JP2013064478A - Belt continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a belt continuously variable transmission in which a fixed sheave has a hollow structure to achieve weight reduction of the belt continuously variable transmission, and which can assure cooling performance of a pulley and a belt.SOLUTION: The belt continuously variable transmission includes: the belt 4; the fixed sheave 6 formed with a tapered surface 6a and a rear face 6c on the opposite side in the axial direction of a rotation shaft 2 with respect to the tapered surface 6a, and provided with a hollow part 6e between the tapered surface 6a and the rear face 6c; a movable sheave 5 formed with a tapered surface 5a and slidably attached in the axial direction of the rotation shaft 2; and the pulley 3 composed of the fixed sheave 6 and the movable sheave 5, wherein an intake port 9 for supplying air from the outside of the fixed sheave 6 to the hollow part 6e is provided at the rear face 6c, and an exhaust port 10 for discharging air from the hollow part 6e to a bearing 7 at the rear face 6c side is provided at a position of inner diameter side of the bearing 7 supporting the rotation shaft 2 at the rear face 6c.

Description

  The present invention relates to a belt-type continuously variable transmission that transmits power via a belt wound between a driving pulley and a driven pulley and continuously controls a gear ratio. In particular, the present invention relates to a structure for cooling a pulley and a belt of the belt type continuously variable transmission.

  A belt-type continuously variable transmission is a transmission that can change the effective diameter of the pulley, that is, the belt winding radius, by changing the groove width of the pulley around which the belt is wound, so that the gear ratio can be set continuously. It is. Therefore, each pulley on the drive side (or input side) and driven side (or output side) is formed by a fixed sheave and a movable sheave that slides in the axial direction with respect to the fixed sheave and moves close to and away from it. . Then, by moving the movable sheave using, for example, hydraulic pressure, the groove width of each pulley is changed, so that the belt winding radius can be continuously changed.

  An example of such a belt-type continuously variable transmission is described in Patent Document 1. The belt type continuously variable transmission described in Patent Document 1 includes a fixed sheave having a cone surface formed integrally with a rotating shaft, and a rotating shaft having a cone surface facing the cone surface of the fixed sheave. A belt type continuously variable transmission having a movable sheave that is slidably mounted in the axial direction of the first flange portion having a cone surface and opposite to the cone surface in the axial direction of the rotary shaft The second flange portion on which the rear surface is formed is joined by friction welding at the annular joint surface. Therefore, the inside of the fixed sheave is configured to have an annular hollow structure.

  In Patent Document 2, a pulley face having a gear portion formed on the outer periphery, a drive fixing sheave formed by a cylindrical boss portion that rotates with the drive shaft, and a drive fixing sheave that rotates with the drive shaft are close to the drive fixing sheave. A drive movable sheave that is separated, a fan member formed with a base plate portion and a plurality of blade pieces, and a starter motor provided with a pinion gear that protrudes in the axial direction and meshes with the gear portion. And an invention relating to a V-belt type automatic transmission configured to be attached to the back side of the drive fixing sheave while having elasticity with each other.

  Patent Document 3 discloses a V-belt automatic transmission in which a cooling air passage is formed in a movable sheave of a drive pulley, and a plurality of axial passages formed so as to extend in the axial direction of the movable sheave. A cooling air passage is formed by the radially formed radial passage, and one end of the axial passage opens at the end of the movable sheave opposite to the transmission portion, and the other end is in the radial direction of the radial passage. There is described an invention relating to a V-belt type automatic transmission which is connected to an inner end portion and is configured such that a radially outer end portion of a radial passage opens to an outer peripheral portion of a movable sheave.

  In Patent Document 4, a set of continuously variable transmission pulleys and a belt are installed in a continuously variable transmission case, an input shaft is supported on one side of the continuously variable transmission case, and an output shaft is provided on the other side. A continuously variable transmission that is supported and configured so that a pulley is supported on each of an input shaft and an output shaft, the continuously variable transmission having a ventilation hole through which cooling air is passed in the shaft of the input shaft The invention relating to the cooling mechanism is described.

  And in patent document 5, the continuously variable transmission comprised by a belt being wound between the input side pulley and the output side pulley in the belt chamber formed in the case main body is installed, and the output side pulley This is a dry-type continuously variable transmission in which a fan for cooling the belt chamber is provided on the outer periphery of the pulley shaft, and the outside of the boss that supports the pulley shaft on the output side of the case body is sucked into the center of the fan. An invention relating to a cooling structure for a dry-type continuously variable transmission in which a plurality of communication ports are formed therethrough is described.

JP 2002-106659 A JP 2008-196528 A JP 2002-206604 A Japanese Patent Laid-Open No. 9-280333 JP-A-9-329217

  As in the belt-type continuously variable transmission described in Patent Document 1 above, the fixed sheave of the pulley is formed in a hollow structure, so that a fixed sheave that is integrally formed with a conventional rotary shaft, that is, a solid The pulley can be reduced in weight compared to the case where the pulley is configured by a fixed sheave having a structure. As a result, the belt type continuously variable transmission using the pulley can be reduced in weight, and the cost can be reduced.

