JPH0135225B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a continuously variable transmission using a V-belt.

[Prior Art] A conventional belt-type continuously variable transmission has a V-belt with a movable flange driven in the axial direction by a hydraulic servo and a fixed flange on each of an input shaft and an output shaft arranged in parallel. These pulleys are connected by a V-belt, and the width of the V-shaped space is increased or decreased by supplying and discharging hydraulic pressure to a hydraulic servo. The rotation radius of the belt was increased or decreased to achieve continuously variable speed.

[Problems to be solved by the invention] In conventional continuously variable transmissions, power is transmitted from the fixed flange to the belt on the drive side pulley, and from the belt to the movable flange. For example, in a deceleration state, the belt In order to move toward the axis of the movable flange, the movable flange moves away from the fixed flange.
In this case, there may be a limit to the urging force of the means for controlling the operation of the movable flange. For example, when an oil chamber is formed in a predetermined space and a movable flange is controlled by hydraulic pressure, when the input torque exceeds a predetermined value, the torque exceeding the maximum biasing force due to the hydraulic pressure is transmitted to the belt, so the pulley Slippage occurs between the pulley and the belt, and when the slippage increases, a problem arises in that sliding wear occurs between the pulley and the belt and the durability of the belt is impaired.

In order to solve this problem, the patent application
In No. 146878, a spiral groove is formed between the movable flange and the shaft, and the thrust force proportional to the input torque is generated in the movable flange through a rigid ball by disposing it in a spiral space, thereby increasing the belt clamping force. Proposals have been made to eliminate slippage between belts and pulleys.

However, in order to cause the movable flange to generate a thrust force in the direction of the fixed flange that is proportional to the input torque through the rigid ball, it is necessary to allow relative rotation between the movable flange and the shaft on which the movable flange is disposed. Is required. If a structure in which the fixed flange and the shaft rotate integrally is adopted, the relative rotation generated between the shaft and the movable flange causes relative rotation between the movable flange and the fixed flange, and the fixed flange and the movable flange The belt that is held between the belts will tilt, and the durability of the belt will be reduced.

Therefore, the present invention uses rigid balls loosely inserted into each spiral groove formed between the movable flange and the shaft.
The relative rotation between the movable flange and the shaft that occurs in order to generate a thrust force proportional to the input torque on the movable flange is not generated between the movable flange and the fixed flange that sandwich the belt.
The purpose is to provide a structure that improves the durability of the belt.

[Means for Solving the Problem] The present invention includes a movable flange which is disposed on each of an input shaft and an output shaft disposed in parallel and is actuated in the axial direction by a driving means, and which is rotatable relative to the shaft. A pulley is installed that forms a V-shaped space in which the V-belt is held between a fixed flange that is locked in the axial direction, and these pulleys are connected by the V-belt, and the rotation radius of the V-belt in contact with the pulley is In a belt-type continuously variable transmission that performs continuously variable speed by increasing and decreasing speed, a spiral groove is formed between the shaft on which the movable flange is disposed and the movable flange, and the helical groove is formed in the spiral space formed by the groove. A plurality of rigid balls are loosely inserted to lock the relative movement between the movable flange and the shaft, and a thrust force proportional to the input torque is generated on the movable flange through the rigid balls, so that the movable flange is subjected to lateral pressure in the direction of the fixed flange. the movable flange has a sleeve extending in the direction of the fixed flange, the fixed flange is arranged to be rotatable relative to the shaft and slidable in the axial direction on the sleeve, and the fixed flange and a movable flange, a vertical groove is formed between the movable flange and a rigid ball is loosely inserted into the vertical groove to prevent relative rotation between the fixed flange and the movable flange, and the movable flange is provided with a rigid ball in the direction of the fixed flange. The movable flange can be slid in the axial direction with respect to the fixed flange without causing a relative rotation between the shaft and the movable flange to generate a thrust force between the movable flange and the fixed flange. An object of the present invention is to provide a belt type continuously variable transmission characterized by the following.

