JP2000352428A - Power transmission mechanism and compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure a timeliness of a power interruption motion at an overload of two members constituting a connection means for connecting a first rotor at a driving source side with a second rotor at a driven device side s as to be integrally rotatable. SOLUTION: An arm part 73 of the engaging members 71, 72 fixed to be integrally rotatable to a pulley side rotating and driving via an output shaft of an engine and a belt is engaged to an engaging protrusion part 63 formed at two plate springs 61, 62 fixed to be integrally rotatable to a driving shaft side of a compressor. The driving shaft of the compressor and the pulley are disposed on the same axis to be integrally rotatable, and integrally rotate when power is transmitted from the pulley to the driving shaft via a latching between the plate springs 61, 62 and the engaging members 71, 72. When a load torque at the compressor side becomes excessively increased, the arm part 73 slides on an engaging surface 64 to disconnect the latching. In the arm part 73, a solid lubricating coating made of polytetrafluoroethylene is formed at least on a surface corresponding to a contact part against the engaging surface 64, and coefficient μ of friction is set low.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive source and a driven device that are operatively connected to each other so that power can be transmitted thereto, and the power transmission is interrupted by releasing the operative connection between the drive source and the driven device according to the magnitude of a load on the driven device. The present invention relates to a power transmission mechanism and a compressor that can perform the power transmission.

[0002]

2. Description of the Related Art In a power transmission path from a drive source such as an engine or a motor to a driven device such as a compressor, when an abnormal condition (for example, deadlock) occurs in the driven device, an excessive load torque is driven as a reaction thereto. In order to prevent spillover to the source, a power transmission mechanism capable of forcibly releasing the operative connection between the two may be provided. For example, the actual opening 63-1
The vehicle clutchless compressor disclosed in Japanese Patent Publication No. 9083 employs a power transmission mechanism that couples a pulley connected to the engine and a drive shaft of the compressor using an overload breakable material (specifically, a shear pin). . That is, in this power transmission mechanism, a pair of shear pins are erected on a driving force receiving body fitted and fixed to a driving shaft, and each pin is engaged with a hole formed in a side wall of the pulley to be operatively connected. Relationships are being built.
Then, the load torque on the compressor side increases due to an abnormality inside the compressor, etc., and when a stress exceeding a predetermined limit value acts on the shear pin due to the load torque, the two pins break almost at the same time and compress with the engine. The operative connection with the machine is released.

[0003]

However, even if the shear pin is designed so that it breaks as scheduled when the load torque reaches a predetermined value (assumed breaking torque) at which the shear pin breaks, the expected breaking torque does not increase. The shear pin may be broken by a load torque less than the above. This is because the shear pin gradually fatigues due to the repetitive stress caused by the load torque (less than the breaking torque) that fluctuates during normal operation, and as a result, the limit stress required to break the shear pin gradually decreases with time. That's why. On the other hand, if strength improvement measures such as enlarging the pin diameter are adopted to prevent such breakage due to stress fatigue, this time, the same shear pin as new, which is not affected by stress fatigue, is broken at the assumed break torque. There is a dilemma that makes it difficult.

As described above, in the conventional power transmission mechanism, it is very difficult to achieve both the improvement of the accuracy of the breaking torque and the securing of the strength of the shear pin (ie, the mechanical resistance to the repetitive stress).

[0005] The above example relates to a power transmission mechanism of a type in which power is cut off by breaking a member.
A type of power that secures the operative connection between the drive source and the driven device based on the engagement of the two members, while achieving power shutoff by releasing the engagement between the two members due to excessive load torque. The transmission mechanism also has a similar trade-off problem. For example, if the mechanical strength of the elastic connecting member provided on one of the two rotating bodies and involved in the engagement and disengagement with the other of the rotating bodies is sufficiently ensured, the elasticity of the connecting member is increased more than necessary. As a result, there is a problem that the detaching operation of the elastic connecting member is hindered (that is, the power is not cut off in a timely manner with a predetermined load torque).

The present invention has been made in view of such circumstances, and an object thereof is to form a connecting means for connecting a first rotating body on a driving source side and a second rotating body on a driven device side so as to be integrally rotatable. An object of the present invention is to provide a power transmission mechanism and a compressor that can more reliably assure the timeliness of a power cutoff operation when a member is overloaded.

[0007]

According to the first aspect of the present invention, the first rotating body on the driving source side and the second rotating body on the driven equipment side are coaxially rotatably provided, and the first and the second rotating bodies are provided coaxially. A power transmission mechanism comprising: a connecting means for operatively connecting the two rotators while releasing the operative connection between the two according to the magnitude of the load on the driven device side, wherein the connecting means comprises the first and second
A spring member provided on one of the rotating bodies, and an engagement provided on the other side of the first and second rotating bodies with the spring material and capable of engaging with the spring material so as to transmit power. And the friction coefficient of the contact surface between the spring member and the engagement member is set to a value small enough that both can be stably disengaged with a disengagement torque in a target range in which the operative connection between them is to be released. Set.

