JPH037634Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is a pulley type (belt type) in which the movable sheave of the variable pulley is brought into contact with and separated from the fixed sheave to switch the rotational gear ratio between a pair of rotating shafts. This invention relates to a clutch structure for interrupting power transmission between both rotary shafts in a continuously variable transmission of the formula (2), and particularly to one in which a clutch bearing is provided at the bottom of a belt groove between both shafts.

(Prior Art) Conventionally, this type of pulley-type continuously variable transmission has been widely employed in relatively low-load power transmission systems, such as transmission devices in agricultural machinery and vehicles, for example. This transmission basically has a variable pulley attached to at least one of a pair of rotating shafts arranged parallel to each other, and the variable pulley is disclosed in, for example, Japanese Utility Model Publication No. 43-1961. A belt having a V-shaped cross section is provided between a fixed sheave that is rotationally integrally and non-slidably fixed to the rotating shaft, and a belt that is rotationally integrally and slidably supported on the rotating shaft and is connected to the fixed sheave. It consists of a movable sieve that forms a groove,
By moving the movable shaft toward and away from the fixed shaft and changing the diameter of the pulley (the effective radius of the belt groove), the gear ratio between both rotating shafts can be switched from a low speed state to a high speed state.

By the way, in such a pulley-type continuously variable transmission, a bearing is conventionally installed on the rotating shaft at the bottom of the belt groove between both sheaves of the variable pulley as a clutch for interrupting power transmission between the two rotating shafts. When the movable shaft is farthest from the fixed shaft, the belt is transferred from both shafts onto the outer race of the bearing, thereby establishing a driving connection between the rotating shaft and the belt through relative rotation between the outer and inner races of the bearing. It is known to cut off the power transmission between both rotating shafts.

(Problem to be solved by the invention) Then, when the belt rides on the outer periphery of the bearing in the above neutral state, if the belt is tilted so that the height on the fixed sheave side becomes higher, the contact area between the belt and the fixed sheave increases. This makes it possible to suppress the rotation of the belt to the variable pulley and reliably achieve so-called clutch disengagement. In that case,
As a structure for tilting the belt mounted on the bearing, the outer race outer surface of the bearing itself is tapered, or a truncated conical ring with a tapered outer periphery is fitted and fixed on the outer race outer periphery. Possible structures such as

However, in these structures, the outer periphery of the outer race or ring of the bearing must be tapered, and the shape is unique and the cost is unavoidable.

This invention was made in view of these points,
The purpose of this is to make it possible to tilt the belt in the neutral state while using a normal bearing when using the above-mentioned bearing as the clutch, thereby preventing the belt from rotating in the neutral state with an inexpensive and simple structure. It's about trying to get it.

(Means for Solving the Problem) In order to achieve the above object, the solving means of the present invention integrally attaches a ring in an externally fitted state near the fixed shaft of the variable pulley on the outer periphery of the outer race of the bearing.

Specifically, the present invention provides a fixed shaft provided on at least one of a pair of rotating shafts arranged parallel to each other, and fixed to the one rotating shaft in a rotationally integral manner and non-slidably. and a movable sheave that is rotatably and slidably supported on the rotating shaft and that forms a belt groove with a V-shaped cross section between it and the fixed sheave, and the movable sheave is fixed. This pulley-type continuously variable transmission is equipped with a speed change mechanism that changes the diameter of the pulley by moving it toward and away from the shaft, and by changing the pulley diameter of the variable pulley, the speed ratio between both rotating shafts can be changed from a low speed state to a high speed state. machine is a prerequisite.

In this transmission, a bearing having an outer race rotatable with respect to the rotating shaft is rotatably mounted on the rotating shaft at the bottom of the belt groove between the two sheaves, and the outer race of the bearing has an outer periphery near the fixed sheave. A ring that is narrower than the width of the outer race and protrudes beyond the outer peripheral surface of the outer race is attached to the outer race.

Furthermore, in order to securely fix the ring to the bearing without coming off, a ring groove is formed on the outer periphery of the bearing's outer race near the fixed shaft of the variable pulley. On the other hand, the ring is shaped like a snap spring with one circumferential portion cut off, and is fixed to the outer race by fitting into the ring groove.