  However, when the fixed sheave is formed in a hollow structure, there is a problem that the cooling performance of the pulley and the belt is lowered as compared with the case where the fixed sheave is formed in a solid structure. That is, in the belt type continuously variable transmission, power is transmitted by the frictional force between the pulley and the belt wound around the pulley, so that frictional heat is generated between the pulley and the belt. Therefore, it is necessary to cool the heat generating part between the pulley and the belt. In that case, if the fixed sheave is a solid structure, heat generated on the contact surface (cone surface) with the belt of the fixed sheave can be relatively easily transferred to the back surface on the opposite side in the direction of the rotation axis of the pulley. Can be transmitted. The heat can be radiated from the back surface of the fixed sheave to the outside of the pulley. On the other hand, when the fixed sheave is formed in a hollow structure as in the belt-type continuously variable transmission described in Patent Document 1, air intervening in the hollow portion of the fixed sheave becomes a heat insulating layer. The heat generated on the contact surface of the fixed sheave with the belt is not easily transmitted to the back side. That is, it becomes difficult for the heat of the pulley to be radiated to the outside. Therefore, when the fixed sheave is formed in a hollow structure, the cooling efficiency of the pulleys and the belt is lowered as compared with the case where the fixed sheave is formed in a solid structure. The difference in cooling performance between the hollow fixed sheave and the solid fixed sheave is that of an air-cooled (or dry) belt-type continuously variable transmission that does not use lubricating oil to cool the pulley and belt. Especially noticeable.

  In this way, the pulley fixed sheave has a hollow structure to reduce the weight of the belt-type continuously variable transmission, and the cooling performance of the pulley and belt, particularly the cooling performance of the air-cooled belt-type continuously variable transmission is ensured. There was still room for improvement in order to achieve both.

  The present invention has been made paying attention to the above technical problems, and even when the pulley fixed sheave is formed in a hollow structure for weight reduction and cost reduction, the cooling performance of the pulley and the belt is good. An object of the present invention is to provide a belt-type continuously variable transmission.

  In order to achieve the above object, the invention of claim 1 is characterized in that the belt and the rotating shaft are fitted and fixed together, and one tapered surface of the V-shaped groove around which the belt is wound and its taper. A fixed sheave formed with a back surface opposite to the surface in the axial direction of the rotating shaft and having a hollow portion between the tapered surface and the back surface, and the other tapered surface of the V-shaped groove The V-shaped groove is formed by the movable sheave that is integrally formed with the rotating shaft and is slidably mounted in the axial direction of the rotating shaft, and the fixed sheave and the movable sheave. In a belt-type continuously variable transmission including a pulley around which a belt is wound, an intake port for supplying air from the outside of the fixed sheave to the hollow portion is provided on the back surface, and the rotating shaft on the back surface Shaft to support The position of the inner diameter side of, and is characterized in that the exhaust port for discharging air toward the bearing of the back side from the hollow portion is provided.

  According to a second aspect of the present invention, in the first aspect of the invention, the exhaust port is provided at a fitting portion between the fixed sheave and the rotating shaft, and the hollow portion is directed to the bearing on the back side. And a tapered surface side exhaust port for exhausting air from the hollow portion to the outside of the fixed sheave on the tapered surface side. It is characterized by that.

  According to a third aspect of the present invention, in the second aspect of the present invention, the back side exhaust port has the fixed sheave provided in the fitting portion extending from the hollow portion of the fixed sheave to the back surface, and the rotating shaft. And the tapered surface side exhaust port includes a clearance between the fixed sheave provided in the fitting portion extending from the hollow portion of the fixed sheave to the tapered surface and the rotating shaft. It is characterized by.

  The invention of claim 4 is characterized in that, in the invention of claim 3, the clearance of the tapered surface side exhaust port is larger than the clearance of the back side exhaust port.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the intake port has an opening that opens in a forward rotation direction of the pulley, and the pulley is in the forward rotation direction. The air around the opening is taken into the hollow portion when rotating in the reverse direction, and a negative pressure is generated around the opening when the pulley rotates in the reverse rotation direction. It is a feature.

  According to the invention of claim 1, since the fixed sheave of the pulley is formed in a hollow structure, the pulley can be reduced in weight accordingly. In addition, by providing an intake port and an exhaust port on the back of the fixed sheave, air is sent from the intake port to the hollow portion of the fixed sheave, and the air sent to the hollow portion is discharged from the exhaust port to the outside of the fixed sheave. can do. That is, the cooling air can be caused to flow in the hollow portion of the fixed sheave. Therefore, the taper surface of the fixed sheave and the belt whose temperature rises due to frictional contact with the belt can be cooled from the hollow portion side of the fixed sheave. Furthermore, the air discharged from the exhaust port of the fixed sheave can be radiated to the pulley and the bearing that supports the rotating shaft of the pulley. Therefore, it is possible to cool the bearing whose temperature rises as the pulley and the rotation shaft rotate. Therefore, even when the fixed sheave is made hollow to reduce the weight, it is possible to provide a dry belt-type continuously variable transmission with good cooling performance.

  According to the invention of claim 2, the rear side exhaust port for discharging air from the hollow portion of the fixed sheave toward the rear side bearing at the fitting portion of the fixed sheave and the rotating shaft, and the hollow of the fixed sheave And a taper surface side exhaust port for discharging air from the portion to the outside on the taper surface side. Accordingly, the air that is supplied from the intake port to the hollow portion of the fixed sheave and cools the fixed sheave and the belt is discharged from the back side exhaust port and the taper side exhaust port, and the back side bearing and the taper surface of the pulley are discharged. And the space surrounded by the inner peripheral surface of the belt and the outer peripheral surface of the rotating shaft. Therefore, the heat generating parts such as pulleys, belts and bearings can be efficiently cooled, and the cooling performance of the belt type continuously variable transmission can be improved.

