JP2015178868A - Pulley mechanism, transmission including pulley mechanism, and vehicle including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulley mechanism capable of setting a thrust to have an appropriate magnitude.SOLUTION: A pulley mechanism comprises: a fixed pulley 3; a movable pulley 10 extending to an opposite side to the fixed pulley 3 and including a cylindrical portion 12; a plunger 20 provided on an opposite side to the fixed pulley 3 across the movable pulley 10; and a pressure reception chamber 40 that is surrounded by the movable pulley 10, the plunger 20, and a seal member 30 and to which oil is supplied, an inner circumferential surface 15 of the cylindrical portion 12 has a larger inside diameter as being farther from the fixed pulley 3.

Description

  The present invention relates to a pulley mechanism including a movable pulley and a fixed pulley for clamping a power transmission member by hydraulic pressure, a transmission having the pulley mechanism, and a vehicle including the transmission.

  Some continuously variable transmissions include two pulley mechanisms each connected to a rotating shaft, and a belt or chain (hereinafter collectively referred to as “belt”) wound around these pulley mechanisms.

  In such a continuously variable transmission, power is transmitted from one pulley mechanism to the other pulley mechanism via a belt.

  The two pulley mechanisms are similarly configured.

  As shown in FIG. 6, the pulley mechanism includes a fixed pulley 3 and a movable pulley 100.

  Each of the fixed pulley 3 and the movable pulley 100 rotates together with the rotating shaft 1.

  A groove 9 having a V-shaped cross section is formed between the fixed pulley 3 and the movable pulley 100.

  The belt 2 is clamped to the fixed pulley 3 and the movable pulley 100 that form the V-shaped groove 9.

  The movable pulley 100 has a cylinder 120 extending toward the side opposite to the fixed pulley 3 (hereinafter referred to as “back side”).

  An inner peripheral surface 150 of the cylinder 120 is provided in parallel with the rotation shaft 1.

  That is, the inner diameter of the cylinder 120 is constant regardless of the axial position.

  In other words, the inner peripheral surface 150 of the cylinder 120 is formed such that the distance from the axis C of the rotary shaft 1 is equal regardless of the axial position.

  Furthermore, the pulley mechanism includes a plunger 200 provided on the opposite side of the movable pulley 100 from the fixed pulley 3, and a seal member 300 that seals (seals) the space between the plunger 200 and the inner peripheral surface 150 of the cylinder 120. The movable pulley 100 is provided with a pressure receiving chamber 400 for applying hydraulic pressure from the opposite side to the fixed pulley 3.

  The plunger 200 has a fixed axial position with respect to the rotary shaft 1.

  The seal member 300 seals a gap formed between the plunger 200 and the movable pulley 100 in the radial direction (direction orthogonal to the axial direction).

  The pressure receiving chamber 400 is a space surrounded by the movable pulley 100, the plunger 200, and the seal member 300.

  The pressure receiving chamber 400 is supplied with oil from an oil pump (not shown).

  When the pressure of oil supplied to the pressure receiving chamber (hereinafter referred to as “hydraulic pressure P”) acts on the movable pulley 100, a force for moving the movable pulley 100 in the axial direction is generated.

  This axial movement force acts as a force for clamping the belt 2 between the movable pulley 100 and the fixed pulley 3 (hereinafter referred to as “thrust force F”).

  This thrust F is generated by the hydraulic pressure P acting in the direction along the axial direction.

That is, the thrust F is in accordance with the hydraulic pressure P and the axial projected area of the pressure receiving surface of the movable pulley 100 (hereinafter referred to as “pressure receiving area A”), as represented by the following formula (1).
F = P × A (1)

  When this thrust F acts on the movable pulley 100, the distance between the fixed pulley 3 and the movable pulley 100, that is, the groove width changes.

If the hydraulic pressure in _one pulley mechanism is P1, the thrust F1 in _one pulley mechanism is expressed by the following equation (2).
F ₁ = P ₁ × A (2)

Similarly, if the hydraulic pressure in the other pulley mechanism and P _2, the thrust F ₂ in the other pulley mechanism is represented by the following formula (3).
F ₂ = P ₂ × A (3)

The wrapping radius of the belt 2 in each pulley mechanism is changed by changing the groove width in each pulley mechanism in accordance with the ratio of these thrusts (F ₁ / F ₂ , hereinafter referred to as “thrust ratio Z”). The

  Therefore, the gear ratio of the continuously variable transmission is changed.

  Such a continuously variable transmission mechanism is disclosed in Patent Document 1, for example.

JP 2005-3012 A

By the way, the minimum hydraulic pressure P (hereinafter referred to as “minimum pressure P _min ”) is set to a constant magnitude for the following reasons 1 and 2.
(Reason 1) To ensure the responsiveness of shifting when the hydraulic pressure P is changed from the minimum pressure _Pmin .
(Reason 2) Because the minimum pressure P _min that can be stably generated is set by the oil pump.