(Function) With the above configuration, in the present invention, when the movable sheave of the variable pulley is farthest from the fixed sheave and the transmission is in the neutral state, the belt that was previously on both sheaves is moved from both said sheaves to the bottom of the belt groove. The belt transfers onto the outer race of the bearing, and the driving connection between the belt and the rotating shaft is cut off by the rotation blocking action of the bearing, resulting in a neutral state in which power transmission between the two rotating shafts is cut off.

In that case, a ring is attached to the outer circumferential surface of the outer race of the bearing that protrudes from the outer circumferential surface of the outer race closer to the fixed sheave of the variable pulley, so when the belt rides on the outer circumference of the bearing, the belt is on the fixed sheave side. The belt is tilted to a higher height, and the contact area between the belt and the fixed sheave is reduced, thereby suppressing the rotation of the belt to the variable pulley and ensuring reliable clutch disengagement.

Furthermore, since the ring is fixed to a part of the outer periphery of the bearing, the structure is extremely simple and can be manufactured at low cost.

Then, a ring groove is formed on the outer periphery of the outer race of the bearing near the fixed shaft of the variable pulley, and a snap spring-shaped ring cut at one point in the circumferential direction is fitted into the ring groove to fix the ring to the outer race. With this structure, since the ring is fixed in an engaged state in the ring groove of the bearing, the ring is difficult to come off from the bearing, and thus the ring can be securely fixed to the bearing.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

In FIG. 1, reference numeral 1 denotes an output shaft of an engine, and a cylindrical drive shaft 4, which serves as one rotational shaft in the present invention, is attached to the output shaft 1 so as to rotate integrally therewith. That is, a center hole 4a is formed through the inside of the drive shaft 4, and an enlarged portion 4b having a larger diameter than the other portion is formed near one end of the center hole 4a (close to the right end in the figure). Further, a ring-shaped stopper 3 is fitted into one end of the center hole 4a.
Insert the output shaft 1 of the engine into the center hole 4a of the drive shaft 4 from the other end side (left end side in the figure), and insert the output shaft 1 of the engine into the center hole 4a of the drive shaft 4.
By inserting a stopper 3 into one end and screwing the fastening bolt 2 to the end of the output shaft 1 through the stopper 3, the drive shaft 4 is attached to the engine output shaft 1 so as to rotate integrally. I have to.

A drive pulley 5 consisting of a variable pulley is attached to the other end of the drive shaft 4. The drive pulley 5 includes a flange-shaped fixed sheave 6 concentrically fixed to one end of the drive shaft 4 so as to rotate integrally and non-slidably, and a boss portion 7a on the drive shaft 4 that rotates integrally and slidably. The fixed sieve 6 is
and a flange-shaped movable sheave 7 forming a belt groove 8 with a V-shaped cross section between the belt groove 8 and the belt groove 8. The fixed shaft 6 and the boss portion 6a have a center hole 4a of the drive shaft 4.
A center hole 6b having the same diameter is formed, and the fixed sheave 6 is integrally joined to the end of the drive shaft 4 with both center holes 4a, 6a flush.

On the other hand, on the inner periphery of the boss portion 7a of the movable shaft 7, a bottomed engagement groove 9 is cut at one location in the circumferential direction and extends parallel to the axis of the drive shaft 4 over the entire boss portion 7a. A chip is formed. Further, a pin fitting hole 11 passing through the inside and outside of the drive shaft 4 is formed in a portion of the drive shaft 4 corresponding to the enlarged portion 4b of the center hole 4a, and a pin 10 is inserted into the pin fitting hole 11 at its outer end. The drive shaft 4 is fitted and fixed by press-fitting with the drive shaft 4 protruding outward. Therefore, a pin 10 is provided protruding from the outer periphery of the drive shaft 4. A roller 12 that rolls within the engagement groove 9 of the movable sheave 7 is rotatably supported at the tip of the pin 10, and as the roller 12 rolls within the engagement groove 9, A movable shaft 7 is rotatably and slidably supported on the drive shaft 4.