  According to the invention of claim 3, the back side exhaust port and the tapered surface side exhaust port as described above are formed as a clearance provided at a fitting portion between the fixed sheave and the rotating shaft. For example, the rear side exhaust port and the tapered surface side exhaust port are formed as a clearance provided between the key groove formed in the fixed sheave, the rotating shaft, and the fitting portion and the key inserted into the key groove. Alternatively, the rear-side exhaust port and the tapered surface-side exhaust port are formed as clearances provided between the fixed sheave, the rotating shaft, and the spline and spline groove formed in the fitting portion or between the serration and the serration groove. Therefore, the rear side exhaust port and the taper surface side exhaust port can be formed by using a keyway structure, a spline structure, or the like provided for fixing the fixed sheave and the rotating shaft. That is, the back side exhaust port and the tapered surface side exhaust port can be easily formed without performing special processing for the back side exhaust port and the tapered surface side exhaust port.

  According to the invention of claim 4, the back side exhaust port and the tapered surface side exhaust port as described above are formed such that the clearance of the tapered surface side exhaust port is larger than the clearance of the back side exhaust port. . That is, the back surface side exhaust port and the taper surface side exhaust port are formed so that the amount of air flowing through the tapered surface side exhaust port is larger than the amount of air flowing through the back surface side exhaust port. Therefore, cooling air can be preferentially sent to the space surrounded by the tapered surface of the pulley, the inner peripheral surface of the belt, and the outer peripheral surface of the rotating shaft, which are difficult to cool from the outside. And the like can be efficiently cooled.

  According to the fifth aspect of the present invention, air is taken into the hollow portion of the fixed sheave from the intake port when the pulley rotates in the forward direction. Therefore, when rotating in the forward direction, which is frequently used, air can be actively supplied to the hollow portion of the fixed sheave, and the pulley and belt can be efficiently cooled. In addition, air can be supplied from the intake port to the hollow portion of the fixed sheave with a simple configuration without providing a separate air-cooling blower. Further, when the pulley rotates in the reverse direction, a negative pressure is generated in the vicinity of the opening of the intake port, so that the air in the hollow portion of the fixed sheave is sucked from the intake port to the outside by the negative pressure. Is issued. Therefore, even when the pulley rotates in the reverse direction, air can flow into the hollow portion of the fixed sheave from the exhaust port, and the introduced air can be discharged from the intake port to the outside, thereby cooling the pulley and the belt. be able to.

It is sectional drawing and the arrow view which show the structural example of the belt-type continuously variable transmission which concerns on this invention. FIG. 2 is an enlarged cross-sectional view illustrating details of a configuration example of an intake port according to the present invention and illustrating an air flow at the intake port, where (a) shows an air flow when the pulley rotates in the forward rotation direction. (B) is a figure which shows the flow of air when a pulley rotates in a reverse rotation direction. It is an expanded sectional view for demonstrating the detail of the structural example of the exhaust port of this invention, and demonstrating the flow of the air in the exhaust port. It is sectional drawing which shows the other structural example of the exhaust port of this invention. FIG. 5 is an enlarged cross-sectional view for illustrating the details of another configuration example of the exhaust port illustrated in FIG. 4 and for explaining the flow of air at the exhaust port. It is an arrow line view which shows the detail of the other structural example of the exhaust port shown in FIG.

  Next, the configuration of the present invention will be described with reference to the drawings. FIG. 1 schematically shows a main part of a configuration example of a belt type continuously variable transmission 1 according to the present invention. This belt type continuously variable transmission 1 has the same basic configuration and operating principle as the conventional belt type continuously variable transmission. That is, the main part of the belt type continuously variable transmission 1 includes two driving shafts (or input side) and driven side (or output side) arranged in parallel, and only one of them is shown in FIG. And two pulleys 3 on the driving side (or input side) and driven side (or output side) attached to the rotary shaft 2 and the belt winding groove 3a of the two pulleys 3 is wound around. And a belt 4 for transmitting torque between the two pulleys 3. The gear ratio is continuously changed, that is, the gear ratio is continuously changed by continuously changing the wrapping radius of the belt 4 with respect to each pulley 3 on the driving side and the driven side. Has been.

  The pulley 3 will be described in detail. As shown in FIG. 1, the movable sheave 5 is attached to the rotary shaft 2 so as to rotate integrally with the rotary shaft 2 and to be movable in the rotational axis direction of the rotary shaft 2. Yes. A fixed sheave 6 is attached to the rotary shaft 2 so as to rotate integrally with the rotary shaft 2 and cannot move in the direction of the rotational axis of the rotary shaft 2. That is, the fixed sheave 6 is integrally fixed to the rotating shaft 2. The movable sheave 5 and the fixed sheave 6 are arranged such that the taper surface 5a of the movable sheave 5 and the taper surface 6a of the fixed sheave 6 face each other in the rotation axis direction of the rotary shaft 2, and the taper surface 5a. And a taper surface 6a, a V-shaped belt winding groove 3a is formed. Therefore, the movable sheave 5 and the fixed sheave 6 constitute a pulley 3.