Therefore, as represented by the following formula (4), the minimum thrust F (hereinafter referred to as “minimum thrust F _min ”) has a magnitude corresponding to the minimum pressure P _min .
F _min = P _min × A (4)

If this minimum thrust F _min is larger than the minimum thrust required to transmit power by the belt (hereinafter referred to as “required thrust F _rq ”), the pulley mechanism will have an excessive thrust (hereinafter referred to as “excess thrust F F”). _o ") will act.

This excessive thrust _Fo is expressed by the following equation (5).
F _o = F _min −F _rq (5)

Further, the necessary thrust F _rq is proportional to the torque to be transmitted (hereinafter referred to as “transmission torque T”).

For example, small wrapping radius R in the pulley mechanism, when the wrapping radius R becomes large in the other pulley mechanism, the transmission torque T ₁ in the pulley mechanism, than the transmission torque T ₂ in the other pulley mechanism Get smaller.

At this time, required thrust F _rq in the pulley mechanism is small, required thrust F _rq in other pulley mechanism increases.

However, in the continuously variable transmission, since the speed ratio is changed according to the thrust ratio Z, when the minimum thrust _Fmin is larger than the required thrust _Frq , an excessive thrust _Fo is generated in each pulley mechanism.

In particular, in the pulley mechanism, when the winding radius R is small and the transmission torque T is small, in other words, when the fixed pulley and the movable pulley are separated from each other and the groove width is large, the necessary thrust F _rq is small. There is a possibility that the excessive thrust _Fo becomes large.

  One of the objects of the present invention has been invented in view of such a problem, and is a pulley mechanism, a transmission having the pulley mechanism, and a transmission capable of appropriately setting the thrust. And a vehicle equipped with a vehicle.

  Note that the present invention is not limited to this purpose, and other effects of the present invention can also be achieved by the functions and effects derived from the respective configurations shown in the embodiments for carrying out the invention which will be described later. Can be positioned as

  (1) In order to achieve the above object, a pulley mechanism according to the present invention includes a fixed pulley, a movable pulley having a cylindrical portion extending toward the opposite side of the fixed pulley, and the movable pulley. A plunger provided on the opposite side of the fixed pulley, a pressure receiving chamber surrounded by the movable pulley and the plunger and supplied with oil, and an inner peripheral surface of the cylindrical portion is fixed As the distance from the pulley increases, the distance from the axis of the rotation shaft increases.

  (2) It is preferable to provide a seal member that seals between the inner peripheral surface of the cylindrical portion and the plunger.

  (3) It is preferable that the seal member is provided so as to protrude from the plunger as the movable pulley comes closer to the fixed pulley.

  (4) It is preferable to provide an oil passage formed on the plunger and applying hydraulic pressure to the seal member.

  (5) Furthermore, it is preferable that the oil passage communicates with the pressure receiving chamber.

  (6) Moreover, it is preferable that oil of a pressure different from the pressure of the oil in the pressure receiving chamber is supplied to the oil passage.

  (7) It is preferable that the pressure receiving chamber has a frustum shape in which two bottom surfaces each have a polygonal shape, and the sealing member has the polygonal shape in which the length of each side is variable.

  (8) The transmission of the present invention has the pulley mechanism described above.

  (9) Moreover, the vehicle of this invention is provided with the transmission which has said pulley mechanism.

  According to the pulley mechanism of the present invention, the distance between the inner peripheral surface of the cylindrical portion of the movable pulley and the axis of the rotating shaft increases as the distance from the fixed pulley increases. As the winding radius of the power transmission member decreases, the area (pressure receiving area) obtained by projecting the pressure receiving surface of the pressure (hydraulic pressure) by the oil in the pressure receiving chamber in the axial direction can be reduced.

  Therefore, the thrust can be suppressed as the transmission torque decreases as the movable pulley moves away from the fixed pulley (the winding radius of the power transmission member decreases).

  For example, even if the minimum pressure of the oil pressure in the pressure receiving chamber is set to a constant magnitude, the pressure receiving area decreases as the movable pulley is separated from the fixed pulley, so the groove width between the movable pulley and the fixed pulley increases. The thrust can be reduced.

  Therefore, it is possible to prevent an excessively large thrust from acting on the pulley mechanism.

  For example, even if the hydraulic pressure in the pressure receiving chamber is the same, the thrust can be suppressed when the wrapping radius of the power transmission member is small and the transmission torque is small, and conversely, the wrapping radius of the power transmission member is When the torque increases and the transmission torque increases, the thrust can be secured.

  In this way, excessive thrust can be suppressed while securing necessary thrust, and the thrust can be appropriately sized.

  Further, according to the transmission having the pulley mechanism described above, it is possible to reliably transmit power while suppressing excessive thrust.

  Moreover, according to the vehicle provided with the transmission having the pulley mechanism described above, for example, if oil is supplied to the pressure receiving chamber by an oil pump, energy applied to the oil pump can be suppressed, and fuel consumption can be improved. Can be made.

It is sectional drawing which shows typically the whole structure of the pulley mechanism concerning one Embodiment of this invention. It is a single figure which shows the movable pulley of the pulley mechanism concerning one Embodiment of this invention. It is a perspective view which takes out the seal member of the pulley mechanism concerning one Embodiment of this invention, and expands and shows a principal part. It is the side view which takes out the sealing member of the pulley mechanism concerning one Embodiment of this invention, and expands and shows the principal part, (a) shows the sealing member of a 1st state, (b) is the sealing of a 2nd state The member is shown. It is a schematic diagram which shows the modification of the pulley mechanism concerning one Embodiment of this invention. FIG. 5 corresponds to FIG. It is sectional drawing which shows the conventional pulley mechanism typically.