A cylindrical cam 13 having a cam surface 13a on the opposite side from the fixed sheave 6 is arranged around the boss portion 7a of the movable sheave 7, and the cam 13 is rotatable with respect to the outer circumference of the boss portion 7a by a bearing 27. and are integrally connected for movement in the axial direction. Further, an operating lever 14 is rotatably attached to the outer periphery of the cam 13. On the other hand, an inner race 15a of a bearing 15 is clamped and fixed to rotate integrally between one end of the drive shaft 4 and a stopper 3 fitted into its center hole 4a, and an outer race 15b of the bearing 15 is A roller mount 18 connected and fixed to a predetermined fixed body 16 via an arm 17 is integrally fixed. A plurality of taper pins 19, 19, . A cam roller 20 that comes into contact with the cam surface 13a of the cam 13 is rotatably supported. The cam 13, the cam roller 20,
20, . . . etc., the cam 13 is moved to the boss portion 7a of the movable shake 7 according to the switching operation of the operating lever 14.
By rotating the cam rollers 20, 20, . . . on the cam surface 13a,
A speed change switching mechanism 28 is constructed in which the movable sheave 7 is moved in the axial direction to move toward and away from the fixed sheave 6, and the effective radius of the belt groove 8, that is, the pulley diameter of the drive pulley 5 is made variable.

Further, a bearing 21 of a predetermined width is supported on the drive shaft 4 at the bottom of the belt groove 8 between the two shafts 6 and 7 of the drive pulley 5.
is an inner race 21a that rotates together with the drive shaft 4.
And the balls 21b, 21 are attached to the inner race 21a.
The outer race 21c is rotatably fitted to the outside by the rolling motion of the outer race 21b and the outer race 21c. On the outer periphery of this outer race 21c, there is a ring groove 2 near the fixed shield 6.
1d is formed along the circumferential direction, and the ring groove 2
1d, as shown in FIG. 5, a snap spring-shaped ring 23 is cut at one point in the circumferential direction and is narrower than the outer race 21c, with its outer periphery protruding from the outer periphery of the outer race 21c by a predetermined height. It is mated with.

Further, although not shown, a driven shaft serving as the other rotating shaft is arranged parallel to the driving shaft 4 on the side of the driving shaft 4, and a driven pulley consisting of a fixed pulley having a belt groove is attached to the driven shaft. It is being A V-belt 22 tensioned by a tension pulley (not shown) is wound between the belt groove 8 of the drive pulley 5 and the belt groove of the driven pulley. By moving the movable sheave 7 of the drive pulley 5 toward and away from the fixed sheave 6 through the operation, and changing the pulley diameter of the drive pulley 5, the gear ratio between the drive shaft 4 and the driven shaft is changed from a low speed state to a high speed state. When the movable sheave 7 of the drive pulley 5 approaches the fixed sheave 6 and is positioned at the high speed position Hi, as shown by the imaginary line on the left side in FIG. By increasing the rotation speed of the drive shaft 4, the rotation speed of the drive shaft 4 is increased and transmitted to the driven shaft. In addition, as shown by the solid line in the figure, the movable sheave 7 of the drive pulley 5 is separated from the fixed sheave 6 to a low speed position.
When positioned at Lo, by making the pulley diameter of the driving pulley 5 smaller than that of the driven pulley,
The rotation of the drive shaft 4 is decelerated to a low speed state where it is transmitted to the driven shaft. Further, as shown by the virtual line on the right side of the figure, the movable shaft 7 of the drive pulley 5 is moved to a low speed position Lo corresponding to the low speed state of the drive pulley 5.
When the driving pulley 5 is moved to the opposite side (to the right in the figure) from the high-speed position Hi corresponding to the high-speed state and is positioned at the neutral position N, which is the farthest distance from the fixed sheave 6, the distance between the two sheaves 6 and 7 of the drive pulley 5 is the V-belt 22 in the belt groove 8 from both shafts 6 and 7 onto the outer race 21c of the bearing 21 at the bottom of the belt groove 8,
By cutting off the drive connection between the drive shaft 4 and the V-belt 22, a neutral state is created in which power transmission of the rotation of the drive shaft 4 to the driven shaft is cut off.