According to this structure, the operative connection between the first rotating body on the driving source side and the second rotating body on the driven device side is ensured by the engagement between the spring member and the engaging member constituting the connecting means. You.
At the time of this operative connection, power transmission from the first rotating body to the second rotating body is performed via a contact surface between the spring member and the engaging member. When the load on the driven device side becomes excessive, the operative connection between the first rotating body and the second rotating body is released by the engagement and disengagement of the spring member from the engaging member, but the friction of the contact surface at that time is released. Since the coefficient is set to a small value, when the load torque of the second rotating body reaches a value within the target range in which the operative connection should be released, the operative connection between the two is almost certainly released. That is, the timeliness of the power shut-off operation of the members constituting the connecting means is guaranteed.

According to a second aspect of the present invention, in the first aspect, at least one of the spring member and the engaging member has an engaging surface inclined at an acute angle with respect to a power transmission direction.

[0010] According to this configuration, the engagement surface serves as a contact surface between the spring member and the engagement member. When the load on the driven device side becomes excessive, the engagement between the spring member and the engagement member is released by sliding on the engagement surface. That is, when the load on the driven device side becomes excessive, the engagement between the spring member and the engagement member is guided by the engagement surface inclined at an acute angle with respect to the power transmission direction, and is easily released.

According to a third aspect of the present invention, in the first or second aspect, the friction coefficient of a contact portion between the spring member and the engagement member is set to a value within a range of 0.05 to 0.2. Set to.

According to this structure, even if oil is applied to the contact portion between the spring member and the engagement member, for example, and the friction at the contact surface becomes very small, the contact between the spring member and the engagement member becomes small. Since the friction coefficient of the portion is originally a small value in the range of 0.05 to 0.2, a stable separation torque can be obtained regardless of the presence or absence of oil or the like.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, a contact portion between the spring member and the engaging member has a solid surface on at least one surface of both. A lubrication layer is formed.

According to this configuration, the friction coefficient of the contact surface between the spring member and the engagement member can be reduced by the solid lubrication layer without being affected by the material of the base member. That is, the contact portion between the two members can be effectively reduced in friction coefficient by the solid lubricating layer. Further, the degree of freedom in selecting each material of the spring member and the engagement member is increased.

According to a fifth aspect of the present invention, in the fourth aspect, the solid lubricating layer is made of a fluororesin. According to this configuration, since a material having a very high lubricating performance, such as a fluororesin, is employed as the material of the solid lubricating layer, the friction coefficient of the contact portion between the spring material and the engaging member can be extremely reduced.

According to a sixth aspect of the present invention, in the first aspect of the present invention, the engaging member is made of resin. According to this configuration, even if the spring material is metal, since the engaging member is made of resin, the contact between the two members becomes the contact between the metal and the resin, and the friction coefficient at the contact surface is reduced. Further, the weight of the power transmission mechanism can be reduced by the engagement member made of resin.

According to a seventh aspect of the present invention, in the sixth aspect, the pulley as the first rotating body and the engaging member are both made of resin. According to this configuration, the weight of the pulley and the engagement member can be reduced, and the load on the drive source side can be reduced.

According to an eighth aspect of the present invention, in the invention according to any one of the first to seventh aspects, the spring member has a flat plate shape and is used when the first and second rotating bodies are operatively connected. The power transmission from the first rotating body to the second rotating body is performed mainly in the surface direction of the spring member, and the detaching operation of the spring member from the engagement member for releasing the operation connection is performed by the spring member. Are arranged mainly in the thickness direction.

According to this configuration, the power transmission from the first rotating body to the second rotating body is performed mainly in the surface direction of the spring material, and the spring material has sufficient mechanical strength as far as the power transmission direction is concerned. Therefore, the resistance of the spring material to the repeated stress is sufficiently ensured. On the other hand, when the load on the driven device side becomes excessive and the operative connection between the first rotating body and the second rotating body is released, when the spring material is disengaged from the engagement member, the disengagement operation of the spring material is performed. It is mainly performed in the thickness direction. The spring material ensures mechanical resistance to repeated stresses depending on its surface direction, and also allows adjustment of a force required for disengagement (or a load allowing a disengagement operation) by its thickness. Therefore, according to this power transmission mechanism, it is possible to perfectly balance the timeliness of the detaching operation and the resistance to the repeated stress.

According to a ninth aspect of the present invention, in the first aspect of the present invention, the driven device is a compressor, and the second rotating body includes a drive shaft of the compressor. When the first and second rotating bodies are operatively connected, the spring member is disposed so as to urge the drive shaft toward the outside of the compressor.

According to this configuration, the spring material constituting the connecting means also functions as urging means for urging the drive shaft toward the outside of the compressor. For this reason, for example, the spring member can be used for the purpose of positioning the internal mechanism of the compressor including the drive shaft, which can contribute to simplification of the internal mechanism of the compressor.

According to a tenth aspect of the present invention, in the invention according to any one of the first to ninth aspects, at least a portion of the engaging member that contacts the spring member has elasticity.
According to this configuration, when a contact pressure is applied to the engagement member, the engagement member is elastically deformed to secure a large contact area with the spring member, and vibration transmitted to the contact surface between the spring member and the engagement member is elastically absorbed. As a result, a uniform load is applied to the engagement surface, and power transmission is stabilized. In addition, the application of a uniform load makes it difficult for minute foreign matter or the like to enter the gap between the contact surfaces, and contributes to keeping the friction coefficient small.

