JP6721481B2 - Continuously variable transmission pulley - Google Patents

Description

The present invention relates to a pulley provided in a belt type continuously variable transmission.

As a transmission mounted on a vehicle, a belt type continuously variable transmission (CVT) is widely known.

The belt type continuously variable transmission has a structure in which an endless belt is wound around a primary pulley on the input side and a secondary pulley on the output side. When torque from a drive source such as an engine is input to the primary pulley, the frictional force between the primary pulley and the belt causes the torque to be transmitted from the primary pulley to the belt, and the frictional force between the secondary pulley and the belt causes , Torque is transmitted from the belt to the secondary pulley.

FIG. 2 is a cross-sectional view showing the configuration of the conventional secondary pulley 101. Note that, in FIG. 2, the hatching representing the cross section is omitted.

The secondary pulley 101 is formed integrally with the secondary shaft 102, and has a collar-shaped fixed sheave 103 that extends over the outer periphery of the secondary shaft 102, and one side (engine side) that sandwiches the belt 104 with respect to the fixed sheave 103. The movable sheave 105 provided so as to be movable in the rotation axis direction of the shaft 102, and the movable sheave 105 is fixed to the secondary shaft 102 on the side opposite to the fixed sheave 103 with respect to the movable sheave 105, that is, on the engine side, and on the outer periphery of the secondary shaft 102. And a protruding cylinder 106.

The movable sheave 105 has a substantially cylindrical outer fitting portion 111 fitted to the secondary shaft 102 so as to be movable in the rotation axis direction, and a flange shape in the radial direction of rotation from the end portion of the outer fitting portion 111 on the fixed sheave 103 side. The sheave main body 112 is provided with an overhang, and a substantially cylindrical outer peripheral portion 113 extending from the outer peripheral end of the sheave main body 112 toward the engine. The belt 104 is sandwiched between the fixed sheave 103 and the sheave body 112 of the movable sheave 105.

The cylinder 106 includes a substantially annular plate-shaped inner end portion 114 extending in the rotation radial direction, a substantially cylindrical first intermediate portion 115 extending leftward from the inner end portion 114, and a rotation radial direction extending from the first intermediate portion 115. A substantially second annular plate-shaped second intermediate portion 116 that extends to the outside and an outer end portion 117 that bulges to the left from the second intermediate portion 116 and extends to the outside in the radial direction of rotation are continuously formed in this order.

An oil supply groove 121 is formed over the entire circumference of the outer fitting portion 111 on the inner circumferential surface that rubs against the secondary shaft 102. If the oil supply groove 121 is within the movable range of the movable sheave 105 (outer fitting portion 111), the oil supply groove 121 always communicates with the shaft center oil passage 122 formed in the shaft center of the secondary shaft 102 regardless of the position of the movable sheave 105. doing. In addition, the outer fitting portion 111 is formed with an oil introduction passage 123, one end of which is connected to the oil supply groove 121 and the other end of which is open at the outer peripheral surface of the outer fitting portion 111. Hydraulic pressure is supplied to a hydraulic chamber 124 between the movable sheave 105 and the cylinder 106 from an axial oil passage 122 via an oil supply groove 121 and an oil introduction passage 123.

A coil-shaped bias spring 125 wound so as to surround the outer periphery of the outer fitting portion 111 of the movable sheave 105 is provided between the sheave body 112 of the movable sheave 105 and the second intermediate portion 116 of the cylinder 106. Intervened. The elastic force of the bias spring 125 urges the movable sheave 105 and the cylinder 106 in a direction in which they are separated from each other.

Therefore, the hydraulic pressure of the oil in the hydraulic chamber 124 and the biasing force of the bias spring 125 are applied to the movable sheave 105, and the corresponding thrust (clamping force) is applied to the belt 104.

JP, 2005-145682, A

In the state where the gear ratio is minimum, the movable sheave 105 is closest to the cylinder 106, and the bias spring 125 is compressed most. Therefore, the pitch of the bias spring 125 becomes the smallest and the line gap becomes small. The bias spring 125 is provided with a play (play) in the radial direction of rotation with respect to the outer fitting portion 111 of the movable sheave 105. Therefore, there is a possibility that the bias spring 125, which is in a state where the line gap is small, is eccentric and may block the opening end of the oil introduction path 123 on the hydraulic chamber 124 side (the opening opened on the outer peripheral surface of the outer fitting portion 111). However, there is a concern that the hydraulic response of the secondary pulley 101 (rise of the hydraulic pressure in the hydraulic chamber 124) may deteriorate due to this.

An object of the present invention is to provide a pulley that can reduce the conduit resistance to oil supplied to a hydraulic chamber.

