JP2017020535A - Power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the lowering of the durability of a displacement device which makes a rolling bearing for rotatably supporting an idler pulley and the idler pulley contact with or separate from a drive pulley and a driven pulley.SOLUTION: An idler pulley 13 which is rotatably supported by a rolling bearing 17 is arranged between a drive pulley 12 and a driven pulley 15, and an elastic member layer 18 is formed at an outside diameter face of the idler pulley 13. A pair of flanges 22 are arranged on outside diameter faces of the drive pulley 12 and the driven pulley 15, the elastic member layer 18 and one flange 22 are made to abut on each other when an axial force is applied to a direction opposing a pulley contact part at the contact of the idler pulley 13 with both the drive pulley 12 and the driven pulley 15, the axial force is supported by both the drive pulley 12 and the driven pulley 15, and the application of the large rotation moment to the rolling bearing 17 which rotatably supports the idler pulley 13 is prevented.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a power transmission device that transmits rotation of a driving pulley to a driven pulley by frictional contact of an idler pulley.

  In order to reduce carbon dioxide emissions, a generator with motor function (ISG) (Integrated Starter Generator) that stops the engine when the vehicle is stopped and starts the engine instantly when the vehicle is started by depressing the accelerator pedal is installed. In such an engine, the rotation of the crankshaft of the engine is normally transmitted to an auxiliary device such as a water pump or a generator with a motor function by a belt transmission. Further, when the engine is started, the power of the generator with a motor function is transmitted to the crankshaft.

  In a power transmission device for an engine that employs such a belt transmission device as described above, the water pump always rotates as the crankshaft rotates. For this reason, even when it is not necessary to rotate the water pump, such as when the engine is warming up, or when the engine is quickly reached the maximum efficiency, the water pump rotates, resulting in large torque loss and fuel consumption. There is a problem that there are many.

  In order to solve the above problem, in Patent Document 1 below, an idler is provided between a crankshaft pulley as a driving pulley attached to an end of the crankshaft and a friction pulley as a driven pulley attached to a rotating shaft of an auxiliary machine. A friction wheel is provided as a pulley, and the friction wheel can be brought into contact with and separated from the crankshaft pulley and the friction pulley. When the water pump is driven, the friction wheel is displaced to a position in contact with the crankshaft pulley and the friction pulley. The power is transmitted from the crankshaft pulley to the friction pulley by the contact rotation of the friction wheel.

  In addition, when the engine is started by starting the generator with motor function (ISG), the friction wheel is displaced to the separation position to cut off power transmission from the crankshaft pulley to the friction pulley.

Special table 2008-519950 gazette

  By the way, in the power transmission device that transmits the rotation of the crankshaft to the auxiliary machine by the contact rotation of the idler pulley as described above, if the power transmission through the friction wheel is a power transmission by metal contact, the crankshaft pulley and the friction wheel Sliding easily occurs at each of the contact portion and the contact portion of the friction wheel and the friction pulley, and the torque transmission efficiency decreases due to the slip, so an elastic member layer is formed on one of the friction wheel, the crankshaft pulley and the friction pulley, Generally, power is transmitted by elastic contact.

  Here, when the power is transmitted through the elastic member layer as described above, when the friction wheel is in contact, there is an angular deviation between the friction wheel and the crankshaft pulley or between the friction wheel and the friction pulley. When the tolerance of the cylindricity of the outer diameter surface is bad, a force that moves the crankshaft pulley and the friction pulley in the opposite direction acts on the contact portion of the crankshaft pulley and the friction pulley, and the axial force acts on the friction wheel. Works.

  At this time, a large moment load is applied to the rolling bearing that rotatably supports the friction wheel as the idler pulley and the displacement device that contacts and separates the friction wheel (idler pulley) from the crankshaft pulley and the friction pulley. There is a problem that the bearing and the displacement device are easily damaged.

  An object of the present invention is to provide a power transmission that can suppress a decrease in durability of a displacement device that makes a rolling bearing and an idler pulley that rotatably support an idler pulley contact and separate from a driving pulley and a driven pulley. Is to provide a device.