Further, as shown in FIG. 2, the peripheral portion of the pin 10 on the outer peripheral surface of the drive shaft 4 is formed as a flat surface 4c, and the inner end of the roller 12 is brought into sliding contact with the flat surface 4c. ing.

Furthermore, as shown in FIGS. 2 and 3, in the engagement groove 9 of the movable sheave 7, when the drive shaft 4 rotates relative to the movable sheave 7 due to the action of the drive torque on the drive shaft 4, the roller 12 On the side surface that comes into contact with the
A predetermined angle θ (0<θ≦45°) toward the fixed sheave 6 side and toward the relative rotational direction of the drive shaft 4 with respect to the movable sheave 7 and with respect to the length direction of the engagement groove 9.
As shown in FIG. 4, when a drive torque is applied to the drive shaft 4 so as to rotate the movable sheave 7 relative to the drive shaft 4 with the drive pulley 5 in the neutral state, as shown in FIG. To,
The roller 12 presses the inclined surface 24, and the axial component force W of the pressing force F causes the movable sheave 7 to move.
is moved in the direction away from the fixed sheave 6, that is, in the direction from the high speed side to the low speed side.

In FIG. 1, reference numerals 25 and 26 are metal seal rings disposed between both ends of the boss portion 7a of the movable shaft 7 and the drive shaft 4 to prevent leakage of lubricating grease sealed in the engagement groove 9. This also prevents dust from entering into the engagement groove 9.

Therefore, in the above embodiment, the drive shaft 4
When changing the gear ratio between the driven shafts, the cam 13 is rotated around the boss portion 7a of the movable shake 7 by switching the operating lever 14, and the cam rollers 20, 20, . . . are rotated on the cam surface 13a. The movable sheave 7 is moved in the axial direction to move toward and away from the fixed sheave 6. For example, in a high-speed state, when the movable sheave 7 is brought closer to the fixed sheave 6 as shown by the imaginary line in FIG. 1, the pulley diameter of the driving pulley 5 becomes larger than the pulley diameter of the driven pulley. The rotation of the drive shaft 4 is accelerated and transmitted to the driven shaft. In addition, when setting the speed to a low speed state, when the movable sheave 7 of the drive pulley 5 is separated from the fixed sheave 6 as shown by the solid line in the same figure, the pulley diameter of the drive pulley 5 becomes smaller than the driven pulley, and the drive shaft 4 The rotation is decelerated and transmitted to the driven shaft.

Furthermore, when creating a neutral state in which power transmission between the drive shaft 4 and the driven shaft is cut off, the movable sheave 7 of the drive pulley 5 is separated from the fixed sheave 6 to the maximum distance, as shown by the imaginary line in the figure. .
With this movement of the movable sheave 7, the V-belt 22, which had been held between the two sheaves 6 and 7, transfers onto the outer race 21c of the bearing 21 located between the two sheaves 6 and 7, and as a result,
The driving connection between the drive shaft 4 and the V-belt 22 is cut off, and the transmission of power between the drive shaft 4 and the driven shaft by the V-belt 22 is cut off.

In this case, the movable sheave 7 of the drive pulley 5
When the movable shaft 7 is slid on the drive shaft 4, the movable shaft 7
As the roller 12 moves, the roller 12 supported by the pin 10 on the drive shaft 4 rolls while contacting the side surface of the engagement groove 9, and the rolling of the roller 12 reduces the sliding resistance of the movable sheave 7. It is possible to reduce the switching operation force.

Further, since an engagement groove 9 extending along the central axis direction of the boss portion 7a is formed on the inner periphery of the boss portion 7a of the movable sheave 7, the engagement groove 9 is connected to the boss portion 7a.
Machining from the inner circumferential side makes it possible to increase the length of the engagement groove 9 without increasing the overall length of the boss portion 7a, thereby ensuring a large sliding stroke of the movable sheave 7. The size of the transmission can be made more compact.