According to an eleventh aspect of the present invention, the compressor is provided with the power transmission mechanism according to any one of the first to tenth aspects on a drive shaft. According to this compressor, claims 1 to
Since the power transmission mechanism according to any one of the tenth aspects is provided on the drive shaft, the same operation and effect as the invention according to any one of the first to tenth aspects can be obtained.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First and second embodiments in which the present invention is embodied in a variable displacement compressor of a vehicle air conditioner will be described. This variable displacement compressor does not require a clutch mechanism such as an electromagnetic clutch between the engine of a vehicle as a driving source, and is therefore called a clutchless compressor. The power transmission mechanism of the present invention is disposed in a power transmission path between the engine and the variable displacement compressor, and selectively performs normal power transmission and emergency power cutoff.

(First Embodiment) A first embodiment will be described with reference to FIGS. As shown in FIG. 1, the vehicle air conditioner includes a swash plate type variable displacement compressor (hereinafter, simply referred to as a compressor) 10, an external refrigerant circuit 30, and a control device 34 that controls the entire air conditioner. Have. External refrigerant circuit 3
Numeral 0 includes, for example, a condenser 31, a temperature-type expansion valve 32, and an evaporator 33, and forms a refrigeration cycle together with the compressor 10.

First, the configuration of the compressor 10 and the basic operation of air conditioning control will be described. Compressor 10 as driven equipment
A cylinder block 11, a front housing 12 joined and fixed to the front end face thereof, and a cylinder block 11
And a rear housing 13 joined and fixed to the rear end face via a valve forming body 14. These members 11, 12,
13 and 14 constitute a housing of the compressor 10 as a whole.

In the front housing 12, a crank chamber 15 is defined by the front end surface of the cylinder block 11. The crank chamber 15 includes a rotatable drive shaft 16, a rotation support (a lug plate) 18 fixed on the drive shaft 16, and a swash plate 1 as a cam plate.
9 and a hinge mechanism 20 interposed between the lug plate 18 and the swash plate 19. Lug plate 18
Is in contact with the inner wall surface of the front housing 12 via the thrust bearing 17. The swash plate 19 is supported by the drive shaft 16 so as to be slidable and tiltable in the axial direction. The swash plate 19 can slide and tilt with respect to the drive shaft 16 and can rotate integrally with the drive shaft 16 by the lug plate 18 and the hinge mechanism 20.

A plurality of cylinder bores 11a (only one is shown) are formed in the cylinder block 11 so as to surround the drive shaft 16 at equal angular intervals. Each cylinder bore 11a extends in parallel with the drive shaft 16, and a single-headed piston 21 is accommodated in each bore 11a so as to be able to reciprocate. One end of each piston 21 is moored to the outer periphery of the swash plate 19 via a pair of shoes 22. A compression chamber is defined between the piston end face and the valve body 14 in each bore 11a. When the inclined swash plate 19 rotates together with the drive shaft 16, the waving motion of the swash plate 19 causes the pistons 21 to reciprocate via the shoes 22.

The valve body 1 is provided in the rear housing 13.
4 define a suction chamber 25 and a discharge chamber 26, respectively. The discharge chamber 26 and the suction chamber 25 are connected by an external refrigerant circuit 30. The valve forming body 14 is configured by stacking a plurality of metal plate members. The valve forming body 14 has a suction hole and a discharge hole for each of the cylinder bores 11a (or compression chambers). Further, a suction valve 14a formed of a flapper valve corresponding to the suction hole corresponds to the discharge hole. A discharge valve 14b composed of a flapper valve is formed. Then, due to the forward movement of the piston 21, the refrigerant gas in the suction chamber 25 pushes and opens the suction valve 14a and is sucked into the cylinder bore 11a. Thereafter, the refrigerant gas compressed by the backward movement of the piston 21 pushes and opens the discharge valve 14b. It is discharged to the discharge chamber 26.

An air supply passage 23 communicating the crank chamber 15 and the discharge chamber 26 is bored so as to penetrate the cylinder block 11, the valve body 14, and the rear housing 13 through a predetermined path. A capacity control valve 24 is incorporated in the rear housing 13 so as to be interposed on the air supply passage 23. The capacity control valve 24 includes a solenoid 24a, a valve body 24,
b and a port 24c (which constitutes a part of the air supply passage 23). The opening of the port 24c of the displacement control valve 24 is adjusted by the valve element 24b by the demagnetization control of the solenoid 24a by the control device 34.

On the other hand, inside the drive shaft 16, a pressure release passage 16 a penetrates with one end opened to the crank chamber 15 and the other end opened to a recess 11 b formed substantially in the center of the cylinder block 11. Is formed. Recess 11b
Communicates with the suction chamber 25 through a pressure release hole 27 as a throttle formed in the cylinder block 11 and the valve forming body 14. The pressure release passage 16a, the concave portion 11b, and the pressure release hole 27 form a bleed passage for releasing the pressure (crank pressure Pc) of the crank chamber 15 to the suction chamber 25.

The swash plate 19 is restricted to a maximum inclination angle by a stopper 19 a provided on the swash plate 19 abutting against the lug plate 18, and is minimized by abutting on a regulating ring 28 mounted substantially at the center of the drive shaft 16. It is regulated by the tilt angle. Further, an urging spring 29 is disposed in the concave portion 11b, and the entire drive shaft 16 is urged forward by the urging force of the urging spring 29, so that the lug plate 18 is moved through the thrust bearing 17 to the front housing. 12 is always kept in contact with the inner wall surface.

