimension of a movable sheave and a shaft diameter of a rotary shaft. It is to provide a compact V-belt transmission pulley that does not have any problems.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention comprises a fixed sheave that is immovable in the axial direction and a movable sheave that is movable in the axial direction on a rotating shaft, and the movable sheave is axially mounted on the back of the movable sheave. In a V-belt transmission pulley provided with a hydraulic oil chamber for operating the hydraulic oil chamber and a sub-chamber for correcting centrifugal oil pressure generated in the hydraulic oil chamber, a cylindrical inner circumference provided on the back of the movable sheave. A cylinder having a peripheral wall portion having a surface and a side wall portion extending from the end portion of the peripheral wall portion toward the inner diameter side, the outer peripheral portion slidably inscribes the peripheral wall portion of the cylinder, and the inner peripheral portion is fixed to the rotating shaft. , A fixed piston that divides the hydraulic oil chamber and the sub chamber, and a pin that is installed in the axial direction between the back of the movable sheave and the side wall of the cylinder and slidably penetrates the fixed piston, and an outer peripheral portion. Fixed to the side wall of the cylinder, the inner peripheral A flexible film body that is fixed to the rotary shaft or the fixed piston and is displaceable in the axial direction that seals the inner diameter side of the sub-chamber, and an oil passage for supplying oil to the hydraulic oil chamber is provided in the sub-chamber separately. And a supply oil passage for supply.

[Action]

When hydraulic pressure is supplied to the hydraulic oil chamber, centrifugal hydraulic pressure is generated due to rotation, and pushes the movable sheave in the direction of the fixed sheave with a force greater than the hydraulic hydraulic force. However, since an equivalent centrifugal oil pressure is generated in the sub chamber divided by the fixed piston, the centrifugal oil pressure in the hydraulic oil chamber and the centrifugal oil pressure in the sub chamber are canceled out, and accurate hydraulic pressure control can be performed. .

Between the sub chamber and the outside is sealed with a flexible membrane, so
Oil leakage from the sub chamber can be reliably prevented, and since there is no sliding portion, sliding resistance does not occur. In particular, since the flexible film body seals not between the hydraulic oil chamber but between the sub chamber and the outside and also seals the inner diameter side of the sub chamber, the load applied to the flexible film body is small.

Since the lubricating oil is supplied to the sub chamber through an oil passage separate from the oil passage to the hydraulic oil chamber, the hydraulic pressure in the hydraulic oil chamber may drop and the centrifugal oil pressure may not be generated sufficiently in the sub chamber. There is no defect.

〔Example〕

FIG. 1 shows an example in which the V-belt transmission pulley according to the present invention is adopted in a V-belt type continuously variable transmission with a direct coupling mechanism. This continuously variable transmission is roughly composed of an input shaft 13, a direct coupling clutch 15, a continuously variable transmission. Device 30, drive shaft 31, driven shaft 53, starting clutch 80, forward / reverse switching mechanism 83, differential device 94 and output shaft
It consists of 96.

The engine output shaft 10 is connected to the right end of the input shaft 13 via a flywheel 11 and a torsional damper 12 for absorbing torque fluctuations of the engine, and the input shaft 13 is located near the right end of the input shaft 13. Oil pump driven by 14
Are arranged. Direct coupling clutch in the middle of the input shaft 13
A clutch drum 16 of 15 is spline-fitted, and a clutch hub 17 is connected to a direct drive gear 18 rotatably supported on the input shaft 13. The direct coupling clutch 15 connects the direct coupling drive gear 18 to the input shaft 13 during direct coupling drive. The vicinity of the left end of the input shaft 13 is rotatably supported by a bearing 19, and an external gear 20 is integrally formed on the left end of the input shaft 13. The external gear 20 meshes with the internal gear 21 fixed to the right end of the drive shaft 31 of the continuously variable transmission 30 to reduce the driving force of the input shaft 13 and transmit it to the drive shaft 31. Internal gear above
The outer peripheral portion of 21 is rotatably supported by a bearing 22.

The continuously variable transmission 30 includes a drive side pulley 32 provided on a drive shaft 31.
And a driven pulley 54 provided on the driven shaft 53, and an endless V-belt 75 frictionally driven between the two pulleys.