Furthermore, since the peripheral part of the pin 10 on the outer circumferential surface of the drive shaft 4 is formed into a flat surface 4c so that the inner end part of the roller 12 can be slidably contacted, the peripheral part of the pin 10 is separated from the axis of the drive shaft 4. Since the height position is lowered, the length of the pin 10 can be shortened accordingly, and the rigidity of the pin 10 can be increased to increase the transmission power of the drive pulley 5.

In addition, in the above neutral state, the roller 12 on the drive shaft 4 side is moved by the inclined surface 2
In this state, when driving torque acts on the drive shaft 4 and the movable shaft 7 attempts to rotate relative to the drive shaft 4 in the direction of the rotation delay side, the roller 12 moves into the engagement groove 9. The inclined surface 24 will be pressed. And, as shown in Figure 4,
At that time, due to the axial component force W (=F・tanθ) of the pressing force F by which the roller 12 presses the inclined surface 24,
The movable sheave 7 is pushed in the direction away from the fixed sheave 6 (to the right in the figure). Therefore, even if the movable sheave 7 tries to return to the low speed position Lo in the neutral state, it will be pushed back to the neutral state where the belt thrust is eliminated by the pressure of the inclined surface 24 by the roller 12, and thus the space between the drive shaft 4 and the driven shaft will be reduced. power transmission can be reliably interrupted.

Moreover, the outer race 2 of the bearing 21
Since a ring 23 protruding from the outer race 21c is attached to the outer periphery of the 1c near the fixed sheave 6, the V-belt 22 is attached to the outer race 21c.
In the state in which the belt 22 is placed on top of the shaft, the belt 22 is inclined at an angle ψ with respect to the axis of the drive shaft 4, as shown by the imaginary line in FIG. 22 Sheave 6,
7 is suppressed, rotation of the driven shaft is reliably prevented, and power transmission between the drive shaft 4 and the driven shaft can be more reliably interrupted.

In addition, a ring 23 is attached to a part of the outer circumference of the bearing 21.
Since the structure is fixed, the structure is extremely simple and can be manufactured at low cost.

In addition, the outer race 21c of the bearing 21
A ring groove 21d is formed on the outer periphery of the drive pulley 5 near the fixed sheave 6, and the ring groove 21d
Since the ring 23 in the form of a snap spring cut at one point in the circumferential direction is fitted into the ring 23, the ring 23 is engaged and fixed in the ring groove 21d and is difficult to come off from the outer race 21c.
can be securely fixed to the bearing 21.

In the above embodiment, the ring 23 is shaped like a snap spring, and the ring groove 2 on the outer periphery of the bearing 21 is
1d, but as shown in FIGS. 6 and 7, a normal ring 23' may be press-fitted and fixed on the outer periphery of the bearing 21'.

Further, in the above embodiment, the boss portion 7a of the movable sheave 7 in the drive pulley 5 and the drive shaft 4 are engaged by the pin 10, the roller 12, and the engagement groove 9 to rotate integrally and slidably engage. Although one mechanism is provided at one location in the circumferential direction, a plurality of engagement mechanisms may be provided at multiple locations in the circumferential direction at equal angular intervals. In that case, since the drive shaft 4 and the drive pulley 5 are engaged by a plurality of pins, the torque transmitted between them can be increased, and the drive shaft 4 and the drive pulley 5 can be The power transmitted between the driven shafts can be increased. Furthermore, during maintenance of the engagement mechanism, the movable shaft 7 is removed from the drive shaft 4 by removing the fastening bolt 2 and the stopper 3, but in the above case, a plurality of pins are arranged at equal angular intervals in the circumferential direction. Therefore, the movable sheave 7 can be pulled out while keeping it concentric with the drive shaft 4, and it will not be tilted and caught due to uneven contact of the pin, which has the advantage of simplifying maintenance work.