The displacement of the swash plate type variable displacement compressor 10 is variably adjusted by controlling the crank pressure Pc by the displacement control valve 24. The crank pressure Pc is determined by the supply amount of the high-pressure refrigerant gas flowing into the crank chamber 15 from the discharge chamber 26 through the air supply passage 23 when the capacity control valve 24 is opened, and the bleed passages (16a, 11b, 27). And the amount of refrigerant gas flowing out from the crank chamber 15 to the suction chamber 25 through the suction chamber 25. If the crank pressure Pc is induced to be higher, the inclination angle of the swash plate 19 becomes smaller, the stroke of each piston 21 becomes smaller, and the discharge capacity decreases. Also, if the crank pressure Pc is induced lower,
The inclination angle of the swash plate 19 increases, the stroke of each piston 21 increases, and the discharge capacity increases. That is, the control device 34 determines the magnitude of the cooling load in the vehicle cabin based on the detection information from the temperature sensor and other sensors (neither is shown) provided in the evaporator 33, and according to the cooling load. Thus, the amount of electricity supplied to the capacity control valve 24 is adjusted. Then, the crank pressure P is determined in accordance with the opening of the capacity control valve 24 that is controlled to be energized.
c, and thus the inclination angle of the swash plate 19 is determined, and the discharge capacity of the compressor 10 is adjusted to a value corresponding to the cooling load. As described above, in the variable capacity compressor 10, the discharge capacity (compression capacity) is based on the inclination control of the swash plate 19 according to the change in the cooling load.
Is feedback controlled.

Next, the configuration of the power transmission mechanism will be described. As shown in FIG. 1, at the center of the front end of the front housing 12, a support tubular portion 41 is formed to extend in a sleeve shape. A pulley 43 as a first rotating body is rotatably supported on an outer peripheral surface of the support cylindrical portion 41 via an angular bearing 42. The pulley 43 is operatively connected to an output shaft provided on a vehicle engine 35 as a drive source via a power transmission belt 44 such as a V-belt.

As shown in FIGS. 2 and 3, a receiving member 50 is fixed to the front end of the drive shaft 16 by a lock bolt 45, and the receiving member 50 can rotate integrally with the drive shaft 16. I have. The receiving member 50 has a cylindrical portion 51 fitted to the front end of the drive shaft 16 and a pair of plate arms 52 extending in the radial direction from the cylindrical portion 51. The pair of plate arms 52 are disposed at linear positions (180 ° angular position) with the lock bolt 45 interposed therebetween. The second rotating body includes the drive shaft 16, the receiving member 50, and the lock bolt 45.

On the upper surfaces of the pair of plate arms 52,
Two semi-circular leaf springs 61 and 62 as spring materials
The semi-circular arcs are fixed by rivets 46 in a state of facing each other with the arc side facing outward so as to draw a concentric circle with the pulley 43. The two leaf springs 61 and 62 are fixed to the upper surface of the distal end of each plate arm 52 by rivets 46 at the end opposite to the rotation direction (clockwise in FIG. 2) of the pulley 43. Two leaf springs 61 and 6
In FIG. 2, an engagement recess 63 which is recessed when viewed from the rear surface (the lower surface in FIG. 3) is formed by bending at a tip end opposite to the fixed end by, for example, press molding. Engaging recess 63
Has a trapezoidal shape that becomes narrower toward the center of the pulley 43 in plan view of FIG.

In the pulley 43, a pair of engaging members 71 and 72 are provided on the front end surface (the upper end surface in FIG. 3) of the ring-shaped portion 43a which is a portion where the belt 44 is hung.
5 is fixed at two positions (180 ° angular position) opposed to each other. As shown in FIG. 3, the engaging members 71 and 72 have a substantially L-shaped vertical cross section, and an arm portion (engaging portion) 73 at the tip thereof extends toward the center of the pulley 43.
As shown in FIG. 2, the arm portion 73 has a trapezoidal shape that becomes narrower toward the distal end so as to be able to engage with the engagement recess 63 in plan view. The arm portion 73 is located at a predetermined distance away from the fixed ends of the leaf springs 61 and 62 in the forward direction (upward in FIG. 3).

FIGS. 4 and 5 show the leaf springs 61 and 62 in which the leaf springs 61 and 62 are not engaged with the engaging members 71 and 72, respectively.
Shows a state when is in a natural state (normal state). Leaf spring 6
In the natural state, the leaf springs 61 and 62 extend straight and their lower surfaces (rear end surfaces) are in close contact with the surface (front surface) of the plate arm 52 as shown in FIG.

The power transmission mechanism of the present invention is connected to the compressor 10
4 and 5, the distal ends of the leaf springs 61 and 62 are separated from the surface of the plate arm 52 against the elasticity of the leaf springs 61 and 62 in the thickness direction from the state shown in FIGS. So that the front end portion is covered on the front surface of the arm portion 73 of the corresponding engaging member 71, 72. Then, as shown in FIGS.
The arm portion 73 is engaged with the engaging concave portion 63 of the first and the second 62, and the leaf springs 61 and 62 and the engaging members 71 and 72 are engaged. The pulley 43 and the drive shaft 16 are operatively connected so that power can be transmitted by the engagement between the leaf springs 61 and 62 and the engaging members 71 and 72. Note that the connecting means is a plate spring 61, 62.
And engaging members 71 and 72.