  In order to solve the above problems, in the present invention, an idler pulley that is rotatably supported by a rolling bearing is provided on both the drive pulley and the driven pulley so as to be freely contacted and separated, and the idler pulley, the drive pulley, In a power transmission device in which an elastic member layer is provided on one outer diameter surface of a driven pulley and the rotation of the drive pulley is transmitted to the driven pulley by frictional contact of the idler pulley via the elastic member layer, the drive pulley and the driven pulley Among the pulleys and idler pulleys, a configuration is adopted in which a pair of flanges that are opposed to both end surfaces of the elastic member layer in the axial direction are provided on the pulley outer diameter surface on the side where the elastic member layer is not formed. .

  As described above, by providing a pair of flanges on the pulley outer diameter surface on which the elastic member layer is not formed, when the idler pulley contacts the driving pulley and the driven pulley, the angular displacement between the pulleys that contact each other is shifted. When an axial force in the opposite direction acts on the contact portion, one end surface of the elastic member layer and one flange facing the one end surface in the axial direction abut, and the drive pulley from the abutment portion An axial force is applied to both the driven pulley and the driven pulley, and the axial force is supported by each of the drive pulley and the driven pulley.

  Specifically, when the elastic member layer is provided on the outer diameter surface of the idler pulley, and both the driving pulley and the driven pulley are provided with flanges, the axial force acting on the pulley contact portion causes the idler pulley to One end face of the elastic member layer on the outer periphery and one flange on the outer periphery of the drive pulley and the driven pulley come into contact with each other, and the axial force is supported by each of the drive pulley and the driven pulley.

  On the other hand, when an elastic member layer is provided on the outer diameter surface of both the drive pulley and the driven pulley and a flange is provided on the outer diameter surface of the idler pulley, the idler pulley is caused by the axial force acting on the pulley contact portion. One of the outer peripheral flanges and the elastic member layers on the outer periphery of the drive pulley and the driven pulley come into contact with each other, and the axial force is supported by each of the drive pulley and the driven pulley.

  In this case, the pulley shaft that supports each of the drive pulley and the driven pulley is a support having a large proof strength against the moment load. Therefore, a rolling bearing that rotatably supports the idler pulley or an idler pulley that is connected to the drive pulley and the driven pulley. A large moment load is hardly applied to the displacement device that is displaced to a position in contact with the pulley, and it is possible to suppress a decrease in durability of these components.

  Here, when the width dimension of the outer diameter surface between the flange roots of the flanged pulley provided with a pair of flanges is Bw, and the width dimension in the axial direction of the pulley with the elastic member layer is B, the width of the flanged pulley The relationship between the dimension Bw and the width dimension B of the pulley with an elastic member layer is preferably set to Bw ≦ B + 0.5 mm.

  With the dimensional relationship as described above, the angular runout amount of the idler pulley can be suppressed to a small range. Specifically, assuming that the pulley rolling bearing generally has an inner diameter of 17 mm, has a bearing clearance, and the pulley diameter is about 100 mm, the angular deflection on the outer surface of the pulley is 0.5 mm or more. Therefore, by suppressing the angular deflection to 0.5 mm or less, an excessive moment load is not applied to the rolling bearing that rotatably supports the idler pulley, and damage to the rolling bearing and the parts that support the rolling bearing can be prevented. Can do.

  Further, when the radial height on the inner side surface of the flange is H and the thickness of the elastic member layer is t, the relationship between the height H of the flange and the thickness t of the elastic member layer is H> t. It is good.

  With the dimensional relationship as described above, the axial force acting on the pulley contact portion can be reliably supported by the flange.

  Furthermore, it is preferable that the flange is inclined outward so that the outer peripheral portion is positioned axially outward from the inner peripheral portion, and the inclination angle α with respect to a plane perpendicular to the pulley axis of the flange is 10 ° or more. .

  As described above, when the inclination angle α of the flange is set to 10 ° or more, even when the mounting accuracy of the driving pulley and the driven pulley having a small distance between the shaft centers is poor, when moving toward the contact position of the idler pulley In addition, it is possible to prevent inconvenience that the pulley having the elastic member layer on the outer periphery rides on the flange, and to reliably displace the idler pulley to a position where it contacts both the driving pulley and the driven pulley.

  In the present invention, as described above, by providing the pair of flanges on the pulley outer diameter surface on the side where the elastic member layer is not formed, when the idler pulley contacts the drive pulley and the driven pulley, the pulley contact portion Since the axial force in the direction opposite to the action of the actuator can be supported by each of the drive pulley and the driven pulley, a large moment load is applied to the rolling bearing that rotatably supports the idler pulley and the displacement device that displaces the idler pulley. The load can be prevented, and the deterioration of the durability of these components can be suppressed.