  The rotating shaft 2 is rotatably supported by a casing (not shown) by a bearing 7. The bearing 7 is constituted by a rolling bearing such as a radial ball bearing or a radial roller bearing, for example, and is installed so as to support at least one end portion 2a on the side where the fixed sheave 6 of the rotating shaft 2 is fixed. ing. FIG. 1 shows a configuration example in which the rotating shaft 2 is cantilevered at the end 2a. In addition to this, a bearing is installed at the other end 2b of the rotary shaft 2 on the side where the movable sheave 5 is mounted together with the bearing 7 installed at the end 2a, and the rotary shaft 2 is supported at both ends. It may be a configuration.

  The movable sheave 5 has a taper surface 5a and a sheave base 5b that slides on the rotary shaft 2, and a restriction that sets a movement limit of the sheave base 5b on the rotary shaft 2 toward the end 2b. It is comprised from the member 5c. The restricting member 5c is for restricting the range of movement of the sheave base 5b on the rotating shaft 2 toward the end 2b as described above, and is attached to the end 2b of the rotating shaft 2 to rotate. The shaft 2 is fixed to the rotating shaft 2 by a lock nut 8 or the like so that the shaft 2 cannot move in the rotating axis direction. The movable sheave 5 is provided with an actuator (not shown) for sliding the movable sheave 5 in the direction of the rotation axis of the rotary shaft 2 so as to approach and separate from the fixed sheave 6.

  The fixed sheave 6 includes a disk-shaped or truncated cone-shaped sheave base 6b having a tapered surface 6a, and a disk-shaped or conical shape having a tapered surface 6a and a back surface 6c on the opposite side in the rotational axis direction of the rotating shaft 2. It comprises a trapezoidal support member 6d, and a hollow portion 6e formed between the sheave base portion 6b and the support member 6d, that is, between the tapered surface 6a and the back surface 6c. The supporting member 6d is a reinforcing member for preventing the sheave base portion 6b from being deformed toward the back surface 6c when the sheave base portion 6b receives a load or reaction force from the belt 4 on the tapered surface 6a. Accordingly, the shape and strength of the support member 6d are appropriately set according to the shape and strength of the sheave base portion 6b and the load received by the sheave base portion 6b.

  The sheave base portion 6b and the support member 6d are fixed to each other so that a hollow portion 6e is formed between the tapered surface 6a and the back surface 6c when the fixed sheave 6 is formed. The rotating shaft 2 is integrally fixed. Therefore, the hollow portion 6 e is formed as a space surrounded by the base portion 6 b, the support member 6 d, and the outer peripheral surface of the rotating shaft 2.

  In the example shown in FIG. 1, the sheave base portion 6b and the support member 6d are formed as separate bodies, and the sheave base portion 6b and the support member 6d are joined and fixed together to form a sheave base. The structure which formed the hollow part 6e between the part 6b and the supporting member 6d is shown. In addition, the sheave base portion 6b and the support member 6d can be formed integrally, and the hollow portion 6e can be cut and formed between the sheave base portion 6b and the support member 6d by, for example, machining.

  The pulley 3 composed of the movable sheave 5 and the fixed sheave 6 as described above is installed in parallel at two places on the driving side and the driven side of the belt type continuously variable transmission 1, and the two pulleys 3 The belt 4 is wound around the belt winding groove 3a. The belt-type continuously variable transmission 1 according to the present invention is an air-cooled type that does not use lubricating oil for cooling the pulley 3 and the belt 4, and therefore the belt 4 used in the belt-type continuously variable transmission 1. Is a so-called dry transmission belt. And the belt 4 is formed as a so-called V-shaped inclined surface with both left and right side surfaces in the width direction (left and right direction in FIG. 1) as viewed from the front. It fits in the winding groove 3a. That is, the belt 4 is configured as a V-belt that is wound around the pulley 3 in which the V-shaped belt winding groove 3a is formed.

  As described above, in the belt-type continuously variable transmission 1 of the present invention, the fixed sheave 6 of the pulley 3 is formed from the sheave base portion 6b and the support member 6d, so that the fixed sheave 6 is formed in a hollow structure. ing. Therefore, the conventional fixed sheave can be reduced in weight as compared with a belt-type continuously variable transmission having a solid structure. However, as described above, when the fixed sheave 6 has a hollow structure, the air layer interposed in the hollow portion serves as a heat insulating layer, so that the fixed sheave 6 has a solid structure as compared with the solid sheave. The heat on the tapered surface 6a side is not easily transferred to the back surface 6c side. The heat generated by the friction with the belt 4 on the tapered surface 6a of the fixed sheave 6 is transferred to the back surface 6c side, and is radiated from the back surface 6c to the outside of the fixed sheave 6. That is, the heat transmitted from the taper surface 6a side to the back surface 6c side of the fixed sheave 6 is radiated to the outside, whereby the heat generation part of the taper surface 6a and the belt 4 is cooled. Therefore, by making the fixed sheave 6 have a hollow structure, the heat of the tapered surface 6a of the fixed sheave 6 is hardly radiated from the back surface 6c as described above, and the cooling performance of the tapered surface 6a and the belt 4 may be lowered. There was sex.