The leaf springs 61 and 62 are set to have a spring constant so as not to resonate with the frequency of each vibration transmitted from the engine 35 and the compressor 10. The setting of the spring constant of the leaf springs 61 and 62 depends on the width of the leaf springs 61 and 62 (the pulley 43).
(The length in the radial direction). As described above, the leaf springs 61 and 62 have two functions of the resonance prevention function and the operation connection function.
Plays mainly one function.

When the leaf springs 61 and 62 are engaged with the engaging members 71 and 72, the receiving members 50 are caused by a restoring force (spring elastic force) for restoring to a natural state.
Drive shaft 16 forward (toward the outside of the compressor)
, And has the same function as the biasing spring 29. In other words, the drive shaft 16 is also urged by the leaf springs 61 and 62 in a direction to keep the lug plate 18 in contact with the inner wall surface of the front housing 12 via the thrust bearing 17 at all times. When only the urging force of both leaf springs 61 and 62 is sufficient, the urging spring 29 can be omitted.

Next, the leaf springs 61, 62 and the engaging member 7
The configuration of the hooking portions 1 and 72 will be described. FIG. 7 shows a cross section of the engagement recess 63 of the leaf springs 61 and 62. As shown in the drawing, on both sides in the width direction of the inner peripheral surface of the engaging concave portion 63, engaging surfaces 64 and 65 are formed as inclined surfaces (tapered surfaces) that expand toward the rear surface (the lower side in the drawing). I have. That is, the engagement surfaces 64 and 65 are formed such that the inclination angle θ with respect to the rotation surface of the pulley 43 (a plane orthogonal to the paper surface in FIG. 7) is an acute angle (0 <θ <90 °). That is, the engagement surface 64 is inclined at a non-perpendicular angle to the power transmission direction as an inclined surface. The arm portion 73 engaged in the engagement concave portion 63 is in contact with the two engagement surfaces 64 and 65.

A preload F caused by a spring elastic force for restoring the elastic deformation of the leaf springs 61, 62 is applied to the distal ends of the leaf springs 61, 62 in the direction of the arrow shown in FIG. It works in the direction that prevents the removal of 73. Therefore, the arm portion 73 and the engaging concave portion 63 are locked with a relatively strong force. That is, in order for the arm portion 73 to be disengaged from the engagement concave portion 63, a force for overcoming the preload F (FIG. 7) and further lifting the distal end portions of the leaf springs 61 and 62 is required as shown in FIG. 6B. Become. Since the engagement surface 64 functions as a power transmission surface, the engagement recess 63 is
6A and 6B, the engagement surface 64 on the front side in the rotation direction of the pulley 43 slips off the arm 73 as shown in FIGS. Face 6
It is sufficient that 4 is at least an inclined surface.

As shown in FIG. 7, a solid lubricating film 75 as a solid lubricating layer is formed on the surface of the arm 73. In this embodiment, polytetrafluoroethylene (PTFE) is used as the material of the solid lubricating film 75. The coefficient of friction at the contact surface between the arm 73 and the engagement surface 64 is set to a small value by the solid lubricating film 75. Note that other solid lubricating materials can be used instead of PTFE.

The solid lubricant film 75 may be, for example, a film in which a solid lubricant is dispersed in a resin matrix. In this case, the solid lubricant added to the resin may be molybdenum disulfide, tungsten disulfide, graphite, or the like. ,
Examples include boron nitride, antimony oxide, lead oxide, lead (Pb), indium (In) and tin (Sn). As a method for forming the solid lubricating film 75, a known method such as a method of applying and curing a resin, a method of attaching a resin sheet, and the like can be employed. As the matrix resin of the solid lubricant, epoxy resin, phenol resin, furan resin, polyamide imide resin, polyimide resin, polyamide resin, polyacetal resin, fluorine resin (for example, PTF
E) and unsaturated polyester resins.

FIG. 9 is a graph showing the relationship between the inclination angle θ of the engagement surface 64 with respect to the rotation surface of the pulley 43 and the separation torque. Here, the detachment torque T refers to the leaf springs 61 and 6.
This is the transmission torque between the pulley 43 and the drive shaft 16 when the lock between the arm 2 and the arm 73 is released. At the time of the detachment, the leaf springs 61 and 62 are displaced in the detaching direction by the arm portion 73 sliding on the engagement surface 64 against the preload F, so that the detachment torque T is set as shown in FIG. It is also affected by the contact friction resistance f between the portion 73 and the engagement surface 64. The contact frictional resistance f is expressed by the following equation (where f represents the resistance of the arm 73 from the engagement surface 64). Here, μ is a friction coefficient at a contact surface between the engagement surface 64 and the arm portion 73.

As can be seen from the graph of FIG. 9, the release torque T increases as the inclination angle θ of the engagement surface 64 increases (that is, as the gradient of the power transmission surface with respect to the power transmission direction increases).
growing. The detachment torque T increases as the friction coefficient μ at the contact surface between the engagement surface 64 and the arm 73 increases. The inclination angle θ of the engagement surface 64 is an acute angle (0 <θ <90 °)
In the range, the slope of the curve of the separation torque T increases with an increase in the value of the friction coefficient μ, which means that the larger the friction coefficient μ, the more easily the separation torque T varies.

In the present embodiment, the drive shaft 16 of the compressor 10
Is set so that the operative connection between the pulley 43 and the drive shaft 16 is released when the deadlock occurs. Although it is inevitable that the separation torque T varies due to various factors such as environmental changes, the target value of the separation torque T is set to fall within the target range (T1 ≦ T ≦ T2) shown in the graph.

