WO2014157276A1

WO2014157276A1 - Motive-power transmission device

Info

Publication number: WO2014157276A1
Application number: PCT/JP2014/058418
Authority: WO
Inventors: 加藤　基; 義弘黒須; 貴浩神沢
Original assignee: 小倉クラッチ株式会社
Priority date: 2013-03-29
Filing date: 2014-03-26
Publication date: 2014-10-02
Also published as: JPWO2014157276A1; CN105121885B; JP6255387B2; CN105121885A

Abstract

Provided are a pulley (4) connected to a motive power source, and a rotating shaft positioned coaxially with respect to the pulley (4). Also provided are a hub (11) provided to the rotating shaft, and a ring plate (12) separably mated to the hub (11). Also provided is a leaf spring (16) for urging the ring plate (12) toward the hub (11) in the direction parallel to the axis of rotation. When the load on the rotating shaft is below a threshold, the hub (11) and ring plate (12) are caused to rotate as a single entity due to friction. When the load on the rotating shaft is equal to or higher than a threshold, the ring plate (12) rotates in relative fashion with respect to the hub (11) and moves parallel to the axis of rotation due to the spring force of the leaf spring (16), so that the ring plate (12) and the hub (11) separate. It is possible to provide a power transmission device in which power transmission is quickly interrupted after the load torque on a driven-side rotating element has increased.

Description

Power transmission

The present invention relates to a power transmission device. More specifically, the present invention relates to a power transmission system in which power transmission is interrupted when the load torque of the driven side rotating body increases.

As a conventional power transmission device of this type, there is, for example, one described in Patent Document 1. The power transmission device disclosed in Patent Document 1 includes a pulley as a drive-side rotation member to which power is transmitted from a power source via a belt, and a driven-side rotation member connected to the pulley via a transmission mechanism. It is equipped with a hub. The pulley is rotatably supported by the housing of the compressor via a bearing. The hub is mounted to rotate integrally with the tip of the rotary shaft of the compressor.

The transmission mechanism is press-fitted to the outer circumferential surface of the first tubular metal and the first tubular metal fixed to the outer circumferential surface of the circular tubular rubber, the first tubular metal fixed to the outer circumferential surface of the circular tubular rubber. And a combined second tubular metal. The second tubular metal is fixed to the pulley.

In this power transmission device, the rotation of the pulley is transmitted to the hub via the transmission mechanism. In this power transmission state, when an overload occurs on the rotary shaft of the compressor, the first tubular metal slips relative to the second tubular metal, and this slip generates frictional heat. This heat is transferred to the tubular rubber via the first tubular metal. Then, the temperature of the bonding portion between the inner circumferential surface of the first circular tubular metal and the outer circumferential surface of the circular rubber increases, and the circular bonding rubber is separated from the first circular tubular metal by breaking. Power transmission is cut off.

JP, 2001-173674, A

In the conventional power transmission device described above, power transmission is interrupted through a plurality of steps after the load torque is increased due to some abnormality in the compressor. The plurality of steps are steps of generating frictional heat by the first tubular metal slipping with respect to the second circular tubular metal, and the frictional heat generates a circle through the first tubular metal. The steps of transferring to the fixing portion of the tubular rubber and the steps of increasing the temperature of the fixing portion and breaking the circular rubber.
For this reason, in the conventional power transmission device, there is a problem that the time required from the occurrence of overload in the compressor to the interruption of the power transmission becomes long. If power transmission continues for a long time while the compressor is overloaded, the belt wound around the pulleys will be damaged.

The present invention has been made to solve such a problem, and it is an object of the present invention to provide a power transmission system in which power transmission is interrupted in a short time after the load torque of the driven side rotating body increases.