In order to achieve the above-mentioned object, a pulley according to the present invention is a pulley provided in a belt type continuously variable transmission, and is disposed so as to face a fixed sheave fixed to a rotating shaft and a belt sandwiched between the fixed sheave. A movable sheave movably supported on the rotating shaft in the axial direction thereof, and a cylinder fixed to the rotating shaft and forming a hydraulic chamber between the movable sheave and a hydraulic pressure for moving the movable sheave. And a spring that is interposed between the movable sheave and the cylinder and urges the movable sheave and the cylinder in a direction in which the movable sheave and the cylinder are separated from each other. The spring includes a fitting portion, and the spring has a coil shape wound so as to surround the outer circumference of the outer fitting portion, and the outer fitting portion has an oil introduction passage for introducing oil from the oil passage in the rotating shaft into the hydraulic chamber. A groove that is formed and extends in the circumferential direction is formed on the outer peripheral surface of the outer fitting portion, and the oil introduction path is open in the groove.

According to this structure, the movable sheave, which is arranged so as to face the fixed sheave with the belt interposed therebetween, is supported by the rotating shaft so as to be movable in the axial direction thereof, and the hydraulic pressure supplied to the hydraulic chamber formed on the side opposite to the fixed sheave. To move. The hydraulic chamber is formed by a movable sheave and a cylinder, and a coiled spring that urges the movable sheave toward the fixed sheave is interposed between the movable sheave and the cylinder.

The movable sheave includes an outer fitting portion that is fitted onto the rotating shaft so as to be movable in the axial direction. An oil introduction passage for introducing oil from the oil passage in the rotating shaft into the hydraulic chamber is formed in the outer fitting portion. In addition, the outer fitting portion is surrounded by a coil-shaped spring on its outer circumference. In the most compressed state of the coiled spring, its pitch is minimized and the line gap is reduced. Therefore, if the oil introduction path is open at the outer peripheral surface of the outer fitting portion, the opening is blocked by the spring when the most compressed spring contacts the outer peripheral surface of the outer fitting portion, and The supply of oil from the introduction path to the hydraulic chamber may be hindered.

Therefore, a groove extending in the circumferential direction is formed on the outer peripheral surface of the outer fitting portion, and an opening of the oil introducing path on the hydraulic chamber side is formed in the groove. Therefore, even if the spring in the most compressed state contacts the outer peripheral surface of the outer fitting portion, it is possible to prevent the opening of the oil introduction path on the hydraulic chamber side from being blocked by the spring. As a result, the resistance of the pipeline supplied from the oil introduction path to the hydraulic chamber can be reduced, and the hydraulic response of the pulley can be improved.

According to the present invention, the conduit resistance supplied from the oil introduction path to the hydraulic chamber can be reduced, and the hydraulic response of the pulley can be improved.

It is sectional drawing which shows the structure of the secondary pulley which concerns on one Embodiment of this invention.

It is sectional drawing which shows the structure of the conventional secondary pulley.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Secondary pulley>
FIG. 1 is a sectional view showing the configuration of a secondary pulley 1 according to an embodiment of the present invention. In FIG. 1, hatching showing a cross section is omitted.

The secondary pulley 1 is provided in a belt type continuously variable transmission (CVT). The belt type continuously variable transmission has a configuration in which an endless belt is wound around a secondary pulley 1 and an input side primary pulley (not shown).

The secondary pulley 1 includes a fixed sheave 11, a movable sheave 12, and a cylinder 13.

The fixed sheave 11 is formed integrally with the secondary shaft 14, and projects from the secondary shaft 14 to the outside in the radial direction of rotation in a flange shape.

The movable sheave 12 is arranged on one side (right side in FIG. 1, hereinafter referred to as “right side”) of the fixed sheave 11 with the belt 2 interposed therebetween. The movable sheave 12 has a substantially cylindrical outer fitting portion 21 that is fitted onto the secondary shaft 14 so as to be movable in the rotation axis direction, and the fixed sheave 11 side of the outer fitting portion 21 (left side in FIG. 1, hereinafter, “left side”). Of the sheave body 22 protruding outward in the radial direction of rotation from the end of the sheave body 22 and the opposite side of the fixed sheave 11 from the outer peripheral end of the sheave body 22 (right side in FIG. 1, hereinafter, “right side”). That is, it is integrally provided with a substantially cylindrical outer peripheral portion 23 extending in the direction of. The belt 2 is sandwiched between the fixed sheave 11 and the sheave body 22 of the movable sheave 12.