  Therefore, in the belt type continuously variable transmission 1 according to the present invention, even when the heat transferability of the fixed sheave 6 is lowered by adopting the fixed sheave 6 having a hollow structure, the taper surface 6a and the belt 4 are excellent. In order to ensure the cooling performance, the inlet 9 for supplying cooling air into the hollow portion 6e of the fixed sheave 6 to the support member 6d constituting the back surface 6c of the fixed sheave 6, and the hollow portion 6e An exhaust port 10 for discharging the air inside the fixed sheave 6 is formed.

  As shown in FIG. 1, the air inlet 9 penetrates the support member 6d at the outer edge portion of the support member 6d, that is, near the outer periphery in the radial direction of the support member 6d, and the forward rotation of the pulley 3 rotating in the forward direction. It is formed to open in the direction. Specifically, as shown in FIGS. 1 and 2, the air inlet 9 allows air to pass between the outside on the back surface 6c side of the support member 6d and the hollow portion 6e side through the support member 6d. And a hood member 9b that covers the through hole 9a and opens in the forward rotation direction of the pulley 3 on the back surface 6c of the support member 6d.

  The hood member 9b has the opening 9c that opens in the forward rotation direction of the pulley 3 as described above. Further, the portion of the hood member 9b opposite to the opening 9c in the rotation direction of the pulley 3 is formed as an inclined surface 9d inclined so that air resistance is reduced when the pulley 3 rotates in the reverse direction. Yes. The hood member 9b covers the through hole 9a and is integrally fixed to the support member 6d, that is, the back surface 6c so that the through hole 9a and the opening 9c communicate with each other. The hood member 9b may be attached and fixed to the support member 6d as a retrofit, or may be formed integrally with the support member 6d.

  Therefore, as shown in FIG. 2A, when the pulley 3 rotates in the forward rotation direction, the air inlet 9 has air resistance on the opening 9c side of the hood member 9b, and air around the opening 9c is opened. It is formed so as to flow from the portion 9c to the hollow portion 6e through the through hole 9a. At the same time, as shown in FIG. 2B, the intake port 9 is formed so that negative pressure is generated near the outlet of the opening 9c when the pulley 3 rotates in the reverse rotation direction. . That is, since the inclined surface 9d as described above is formed on the hood member 9b, when the pulley 3 rotates in the reverse rotation direction, the relative air flow around the intake port 9 in that case is Before and after the air inlet 9, the flow velocity does not decrease relatively and the flow is not disturbed relatively, and the pulley 3 moves backward (from the right side of FIG. 2B) to the rear (FIG. 2). (Left side of (b)). Therefore, when the pulley 3 rotates in the reverse rotation direction, a negative pressure is generated near the outlet of the opening 9c of the intake port 9, and the air in the hollow portion 6e is fixed through the intake port 9 by the negative pressure. It will be discharged to the outside of the sheave 6.

  In the example shown in FIG. 1, four intake ports 9 and exhaust ports 10 are formed at a pitch of 90 degrees in the circumferential direction of the support member 6d. , At least one point may be formed. For example, the intake ports 9 and the exhaust ports 10 may be formed at three positions at a pitch of 120 degrees in the circumferential direction of the support member 6d. Alternatively, six locations can be formed at a pitch of 60 degrees in the circumferential direction of the support member 6d. In short, the shape and size of the intake port 9 and the exhaust port 10, the number, and the like so that the air supplied from the intake port 9 and discharged from the exhaust port 10 has a desired flow or flows efficiently. Arrangement positions and the like can be set as appropriate.

  The exhaust port 10 is a through hole that penetrates the support member 6d at the inner edge portion of the support member 6d, that is, near the center in the radial direction of the support member 6d and closer to the inner diameter side of the support member 6d than the intake port 9. It is formed as. Specifically, as shown in FIGS. 1, 2, and 3, the exhaust port 10 is near the center in the radial direction of the support member 6 d, and the fixed sheave 6 is disposed on the rotating shaft 2 together with the bearing 7. With a through hole that allows air to flow between the outside on the back surface 6c side of the support member 6d and the hollow portion 6e side at a position closer to the inner diameter side than the outer shape of the bearing 7 Is formed. Further, the opening 10 a on the back surface 6 c side of the exhaust port 10 is formed so as to face the bearing 7 installed adjacent to the back surface 6 c side of the fixed sheave 6 on the rotating shaft 2. Therefore, the air discharged from the hollow portion 6 e through the exhaust port 10 to the outside of the fixed sheave 6 is radiated from the opening 10 a of the exhaust port 10 toward the bearing 7.

  By forming the intake port 9 and the exhaust port 10 on the back surface of the fixed sheave 6 as described above, air can flow between the intake port 9 and the exhaust port 10 when the pulley 3 rotates. . That is, when the pulley 3 rotates in the frequent forward rotation direction, the outside air can be taken in from the intake port 9 and supplied to the hollow portion 6 e of the fixed sheave 6. And the air in the hollow part 6e can be discharged | emitted from the exhaust port 10 to the exterior of the fixed sheave 6. FIG.