In order to achieve this object, a power transmission apparatus according to the present invention comprises a drive-side rotating body connected to and driven by a power source, and a driven-side rotating body located coaxially with the drive-side rotating body. A first rotation member provided on one of the drive-side rotation body and the driven-side rotation body, and integrally rotating on the same axis as the rotation body, and a rotation direction of the first rotation member A second rotary member which is movably disposed in the second direction and is separably fitted by being moved in a direction parallel to the rotation axis; and the second rotary member comprises the drive side rotary body and the driven side rotary body An elastic member coupled to the other rotating body so as to be integrally rotatable on the same axis, and urging the first rotating member in a direction parallel to the axis of rotation; In the member, the load of the driven side rotating body has a predetermined threshold value. In the case where the load is smaller than the first rotation member, the load on the driven-side rotation body is equal to or more than the threshold value. Is rotated with respect to the first rotating member against the frictional force and moved in a direction parallel to the rotation axis with respect to the first rotating member by a spring force of the elastic member. It is separated from the rotating member of

In the power transmission device according to the present invention, the magnitude of the load of the driven-side device connected to the driven-side rotating body becomes equal to or greater than a predetermined threshold, and the fitting portion between the first rotating member and the second rotating member When the slip occurs, the first rotating member and the second rotating member are forcibly separated by the spring force of the elastic member. That is, the power transmission device does not have to heat the parts with frictional heat to shut off the power transmission, and can shut off the power transmission immediately after the slip occurs.
Therefore, according to the present invention, it is possible to provide a power transmission device in which power transmission is interrupted in a short time after the load torque of the driven side rotating body is increased.

FIG. 1 is a front view of a power transmission device according to a first embodiment. FIG. 1 is drawn in a state where power is transmitted. FIG. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is a front view of a ring plate as a second rotating member. FIG. 4 is a front view of the power transmission device according to the first embodiment. FIG. 4 is drawn in the state where the power transmission is cut off. FIG. 5 is a cross-sectional view taken along the line VV in FIG. FIG. 6A is an enlarged sectional view showing a part of the fitting portion between the first rotation member and the second rotation member according to the second embodiment. FIG. 6A shows a case where a part of the second rotating member protrudes in a direction away from the compressor with respect to the first rotating member. FIG. 6B is an enlarged cross-sectional view showing a part of the fitting portion between the first rotating member and the second rotating member according to the second embodiment. FIG. 6B shows the case where a part of the second rotating member protrudes in a direction approaching the compressor with respect to the first rotating member. FIG. 6C is an enlarged sectional view showing a part of the fitting portion between the first rotation member and the second rotation member according to the second embodiment. FIG. 6C shows a state in which the entire area of the second rotating member is engaged with the first rotating member. FIG. 7 is an enlarged front view showing a part of the second rotation member according to the third embodiment. FIG. 8 is a front view of a power transmission device according to a fourth embodiment. FIG. 8 is drawn in a state where power is transmitted. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. FIG. 10 is a front view of a ring plate as a second rotating member. FIG. 11 is a front view of a hub as a first rotating member. FIG. 12 is a front view of a power transmission device according to a fourth embodiment. FIG. 12 is drawn in the state where the power transmission is cut off. FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG.

First Embodiment
Hereinafter, an embodiment of a power transmission device according to the present invention will be described in detail with reference to FIGS.
The power transmission 1 shown in FIG. 1 has the following two functions. The first function is to transmit the power of the automobile engine (not shown) to the compressor 2 for a car air conditioner shown in FIG. The second function is a function of a torque limiter that shuts off power transmission when an overload occurs on the rotary shaft 3 of the compressor 2. In this embodiment, the automobile engine corresponds to the "power source" in the present invention.

The power of the automobile engine is transmitted to the pulley 4 of the power transmission 1 via a belt (not shown).
The pulley 4 is, as shown in FIG. 2, a cylindrical belt hooking portion 6 having a groove 5 around which the belt is wound, an inner cylindrical portion 7 positioned inside the belt hooking portion 6, and both of them. It is comprised by the intermediate part 8 which connects parts. The belt hooking portion 6, the inner cylindrical portion 7 and the middle portion 8 are integrally formed of plastic material by integral molding.

The inner cylindrical portion 7 is rotatably supported by the housing 2 a of the compressor 2 via a bearing 9. The pulley 4 is positioned on the same axis as the rotation shaft 3. In this embodiment, the “driven side rotating body” in the present invention is constituted by the rotating shaft 3, and the “drive side rotating body” in the present invention is constituted by the pulley 4.

A hub 11 is attached to an end of the rotary shaft 3. In this embodiment, the hub 11 corresponds to the "first rotating member" in the present invention. The hub 11 is formed by processing a material made of hot rolled mild steel plate (SPHC) into a predetermined shape.
The hub 11 according to this embodiment includes a boss 11a fixed to the axial end of the rotary shaft 3 and a connecting portion 11b projecting radially outward from the axial tip of the boss 11a. ing.