  Hereinafter, an embodiment according to a pulley mechanism of the present invention will be described with reference to the drawings.

  In the present embodiment, a description will be given of a pulley mechanism used in a transmission.

  This transmission can be mounted on a vehicle such as an automobile or a motorcycle.

  Here, a continuously variable transmission will be described as an example of the transmission.

  The continuously variable transmission includes two pulley mechanisms connected to respective rotary shafts, and a power transmission member such as a belt or a chain wound around these pulley mechanisms.

  In this continuously variable transmission, power is transmitted from one pulley mechanism to the other pulley mechanism via a power transmission member.

  In the following description, a power transmission member using a belt will be described as an example.

  The two pulley mechanisms can be similarly configured.

  For this reason, in this embodiment, it demonstrates paying attention to one pulley mechanism.

  In the present embodiment, a direction along the rotation axis is an axial direction, and a direction orthogonal to the axial direction is a radial direction.

  In the radial direction, the side closer to the rotating shaft is the inner side or inner peripheral side, and the side far from the rotating shaft is the outer side or outer peripheral side.

  In the following description, components having the same configuration as the pulley mechanism in the conventional continuously variable transmission described with reference to FIG.

[1. One Embodiment]
[1-1. Constitution〕
Hereinafter, the configuration of the pulley mechanism according to the embodiment will be described.

  First, the pulley mechanism will be described with reference to FIG.

  The pulley mechanism is for transmitting the rotational power of the rotary shaft 1 to the belt (power transmission member) 2 via the fixed pulley 3 and the movable pulley 10.

  Specifically, the pulley mechanism is for sandwiching the belt 2 between the fixed pulley 3 and the movable pulley 10 in order to transmit rotational power.

  In this pulley mechanism, a thrust F is applied to thrust the movable pulley 10 toward the fixed pulley 3.

  For this purpose, the pulley mechanism includes a fixed pulley 3 and a movable pulley 10 that are connected so as to rotate together with a rotation shaft 1 provided coaxially, and various configurations for generating a thrust F.

  Hereinafter, the basic configuration of the rotating shaft 1, the fixed pulley 3, and the movable pulley 10 will be described, and then the configuration of the movable pulley 10 applied to the thrust F and each configuration for applying the thrust F will be described.

[1-1-1. Basic configuration)
[1-1-1-1. Axis of rotation〕
Power is input to or output from the rotating shaft 1.

  For example, the rotating shaft 1 is connected to an output shaft of a power source (both not shown) such as an engine or an electric motor when power is input.

  On the other hand, the rotating shaft 1 is connected to an input shaft of a speed change mechanism in a continuously variable transmission such as a reduction gear or a sub-transmission when power is output.

  An oil passage 1 a is formed on the rotary shaft 1.

  Oil from an oil pump (not shown) flows through the oil passage 1a.

  The pressure of the oil discharged from the oil pump is regulated by a hydraulic control system such as a pressure control valve and supplied to the oil passage 1a.

  The oil pump is driven by an engine, a motor, etc. (not shown).

  This oil is a hydraulic oil for generating a thrust F, the details of which will be described later.

[1-1-1-2. (Fixed pulley)
The fixed pulley 3 is fixed at an axial position with respect to the rotary shaft 1.

  The fixed pulley 3 has a clamp surface (also referred to as “sheave surface”) 3 a for clamping the belt 2 on the movable pulley 10 side.

  The clamp surface 3a is inclined to the opposite side to the movable pulley 10 side at a predetermined sheave angle α with respect to the axis along the radial direction.

[1-1-1-3. (Main body of movable pulley)
The movable pulley 10 is provided so as to be movable in the axial direction with respect to the rotary shaft 1.

  The movable pulley 10 includes a main body portion 11 formed on the solid pulley 3 side, and a cylinder (cylindrical portion) 12 and an inner cylinder portion 13 extending from the main body portion 11 to the opposite side of the fixed pulley 3. .

  Details of the cylinder 12 and the inner cylinder portion 13 will be described later.

  Similar to the fixed pulley 3, the main body 11 of the movable pulley 10 has a clamp surface (also referred to as “sheave surface”) 11 a that clamps the belt 2 on the fixed pulley 3 side.

  The clamp surface 11a is inclined to the opposite side of the fixed pulley 3 at a predetermined sheave angle α with respect to the axis along the radial direction.

  The main body portion 11 having the clamp surface 11a is formed in a shape in which the axial length becomes smaller toward the outer side in the radial direction.

  Here, a surface (hereinafter, referred to as “fixed pressure receiving surface”) 11b opposite to the fixed pulley 3 in the main body 11 forms a plane along the radial direction.

[1-1-1-4. V-shaped groove]
A groove 9 having a V-shaped radial cross section (hereinafter referred to as “V-shaped groove”) is formed between the fixed pulley 3 and the main body 11 of the movable pulley 10.