  The air supplied from the air inlet 9 into the hollow portion 6e removes heat from the tapered surface 6a of the fixed sheave 6 and the belt 4, and the temperature rises. That is, the heat generating part of the taper surface 6a and the belt 4 is cooled by the air supplied into the hollow part 6e. And since the pressure and volume of the air in the hollow part 6e are considered to be substantially constant, the air that has deprived the heat of the heat generating part in the hollow part 6e is heated before its mass deprives the heat. Lighter than cold air. When the pulley 3 is rotating, the air in the hollow portion 6e is moved by the centrifugal force, so that the air having a relatively low temperature and a large mass moves to the outer peripheral side of the hollow portion 6e, and the temperature is relatively high. The air with a high mass and light mass moves to the center side of the hollow portion 6e. Therefore, the air supplied to the hollow portion 6e from the intake port 9 provided on the outer peripheral side of the fixed sheave 6 takes the heat of the heat generating portion in the hollow portion 6e, and the temperature becomes high, so that the mass becomes light. Move to the center of 6e. Therefore, it becomes easier to discharge from the exhaust port 10 provided on the center side of the fixed sheave 6 than the intake port 9.

  Thus, in the belt type continuously variable transmission 1 according to the present invention, the fixed sheave 6 of the pulley 3 has a hollow structure, and the intake port 9 and the exhaust port 10 as described above are formed on the back surface 6c of the fixed sheave 6. By doing so, the cooling air can efficiently flow in the hollow portion 6e of the fixed sheave 6. As a result, the tapered surface 6a and the heat generating portion of the belt 4 can be efficiently cooled.

  Further, since the opening 10a of the exhaust port 10 is formed so as to face the bearing 7, the air discharged from the hollow portion 6e as described above is blown again to the bearing 7 as cooling air. Can do. Therefore, the bearing 7 whose temperature rises with the rotation of the rotating shaft 2 can be positively cooled. When the bearing 7 is a grease-filled type, the grease that has been stirred and generates heat can be efficiently cooled by the air discharged from the opening 10 a of the exhaust port 10.

  Further, when the pulley 3 rotates in the reverse rotation direction, the intake port 9 is formed so that negative pressure is generated at the opening 9c, so that the pulley 3 rotates in the reverse rotation direction. Even in this case, air can flow between the intake port 9 and the exhaust port 10. That is, outside air is taken into the hollow portion 6e of the fixed sheave 6 from the exhaust port 10, and the air in the hollow portion 6e is sucked out from the intake port 9 to the outside of the fixed sheave 6 by the negative pressure generated at the opening 9c. be able to. Accordingly, even when the pulley 3 rotates in the reverse rotation direction, the cooling air can flow in the hollow portion 6e of the fixed sheave 6 to cool the tapered surface 6a and the heat generating portion of the belt 4.

  4, 5 and 6 show other configuration examples of the exhaust port in the belt type continuously variable transmission 1 of the present invention. As described above, the fixed sheave 6 according to the present invention is attached and fixed to the rotary shaft 2 so as to rotate integrally with the rotary shaft 2 and be unable to move in the rotational axis direction of the rotary shaft 2. Further, the fixed sheave 6 is formed in a hollow structure in which a hollow portion 6e is provided between the tapered surface 6a and the back surface 6c. Therefore, the fixed sheave 6 is formed with a fitting hole for fitting with the rotary shaft 2 at the center in the radial direction. For example, a key is used to fix the fixed sheave 6 to the rotating shaft 2. Alternatively, splines and serrations can be used. When the fixed sheave 6 is fixed to the rotary shaft 2 using such a key or spline, a clearance is inevitably provided between the key and the key groove or between the spline and the spline groove. Or a clearance can be provided in the range which does not impair the fixed state of the fixed sheave 6 and the rotating shaft 2. In this invention, the exhaust port in this invention can be comprised using the clearance provided in the fitting part of the above fixed sheave 6 and the rotating shaft 2 as mentioned above.

  That is, the exhaust port in the present invention shown in FIGS. 4, 5, and 6 is provided at the fitting portion between the support member 6 d and the rotating shaft 2 among the fitting portions between the fixed sheave 6 and the rotating shaft 2. The rear side exhaust port 11 and the tapered surface side exhaust port 12 provided at the fitting portion between the sheave base 6b and the rotary shaft 2 are configured. Specifically, as shown in FIGS. 4, 5, and 6, the fixed sheave 6 is fitted to the rotating shaft 2 and is fixed to the rotating shaft 2 by a key 13. As the key 13, for example, a parallel key, a half moon key, or the like can be adopted. 4, 5, and 6 show examples using parallel keys. The key 13 is fixed by being fitted into a key groove formed on the rotary shaft 2.

  A key groove corresponding to the key 13 fixed to the rotating shaft 2 is formed in the fixed sheave 6. That is, the key groove 14 corresponding to the key 13 attached to the rotary shaft 2 is formed in the fitting portion between the support member 6d and the rotary shaft 2 in the fitting portion between the fixed sheave 6 and the rotary shaft 2. Yes. The key groove 14 is formed in the fitting portion between the support member 6d and the rotary shaft 2 from the hollow portion 6e to the outside on the back surface 6c side of the support member 6d. In addition, a key groove 15 corresponding to the key 13 attached to the rotating shaft 2 is formed in the fitting portion between the sheave base 6b and the rotating shaft 2 among the fitting portions of the fixed sheave 6 and the rotating shaft 2. ing. The key groove 15 is formed in the fitting portion between the sheave base portion 6b and the rotary shaft 2 from the hollow portion 6e to the outside on the tapered surface 6a side of the sheave base portion 6b. Then, the support member 6 d and the sheave base portion 6 b are fitted into the rotary shaft 2 so that the key grooves 14 and 15 are fitted with the key 13 attached to the rotary shaft 2. That is, the fixed sheave 6 is fitted into the rotary shaft 2 and fixed integrally.