The connection portion 11b of the hub 11, which will be described in detail later, as shown in FIGS. 1 and 2, is fitted in a hole 13 of the ring plate 12 described later so as to be movable in the rotational direction and the direction parallel to the rotational axis. It is formed in shape. The connecting portion 11 b according to this embodiment is formed in a triangular shape as viewed from the axial direction of the hub 11.

Outer peripheral walls 14 having arc-shaped wall surfaces as viewed in the axial direction are respectively formed at three apexes of the connecting portion 11 b. These outer peripheral walls 14 are provided at positions dividing the rotation direction of the hub 11 into three equal parts. The wall surface of the outer peripheral wall 14 extends in the rotation direction of the hub 11 and in the axial direction of the hub 11 (a direction parallel to the rotation axis). The thickness of the outer peripheral wall 14 is formed to a predetermined thickness.
A flat portion 15 is formed between the three tops of the connecting portion 11b. The flat portion 15 is formed by a flat surface extending in the axial direction of the hub 11. In this embodiment, the flat portion 15 constitutes a "non-fitting portion" as referred to in the second aspect of the invention.

The ring plate 12 is formed by punching a material made of cold-rolled steel plate (SPCC) into a predetermined shape by press working. In this embodiment, the ring plate 12 constitutes a "second rotating member" in the present invention.
The ring plate 12 is constituted by a disc portion 12a in which a hole 13 is formed in an axial center portion, and three flange portions 12b projecting outward in the radial direction from three places in the circumferential direction of the disc portion 12a There is. These flange portions 12 b are provided at positions dividing the circumferential direction of the disc portion 12 a into three equal parts, and are connected to the pulleys 4 via leaf springs 16 described later. That is, power is transmitted from the pulley 4 to the ring plate 12 through the plate spring 16, and the ring plate 12 rotates integrally with the pulley 4.

The disk portion 12a is formed with a plurality of elongated holes 12c extending in the circumferential direction. These long holes 12c are positioned in the region between the three flange portions 12b in the disc portion 12a. The holes 13 of the ring plate 12 are composed of three inner peripheral walls 17 adjacent to the elongated holes 12 c and a recess 18 formed such that the diameter of the holes is expanded between the inner peripheral walls 17. The wall surface of the inner peripheral wall 17 extends in a direction parallel to the rotational direction and the rotation axis of the hub 11 and is formed in a shape in which the outer peripheral wall 14 of the hub 11 is fitted. The length in the rotational direction of the outer peripheral wall 14 of the hub 11 is shorter than the length in the rotational direction of the recess 18.

Further, the length of the wall surface of the inner peripheral wall 17 in the direction parallel to the rotation axis is substantially equal to the length of the wall surface of the outer peripheral wall 14 in the direction parallel to the rotation axis. That is, the ring plate 12 is detachably engaged with the hub 11 by being movable in the rotational direction and moving in a direction parallel to the rotation axis. The power transmitted from the pulley 4 to the ring plate 12 is transmitted to the hub 11 via the fitting portion 21.

In this embodiment, the hub 11 and the ring plate 12 are fitted by shrink fitting in order to prevent the fitting surface from being damaged by the galling caused by the contact of the two members. When the fitting surface is damaged by galling, the frictional force (pressure contact force) of the fitting portion 21 becomes unnecessarily high. The ring plate 12 according to this embodiment is heated and expanded, and is fitted to the hub 11 in a state where the inner diameter of the hole 13 is expanded. This fitting is performed by fitting the outer peripheral wall 14 of the hub 11 to the inner peripheral wall 17 of the ring plate 12.

The flat portion 15 of the hub 11 does not contact the ring plate 12 in order to face the recess 18 of the ring plate 12 in this fitted state. After this fitting, the temperature of the ring plate 12 returns to normal temperature, and the ring plate 12 contracts to the initial size, whereby the outer peripheral wall 14 of the hub 11 and the inner peripheral wall 17 of the ring plate 12 are coupled in a fitted state Ru. Surface treatment such as cation coating is applied to the surfaces of the hub 11 and the ring plate 12 integrally coupled in this manner. In addition, fitting with the ring plate 12 and the hub 11 can be performed by cold fitting other than the above-mentioned shrink fitting. This cold fitting is performed by fitting the outer peripheral wall 14 to the inner peripheral wall 17 of the ring plate 12 in a state in which the hub 11 is cooled and the outer diameter of the connecting portion 11 b of the hub 11 is reduced.