As shown in FIG. 2, the drive side pulley 32 has a fixed sheave 33 and a movable sheave 34, and the boss portion 33 of the fixed sheave 33.
a is fitted to the drive shaft 31, and the right end surface of the boss 33a is the drive shaft 31.
It is crimped to the left side surface of the flange 31a. Movable sheave 3
The boss portion 34a of 4 is a sleeve 35 inserted through the outer periphery of the drive shaft 31.
The boss portion 34a is slidably supported on the boss portion 34a.The boss portion 34a projects toward the fixed sheave 33 and is inserted inside the boss portion 33a of the fixed sheave 33 in the entire stroke range. It is possible to prevent oil from leaking out. Sealing members 36, 37 are provided on the inner and outer surfaces of the boss portion 34a of the movable sheave 34 so as to be in sliding contact with the inner surface of the boss portion 33a of the fixed sheave 33 and the outer surface of the sleeve 35, whereby the boss portion 33a of the fixed sheave 33 is provided. A space 38 that expands and contracts as the movable sheave 34 moves in the axial direction is formed inside. The oil collected in the space 38 is the boss portion of the sleeve 35 and the fixed sheave 33.
It is discharged to the lubrication space 40 formed on the right side of the flange 31a via a hollow connecting pin 39 that connects the three parts of 33a and the flange 31a of the drive shaft 31. An arcuate groove 33b is formed on the inner circumference of the left end of the boss portion 33a of the fixed sheave 33, and an oil drain hole 33c is formed to communicate from the groove 33b to the outside of the belt drive surface of the fixed sheave 33. ing. Therefore, even if oil leaks from the space 38 through the seal member 36, the oil does not flow to the belt drive surface side.

A cylinder 41 is fixed to the back of the movable sheave 34 with bolts 42. The cylinder 41 is a peripheral wall portion having a cylindrical inner peripheral surface.
41a and a side wall portion 41b extending from the end of the peripheral wall portion 41a toward the inner diameter side.
And the inner peripheral surface of the peripheral wall portion 41a is fixed to the piston 43
The outer periphery of the is inscribed slidably. The inner peripheral portion of the fixed piston 43 is spline-fitted to the drive shaft 31, and is fixed by tightening with a nut 44 screwed to the drive shaft 31. The back part of the movable sheave 34 and the side wall part 41b of the cylinder 41.
A pin that slidably extends through the fixed piston 43.
45 is erected, which allows the movable sheave 34 to
31 is movably guided only in the axial direction, and the drive shaft 31
Is transmitted to the V-belt 75 via the fixed piston 43, the pin 45 and the movable sheave 34.

The inner diameter of the side wall 41b of the cylinder 41 and the fixed piston 43
A flexible film body 46 made of rubber or the like is mounted between the hydraulic fluid chamber 4 and the chamber on the right side partitioned by the fixed piston 43.
7. The left side is a sub chamber 48 for correcting the centrifugal oil pressure generated in the hydraulic oil chamber 47. In the hydraulic oil chamber 47, the oil passage 4a of the support member 4 fixed to the side surface of the case 2, the communication hole 33d formed in the boss portion 33a of the fixed sheave 33, the drive shaft.
The hydraulic oil is guided outside the pipe 49 fixed inside 31 and through the diagonal communication hole 34b of the movable sheave 34.
On the other hand, the lubricating oil is guided to the sub chamber 48 through the lubricating space 40, the inside of the pipe 49, the shaft center hole 31b, and the communication hole 43a of the fixed piston 43. The oil passage 4a of the support member 4 is connected to a hydraulic control device (not shown) so that the operating hydraulic pressure can be controlled to freely adjust the thrust force (axial force) of the movable sheave 11.

The tightening force of the nut 44 screwed into the left end of the drive shaft 31 is applied to the boss of the fixed sheave 33 via the fixed piston 43 and the sleeve 35.
33a is crimped to the flange 31a of the drive shaft 31. In other words, by tightening the nut 44, the fixed piston 4
3, the sleeve 45 and the fixed sheave 33 can be integrally fixed to the drive shaft 31. The tightening force of the nut 44 also has a function of pressing the inner diameter portion of the flexible film body 46 against the fixed piston 43 via the washer 50 and the metal fitting 51. Above nut 44
A bearing 52 is arranged on the outer periphery of the drive shaft 31, and the left end of the drive shaft 31 is rotatably supported by the cover 2 via the nut 44 and the bearing 52.

As shown in FIG. 3, the driven pulley 54 has a fixed sheave 55 and a movable sheave 56 supported on a driven shaft 53. Driven shaft
A boss portion 55a of a fixed sheave 55 is spline-fitted to the left end portion of 53, and is fixed by tightening with a nut 57. The boss 55a is rotatably supported by the cover 3 via a bearing 58. On the other hand, the inner diameter of the movable sheave 56 is a boss portion 56a that can be inserted inside the boss portion 55a of the fixed sheave 55.
Are integrally formed, and the inner peripheral surface of the boss portion 56a is slidable on the driven shaft 53.