When the inclination angle θ of the engagement surface 64 is an acute angle (0 <θ
Under the condition of <90 °), as can be seen from the graph, the condition of the friction coefficient μ for setting the separation torque T in the target range (T1 ≦ T ≦ T2) is 0.05 ≦ μ ≦ 0.2.
Range. In particular, if the inclination angle θ is set in the range of 20 to 70 °, the preferable range of the friction coefficient μ is 0.08
≦ μ ≦ 0.17. The inclination angle θ is set to a value in the range of 20 ° to 70 ° in the present embodiment. The separation torque T is also affected by the preload F, but in a preload based on the spring elastic force of a spring material usually employed in this type of power transmission mechanism, the friction coefficient μ is preferably set to the above condition. . The reason why the target value of the release torque T is set in the above-mentioned target range is that the operation connection is released when the release torque T is less than the lower limit value T1 of the target range. When the separation torque T exceeds the upper limit value T2 of the target range, the belt 4
This is because the engine stalls (locks) due to slippage of 4.

There is another reason for providing the solid lubricating film 75 to set the friction coefficient μ small. Friction coefficient μ
Is likely to change due to environmental changes, and the friction coefficient μ will not be stable if there is contact between metals. For example, in the case of contact between metal surfaces, the friction coefficient μ when the contact surface is dry is μ ≒ 0.4. On the other hand, in the case of contact through the solid lubricating film 75, the friction coefficient μ when the contact surface is dry is μ
≒ 0.15. The environmental change here is a factor that can change the contact condition of the contact portion, such as load, temperature, water,
Examples include oil, dew condensation, and dust. For example, when oil adheres to the contact portion, the friction coefficient μ of the contact surface is not greatly affected by the material, and becomes μ ≒ 0 (<0.05). For this reason, when there is metal-to-metal contact, the variation in the friction coefficient μ between the time of drying and the time of oil adhesion becomes large, whereas the formation of the solid lubricating film 75 on the surface makes it possible to reduce the difference between the time of drying and the time of oil adhesion , The variation in the friction coefficient μ is reduced. By reducing the variation (change) of the friction coefficient μ due to the environmental change, the solid lubricating film 75 is applied so that the operative connection of the power transmission mechanism is not released even if oil adheres to the contact surface. ing. The solid lubricating film 75
It is sufficient that at least the formation area is at the contact portion of the arm 73 with the leaf springs 61 and 62.

Next, the operation of the power transmission mechanism will be described. In a normal operation state, the power of the engine 35 as a driving source is supplied by the belt 44, the pulley 43, the engagement members 71 and 72.
And transmitted to the drive shaft 16 via the leaf springs 61 and 62 (see FIGS. 2, 3 and 6A). At this time, FIG.
As shown in FIG. 6A, the pulley 43 and the drive shaft 16 rotate synchronously while being balanced at angular velocities ω1 and ω2, respectively.

When the swash plate 19 connected to the drive shaft 16 undulates, each piston 21 reciprocates, and performs the work of sucking and compressing the refrigerant gas. This work is drive shaft 1
6 generates a load torque in a direction opposite to the rotation direction of the pulley 43. However, if the load torque does not have an unacceptable effect on the engine 35, the load torque does not reach the target value of the separation torque T, and the power from the pulley 43 to the drive shaft 16 is not increased. Transmission is maintained through the engagement between the engaging members 71, 72 and the leaf springs 61, 62.

On the other hand, when some trouble (for example, deadlock) occurs in the compressor 10 and the load torque on the compressor becomes excessively large so as to reach the target value of the separation torque T, the pulley 43 and the drive shaft 16 are synchronized. The rotation cannot be maintained, and the angular velocity ω1 of the pulley 43 and the angular velocity
6 (ω3 <ω1), the arm portions 73 of the engaging members 71 and 72 pulled by the rotating pulley 43 slide on the engaging surface 54 as shown in FIG. Lift 61 and 62 upward (primary detachment). Then, the distal ends of the leaf springs 61 and 62 move along the upper surface of the arm 73, and finally the distal ends of the leaf springs 61 and 62 are engaged as shown in FIGS. Joint members 71, 7
2 and is pulled back onto the plate arm 52 by the spring elastic force (restoring force) (secondary detachment). Double leaf spring 6
The disengagement operations of 1,62 occur almost simultaneously.

At the time of this detachment, the arm 73 and the engaging surface 64
Since the friction coefficient μ of the contact surface with the solid lubricant film 75 is reduced by the solid lubricating film 75, the separation torque T when power transmission is interrupted almost always takes a value in the target range. That is, since the friction coefficient μ is small (0.08 ≦ μ ≦ 0.17), the frictional resistance f when the arm 73 slides on the engagement surface 64 (FIG. 8).
(See FIG. 3), and as a result, the dispersion of the separation torque T is suppressed. Therefore, power transmission is interrupted only when the compressor 10 has an abnormality such as deadlock. Note that, even after the power transmission is interrupted, the pulley 43 continues to rotate regardless of the circumstances of the compressor 10 as long as the engine 35 continues to be driven.

In some cases, oil adheres to the power transmission mechanism of the compressor 10 disposed in the engine room of the vehicle. Becomes extremely small. However, since the original friction coefficient μ is set to a value sufficiently smaller than the friction coefficient in the case of metal-to-metal contact by the solid lubricating film 75, abnormalities such as deadlock occur in the compressor 10 even when oil adheres. Unless otherwise, power transmission is not interrupted.