The fitting portion 21 between the ring plate 12 and the hub 11 is configured to generate a frictional force (pressure contact force) of a predetermined size when the hub 11 moves relative to the ring plate 12 There is. The magnitude of this frictional force is set to a size that can restrict the movement of the ring plate 12 with respect to the hub 11 when the load of the rotary shaft 3 of the compressor 2 is smaller than a predetermined threshold. Further, the magnitude of the frictional force is set such that the ring plate 12 rotates relative to the hub 11 against the frictional force when the load of the rotary shaft 3 is equal to or greater than the threshold. The threshold corresponds to the value of the load when an overload occurs in the compressor 2.

The three plate springs 16 attached to the flange portion 12b of the ring plate 12 have a function of supporting the ring plate 12 on the pulley 4 and a function of urging the ring plate 12 in a direction parallel to the rotation axis as described later. And. These leaf springs 16 are formed in a thin strip by a spring material. A ring plate side attachment portion 16 a, which is an end portion on the ring plate 12 side of the plate spring 16, is fixed to the flange portion 12 b by a rivet 22.
The pulley side attachment portion 16 b, which is the other end of the plate spring 16, is fixed to the intermediate portion 8 of the pulley 4 by a tapping screw 23. These leaf springs 16 rotatably connect the ring plate 12 to the pulley 4 on the same axis.

The middle portion 8 of the pulley 4 according to this embodiment is, as shown in FIG. 2, the connection portion 11b of the hub 11 and the housing 2a of the compressor 2 in the axial direction (left and right direction in FIG. 2) of the rotary shaft 3. It is positioned between For this reason, the plate spring 16 is attached to the ring plate 12 and the pulley 4 in a state of being elastically deformed in the axial direction. The plate spring 16 is elastically deformed in a state where both ends are pulled, and the ring plate 12 is urged in the axial direction (direction parallel to the rotation axis) with respect to the hub 11 by an elastic return force (spring force). There is. The direction in which the leaf spring 16 according to this embodiment biases the ring plate 12 is the left direction in FIG. 2 and the direction in which the ring plate 12 approaches the housing 2 a of the compressor 2.

Next, the operation of the power transmission 1 configured as described above will be described.
In the power transmission 1 according to this embodiment, the power of the automobile engine is transmitted to the pulley 4 through the belt and transmitted from the pulley 4 to the ring plate 12 through the plate spring 16. At this time, when the magnitude of the load of the compressor 2 is smaller than a predetermined threshold value, the ring plate 12, the hub 11 and the rotating shaft 3 rotate integrally. In this case, the compressor 2 is driven by the power of the engine.

When the magnitude of the load of the compressor 2 is equal to or more than the above-mentioned threshold value, the ring plate 12 rotates (slip) against the hub 11 against the frictional force generated in the fitting portion 21. At this time, the inner circumferential wall 17 of the ring plate 12 rotates with respect to the outer circumferential wall 14 of the hub 11. Further, at this time, the inner peripheral wall 17 is displaced in the axial direction with respect to the outer peripheral wall 14 while slightly by the spring force of the plate spring 16.

When the inner peripheral wall 17 rotates with respect to the outer peripheral wall 14, the inner peripheral wall 17 comes off from the outer peripheral wall 14, and this outer peripheral wall 14 comes to face the recess 18 of the ring plate 12. That is, as shown in FIG. 4, the ring plate 12 separates from the hub 11. In this separated state, as shown in FIG. 5, the ring plate 12 is in the direction parallel to the rotation axis (in the direction close to the housing 2a of the compressor 2) by the spring force of the plate spring 16 without any friction force acting. Moving. At this time, the ring plate 12 moves to a position where it does not contact the connection portion 11 b of the hub 11 and separates from the hub 11. For this reason, the torque limiter comprised by the ring plate 12 and the hub 11 operate | moves, the power transmission to the compressor 2 is interrupted | blocked, and the compressor 2 stops.