  The belt 2 is clamped to the fixed pulley 3 and the movable pulley 10 that form the V-shaped groove 9.

  Specifically, the clamp surface 3 a of the fixed pulley 3 and the clamp surface 11 a of the main body 11 of the movable pulley 10 are in pressure contact with the belt 2.

  Although not shown in FIG. 1, the cross sections of the main body 11 of the fixed pulley 3 and the movable pulley 10 are formed symmetrically with respect to the axis C of the rotating shaft 1.

[1-1-2. Configuration for generating thrust)
Next, a configuration for causing the thrust F to act on the movable pulley 10 will be described.

  As such a configuration, a plunger 20 provided on the opposite side of the movable pulley 10 from the fixed pulley 3, a seal member 30 for sealing (sealing) between the plunger 20 and the movable pulley 10, and the movable pulley 10 A pressure receiving chamber 40 for applying hydraulic pressure from the opposite side to the fixed pulley 3 is mentioned.

  The plunger 20 and the pressure receiving chamber 40 are provided coaxially with the rotary shaft 1.

  Hereinafter, the configuration of the cylinder (cylindrical portion) 12 and the inner cylindrical portion 13 of the movable pulley 10 applied to the thrust F will be described, and then each configuration will be described in the order of the plunger 20, the seal member 30, and the pressure receiving chamber 40.

  The movable pulley 10 includes a cylinder 12 extending from the radially outer peripheral portion 11 c to the opposite side of the fixed pulley 3 in the main body portion 11, and a radially inward inner peripheral portion 11 d of the main body portion 11 from the fixed pulley 3. Has an inner cylinder portion 13 extending on the opposite side.

  An inner cylinder portion 13 is provided on the inner peripheral side of the cylinder 12 with a gap therebetween.

  For this reason, a space (corresponding to the pressure receiving chamber 40) having an opening on the side opposite to the fixed pulley 3 is formed on the side opposite to the fixed pulley 3 with respect to the movable pulley 10.

  This opening is closed by a plunger 20 and a seal member 30 which will be described in detail later.

[1-1-2-1. (Moveable pulley cylinder)
The cylinder 12 is a cylindrical part coaxial with the rotary shaft 1.

  A seal member 30 described later is in sliding contact with the inner peripheral surface 15 of the cylinder 12.

  The inner peripheral surface 15 is formed with a slope 16 whose inner diameter increases as the distance from the fixed pulley 3 increases.

  The inner diameter here corresponds to the distance between the slope 16 and the axis C of the rotary shaft 1.

  FIG. 1 illustrates an example in which the inner diameter of the inclined surface 16 increases linearly as the distance from the fixed pulley 3 increases.

  However, the inner diameter of the slope 16 may be increased nonlinearly as the distance from the fixed pulley 3 increases.

  In FIG. 1, the entire inner peripheral surface 15 is an inclined surface 16, that is, the inner peripheral surface 15 and the inclined surface 16 are the same, but the inclined surface 16 is formed on a part of the inner peripheral surface 15. May be.

  In any case, the inner diameter of at least a part of the inner peripheral surface 15 increases as the distance from the fixed pulley 3 increases.

  It is preferable that the slope 16 includes a sliding contact region of the seal member 30 corresponding to the moving range of the movable pulley 10.

  However, the slope 16 should just contain at least one part of said sliding contact area | region.

  For example, the slope 16 may be provided only on the fixed pulley 3 side of the inner peripheral surface 15, or may be provided only on the opposite side.

  As shown in FIGS. 1 and 2, the inclined surface 16 (inner peripheral surface 15) of the cylinder 12 forms a side surface of a frustum (hereinafter simply referred to as “polygonal frustum”) in which two bottom surfaces form a polygonal shape. .

  The polygonal shape applied to the above-mentioned polygonal frustum is not limited to those having sides that are straight lines, but also includes those having sides that are, for example, gentle curves, and those having roundness around each vertex. It is meant to include.

  Here, the fixed pressure receiving surface 11b of the main body 11 in the movable pulley 10 forms a part of the upper bottom surface of the polygonal frustum.

  Further, the outer peripheral surface 19 of the cylinder 12 is provided in a curved surface forming a cylindrical side surface along the rotation axis 1 (indicated by a two-dot chain line in FIG. 2).

  For this reason, the cylinder 12 is formed in a shape in which the thickness increases (the radial direction length increases) as it approaches the fixed pulley 3.

  In other words, the base end portion 12a (see FIG. 1) of the cylinder 12 is formed thick.

  Although FIG. 2 illustrates a polygon having a hexagonal shape on the frustum, this polygon may be another polygon.

[1-1-2-2. (Inner cylinder of movable pulley)
The inner cylinder portion 13 is a cylindrical portion coaxial with the rotary shaft 1 and is provided adjacent to the outer periphery of the rotary shaft 1.

  As shown in FIG. 1, an oil passage 13 a is formed in the inner cylinder portion 13.

  The oil passage 13 a communicates the inner peripheral side and the outer peripheral side of the inner cylinder part 13.