[Operations and Effects] The belt type continuously variable transmission of the present invention has spiral grooves formed between the shaft on which the movable flange is disposed and the movable flange, and the movable A plurality of rigid balls are loosely inserted to lock the relative movement between the flange and the shaft, and a thrust force proportional to the input torque is transmitted to the movable flange via the rigid balls, so that the movable flange is moved in the direction of the fixed flange. the movable flange has a sleeve extending toward the fixed flange, the fixed flange being axially slidably disposed on the sleeve, and the movable flange having a sleeve extending toward the fixed flange; Longitudinal grooves are formed between each of the movable flanges, and rigid balls are inserted loosely therein to prevent relative rotation between the fixed flange and the movable flange, and the movable flange generates a thrust force in the direction of the fixed flange. The movable flange has a structure that enables relative rotation between the shaft and the movable flange, and allows the movable flange to slide in the axial direction with respect to the fixed flange. The relative rotation between the movable flange and the shaft, which occurs in order to generate a thrust force proportional to the input torque on the movable flange through a rigid ball loosely inserted into each spiral groove, is transferred between the movable flange and the fixed flange that sandwich the belt. It is possible to improve the durability of the belt without causing any damage.

[Embodiment] FIG. 1 is a partially cutaway view showing the essential parts of an embodiment of the present invention, and FIG. 2 is a diagram showing a continuously variable transmission to which the present invention is applied.

1 of the present invention is an input shaft for driving, 2 is an output shaft disposed parallel to the input shaft 1, 30 is a movable flange 3 externally fitted on the input shaft 1 in a loose state, and the input shaft 1 The movable flange 3 has a flange part 31 and a sleeve part 32, and the flange part 31 and the fixed flange 4 have a V-shape for receiving a V-belt. It covers the space 5. Said movable flange 3
The fitting surface 33 with the input shaft 1 and the input shaft 1
The fitting surface 19 with the movable flange 3 is formed with opposing spiral grooves 34 and 18 having an inclination angle α, and a large number of hard balls 6 are formed in the spiral space formed by these grooves 34 and 18. is loosely inserted. The hard ball 6
acts to lock relative movement in the axial direction between the input shaft 1 and the movable flange 3.

30' is a driven pulley that has the same structure as the pulley 30 and is attached to the output shaft 2, 3' is a movable flange thereof, 4' is a fixed flange, and 18' is a driven pulley formed on the output shaft 2. A spiral groove 34' is a spiral groove formed in the movable flange 3', and 6' is a spiral groove 1.
A large number of rigid spheres are loosely inserted into the spiral space formed by 8' and 34'. 50 is a V-belt stretched between the pulley 30 and the pulley 30'.

When torque is transmitted from the input shaft 1 to the V-belt via the pulley 30, half of the torque is transmitted via the movable flange 3 and the other half is transmitted via the fixed flange 4. in this case,
As shown in FIG. 3, the torque T1 transmitted from the input shaft 1 to the movable flange ₃ is a force a in the rotational direction.
is generated, and the contact point A between the groove 18 and the rigid ball 6 is
and an arrow C connecting the contact point B between the rigid ball 6 and the groove 34
A force having a magnitude of a/sin α is generated in the direction of , and this force imparts a thrust F of a magnitude of a/tan α to the movable flange 3. Therefore, if the transmitted torque between the input and output shafts increases or decreases, the force a also changes proportionally, and accordingly, the thrust F also increases or decreases, causing the movable flange 3
is driven to expand and contract the V-shaped space 5, and the lateral pressure of the V-belt 50 in contact with the pulley 30 increases and decreases. In the driven pulley 30', as shown in FIG. 4, a/sin α and force C' are applied to the output shaft 2 from the movable flange 3' via the rigid ball 6', and as a result, the force C' is applied to the output shaft 2 from the output shaft 2 in the opposite direction. A reaction force C' is generated in the direction, and the movable flange 3' receives a thrust F' of magnitude a/sin α. As a result, the movable flange 3' is driven to contract or expand the V-shaped space 5', and the lateral pressure decreases or increases in proportion to the input torque from the V-belt 50 in contact with the pulley 30.