Therefore, according to this embodiment, when the magnitude of the load of the compressor 2 becomes equal to or greater than a predetermined threshold and a slip occurs in the fitting portion 21 between the hub 11 and the ring plate 12, the ring plate 12 becomes a hub 11 is forcibly separated by the spring force of the plate spring 16. That is, the power transmission device 1 does not have to heat the parts with frictional heat to shut off the power transmission, and can shut off the power transmission immediately after the slip occurs.
As a result, according to this embodiment, it is possible to provide a power transmission system in which power transmission is interrupted in a short time after the load torque of the compressor 2 is increased.

In this embodiment, when a slip occurs in the fitting portion 21 between the hub 11 and the ring plate 12, the outer peripheral wall 14 of the hub 11 enters the recess 18 of the ring plate 12 and the ring plate does not act. 12 moves in a direction parallel to the rotation axis by the spring force of the plate spring 16.
Therefore, power transmission is interrupted in a short time as compared with the case where ring plate 12 moves in a direction parallel to the rotation axis by the spring force of leaf spring 16 against the frictional force and separates from hub 11. As a result, according to this embodiment, it is possible to provide a power transmission device capable of interrupting the power transmission more quickly.

The hub 11 and the ring plate 12 according to this embodiment are fitted by shrink fitting or cold fitting.
Therefore, the fitting surface of the hub 11 and the fitting surface of the ring plate 12 are fitted without damage. When the hub 11 and the ring plate 12 are press-fit and fitted with a press, so-called "gage" tends to occur on the fitting surface (surface to be fitted by press-fitting). When galling occurs on the fitting surface, the pressure contact force of the fitting portion 21, that is, the frictional force when one rotating member is displaced in the rotating direction with respect to the other rotating member in the fitting portion 21 becomes larger than necessary. It will

As described above, when the pressing force increases, the power transmission can not be interrupted unless the magnitude of the load is larger than the design value, and the timing of the interruption of the power transmission may be delayed. According to the power transmission device 1 according to this embodiment, since no galling occurs on the fitting surface, the magnitude of the load when the power transmission is interrupted is as designed. Therefore, according to this embodiment, the reliability of the maximum value of the torque that can be transmitted without operating the torque limiter, that is, the limit value of the transmission torque referred to as so-called blocking torque or limit torque is enhanced, and power of high quality is obtained. A transmission device can be provided.

The plate spring 16 according to this embodiment is provided between the ring plate 12 and the pulley 4 in a state of being pulled and elastically deformed. However, the present invention is not bound by such limitations. That is, the leaf spring 16 can be provided between the ring plate 12 and the pulley 4 in a compressed state. When this configuration is applied to the power transmission 1 described above, the ring plate 12 is displaced in a direction away from the pulley 4 after being separated from the hub 11.

In the power transmission device 1 according to the above-described embodiment, a coating for surface protection can be applied to the wall surface of the outer peripheral wall 14 of the hub 11 and the wall surface of the inner peripheral wall 17 of the ring plate 12. In addition, these wall surfaces can also be treated to increase the hardness. The coating process and the curing process are applied to the wall surface, thereby reducing the occurrence of metal-to-metal scuffing when the ring plate 12 is separated from the hub 11. As a result, it is possible to set the size of the load when the power transmission is interrupted with higher accuracy.

Second Embodiment
In the embodiment described above, the mounting position of the ring plate 12 can be changed to a position biased to one or the other in the axial direction of the hub 11, as shown in FIGS. 6A and 6B. 6A and 6B, the same or equivalent members as or to those described with reference to FIGS. 1 to 5 are denoted by the same reference numerals, and the detailed description will be appropriately omitted.

The ring plate 12 shown in FIG. 6A is offset with respect to the outer peripheral wall 14 of the hub 11 in a direction away from the housing 2a of the compressor 2 (not shown) (in the right direction in the figure). Further, the ring plate 12 is biased in the direction (the direction indicated by the arrow R in the figure) separated from the housing 2a by the spring force of a plate spring 16 (not shown). An end 17 a of the inner peripheral wall 17 of the ring plate 12 opposite to the housing 2 a protrudes from the connecting portion 11 b of the hub 11 in the axial direction. The corner portion P located at the tip of the inner peripheral edge of the inner peripheral wall 17 in the direction indicated by the arrow R is not fitted to the outer peripheral wall 14 of the hub 11.