Schematic which shows embodiment of the power transmission device which concerns on this invention The front view which expands and shows the power transmission part of FIG. Sectional view along line III-III in FIG. Front view showing another example of power transmission unit

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, a crankshaft pulley 12 provided at an end of a crankshaft 11 of an engine 10 is used as a driving pulley, and the rotation of the driving pulley 12 is attached to a rotating shaft 14 a of an auxiliary machine 14 via an idler pulley 13. 1 shows a power transmission device for transmitting power to a driven pulley 15 comprising a friction pulley. The auxiliary machine 14 is composed of a water pump.

  Here, like the idler pulley described in Patent Document 1, the idler pulley 13 can be brought into contact with and separated from the drive pulley 12 and the driven pulley 15, and the contact position and the separated position are set by the actuator A as a displacement device. It is designed to be displaced. As the actuator A, a cam actuator using an eccentric cam described in JP-A-2008-506342 can be adopted. Therefore, the details of the actuator A are omitted here, and the idler pulley 13 is connected to the drive pulley 12 and It is shown in a state where it is displaced to a contact position that contacts both of the driven pulleys 15.

  As shown in FIGS. 2 and 3, the idler pulley 13 is provided with a cylindrical contact wheel 13a, a disk part 13b provided on the inner periphery of the contact wheel 13a, and an inner periphery of the disk part 13b. The support shaft 16 is inserted into the boss portion 13c, and the idler pulley 13 is rotated around the support shaft 16 by a rolling bearing 17 incorporated between the support shaft 16 and the boss portion 13c. It is supported freely.

  A roller bearing 17 with a seal is employed as the rolling bearing 17 but is not shown here.

  An elastic member layer 18 is provided on the outer diameter surface of the contact wheel 13 a of the idler pulley 13. In the embodiment, the elastic member layer 18 is formed on the contact wheel 13a. However, the elastic member layer formed in a ring shape may be fitted to the contact wheel 13a and integrated by adhesion. The axial width dimension B of the elastic member layer 18 is made equal to the axial width dimension of the contact ring 13a and covers the entire outer diameter surface of the contact ring 13a.

  The driven pulley 15 has a configuration in which a disc portion 21 is provided on the inner diameter surface of the contact wheel 20 and a boss portion 23 is provided on the inner peripheral portion of the disc portion 21. On the other hand, since the drive pulley 12 has the same configuration as the driven pulley 15, the same parts are denoted by the same reference numerals and description thereof is omitted.

  The driven pulley 15 is attached so as to be integrally rotatable with respect to the rotating shaft 14 a of the auxiliary machine 14. On the other hand, the drive pulley 12 is attached so that it can rotate integrally with the crankshaft 11 shown in FIG.

  As shown in FIG. 3, flanges 22 are provided at both ends of the outer diameter surface of the contact wheel 20 of the driving pulley 12 and the driven pulley 15. Each of the pair of flanges 22 is inclined outward so that the outer peripheral portion is positioned outward in the axial direction from the inner peripheral portion.

  Here, in the outer diameter surface of the contact wheel 20 in the driving pulley 12 and the driven pulley 15, when the axial width dimension between the roots of the pair of flanges 22 is Bw, the width dimension Bw is the outer diameter surface of the idler pulley 13. The relation Bw ≦ B + 0.5 mm is established with respect to the width dimension B in the axial direction of the elastic member layer 18 provided on the surface.

  Further, when the height in the radial direction on the inner surface of the flange 22 is H and the thickness of the elastic member layer is t, the relationship between the height H of the flange 22 and the thickness t of the elastic member layer 18 is H> t.

  Here, if the distance between the shaft centers of the drive pulley 12 and the driven pulley 15 shown in FIG. 1 is relatively small, the drive pulley 12 and the driven pulley 15 are supported with an inclination, and the perpendicularity of the shaft center is 1 °. When the idler pulley 13 is displaced by the actuator A to a position where it is in contact with both the drive pulley 12 and the driven pulley 15, there is a possibility of riding on a pair of flanges 22 that are inclined outward. In order to prevent such a problem from occurring, the inclination angle α of the pair of flanges 22 that are inclined outward with respect to a plane perpendicular to the pulley axis is set to 10 ° or more.