  More specifically, the oil passage 13a communicates with the oil passage 1a of the rotary shaft 1 provided on the inner peripheral side, and communicates with the pressure receiving chamber 40 provided on the outer peripheral side.

  Note that the oil passage 13a of the inner cylinder portion 13 allows the oil passage 1a of the rotary shaft 1 and the pressure receiving chamber 40 to communicate with each other regardless of whether the movable pulley 10 is positioned in the axial direction within the movable range.

[1-1-2-3. (Plunger)
The plunger 20 has a fixed axial position with respect to the rotary shaft 1.

  Here, the plunger 20 is provided in a hat shape.

  More specifically, the plunger 20 has a cylindrical main body 21 whose side opposite to the fixed pulley 3 is closed and whose opening is directed to the fixed pulley 3 side, and projects radially outward from the opening of the main body 21. And a flange portion 22 provided.

  The rotation shaft 1 passes through the center of the main body portion 21 in the radial direction.

  The flange portion 22 has a shape obtained by removing a polygon having a similar shape smaller than the polygon on the polygonal frustum as viewed from the axial direction.

  Here, the flange portion 22 has a hexagonal shape as viewed in the axial direction.

  The flange portion 22 is provided with a holding groove 22a that holds the seal member 30 so that it can protrude and retract, and an oil passage 22b that allows the holding groove 22a and the pressure receiving chamber 40 to communicate with each other.

  The holding groove 22 a has an opening on the radially outer peripheral side of the flange portion 22.

  The holding groove 22 a is provided over the entire circumference of the flange portion 22.

  The oil passage 22 b communicates the holding groove 22 a and the pressure receiving chamber 40, and applies pressure (hereinafter referred to as “hydraulic pressure”) in the pressure receiving chamber 40 to the seal member 30.

  The plunger 20 and the seal member 30 receive the hydraulic pressure when the hydraulic pressure of the pressure receiving chamber 40 acts on the movable pulley 10.

[1-1-2-4. (Seal member)
The seal member 30 seals between the plunger 20 and the inclined surface 16 formed on the inner peripheral surface 15 of the cylinder 12 in the movable pulley 10.

  Further, the seal member 30 is pressed against the inclined surface 16 by the oil pressure of the pressure receiving chamber 40 acting through the oil passage 22b.

  The seal member 30 can be formed of an elastically deformable material such as rubber or resin.

  Here, the outer peripheral surface 30 a of the seal member 30 is formed in a shape that is inclined according to the inclined surface 16.

  However, since the inner diameter of the slope 16 increases as the distance from the fixed pulley 3 increases, the radial position (corresponding to the inner diameter) of the slope 16 corresponding to the axial position of the seal member 30 as the movable pulley 10 moves in the axial direction. And the circumferential length (corresponding to the length of the side of the polygon) changes.

  In order to cope with this change, the seal member 30 has the following configuration.

  First, the structure for responding to the change in the radial position of the inclined surface 16 of the seal member 30 will be described.

The radial length L ₁ of the seal member 30 is formed larger than the radial length L ₂ of the slope 16.

Also, the radial length _{L 1} of the seal member 30, the depth (radial length) of the holding groove 22a is larger than _{L 3.}

Accordingly, the seal member 30 protrudes and retracts from the holding groove 22a while a part of the seal member 30 is always protruded from the holding groove 22a, thereby changing the radial position of the slope 16 (the radial length L _{2 of the} slope 16). Corresponds to).

  In other words, the seal member 30 protrudes from the holding groove 22 a provided in the plunger 20 as the movable pulley 10 is closer to the fixed pulley 3, and conversely, the seal member 30 is provided in the plunger 20 as the movable pulley 10 is separated from the fixed pulley 3. It is provided so as to be immersed in the holding groove 22a.

  Next, the structure for respond | corresponding to the change of the circumferential direction length of the slope 16 about the sealing member 30 is demonstrated.

  The seal member 30 has a polygonal shape corresponding to the inclined surface 16 when viewed from the axial direction.

  More specifically, the seal member 30 has a shape obtained by removing a similar polygon smaller than this from the polygon on the polygonal frustum when viewed in the axial direction.

  Further, the seal member 30 has a polygonal shape in which the length of each side is variable.

  For this reason, the seal member 30 is configured to be connected at a position corresponding to each side of the polygon.

  In other words, the seal member 30 is configured by connecting the elements corresponding to the vertices of the polygon to each other.

  Hereinafter, description will be given focusing on two adjacent elements of the seal member 30.

  Here, one of the two elements is referred to as a first seal member 31 and the other element is referred to as a second seal member 32.

  As shown in FIG. 3, the joint of the first seal member 31 and the second seal member 32 is connected to each other.

  Specifically, the first seal member 31 and the second seal member 32 are formed in a corresponding uneven shape.

  Here, a concave portion 31 a is formed in the first seal member 31, and a convex portion 32 a is formed in the second seal member 32.

  When the seal member 30 is held in the holding groove 22a (see FIG. 1), the protrusion 32a of the second seal member 32 is always placed in the recess 31a of the first seal member 31.

  The concave portion 31a and the convex portion 32a are slidable with each other, and are configured to be able to change the degree of entry.