The ring plate 12 shown in FIG. 6B is offset from the outer peripheral wall 14 of the hub 11 in the direction (left direction in FIG. 6) close to the housing 2 a of the compressor 2. Further, the ring plate 12 is biased in the direction approaching the housing 2a (in the direction indicated by the arrow R in the figure) by the spring force of a plate spring 16 (not shown). An end 17a of the inner peripheral wall 17 of the ring plate 12 adjacent to the housing 2a protrudes from the connecting portion 11b of the hub 11 in the axial direction. The corner portion P located at the tip of the inner peripheral edge of the inner peripheral wall 17 in the direction indicated by the arrow R is not fitted to the outer peripheral wall 14 of the hub 11.

The leaf spring 16 urges the radially outer end of the ring plate 12 in the axial direction. Therefore, as shown in FIG. 6C, in a state in which the entire area of the inner peripheral wall 17 is fitted to the outer peripheral wall 14 of the hub 11, the ring plate 12 is loaded so that the corner portion P becomes a fulcrum 16 spring force). In this case, the surface pressure of the fitting portion between the portion around the corner portion P in the inner circumferential wall 17 and the outer peripheral wall 14 is higher than that of the other fitting portions. When the ring plate 12 is moved in the axial direction by the spring force of the plate spring 16 in such a fitted state, galling is likely to occur at the contact portion between the corner portion P and the outer peripheral wall 14.

However, as shown in FIG. 6A or 6B described above, by adopting a configuration in which the corner portion P is not fitted to the outer peripheral wall 14 of the hub 11, the occurrence of galling can be reliably prevented. Moreover, since the press-fit depth (contact area of a fitting surface) of the fitting part 21 reduces when taking this structure, the press-contacting force of the fitting part 21 reduces. Furthermore, in the case of adopting this configuration, the ring plate 12 can be formed thin except for the end portion 17a located on the protruding side from the alternate long and short dash line L shown in FIGS. 6A and 6B.

Third Embodiment
In the power transmission device 1 according to the present invention, in order to increase the pressure contact force of the fitting portion 21, the configuration shown in FIG. 7 can be employed. In FIG. 7, the same or equivalent members as or to those described with reference to FIGS. 1 to 5 are denoted by the same reference numerals, and the detailed description will be appropriately omitted.
On the inner peripheral wall 17 of the ring plate 12 shown in FIG. 7, a plurality of protrusions 31 meshing with the outer peripheral wall 14 of the hub 11 in the rotational direction are formed.

These projections 31 are formed in a mountain shape in cross section by knurling the inner peripheral wall 17. When these projections 31 are pressed against the outer peripheral wall 14 of the hub 11 by shrink fitting or cold fitting, the gaps between the protrusions 31 and the outer peripheral wall 14 are filled by so-called plastic flow of metal. As a result, the contact area between the ring plate 12 and the hub 11 is increased, and the pressing force is increased.

Fourth Embodiment
The power transmission device according to the present invention can be configured as shown in FIG. 8 to FIG. In FIGS. 8 to 13, in these drawings, the same or equivalent members as or to those described with reference to FIGS. 1 to 5 are denoted by the same reference numerals, and the detailed description will be appropriately omitted.
The hub 11 of the power transmission device 41 shown in FIG. 8 is formed in a predetermined shape by a powder alloy (sintered alloy). The powder alloy is formed by pressing and sintering metal powder.

As shown in FIG. 9, the boss 11a of the hub 11 according to this embodiment is connected to the rotary shaft 3 so as to be integrally rotated by spline fitting, and is fixed by a fixing bolt 42 located at the axial center. ing. The fixing bolt 42 penetrates the axial center portion of the hub 11 and is screwed into the screw hole 3 a of the rotating shaft 3. Also in this embodiment, the hub 11 constitutes the “first rotary member” in the present invention, and the ring plate 12 constitutes the “second rotary member” in the present invention.

The connecting portion 11b of the hub 11 according to this embodiment is formed in a disk shape as shown in FIGS. The connecting portion 11 b has three engaging grooves 43, a plurality of outer peripheral walls 14, and a non-fitting portion 44. The thickness of the connection portion 11 b is formed thicker than the thickness of the ring plate 12 as shown in FIG. 9.
The engagement groove 43 is formed at a position that divides the outer peripheral portion of the connection portion 11 b into three equal parts in the circumferential direction. The engagement grooves 43 are formed to be engageable with the jig 45 (see FIG. 9). In this embodiment, the "engagement portion" in the invention according to claim 3 is constituted by the engagement groove 43.