Two seal members 59 and 60 such as O-rings or oil seals are attached to the outer peripheral surface of the driven shaft 53 and the inner peripheral surface of the boss portion 56a. Oil leaks from the seal are double sealed. In addition,
Even if part of the oil leaks from the outer seal member 60, the tip of the boss portion 56a of the movable sheave 56 is always located inside the boss portion 55a of the fixed sheave 55. Part 5
It is collected in the peripheral groove 55b inside 5a, and is further discharged to the outside of the belt driving surface of the pulley 54 through the oil drain hole 55c formed in the fixed sheave 55.

At the back of the movable sheave 56, a peripheral wall portion 61a having a cylindrical inner peripheral surface, and a side wall portion 61 extending from the end of the peripheral wall portion 61a toward the inner diameter side.
A cylinder 61 having b and is fixed by a bolt 62, and an outer peripheral portion of a fixed piston 63 is slidably inscribed on an inner peripheral surface of a peripheral wall portion 61a of the cylinder 61. The inner diameter portion of the fixed piston 63 is spline-fitted to the driven shaft 53, and the back surface (right side surface) of the fixed piston 63 is positioned by abutting on the left end surface of the collar portion 53a formed on the driven shaft 53, and Since the compression spring 64 provided between the movable sheave 56 and the fixed piston 63 and the hydraulic pressure described later are biased to the right, the fixed piston 63 is stably fixed to the driven shaft 53. The compression spring 64 has a function of urging the fixed piston 63 and a function of assisting the coast down function by constantly urging the movable sheave 56 to the left, that is, toward the maximum gear ratio side. Further, the outer end portion of the right end surface of the collar portion 53a has an outer end portion which is a side wall portion 61b of the cylinder 61.
The inner end of the flexible film body 65 fixed to is supported by this, and the inner end is fixed to the driven shaft 53 by the metal fitting 66 and the ring 67.

The left chamber partitioned by the fixed piston 63 is a hydraulic oil chamber 68, and the right chamber is a sub chamber 69 for correcting the centrifugal hydraulic pressure generated in the hydraulic oil chamber 68. The working oil pressure is introduced into the working oil chamber 68 through the inside of the pipe 70 inserted in the shaft center hole 53b of the driven shaft 53, the hole 70a of the pipe 70, and the hole 53c of the driven shaft 53, and the sub chamber 69 On the outside of the pipe 70, the driven shaft 53
The lubricating oil is guided through the hole 53d and the notch 63a of the fixed piston 63. The lubricating oil passage extends to the inner part of the shaft center hole 53b through a recess 70b formed on the outer peripheral surface of the pipe 70, and communicates with an oil drain hole 53e opening to the outer peripheral surface of the driven shaft 53. There is. Further, in order to prevent the hydraulic pressure from leaking to the lubricating oil passage guided to the sub chamber 69, the fixed piston 63 and the driven shaft 53
A seal ring 71 is provided at the spline engagement portion with.

A pin 72 slidably penetrating the fixed piston 63 is provided between the back portion of the movable sheave 56 and the side wall portion 61b of the cylinder 61, and the fixed piston 63 is integrally rotatable with respect to the driven shaft 53. Since it is fixed, the movable sheave 56 and the cylinder 61 are guided so as to be movable only in the axial direction with respect to the driven shaft 53.

A starting clutch 80 is provided at the right end of the driven shaft 53, and the clutch drum 81 of the starting clutch 80 has a driven shaft 53.
The clutch hub 82 is a forward / reverse switching mechanism.
It is connected to the spline hub 84 of 83. The starting clutch 80 is engaged when the belt is driven, is disconnected when the belt is directly driven, and is half-clutch controlled by finely controlling the clutch hydraulic pressure when starting. A forward gear 85 and a reverse gear 86 are rotatably provided on both sides of the spline hub 84, and either one of the gears is connected to the spline hub 84 by a switching sleeve 87. The idle shaft 88 arranged parallel to the driven shaft 53 has a reverse idle gear 89 that meshes with the reverse gear 86.
And another reverse idle gear 90 are integrally formed.
The reduction shaft 91 is also arranged in parallel with the driven shaft 53, and the reduction gear 92 and the final reduction gear 93, which are integrally formed, are rotatably supported on the reduction shaft 91. The reduction gear 92 simultaneously meshes with the direct drive gear 18, the forward gear 85, and the reverse idle gear 90, and also serves as a direct drive gear. The final reduction gear 93 meshes with the ring gear 95 of the differential device 94 and transmits power to the output shaft 96.