Further, in the above embodiment, a speed change switching mechanism 28 consisting of a cam 13 and cam rollers 20, 20, etc. for sliding the movable sheave 7 on the drive pulley 5 consisting of a variable pulley is provided, and the drive shaft However, conversely, the driven pulley is configured with a variable pulley, the drive pulley is configured with a fixed pulley, and a speed change switching mechanism similar to that of the above embodiment is disposed on the driven pulley side. It is also possible to set Further, both the driving and driven pulleys may be configured with variable pulleys, and either the driving or driven pulley may be provided with a speed change switching mechanism. In either case, the same effects as in the above embodiment can be obtained. can play.

(Effects of the invention) As described above, according to the invention, in the variable pulley of a pulley-type continuously variable transmission, a bearing is disposed on the rotating shaft at the bottom of the belt groove between the movable and fixed sheaves, and the outer race of the bearing is By attaching a ring that is narrower than the width of the outer race and protrudes from the outer surface of the outer race near the fixed shaft on the outer periphery, the belt is fixed when the driving connection between the belt and the variable pulley is cut off by the bearing in the neutral state. By slanting the sheave side to be higher, the contact area between the belt and the fixed sheave can be reduced, suppressing the rotation of the belt to the variable pulley and ensuring clutch disengagement. It can be obtained with an extremely simple and inexpensive structure by simply fixing the ring to a part of the outer periphery.

In addition, a ring groove is formed on the outer periphery of the outer race of the bearing near the fixed shaft of the variable pulley, and the ring is cut at one point in the circumferential direction in the form of a snap spring, and this ring is fitted into the ring groove. If this structure is used to fix the ring to the outer race, the ring will be fixed in an engaged state in the ring groove of the bearing, making it difficult for the ring to come off from the outer race of the bearing.This will securely fix the ring to the bearing and achieve the above effect. can be maintained stably.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a sectional view showing the drive pulley and gear change mechanism of a continuously variable transmission, FIG. 2 is an enlarged sectional view taken along the line -- in FIG.
The figure is a sectional view taken along the line -- in FIG. 2, FIG. 4 is a diagram showing the force acting on the movable shaft in a neutral state, and FIG. 5 is a perspective view of the ring. FIG. 6 is an enlarged sectional view of a main part of another embodiment, and FIG. 7 is a view corresponding to FIG. 5. 4... Drive shaft (rotating shaft), 4c... Flat surface, 5
...Drive pulley (variable pulley), 6...Fixed sheave, 7...Movable sheave, 7a...Boss part, 8
...Belt grooves 8, 9...Engagement groove, 10...Pin,
12...Roller, 13...Cam, 20...Cam roller, 21, 21'...Bearing, 21c,
21c'...Outer race, 21d...Ring groove,
22...V belt, 23, 23'...Ring, 2
4... Inclined surface, 28... Speed change switching mechanism.

Claims (1)

[Claims for Utility Model Registration] (1) A fixed shaft provided on at least one of a pair of rotating shafts arranged parallel to each other, and fixed to the one rotating shaft integrally and non-slidably. is rotatably and slidably supported on the rotating shaft, and has a cross section V between it and the fixed shaft.
A variable pulley consisting of a movable sheave forming a letter-shaped belt groove is provided, and a speed change switching mechanism is provided for changing the diameter of the pulley by moving the movable sheave toward and away from the fixed sheave, and the pulley diameter of the variable pulley is changed. In a pulley type continuously variable transmission in which the gear ratio between both rotating shafts is switched between a low speed state and a high speed state, a rotary shaft rotatable with respect to the rotating shaft is mounted on the rotating shaft at the bottom of the belt groove between the two shafts. A bearing having an outer race is rotatably attached to the outer race of the bearing, and a ring is attached to the outer periphery of the bearing near the fixed shaft, the ring being narrower than the width of the outer race and protruding from the outer periphery of the outer race. The clutch structure of a pulley-type continuously variable transmission. (2) A ring groove is formed on the outer periphery of the outer race of the bearing near the fixed shaft of the variable pulley, and the ring is cut at one point in the circumferential direction, and is fitted into the ring groove and fixed to the outer race. A clutch structure for a pulley-type continuously variable transmission according to claim (1).