Although not shown in detail, the jig 45 engaged with the engagement groove 43 is at least one jig of a tightening jig and a disassembling jig. The fastening jig is used when the hub 11 is fixed to the rotating shaft 3 by the fixing bolt 42. The clamping jig has an arm 45 a inserted into the engagement groove 43 and engaged with the hub 11. When the fixing bolt 42 is tightened into the screw hole 3 a of the rotating shaft 3, the hub 11 is restricted by pressing the hub 11 with this tightening jig, whereby the rotation of the hub 11 is restricted.

The disassembly jig is used to pull out the hub 11 from the rotating shaft 3. The disassembling jig is inserted into the engagement groove 43 and is inserted into the through hole of the hub 11 generated by the arm 45a engaging with the hub 11 and the fixing bolt 42 being pulled out, and pushes the rotating shaft 3 And a bolt (not shown).

The plurality of outer peripheral walls 14 of the hub 11 according to this embodiment are located between the engagement grooves 43 described above. The non-fitting portion 44 is formed between the outer peripheral walls 14 so that the outer diameter of the connecting portion 11 b is smaller.
As shown in FIG. 11, the outer peripheral wall 14 is formed in a trapezoidal shape projecting outward in the radial direction of the connecting portion 11b when viewed from the axial direction of the boss portion 11a. The outer peripheral walls 14 are provided at three locations between the two engaging grooves 43 so as to be separated from each other at a predetermined interval in the circumferential direction of the hub 11.

The inner peripheral wall 17 of the ring plate 12 with which the outer peripheral wall 14 is fitted is formed in a trapezoidal shape projecting toward the center of the hole 13 as shown in FIG. It is arranged. The ring plate 12 according to this embodiment is formed of carbon tool steel material (SK material). The fitting of the outer peripheral wall 14 and the inner peripheral wall 17 can be performed by shrink fitting or cold fitting, as in the first embodiment.

Further, the ring plate 12 according to this embodiment is biased by the plate spring 16 in a direction away from the compressor 2. That is, the ring plate side attachment portion 16 a of the plate spring 16 is attached to the ring plate 12 in a state of being elastically deformed in a direction approaching the compressor 2. The plate spring 16 urges the rotating shaft 3 in the direction of pulling it out of the housing 2 a of the compressor 2. Therefore, the power transmission device 41 according to this embodiment has a so-called shaft tension specification. The pulley side attachment portion 16 b of the plate spring 16 is attached to a nut member 46 embedded in the pulley 4 by an attachment screw 47.

In the power transmission device 41 configured as described above, when the magnitude of the load of the compressor 2 is equal to or more than the above-described threshold value, the ring plate 12 resists the friction force generated in the fitting portion 21 against the hub 11. Rotate (slip). When slippage occurs in this manner, in the contact portion between the hub 11 and the ring plate 12, the metals may rub against each other and one metal may be scraped by the other metal. When the hub 11 made of powder alloy is scraped, the swarf becomes powdery rather than connected swarf.

For this reason, according to this embodiment, it is considered that "gage" does not occur at the contact portion between the hub 11 and the ring plate 12. Therefore, in this embodiment, no “gnawing” occurs at the contact portion between the hub 11 and the ring plate 12 or little if any. Therefore, the reliability of the limit value of the transfer torque called limit torque is obtained. This makes it possible to provide a power transmission device of higher quality and higher quality.

When the ring plate 12 rotates with respect to the hub 11 due to the slip described above, the outer peripheral wall 14 of the hub 11 enters the recess 18 of the ring plate 12 as shown in FIG. When the hub 11 and the ring plate 12 are separated as described above, as shown in FIG. 13, the ring plate 12 is moved in the axial direction of the rotary shaft 3 by the spring force of the plate spring 16. At this time, the direction in which the ring plate 12 moves is the direction away from the compressor 2. For this reason, the torque limiter comprised by the hub 11 and the ring plate 12 operate | moves, the power transmission to the compressor 2 is interrupted | blocked, and the compressor 2 stops.
Therefore, even in the case of adopting this embodiment, the same effect as in the case of adopting the above-described embodiment can be obtained.