As described above, according to the first embodiment, the following effects can be obtained. (1) A solid lubricating film 75 is formed on the surface of the arm 73 and the friction coefficient μ of the contact surface between the arm 73 and the engagement surface 64
Is set small, when excessive load torque is generated in the compressor 10 due to an abnormality such as deadlock, the locking between the plate springs 61 and 62 and the engaging members 71 and 72 is surely released, and the compressor 35 and the engine 35 are compressed. Power transmission to and from the machine 10 can be reliably shut off. That is, the variation range of the separation torque T can be suppressed small, and the timeliness of shutting off the power transmission between the engine 35 and the compressor 10 can be guaranteed. Therefore, it is possible to reliably protect the engine 35 and the like from excessive repulsive load torque.

(2) Since the friction coefficient μ is set in the range of 0.08 ≦ μ ≦ 0.17 by forming the solid lubricating film 75, the separation torque T can be set in the target range at an appropriate inclination angle θ. it can.

(3) By using the leaf springs 61 and 62, the spring elastic force for engaging with the engaging members 71 and 72 is mainly in the thickness direction, and the repetitive stress received from the power transmission surface is mainly in the plane direction. Therefore, it is possible to perfectly balance the reciprocal demands of the conventional power transmission mechanism, namely, ensuring the resistance to the repeated stress of the member and ensuring the timeliness of the power cutoff operation.

(4) The ends of the leaf springs 61 and 62 are positioned at equal angular intervals in the circumferential direction around the axis of the drive shaft 16 (ie, at positions opposite to each other by 180 °), and the receiving member 50 and the engaging member It is connected to each of the joining members 71 and 72. Therefore, when transmitting the power from the engine 35, no moment is generated so as to incline the drive shaft 16 with respect to the center axis thereof, and the posture of the drive shaft 16 is stabilized and torque is transmitted without waste.

(5) Leaf springs 61 and 62 and engaging member 7
In a state in which the pulley 43 and the drive shaft 16 are operatively connected to each other through the engagement between the drive shaft 16 and the drive shaft 16, the drive shaft 16 is moved by the spring elastic force (restoring force) of the leaf springs 61 and 62. It is urged to. Therefore, the spring material for urging the entire drive shaft 16 forward, such as the urging spring 29, can be reduced in size and further eliminated, and the internal structure of the compressor 10 can be simplified.

(6) The pulley 43 and the drive shaft 16 are operatively connected by bending the leaf springs 61 and 62 against the repulsive urging force and moving the distal ends in the thickness direction (axial direction). Since the structure is such that the engaging members 71 and 72 are released from the engagement between the leaf springs 61 and 62 and the engaging members 71 and 72, interference between the leaf springs 61 and 62 and the engaging members 71 and 72 occurs. Can be prevented.

(Second Embodiment) In this second embodiment,
The friction coefficient μ of the contact surface between the leaf springs 61 and 62 and the arm 73 is reduced without using a solid lubricating film. Less than,
FIG. 10 mainly shows the difference between the second embodiment and the first embodiment.
This will be described with reference to FIG. Note that the same parts as those in the first embodiment are denoted by the same reference numerals in the drawings to avoid redundant description as much as possible.

The structure of the compressor 10 as a driven device is the same as that of the first embodiment. As shown in FIGS. 10 and 11, the configuration of the power transmission mechanism is basically the same as that of the first embodiment, but the materials of the pulley 48 and the engaging members 81 and 82 are different from those of the first embodiment. .

The material of the pulley 48 and the engaging members 81 and 82 are made of plastic (resin). As shown in FIG. 12, the contact between the leaf springs 61 and 62 and the arm 83 is a contact between the metal and the plastic. It is smaller than. The friction coefficient μ is 0.05 to 0.2
, And particularly satisfies the preferable range of 0.08 to 0.17. For example, when the friction coefficient μ exceeds 0.17 due to the selection of plastic (for example, 0.1 μm).
17 <μ ≦ 0.25), the setting of the preload F and the inclination angle θ is changed to set the separation torque T to the target range (T1 ≦ T ≦ T).
2). That is, the leaf spring 61,
62, and the amount of displacement when the leaf springs 61 and 62 are bent in the hooked state is reduced to reduce the preload F.
Is set smaller, or the inclination angle θ is set smaller.

Therefore, as in the first embodiment, the preload F and the inclination angle θ (that is, the contact angle) are set such that the friction coefficient μ is set to be small and the release torque T is within the target range. Therefore, when there is an abnormality such as deadlock in the compressor 10, the engagement between the springs 61 and 62 and the arm portion 83 is almost certainly released, and the power transmission between the pulley 48 and the drive shaft 16 is cut off.

According to the second embodiment, the same effects as (1) to (6) in the first embodiment can be obtained, and further, the following additional effects can be obtained. (7) It is not necessary to provide a technically troublesome solid lubricating film for adhering a resin to the surface of the metal which is the base material of the engaging member. For this reason, for example, various steps for forming a solid lubricating film such as a pretreatment step such as roughening a metal surface and a film forming step can be eliminated.

(8) If a resin having a low coefficient of friction, such as that used for a solid lubricating film, is used as the material of the engaging members 81 and 82, the arm portions 83 of the engaging members 81 and 82 and the engaging surface 6
The friction coefficient μ of the contact portion surface with the contact portion 4 can be made very small.