  As described above, the support member 6d and the sheave base 6b are fitted and fixed to the rotary shaft 2 to which the key 13 is attached. Therefore, the key groove 14 of the support member 6d and the key groove 15 of the sheave base portion 6b are arranged on the key 13 fixed to the rotary shaft 2 with respect to the key groove 14 of the support member 6d and the key groove 15 of the sheave base portion 6b. A predetermined clearance is provided for fitting while sliding. This clearance is, for example, a clearance that is unavoidably provided to fit the key 13 in each of the key grooves 14 and 15. Further, as much clearance as possible can be provided as long as the fixed state of the fixed sheave 6 and the rotating shaft 2 is not impaired.

  As shown in FIG. 5, the clearance between the support member 6d and the key 13 provided in the key groove 14, particularly the clearance provided in the depth direction of the key groove, that is, in the radial direction of the rotary shaft 2 and the fixed sheave 6, is hollow. The through hole penetrates from the portion 6e to the outside on the back surface 6c side of the support member 6d. Also, the clearance between the sheave base 6b and the key 13 provided in the key groove 15, particularly the clearance provided in the depth direction of the key groove, that is, in the radial direction of the rotary shaft 2 and the fixed sheave 6, is from the hollow portion 6e to the sheave. It becomes a through-hole penetrating to the outside on the tapered surface 6a side of the base portion 6b.

  For this reason, in the present invention, the clearance provided in each of the key groove 14 and the key groove 15 as described above is configured to function as an exhaust port in the present invention. That is, the back side exhaust port 11 in the present invention is constituted by the clearance between the key member 14 provided in the depth direction of the key groove 14 of the support member 6d. Further, as shown in FIG. 6, for example, the clearance between the sheave base 6b and the key 13 provided in the depth direction of the key groove 15 constitutes the tapered surface side exhaust port 12 in the present invention.

  Therefore, as shown in FIG. 5, when the pulley 3 rotates in the forward rotation direction, the air taken into the hollow portion 6e of the fixed sheave 6 from the intake port 9 is returned to the rear side exhaust port 11 and the tapered surface side exhaust port. 12 and discharged to the outside of the fixed sheave 6. The air discharged from the back side exhaust port 11 is radiated to the bearing 7 installed on the back surface 6 c side of the fixed sheave 6 in the same manner as the air discharged from the exhaust port 10 described above. Therefore, as described above, the rear side exhaust port 11 is configured using the clearance between the key groove 14 and the key 13 of the support member 6d, so that the exhaust from the hollow portion 6e is performed as in the above configuration example. The air to be blown can be sent again to the bearing 7 as cooling air, and the bearing 7 whose temperature rises as the rotating shaft 2 rotates can be positively cooled.

  On the other hand, the air discharged from the tapered surface side exhaust port 12 is discharged into a space isolated by both the tapered surfaces 5 a and 6 a of the pulley 3 and the inner peripheral surface of the belt 4 and the outer peripheral surface of the rotating shaft 2. . Therefore, as described above, the tapered surface side exhaust port 12 is configured using the clearance between the key groove 15 and the key 13 of the sheave base portion 6b, whereby both the tapered surfaces 5a and 6a of the pulley 3 and the belt are formed. The air exhausted from the hollow portion 6e can be sent to a space that is isolated by the inner peripheral surface 4 and the outer peripheral surface of the rotary shaft 2 and is difficult to be cooled from the outside. Can be cooled.

  Further, as shown in FIG. 5, each of the tapered surface side exhaust port 12 and the back surface side exhaust port 11 has a larger flow rate of air flowing through the tapered surface side exhaust port 12 than the flow rate of air flowing through the back surface side exhaust port 11. It is formed to become. That is, the keys of the support members 6d are arranged such that the clearance between the key groove 15 of the sheave base 6b and the key 13 is larger than the clearance between the key groove 14 and the key 13 of the support member 6d. A clearance between the groove 14 and the key 13 and a clearance between the key groove 15 of the sheave base 6b and the key 13 are set. Therefore, as described above, cooling air is preferentially fed into the space separated by the both tapered surfaces 5a, 6a of the pulley 3 and the inner peripheral surface of the belt 4 and the outer peripheral surface of the rotary shaft 2 that are not easily cooled from the outside. be able to.

  As described above, according to the belt-type continuously variable transmission 1 according to the present invention, the fixed sheave 6 of the pulley 3 is formed in a hollow structure, so that the pulley can be reduced in weight. Further, the back surface 6 c of the fixed sheave 6 is provided with an intake port 9 and an exhaust port 10 that can supply and discharge air to and from the hollow portion 6 e of the fixed sheave 6. Air can be sent into the hollow portion 6 e, and the air sent into the hollow portion 6 e can be discharged from the exhaust port 10 to the outside of the fixed sheave 6. That is, the cooling air can flow in the hollow portion 6 e of the fixed sheave 6. Therefore, the tapered surfaces 5 a and 6 a of the pulley 3 and the belt 4 whose temperature rises due to frictional contact with the belt 4 can be cooled from the hollow portion 6 e side of the fixed sheave 6. Furthermore, the air discharged from the exhaust port 10 of the fixed sheave 6 can be radiated to the bearing 7 that supports the pulley 3 and the rotary shaft 2. Therefore, it is possible to cool the bearing whose temperature rises as the pulley 3 and the rotating shaft 2 rotate. Therefore, even when the stationary sheave 6 is hollow to reduce the weight, the dry belt-type continuously variable transmission 1 with good cooling performance can be provided.