The cylinder 13 is externally fitted to the secondary shaft 14 at a position on the right side of the movable sheave 12. The cylinder 13 has a substantially annular plate-shaped inner end portion 24 extending in the radial direction of rotation, a substantially cylindrical first intermediate portion 25 extending leftward from the inner end portion 24, and a radial direction of rotation from the first intermediate portion 25. A substantially circular plate-shaped second intermediate portion 26 that extends outwardly of the second intermediate portion 26 and an outer end portion 27 that bulges to the left from the second intermediate portion 26 and extends outward in the radial direction of rotation are continuously formed in this order.

A portion of the secondary shaft 14 to which the cylinder 13 is fitted is formed to have a smaller diameter than a portion of the movable sheave 12 to which the outer fitting portion 21 is fitted. As a result, a step is formed on the outer peripheral surface of the secondary shaft 14 between the portion where the outer fitting portion 21 of the movable sheave 12 is fitted and the portion where the cylinder 13 is fitted.

An annular plate-shaped stopper 32 for restricting the movement of the movable sheave 12 is interposed between the surface 31 formed by the step and the inner end portion 24 of the cylinder 13.

Further, on the outer peripheral surface of the secondary shaft 14, a screw is formed on the right side of the portion where the inner end portion 24 of the cylinder 13 is externally fitted. A lock nut 33 is screwed onto the threaded portion. By tightening the lock nut 33, the inner end 24 of the cylinder 13 and the inner peripheral end of the stopper 32 are pressed against each other between the surface 31 and the lock nut 33, and the cylinder 13 and the stopper 32 are fixed to the secondary shaft 14. ing.

The outer end portion 27 of the cylinder 13 is in liquid-tight contact with the inner peripheral surface of the outer peripheral portion 23 of the movable sheave 12, and oil (hydraulic pressure) is supplied between the movable sheave 12 and the cylinder 13. The hydraulic chamber 34 is formed.

A bias spring 35 is provided in the hydraulic chamber 34. The bias spring 35 has a coil shape wound so as to surround the outer periphery of the outer fitting portion 21 of the movable sheave 12. The left end of the bias spring 35 elastically contacts the sheave body 22 of the movable sheave 12, and the right end elastically contacts the second intermediate portion 26 of the cylinder 13. The elastic force of the bias spring 35 urges the movable sheave 12 and the cylinder 13 in a direction in which they are separated from each other.

The hydraulic pressure of the oil in the hydraulic chamber 34 and the biasing force of the bias spring 35 are applied to the movable sheave 12, and the thrust (clamping force) corresponding thereto is applied to the belt 2.

<Oil supply structure>
The secondary shaft 14 is formed with a shaft center oil passage 41 extending on the shaft center thereof. Oil is supplied to the axial oil passage 41 from a valve body (not shown). A communication oil passage 42 is formed in the secondary shaft 14. One end of the communication oil passage 42 is connected to the shaft center oil passage 41, and the communication oil passage 42 communicates with the shaft center oil passage 41. The other end of the communication oil passage 42 is open at the outer peripheral surface of the secondary shaft 14.

In the outer fitting portion 21 of the movable sheave 12, an oil supply groove 43 is formed over the entire circumference on the inner peripheral surface that rubs against the secondary shaft 14. The oil supply groove 43 is designed in its formation position and the dimension in the rotation axis direction so that the oil supply groove 43 always communicates with the communication oil passage 42 regardless of the position of the movable sheave 12 (outer fitting portion 21).

An oil discharge groove 44 is formed on the outer peripheral surface of the outer fitting portion 21 over the entire circumference. The oil discharge groove 44 is inclined from the outer peripheral surface of the outer fitting portion 21 to the right so as to be inclined toward the rotation axis, and is inclined from the right end of the first inclined surface 45 to the right toward the rotation axis. And a second inclined surface 46 that extends so as to have a substantially triangular cross section.

An oil introduction passage 47 is further formed in the outer fitting portion 21. One end of the oil introduction passage 47 is connected to the oil supply groove 43, and the oil introduction passage 47 communicates with the inside of the oil supply groove 43. The other end of the oil introduction path 47 is connected to the first inclined surface 45 of the oil discharge groove 44 and opens at the first inclined surface 45.

The oil supplied from the valve body to the shaft center oil passage 41 is supplied to the oil supply groove 43 through the communication oil passage 42. Then, the oil is supplied from the oil supply groove 43 to the oil discharge groove 44 through the oil introduction path 47, and is discharged from the oil discharge groove 44 to the hydraulic chamber 34.