The power transmission device 41 shown in this embodiment includes a hub 11 formed of a powder alloy. However, the present invention is not bound by such limitations. For example, the power transmission device 41 can include a hub 11 formed of hot-rolled mild steel plate (SPHC) and a ring plate 12 formed of a powder alloy. The power transmission device 41 can also include the hub 11 and the ring plate 12 formed of a powder alloy. Furthermore, also in the power transmission device shown in FIGS. 1 to 7, the hub 11 and the ring plate 12 can be formed of a powder alloy.

In the embodiment illustrated in FIGS. 1 to 5 and 8 to 13, the ring plate 12 is moved from the hub 11 by the outer peripheral wall 14 of the hub 11 entering the recess 18 formed in the hole 13 of the ring plate 12. It is configured to be separated. However, the present invention is not bound by such limitations. That is, the opening shape of the holes 13 of the ring plate 12 can be formed circular. When this configuration is adopted, the ring plate 12 is moved in the axial direction against the frictional force by the spring force of the plate spring 16 in a state where the slip is generated in the fitting portion 21 and the frictional force is reduced, and the ring plate 12 is separated from the hub 11 Do.

Further, in the embodiments illustrated in FIGS. 1 to 5 and 8 to 13, the example in which the pulley 4 is used as the driving side rotating body and the rotating shaft 3 is used as the driven side rotating body is shown. However, in the power transmission device 1 according to the present invention, the rotary shaft 3 can be used as a drive side rotating body, and the pulley 4 can be configured as a driven side rotating body. That is, the present invention can adopt a configuration in which power is transmitted from the hub 11 to the ring plate 12.

DESCRIPTION OF

SYMBOLS

1, 41 ... Power transmission apparatus, 2 ... Compressor, 3 ... Rotating shaft, 4 ... Pulley, 11 ... Hub, 12 ... Ring plate, 13 ... Hole, 14 ... Outer peripheral wall, 15 ... Flat part, 16 ... Leaf spring, 17 ... inner peripheral wall, 18 ... recessed part, 21 ... fitting part, 42 ... fixing bolt, 43 ... engaging groove, 44 ... non-fitting part.

Claims

A drive-side rotating body connected to and driven by a power source;
A driven side rotating body located coaxially with the driving side rotating body;
A first rotating member provided on one of the drive side rotating body and the driven side rotating body, and integrally rotating on the same axis as the rotating body;
A second rotating member detachably coupled to the first rotating member by being movable in the rotational direction and moving in a direction parallel to the rotation axis;
The second rotating member is integrally rotatably connected to the other of the drive side rotating body and the driven side rotating body on the same axial line, and the rotation with respect to the first rotating member is performed. And an elastic member biased in a direction parallel to the axis,
The second rotating member is
When the magnitude of the load of the driven side rotating body is smaller than a predetermined threshold value, it rotates integrally with the first rotating member by the frictional force generated in the fitting portion with the first rotating member,
When the magnitude of the load of the driven side rotating body is equal to or more than the threshold value, the first rotating member rotates with respect to the first rotating member against the frictional force and the spring force of the elastic member A power transmission device which is separated from the first rotary member by moving in a direction parallel to the rotation axis.
In the power transmission device according to claim 1,
The second rotating member has a hole formed in an axial center of the second rotating member,
The hole wall of the hole has a plurality of inner circumferential walls fitted with the first rotating member, and a recess formed between the inner circumferential walls so as to expand the hole diameter.
The first rotating member has a plurality of outer peripheral walls fitted to the inner peripheral wall, and a non-fitted portion formed between the outer peripheral walls such that the outer diameter is smaller.
The power transmission device, wherein a length in a rotational direction of the outer peripheral wall is shorter than a length in the rotational direction of the recess.
In the power transmission device according to claim 2,
The first rotary member is connected by spline fitting to a shaft end portion of a rotary shaft constituting one of the drive side rotary body and the driven side rotary body and is fixed by a bolt, for tightening. A power transmission device characterized by comprising an engagement portion engageable with at least one of a jig and a disassembly jig.
The power transmission device according to any one of claims 1 to 3.
The power transmission device, wherein the first rotating member and the second rotating member are fitted by shrink fitting or cold fitting.
The power transmission device according to any one of claims 1 to 3.
A power transmission device characterized in that at least one of the first rotating member and the second rotating member is formed of a powder alloy.