  In FIG. 3, the first seal member 31 and the second seal member 32 are separated from each other for easy understanding.

  In FIG. 3, for convenience, the outer peripheral surface 30a (see FIG. 1) of the seal member 30 is not inclined.

  The state in which the movable pulley 10 is farthest from the fixed pulley 3 (the state in which the groove width is the largest) is the first state (indicated by a solid line in FIG. 1). Conversely, the movable pulley 10 is closest to the fixed pulley 3. If the state (the state where the groove width becomes the smallest) is the second state (indicated by a two-dot chain line in FIG. 1), the seal member 30 in each state is as follows.

  As shown in FIG. 4A, the seal member 30 in the first state has a high degree of entry of the convex portion 32 a of the second seal member 32 into the concave portion 31 a of the first seal member 31.

  Moreover, the sealing member 30 has a large accommodation degree (accommodation depth) in the holding groove 22a (see FIG. 1) of the flange portion 22 (indicated by a two-dot chain line).

  On the other hand, as shown in FIG. 4B, the sealing member 30 in the second state has a small entry degree of the convex portion 32 a of the second seal member 32 into the concave portion 31 a of the first seal member 31.

  Moreover, the sealing member 30 has a small accommodation degree (accommodation depth) of the flange portion 22 (indicated by a two-dot chain line) in the holding groove 22a (see FIG. 1).

  Therefore, the sealing member 30 changes the length of each side of the polygon according to the change in the circumferential length of the slope 16.

  In this way, the plunger 20 and the slope 16 are securely sealed.

[1-1-2-3. (Pressure receiving chamber)
As shown in FIG. 1, the pressure receiving chamber 40 is a space surrounded by the rotary shaft 1, the movable pulley 10, the plunger 20, and the seal member 30.

  Oil from an oil pump (not shown) is supplied to the pressure receiving chamber 40 through the oil passages 1a and 13a.

  The oil supplied to the pressure receiving chamber 40 contacts the fixed pressure receiving surface 11 b of the main body 11 and the inner peripheral surface 15 of the cylinder 12 in the movable pulley 10.

  Since the inner peripheral surface 15 of the cylinder 12 forms a side surface of a polygonal frustum, and the fixed pressure receiving surface 11b of the main body 11 forms a part of the upper bottom surface of the polygonal frustum, the pressure receiving chamber 40 has a polygonal frustum shape. It has a shape.

  More specifically, the pressure receiving chamber 40 has a shape obtained by removing the rotary shaft 1 and the inner cylindrical portion 13 of the movable pulley 10 from the polygonal frustum.

[1-2. Action and effect)
Since the pulley mechanism according to the embodiment of the present invention is configured as described above, the following operations and effects can be obtained.

  First, the operation of the pulley mechanism according to the present embodiment will be described.

  The pressure of the oil supplied to the pressure receiving chamber 40, that is, the hydraulic pressure P acts on the movable pulley 10 from the side opposite to the fixed pulley 3.

  The thrust F is generated by the oil pressure P acting in the direction along the axial direction.

  With this thrust F, the movable pulley 10 is moved in the axial direction, the width (groove width) of the V-shaped groove 9 is changed, and the winding radius R of the belt 2 is changed.

  The thrust F is a function of the hydraulic pressure P and the axial projected area of the pressure receiving surface of the oil in the movable pulley 10, that is, the pressure receiving area A, as shown in the above equation (1).

  In the first state in which the movable pulley 10 is farthest from the fixed pulley 3 (the groove width is the largest), the seal member 30 is pressed against a portion of the inclined surface 16 having a small inner diameter.

  For this reason, the pressure receiving area A in a 1st state becomes small.

  On the other hand, in the second state in which the movable pulley 10 is closest to the fixed pulley 3 (the groove width is the smallest), the seal member 30 is pressed against a portion of the slope 16 having a large inner diameter.

  For this reason, the pressure receiving area A in the second state is increased.

  A comparison between the conventional structure and the pulley mechanism of this embodiment is shown below.

  The pressure receiving area A in the first state is smaller in the pulley mechanism of the present embodiment than in the conventional structure.

  Further, the pressure receiving area A in the second state is larger in the pulley mechanism of the present embodiment than in the conventional structure.

  Next, effects derived from the configuration of the pulley mechanism according to the present embodiment will be described.

  Since the inner peripheral surface 15 of the cylinder 12 is formed with a slope 16 whose inner diameter increases as the distance from the fixed pulley 3 increases, the winding radius of the belt 2 increases as the movable pulley 10 moves away from the fixed pulley 3. As R becomes smaller, the pressure receiving area A can be made smaller.

  Therefore, the thrust F can be suppressed as the winding radius R of the belt 2 decreases and the transmission torque T decreases.

For example, even if the minimum pressure P _min of the hydraulic pressure P in the pressure receiving chamber 40 is set to a constant magnitude, the pressure receiving area A becomes smaller as the movable pulley 10 is separated from the fixed pulley 3, so that the movable pulley 10 is fixed. The thrust F can be reduced as the groove width between the pulley 3 increases.

Therefore, in the pulley mechanism, the excessive thrust F _o can be suppressed and the necessary thrust F _rq can be applied.