As described above, the parts constituting the V-belt type continuously variable transmission are covered with the cases 1 and 2 and the cover 3, and in particular, the continuously variable transmission 30 is provided with the partition walls 2a of the case 2 to clutches 15 and 8.
It is separated from oil-lubricated parts such as 0 and gear mechanism, and is driven without lubrication. The chamber accommodating the continuously variable transmission 30 communicates with the atmosphere through an air hole (not shown) provided in the cover 3, and cooling fins 73 and 74 are integrated behind the drive side pulley 32 and the driven side pulley 54, respectively. By forming it, the air cooling effect of the V-belt 75 is enhanced.

In the V-belt type continuously variable transmission configured as described above, the input shaft 13,
The direct coupling clutch 15, the direct coupling drive gear 18, the reduction gear 92, the final reduction gear 93, the differential device 94, and the output shaft 96 form a direct coupling drive path, and the input shaft 13, the drive shaft 31, the continuously variable transmission 3
The 0, the starting clutch 80, the forward gear 85, the reduction gear 92, the final reduction gear 93, the differential device 94, and the output shaft 96 form a belt drive path (during forward movement). The transmission ratio between the input shaft 13 and the output shaft 96 in the direct drive path is set near the maximum speed ratio between the input shaft 13 and the output shaft 96 in the belt drive path. Therefore, by switching from the belt drive to the direct drive at the time of high speed traveling, the transmission efficiency is increased and the drive time of the V belt 75 is shortened to reduce the V belt.
The life of 75 can be improved.

The present invention is not limited to the case where the V belt is tension driven without lubrication (tension drive type), but is applicable to the case where the V belt is oil-lubricated and compression driven (compression drive type). Effective for belt continuously variable transmission. The reason is as follows.

That is, in the case of the compression drive type, there is no problem even if some oil leaks from the oil chamber, but in the case of the tension drive type, if a little oil adheres to the V-belt or pulley surface, the transmission efficiency becomes extremely high. Therefore, prevention of oil leakage is the most important issue of the tension drive system. On the other hand, in the case of the tension drive type, the coefficient of friction between the V-belt and the pulley surface is significantly higher than that in the compression drive type, so that the pulley thrust force for crimping both sides of the V-belt is small, and therefore the pulley operation is performed. The hydraulic pressure can be low, but on the other hand, it is necessary to minimize the fluctuation of the operating hydraulic pressure due to oil leakage. In this respect, the present invention not only prevents oil from adhering to the surface of the V-belt or the pulley, but also maximizes the advantages of the tension drive system, so that it is possible to ensure that a relatively low hydraulic pressure can be used without leakage. The present invention provides a pin drive system capable of sealing, which makes it possible to improve transmission efficiency, improve control accuracy, and reduce hydraulic pressure loss.

In the present invention, the flexible film body is used for sealing between the sub chamber and the outside, but the following effects are obtained as compared with the case where a sliding seal such as an O-ring or an oil seal is used.

Firstly, since there is no sliding portion, the sealing effect is superior to that of a sliding seal, and sliding resistance is not generated. However, the flexible membrane has a drawback that it is generally low in durability against high pressure, but the flexible membrane of the present invention seals between the sub chamber and the outside, not the hydraulic oil chamber. Therefore, only the centrifugal oil pressure acts on the flexible membrane body, and since the inner diameter side of the sub chamber is sealed, the centrifugal oil pressure is also low. Therefore, sufficient durability can be ensured even with a flexible film body such as rubber.

Secondly, in the case of the sliding seal, the sliding surface needs to be formed on the rotary shaft or the fixed piston, whereas in the case of the present invention, the sliding surface is not required and the degree of freedom in design is high. The point is that it can be compactly arranged. For example, as shown in FIG. 2, when the fixed piston 43 is arranged behind the movable sheave 34 of the drive side pulley 32, and the washer 50 and the nut 44 are arranged behind it, the rear portion of the rotary shaft 31 (second It is difficult to form a sliding surface on which the seal slides at the left end of the figure). If it were intentionally provided, the shaft 31 would be extended rearward (left in FIG. 2), but this would lengthen the axial dimension method. On the other hand, in the present invention, it is not necessary to extend the shaft 31, and the structure can be made compact.