  The power transmission device shown in the embodiment has the above-described structure. When power is transmitted from the drive pulley 12 to the driven pulley 15, the actuator A shown in FIG. The elastic member layer 18 provided on the outer diameter surface is displaced to a position where it contacts the outer diameter surfaces of both the drive pulley 12 and the driven pulley 15, and the rotation of the drive pulley 12 is driven by the contact rotation of the idler pulley 13. It is transmitted to the pulley 15.

  Here, when the idler pulley 13 is in contact with the drive pulley 12 and the driven pulley 15, the outer surface of the contact wheel 20 in the drive pulley 12 and the driven pulley 15, as shown in FIG. The axial width dimension Bw between the roots of the pair of flanges 22 has a relationship of Bw ≦ B + 0.5 mm with respect to the axial width dimension B of the elastic member layer 18 provided on the outer diameter surface of the idler pulley 13. Further, since the height H of the flange 22 and the thickness t of the elastic member layer 18 are in a relationship of H> t, the pair of flanges 22 of the driving pulley 12 and the driven pulley 15 are elastic of the idler pulley 13. Opposite the member layer 18 in the axial direction.

Further, when the idler pulley 13 contacts the driving pulley 12 and the driven pulley 15, the axial force F in the direction opposite to the pulley contact portion as shown by the arrow in FIG. ₁ , F ₂ may act.

As described above, when the axial forces F ₁ and F ₂ are applied to the pulley contact portion, one end surface of the elastic member layer 18 provided on the outer diameter surface of the idler pulley 13, the outside of the drive pulley 12 and the driven pulley 15. One of the pair of flanges 22 formed on the radial surface comes into contact with each other, and axial force is applied to both the drive pulley 12 and the driven pulley 15 from the contact portion, so that each of the drive pulley 12 and the driven pulley 15 is provided. Thus, the axial force is supported.

  Therefore, a large moment load is applied to the rolling bearing 17 that rotatably supports the idler pulley 13 and the displacement device A (see FIG. 1) that displaces the idler pulley 13 to a position where the idler pulley 13 contacts the driving pulley 12 and the driven pulley 15. And these parts are not damaged.

  In FIG. 3, the elastic member layer 18 is provided on the outer diameter surface of the idler pulley 13, and the pair of flanges 22 are provided on the outer diameter surfaces of the drive pulley 12 and the driven pulley 15. However, as shown in FIG. A pair of flanges 22 may be provided on the outer diameter surface of each of the elastic members and the elastic member layer 18 may be provided on the outer diameter surfaces of the drive pulley 12 and the driven pulley 15.

12 Drive pulley 13 Idler pulley 15 Driven pulley 17 Rolling bearing 18 Elastic member layer 22 Flange

Claims (4)

An idler pulley that is rotatably supported by a rolling bearing with respect to both of the driving pulley and the driven pulley is provided so as to be able to contact and separate, and an elastic member is provided on an outer diameter surface of the idler pulley, the driving pulley, or the driven pulley. In the power transmission device that provides a layer, and transmits the rotation of the drive pulley to the driven pulley by frictional contact of the idler pulley through the elastic member layer,
A pair of flanges facing the both end surfaces of the elastic member layer in the axial direction are provided on the pulley outer diameter surface of the drive pulley, the driven pulley, and the idler pulley on the side where the elastic member layer is not formed. A power transmission device characterized by.   The width dimension Bw of the flanged pulley when the width dimension of the outer diameter surface between the flanged roots of the flanged pulley provided with the pair of flanges is Bw and the width dimension in the axial direction of the pulley with the elastic member layer is B. The power transmission device according to claim 1, wherein a relationship between the width dimension B of the pulley with elastic member layer and B is Bw ≦ B + 0.5 mm.   The relationship between the height H of the flange and the thickness t of the elastic member layer is H> t, where H is the radial height of the inner surface of the flange and t is the thickness of the elastic member layer. Item 3. The power transmission device according to Item 1 or 2.   The flange is inclined outward so that the outer peripheral portion is positioned axially outward from the inner peripheral portion, and an inclination angle α with respect to a plane orthogonal to the pulley axis of the flange is set to 10 ° or more. 4. The power transmission device according to claim 1.

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