  Further, in the belt type continuously variable transmission 1 according to the present invention, the fixed sheave 6 is hollow in the fitting portion between the fixed sheave 6 and the rotary shaft 2 as in the configuration examples shown in FIGS. A back side exhaust port 11 for discharging air from the portion 6e toward the bearing 7 on the back side 6c side, and a tapered surface side exhaust port 12 for discharging air from the hollow portion 6e of the fixed sheave 6 to the outside on the tapered surface 6a side. Can be provided. In that case, the air supplied from the intake port 9 to the hollow portion 6e of the fixed sheave 6 to cool the pulley 3 and the belt 4 is exhausted from the back side exhaust port 11 and the tapered surface side exhaust port 12, and the back side 6c side The bearing 7 and the space surrounded by the tapered surfaces 5 a and 6 a of the pulley 3 and the inner peripheral surface of the belt 4 and the outer peripheral surface of the rotating shaft 2 can be radiated. Therefore, heat generating portions such as the pulley 3 and the belt 4 and the bearing 7 can be efficiently cooled, and the cooling performance of the belt type continuously variable transmission can be improved.

  The back side exhaust port 11 and the tapered surface side exhaust port 12 as described above are formed in, for example, the key grooves 14 and 15 formed in the fitting portion of the fixed sheave 6, the rotating shaft 2, and the key grooves 14 and 15. Fixed, such as a clearance provided between the inserted key 13 or a clearance provided between the fixed sheave, the rotating shaft, and the spline and spline groove formed in the fitting portion or between the serration and the serration groove It can be formed as a clearance provided at a fitting portion between the sheave and the rotating shaft. That is, the back side exhaust port 11 and the tapered surface side exhaust port 12 can be formed by using a keyway structure, a spline structure, or the like that is provided for fixing the fixed sheave 6 and the rotary shaft 2 in the related art. Therefore, the back side exhaust port 11 and the tapered surface side exhaust port 12 can be easily formed without performing special processing for the back side exhaust port 11 and the tapered surface side exhaust port 12.

  DESCRIPTION OF SYMBOLS 1 ... Belt type continuously variable transmission, 2 ... Rotating shaft, 3 ... Pulley, 3a ... V-shaped groove (belt winding groove), 4 ... Belt, 5 ... Movable sheave, 5a ... Tapered surface, 6 ... Fixed sheave, 6a ... Tapered surface, 6c ... Back surface, 6d ... Support member, 6e ... Hollow portion, 7 ... Bearing, 9 ... Intake port, 9b ... Opening portion, 10 ... Exhaust port, 11 ... Back side exhaust port, 12 ... Tapered surface side exhaust Mouth, 13 ... key.

Claims (5)

A belt, and one fixed surface of the V-shaped groove around which the belt is wound, and a back surface opposite to the tapered surface in the axial direction of the rotary shaft. And a fixed sheave provided with a hollow portion between the tapered surface and the back surface, and the other tapered surface of the V-shaped groove is formed, and rotates together with the rotating shaft and rotates. A belt-type continuously variable transmission comprising: a movable sheave slidably mounted in the axial direction of the shaft; and a pulley around which the belt is wound by forming the V-shaped groove by the fixed sheave and the movable sheave. In
An intake port for supplying air to the hollow portion from the outside of the fixed sheave is provided on the back surface,
A belt type characterized in that an exhaust port for exhausting air from the hollow portion toward the bearing on the back side is provided at a position on the inner diameter side of the bearing supporting the rotating shaft on the back side. Continuously variable transmission.
The exhaust port includes a back side exhaust port that is provided at a fitting portion between the fixed sheave and the rotating shaft, and discharges air from the hollow part toward the bearing on the back side,
The belt according to claim 1, wherein the fitting portion is further provided with a tapered surface side exhaust port for discharging air from the hollow portion to the outside of the fixed sheave on the tapered surface side. Type continuously variable transmission.
The back side exhaust port includes a clearance between the fixed sheave provided in the fitting portion extending from the hollow portion of the fixed sheave to the back surface and the rotating shaft,
The taper surface side exhaust port includes a clearance between the fixed sheave provided in the fitting portion extending from the hollow portion of the fixed sheave to the tapered surface and the rotating shaft. The belt type continuously variable transmission described in 1.
The belt-type continuously variable transmission according to claim 3, wherein the clearance of the tapered surface side exhaust port is larger than the clearance of the back surface side exhaust port.
  The intake port has an opening that opens in the forward rotation direction of the pulley, and when the pulley rotates in the forward rotation direction, takes air around the opening into the hollow portion, and The belt-type continuously variable transmission according to any one of claims 1 to 4, wherein the pulley is formed in a shape in which a negative pressure is generated around the opening when the pulley rotates in the reverse rotation direction.

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