  That is, even if the hydraulic pressure P of the pressure receiving chamber 40 is the same, the thrust F can be suppressed when the winding radius R of the belt 2 is reduced and the transmission torque T is reduced. When the winding radius R increases and the transmission torque T increases, the thrust F can be secured.

In this way, as required thrust F _rq varies, it is possible to suppress excessive thrust F _o while ensuring the required thrust F _rq, the thrust F can be sized appropriately.

  For example, when focusing on the second state, the pressure receiving area A of the pulley mechanism of the present embodiment is larger than that of the conventional structure under the condition that the hydraulic pressure P of the same magnitude acts.

  For this reason, according to the pulley mechanism of the present embodiment, it is possible to lower the maximum discharge pressure required for the oil pump compared to the conventional structure in order to generate the thrust F having the same magnitude.

  Oil pumps tend to increase in size as the maximum discharge pressure increases, but reducing this maximum pressure contributes to downsizing of the oil pumps employed.

  As a result, it contributes to weight reduction and fuel efficiency improvement.

  Further, since the space between the inner peripheral surface 15 of the cylinder 12 and the plunger 20 is sealed by the seal member 30, the pressure receiving chamber 40 can be reliably sealed and the hydraulic pressure P can be applied reliably.

  Since the seal member 30 is provided so as to protrude from the holding groove 22a provided in the plunger 20 as the movable pulley 10 approaches the fixed pulley 3, the seal member 30 is pressed by the axial movement of the movable pulley 10. Even if the radial position of the slope 16 is changed, that is, the inner diameter of the slope 16 is changed, the gap between the plunger 20 and the movable pulley 10 can be sealed in response to this change.

  Since the plunger 20 is formed with an oil passage 22b that communicates with the pressure receiving chamber 40 and applies the oil pressure P to the seal member 30, the oil pressure P of the pressure receiving chamber 40 reliably presses the seal member 30 against the cylinder 12. The pressure receiving chamber 40 can be reliably sealed.

  Since the pressure receiving chamber 40 has a polygonal frustum shape and the sealing member 30 has a polygonal shape in which the length of each side is variable, the pressure receiving chamber is formed by the sealing member 30 corresponding to the shape of the pressure receiving chamber 40 to be sealed. 40 can be securely sealed.

According to a transmission having a pulley mechanism of the present embodiment, it is possible to reliably power transmission to suppress an excessive thrust F _o while ensuring the required thrust F _rq, also energy efficiency downsizing of the oil pump Can be improved and the weight can be reduced.

  Moreover, according to the vehicle provided with the transmission having the pulley mechanism of the present embodiment, the energy applied to the oil pump can be suppressed, and the fuel consumption and power consumption can be improved.

  In the movable pulley 10, since the base end portion 12a of the cylinder 12 is formed thick, the axial length of the outer peripheral portion 11c of the main body portion 11 can be shortened while ensuring strength or rigidity.

  This contributes to suppression of the axial length of the pulley mechanism.

  As a result, it contributes to shortening the overall length of the transmission.

[2. (Modification)
Next, a modification according to an embodiment of the present invention will be described.

  In the pulley mechanism according to the modification of the present invention, the oil passage in the plunger is different from that described above.

  In the following description, these different points will be described.

  Except for the differences described here, the configuration is the same as the configuration of the above-described embodiment, and the same reference numerals are given thereto, and detailed description thereof is omitted.

  As shown in FIG. 5, in the pulley mechanism of this modification, the oil passage 20 a formed in the plunger 20 is not in communication with the pressure receiving chamber 40.

  Oil having a pressure different from the hydraulic pressure P of the pressure receiving chamber 40 is supplied to the oil passage 20a.

  The oil passage 20 a is formed inside the main body portion 21 and the flange portion 22 of the plunger 20.

  Further, in addition to the oil passage 1a described above, the rotating shaft 1 is provided with an oil passage 1b of a system different from the oil passage 1a.

In this way, from the oil passage 1b of the different strains, the oil passage 1a, different pressure P _D is supplied to the oil pressure P of 13a and the pressure receiving chamber 40.

  For example, a pressure control system provided between the oil pump and the oil passage 1a is different from a pressure control system provided between the oil pump and the oil passage 1b.

According to such a configuration, a common oil pump, oil pressure P different for an oil passage 1a and the oil passage 1b, can act P _D.

  An oil pump that is different from the oil pump that supplies oil to the oil passage 1a may be provided, and the oil may be supplied to the oil passage 1b from this other oil pump.

  Since the pulley mechanism according to this modification is configured as described above, the following actions and effects can be obtained in addition to the actions and effects according to the pulley mechanism of the embodiment described above.

Since the oil passage 20a different pressure P _D is supplied to the oil pressure P of the pressure-receiving chamber 40, if it is supplied with oil negative pressure P _D to the oil passage 20a, as shown by the two-dot chain line, the sealing member 30 can be moved to immerse the plunger 20.

  For this reason, the oil in the pressure receiving chamber 40 can be leaked.

  Therefore, the hydraulic pressure P of the pressure receiving chamber 40 can be rapidly reduced.

  This is effective for quickly bringing the pulley mechanism into the first state.