In this embodiment, the fixed flange 4 is formed separately from the input shaft 1, and 135 is a sleeve integrally molded with the movable flange, and an axial groove (longitudinal groove) 136 is formed on the outer periphery of the sleeve. It is inserted between the shaft 1 and the fixed flange 4. The fixed flange 4 is fitted onto the sleeve 135 so as to be movable in the axial direction, and is fitted into the groove 13.
A groove (vertical groove) 141 opposite to the groove 6 (vertical groove) is formed, and these grooves (vertical groove) 136 and 141
A rigid ball 112 is loosely inserted into the space formed by the movable flange 3 and the fixed flange 4 to prevent relative rotation. Reference numeral 110 denotes a flange-shaped portion provided on the input shaft 1, which functions to prevent the movable flange 4 from moving in the axial direction via a bearing 111. A pulley having the same structure as the pulley 30 is also attached to the output shaft, and V is connected between these pulleys.
Connect with a belt. In this embodiment, when the transmission torque between the input and output shafts changes and the movable flange 3 moves in the axial direction while rotating according to the spiral groove 18 or 34, the fixed flange 4 also moves in sync with the movable flange 3. Since the V-belt and the movable flange or the fixed flange rotate with each other, slippage between the V-belt and the movable flange or the fixed flange can be prevented, and smoother continuously variable speed can be achieved.

As mentioned above, the belt type continuously variable transmission of the present invention is
Spiral grooves are formed between the shaft on which the movable flange is disposed and the movable flange, and a plurality of hard balls are suspended in the spiral spaces formed by the grooves to lock the relative movement between the movable flange and the shaft. a thrust force proportional to the input torque is transmitted to the movable flange through the rigid ball, and the movable flange is moved in the direction of the fixed flange to increase the lateral pressure of the pulley against the belt; The fixed flange has a sleeve extending in the direction of the fixed flange, and the fixed flange is slidably disposed on the sleeve in the axial direction, and longitudinal grooves are formed between the fixed flange and the movable flange, respectively. A rigid ball is inserted loosely in order to stop the relative rotation of the movable flange, and the relative rotation between the shaft and the movable flange is enabled to generate a thrust force on the movable flange in the direction of the fixed flange. Since the movable flange is configured to be slidable in the axial direction with respect to the fixed flange, input torque is applied to the movable flange through rigid balls loosely inserted into respective spiral grooves formed between the movable flange and the shaft. The durability of the belt can be improved by preventing the relative rotation between the movable flange and the shaft, which occurs in order to generate a proportional thrust force on the movable flange, between the movable flange and the fixed flange that sandwich the belt. can.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway diagram showing the main part of an embodiment of the present invention, Fig. 2 is a diagram showing a continuously variable transmission to which the present invention is applied, and Fig. 3 is a diagram showing the connection from the input shaft to the movable flange. FIG. 4 is a partially enlarged view showing the state of torque transmission from the movable flange to the input shaft. 1... Input shaft, 2... Output shaft, 3, 3'... Movable flange, 4, 4'... Fixed flange, 5,
5'...V-shaped space, 6,112...Hard sphere, 18,
18', 34, 34'...Spiral groove, 110...Brim portion, 111...Bearing, 135...Sleeve, 136, 141...Groove (vertical groove)

Claims (1)

[Scope of Claims] 1. A movable flange disposed on each of an input shaft and an output shaft disposed in parallel and actuated in the axial direction by a driving means and locked in the axial direction so as to be rotatable relative to the shaft. A pulley is installed that forms a V-shaped space between which the V-belt is held between fixed flanges, these pulleys are connected by a V-belt, and the radius of rotation of the V-belt in contact with the pulley is increased or decreased. In a belt-type continuously variable transmission that performs speed change, a spiral groove is formed between the shaft on which the movable flange is arranged and the movable flange, and the movable flange and the shaft are arranged in a spiral space formed by the groove. loosely inserting a plurality of rigid balls that lock the relative motion of the movable flange, generate a thrust force proportional to the input torque on the movable flange through the rigid balls, and increase the lateral pressure of the movable flange in the direction of the fixed flange; The movable flange has a sleeve extending in the direction of the fixed flange, and the fixed flange is arranged to be rotatable relative to the shaft and slidable in the axial direction on the sleeve, and the fixed flange and the movable flange A vertical groove is formed between each of the two, and a rigid ball is loosely inserted into the vertical groove to prevent relative rotation between the fixed flange and the movable flange, thereby generating a thrust force on the movable flange in the direction of the fixed flange. The movable flange is made to be able to slide in the axial direction with respect to the fixed flange without causing a relative rotation between the shaft and the movable flange that occurs between the movable flange and the fixed flange. Belt type continuously variable transmission. 2. The shaft has an upper collar, and a bearing is disposed between the upper collar and the fixed flange, and the fixed flange is disposed radially outward of the sleeve. Range 1
The belt-type continuously variable transmission described in .