<Effect>
According to this configuration, the movable sheave 12, which is arranged to face the fixed sheave 11 with the belt 2 interposed therebetween, is supported by the secondary shaft 14 so as to be movable in the axial direction thereof, and is formed in the hydraulic chamber formed on the opposite side of the fixed sheave 11. It moves by the hydraulic pressure supplied to 34. The hydraulic chamber 34 is formed by the movable sheave 12 and the cylinder 13, and a coil-shaped bias spring 35 that urges the movable sheave 12 toward the fixed sheave 11 is interposed between the movable sheave 12 and the cylinder 13. It

The movable sheave 12 includes an outer fitting portion 21 that is fitted onto the secondary shaft 14 so as to be movable in the rotation axis direction. An oil introduction passage 47 for introducing oil from the oil passage in the secondary shaft 14 into the hydraulic chamber 34 is formed in the outer fitting portion 21. Further, the outer fitting portion 21 is surrounded by the bias spring 35 on the outer circumference thereof. When the bias spring 35 is in the most compressed state, its pitch becomes the minimum and the line gap becomes small. Therefore, when the oil introduction path 47 is open on the outer peripheral surface of the outer fitting portion 21, when the bias spring 35 in the most compressed state comes into contact with the outer peripheral surface of the outer fitting portion 21, the opening is opened. There is a risk that the supply of oil from the oil introduction path 47 to the hydraulic chamber 34 will be blocked by the above.

Therefore, an oil discharge groove 44 is formed on the outer peripheral surface of the outer fitting portion 21 over the entire circumference, and an opening of the oil introduction path 47 on the hydraulic chamber 34 side is formed in the oil discharge groove 44. Therefore, even if the bias spring 35 in the most compressed state comes into contact with the outer peripheral surface of the outer fitting portion 21, it is possible to prevent the opening of the oil introduction path 47 on the hydraulic chamber 34 side from being blocked by the bias spring 35. Then, since the oil is distributed in the oil discharge groove 44, the oil can be supplied to the hydraulic chamber 34 from any position of the entire circumference 360° of the oil discharge groove 44. As a result, the conduit resistance supplied from the oil introduction path 47 to the hydraulic chamber 34 can be reduced, and the hydraulic response of the secondary pulley 1 (movable sheave 12) can be improved.

<Modification>
Although one embodiment of the present invention has been described above, the present invention can be implemented in other forms.

For example, although the oil discharge groove 44 is formed to have a substantially triangular cross section having the first inclined surface 45 and the second inclined surface 46, the shape of the oil discharge groove 44 is not limited to this, and the substantially rectangular cross section. It is possible to adopt an arbitrary shape such as or a semi-circular cross section.

However, the oil discharge groove 44 having the first inclined surface 45 and the second inclined surface 46 and having a substantially triangular cross section has various advantages. That is, due to the shape of the oil discharge groove 44, when the oil introduction path 47 is formed by drilling, it is possible to avoid interference between the drill and the outer peripheral portion 23, and a complicated drill or equipment is not required. Further, as compared with the case where a drill is inserted into the outer fitting portion 21 from a direction orthogonal to the rotation axis, the drill is inserted obliquely with respect to the rotation axis from a direction orthogonal to the first inclined surface 45, so The opening area of the oil introduction path 47 can be made large, and the conduit resistance can be further reduced.

In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

1: Secondary pulley (pulley)
2: Belt 11: Fixed sheave 12: Movable sheave 13: Cylinder 14: Secondary shaft (rotating shaft)
21: External fitting portion 34: Hydraulic chamber 35: Bias spring (spring)
41: Shaft center oil passage (oil passage in the rotating shaft)
42: communication oil passage (oil passage in the rotary shaft)
44: Oil discharge groove (groove)
47: Oil introduction path

Claims (1)

A pulley provided in a belt type continuously variable transmission,
A fixed sheave fixed to the rotating shaft,
A movable sheave, which is arranged to face the fixed sheave with a belt interposed therebetween, and is supported by the rotating shaft so as to be movable in the axial direction thereof,
A cylinder that is fixed to the rotating shaft and that forms a hydraulic chamber between the movable sheave and the movable sheave, to which hydraulic pressure for moving the movable sheave is supplied;
A spring interposed between the movable sheave and the cylinder, for urging the movable sheave and the cylinder in directions away from each other,
The movable sheave includes an outer fitting portion that is fitted onto the rotating shaft so as to be movable in the axial direction.
The spring has a coil shape wound so as to surround the outer periphery of the outer fitting portion,
An oil introduction path for introducing oil from an oil path in the rotary shaft to the hydraulic chamber is formed in the outer fitting portion,
A groove extending in the circumferential direction is formed on the outer peripheral surface of the outer fitting portion ,
The spring and the groove are adjacent to each other,
A pulley in which the oil introduction path is open in the groove.

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