There is also a method of using oil that leaks from the hydraulic oil chamber to the sub chamber as a means for supplying oil to the sub chamber, but this causes a decrease in hydraulic pressure in the hydraulic chamber or sufficient centrifugal hydraulic pressure in the sub chamber. It may not occur. That is, when the movable sheave is retracted from the maximum forward position, the volume of the sub chamber expands, but in the method of leaking oil from the hydraulic oil chamber to the sub chamber as described above, when the amount of leak is large, the hydraulic oil There is a possibility that the oil pressure in the chamber will decrease, and conversely, when the leak amount is small, the sub chamber cannot be rapidly filled with oil, and the required centrifugal oil pressure cannot be generated. On the other hand, in the present invention, since the oil passage for supplying the lubricating pressure to the sub chamber and the oil passage for supplying the operating pressure to the hydraulic oil chamber are formed separately, the hydraulic pressure in the hydraulic oil chamber does not decrease. In addition, it is possible to solve the problem when the volume of the sub chamber changes greatly.

〔The invention's effect〕

As is clear from the above description, according to the present invention, since the ball spline is eliminated and the pin guides the movable sheave in the axial direction, the inner diameter side of the movable sheave and the rotary shaft can be brought into surface contact, and the oil A simple seal member such as a seal or an O-ring can sufficiently prevent a decrease in operating hydraulic pressure and can avoid the risk of oil leakage to the outside. Further, even if oil leaks from the hydraulic oil chamber through the gap between the pin and the fixed piston, this oil only escapes to the sub chamber, so that there is no extreme decrease in hydraulic pressure and no oil leak to the outside.

Further, since the ball spline is not required, the inner diameter of the movable sheave and the shaft diameter of the rotary shaft can be shortened. In other words, a large pressure receiving area of the hydraulic oil chamber can be secured even with the movable sheave having the same outer diameter.

Furthermore, in the case of a ball spline, a slight clearance between the tooth surfaces causes a large amount of play in the circumferential direction and a displacement of the shaft center between the movable sheave and the rotary shaft, but in the present invention, the pin slides with respect to the fixed piston. Since it freely penetrates, it is possible to greatly reduce backlash in the circumferential direction and misalignment of the shaft center, and to secure stable operability of the movable sheave.

Further, in the present invention, since the flexible film body is used to seal between the sub chamber and the outside, the sealing effect is excellent and no sliding resistance is generated. Moreover, since it is not necessary to form a sliding surface on the rotary shaft or the fixed piston, there is an advantage that the degree of freedom in design is high and the structure can be made compact.

Further, since the lubricating oil is supplied to the sub chamber through an oil passage separate from the oil passage to the hydraulic oil chamber, the hydraulic pressure in the hydraulic chamber decreases and the centrifugal pressure is sufficiently generated in the sub chamber. It is possible to solve the inconvenience.

[Brief description of drawings]

FIG. 1 is a sectional view of an example of a V-belt type continuously variable transmission with a direct coupling mechanism using a V-belt transmission pulley according to the present invention, FIG. 2 is a detailed sectional view of a drive side pulley, and FIG. 3 is a driven side. It is a detailed sectional view of a pulley. 30 ... Continuously variable transmission, 31 ... Drive shaft, 32 ... Drive side pulley, 34
… Movable sheave, 41… Cylinder, 43… Fixed piston, 45…
Pin, 46 ... Flexible film body, 47 ... Hydraulic oil chamber, 48 ... Sub chamber, 53 ... Driven shaft, 54 ... Driven pulley, 56 ... Movable sheave, 61 ... Cylinder, 63 ... Fixed piston, 65 ... Flexible film Body, 68 ... hydraulic oil chamber,
69 ... Sub chamber, 72 ... Pin, 75 ... V-belt.

Claims (1)

[Claims] 1. A hydraulic oil for supporting a fixed sheave immovable in the axial direction and a movable sheave movable in the axial direction on a rotating shaft, the hydraulic oil for operating the movable sheave in the axial direction on the back part of the movable sheave. A V-belt transmission pulley provided with a chamber and a sub-chamber for correcting centrifugal oil pressure generated in the hydraulic oil chamber, a peripheral wall portion provided on the back of the movable sheave and having a cylindrical inner peripheral surface, A cylinder having a side wall portion extending from the end of the peripheral wall portion toward the inner diameter side, and an outer peripheral portion slidably inscribed in the peripheral wall portion of the cylinder, the inner peripheral portion being fixed to the rotating shaft, and a hydraulic oil chamber and a sub chamber. A fixed piston for partitioning between the movable sheave and a side wall of the cylinder, and a pin penetrating slidably through the fixed piston, and an outer peripheral portion fixed to the side wall of the cylinder. The inner peripheral part is the above-mentioned rotary shaft or fixed A flexible film body that is fixed to the piston and that is movable in the axial direction to seal the inner diameter side of the sub chamber and a supply oil passage that supplies lubricating oil to the sub chamber separately from the supply oil passage to the hydraulic oil chamber. And a V-belt transmission pulley.