  For example, it can contribute to improvement of so-called Low return performance.

On the other hand, if it is supplied with oil positive pressure P _D to the oil passage 20a, it may be pressed against the seal member 30 to cause the inner peripheral surface 15 or the slope 16 projecting from the plunger 20.

By adjusting the positive pressure P _D, it can be adjusted sealing of the pressure receiving chamber 40.

  In this way, the seal member 30 can be made to perform a desired operation.

[3. Others]
Although one embodiment and modification of the present invention have been described above, the present invention is not limited to the above-described one embodiment and modification, and various modifications are made without departing from the spirit of the present invention. be able to.

  Each composition of one embodiment and a modification mentioned above can be chosen as needed, and may be combined suitably.

  In the above-described embodiment, the concave and convex shapes corresponding to the locations where the first seal member 31 and the second seal member 32 of the seal member 30 are connected to each other have been shown. However, the seal member 30 is integrally formed and sealed. It is good also as a structure corresponding to the change of the circumferential direction length of the slope 16 by the elastic deformation of the member 30. FIG.

  The outer peripheral surface 30a of the seal member 30 is not limited to a shape inclined according to the inclined surface 16, and may be formed in a plane along the axial direction.

  In this case, the seal member 30 pressed against the slope 16 is elastically deformed, and the seal member 30 and the slope 16 are in close contact with each other.

  Further, the seal member 30 is not limited to the one protruding and retracted by the hydraulic pressure acting via the oil passages 13a and 22b, and may be configured to respond to the inner diameter change of the inclined surface 16 by the elastic deformation of the seal member 30. In this case, the oil passages 13a and 22b can be omitted.

  The shape of the pressure receiving chamber 40 is not limited to a polygonal frustum shape, and may be a truncated cone shape.

  In this case, the inclined surface 16 or the inner peripheral surface 15 of the cylinder 12, the flange portion 22 of the plunger 20, and the seal member 30 are formed in a shape corresponding to the truncated cone shape.

  At this time, it is preferable to prevent the seal member 30 from rotating in the circumferential direction.

  Further, for example, if the gap between the plunger 22 and the cylinder 12 is closed while allowing the movable pulley 10 to move in the axial direction and the hydraulic pressure P of the pressure receiving chamber 40 is maintained, the seal member 30 is not essential.

1 Rotating shaft 1a Oil passage 2 Belt (power transmission member)
DESCRIPTION OF SYMBOLS 3 Fixed pulley 3a Clamp surface 9 V-shaped groove | channel 10,100 Movable pulley 11 Main body part 11a Clamp surface 11b Fixed pressure receiving surface 11c Outer peripheral part 11d Inner peripheral part 12,120 Cylinder (tubular part)
12a Base end portion 13 Inner cylinder portion 13a Oil passage 15,150 Inner peripheral surface 16 Slope 19 Outer peripheral surface 20, 200 Plunger 21 Main body portion 22 Flange portion 22a Holding groove 22b Oil passage 30, 300 Seal member 30a Outer peripheral surface 31 First seal thrust _{F 2} in member 31a recess 32 the second seal member 32a projecting portions 40, 400 receiving chamber a axis F thrust pressure receiving area C rotary shaft 1 _{F min} minimum thrust _{F rq} required thrust _{F o} excessive thrust _{F 1} one pulley mechanism in the other of the radial length _{L 3} holding groove 22a of the radial length _{L 2} slopes 16 of the thrust _{L 1} sealing member in a pulley mechanism depth P hydraulic _{P min} minimum pressure _{P 1} one pulley mechanism hydraulic _{P 2} other different pressure P _D at the pulley mechanism hydraulic T transmission torque R wrapping radius Z thrust ratio

Claims (9)

A fixed pulley;
A movable pulley having a cylindrical portion extending toward the opposite side of the fixed pulley;
A plunger provided on the opposite side of the movable pulley with respect to the movable pulley;
A pressure receiving chamber surrounded by the movable pulley and the plunger and supplied with oil;
The pulley mechanism according to claim 1, wherein the inner peripheral surface of the cylindrical portion has a greater distance from the axis of the rotation shaft as the distance from the fixed pulley increases. The pulley mechanism according to claim 1, further comprising a seal member that seals between the inner peripheral surface of the cylindrical portion and the plunger. The pulley mechanism according to claim 2, wherein the seal member is provided so as to protrude from the plunger as the movable pulley comes closer to the fixed pulley. The pulley mechanism according to claim 2 or 3, further comprising an oil passage formed on the plunger and applying hydraulic pressure to the seal member. The pulley mechanism according to claim 4, wherein the oil passage communicates with the pressure receiving chamber. The pulley mechanism according to claim 4, wherein the oil passage is supplied with oil having a pressure different from the pressure of the oil in the pressure receiving chamber. The pressure receiving chamber has a frustum shape in which two bottom surfaces each form a polygonal shape,
The pulley mechanism according to any one of claims 2 to 5, wherein the sealing member has the polygonal shape in which the length of each side is variable. A transmission comprising the pulley mechanism according to any one of claims 1 to 7. A vehicle comprising a transmission having the pulley mechanism according to any one of claims 1 to 7.

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