(9) Since the low friction coefficient of the plastic (resin) itself, which is the material of the engaging members 81 and 82, is used,
Problems such as peeling, abrasion, and perforation of the solid lubricating film can be solved. That is, even if the engaging members 81 and 82 are worn, the surfaces thereof are always kept at a low friction coefficient where the resin is exposed, so that the releasing torque T can be stably maintained for a long time.

(10) Pulley 43 and engaging member 81,
Since 82 is made of plastic, the power transmission mechanism can be reduced in weight. Therefore, the weight reduction of the power transmission mechanism contributes to the improvement of fuel efficiency.

The embodiment of the present invention is not limited to the above-described configuration, but can be implemented in the following modes. (Circle) the contact part of at least one of a spring material and an engagement member can be formed with a soft material which is more elastic than metal. For example, as shown in FIG.
The surface of a base material (eg, metal) 77 of the arm portion 72 is covered with a rubber layer 78, and a solid lubricating film 75 is applied to the surface of the rubber layer 78. As shown in FIG. 13 (b), the rubber layer 78 is deformed, so that the contact area between the engagement surface 64 and the arm portion 73 is widened, and the load imbalance is eliminated, so that torque can be transmitted evenly. Becomes Also, the compressor 10
The vibration of the engine 35, the vibration from the engine 35, and the vibration from other auxiliary devices cause micro vibration at the contact portion between the arm portion and the engagement surface. However, the soft material such as the rubber layer 78 absorbs the vibration to reduce the vibration. Since the shock is relieved, there is no fear that the transmission torque fluctuates. Further, when the load uniformly acts on the contact portion, minute foreign matters such as dust and the like are less likely to enter the gap, thereby contributing to stabilization of the friction coefficient. Note that the present invention is not limited to a configuration in which a layer of a soft material such as a rubber layer is applied. It may be formed. Further, the solid lubricating layer itself can be formed of a soft material.

The members forming the solid lubricating film are not limited to the engaging members. A solid lubricating film may be formed on the spring material. For example, as shown in FIG.
The solid lubricating film 76 is formed so as to cover at least the inner surfaces of the engaging concave portions 63 of the first and second engagement portions 62. Further, as shown in FIG. 14B, in a configuration using a plastic engaging member as in the second embodiment, a solid lubricating film is formed so as to cover at least the inner surfaces of the engaging recesses 63 of the plate springs 61, 62. 76
To form Further, as shown in FIG. 14C, solid lubricating films 75 and 76 are formed on both the engaging members 71 and 72 and the leaf springs 61 and 62 so as to cover at least the contact surface. According to these configurations, FIG.
In the case of (b), the friction coefficient of the leaf springs 61 and 62 can be reduced, and the contact friction resistance between the arm portion 73 (83) and the engagement surface of the engagement recess 63 can be reduced. Also, in the case of FIG.
Can further reduce the contact friction resistance with the engagement surface. Therefore, in any case, the release torque can be stabilized when the engagement between the spring member and the engagement member is released.

As shown in FIG. 15, a solid lubricating film 75 may be formed on the surface of the arm 83 of the plastic engaging members 81 and 82 as in the second embodiment. In this case, the friction coefficient is made smaller than when the base materials (plastics) of the engaging members 81 and 82 are brought into contact with each other as it is,
The separation torque can be further stabilized. Further, since it is technically simpler to attach the resin to the plastic than to attach the resin to the metal, the film forming process can be simplified.

As shown in FIG. 16, an engagement surface 74 formed of a tapered surface is formed at a position facing the engagement surfaces 64 and 65 of the arm portion 73, and the arm portion 73 and the engagement surfaces 64 and 65 are formed. A configuration that makes surface contact can be adopted.

The inclined surface serving as the power transmission surface is not limited to the spring material. For example, as shown in FIG.
An engagement recess 66 having a surface substantially perpendicular to the power transmission direction is formed in the leaf springs 61 and 62, and an engagement surface 74 having an inclined angle that forms an acute angle with the power transmission direction is formed in the engagement members 71 and 72. Can be adopted. Even with this configuration, the effect of stabilizing the separation torque can be similarly obtained by forming the solid lubricating film 75 on the surface of the arm portion 73.
In this case, a solid lubricating film may be formed only on the spring material, or a solid lubricating film may be formed on both members.

The engaging member may be made of a spring material. For example, as shown in FIG. 18, when the spring material 91 as an engaging member comes into contact with the engaging concave portion 63 of the leaf springs 61 and 62, the two members 61 (62) and 91 are engaged. The leaf spring 61 (62) and the spring material 91 are elastically urged in a direction to approach each other, and are preloaded in a direction to assist the latch. Both the leaf spring 61 (62) and the spring material 91 have solid lubricating films 75 and 76 on the surface. Even with such a configuration, the separation torque can be stabilized.

The present invention is not limited to the combination in which the engagement member is provided on the pulley side and the spring material is provided on the drive shaft side. For example, FIG.
As shown in FIG. 0, a combination in which a spring material is provided on the pulley side and an engaging member is provided on the drive shaft side may be adopted. As shown in the figure, a receiving member 50 as an engaging member is fixed to the front end of the drive shaft 16 by a lock bolt 45. Receiving member 50
Has a pair of plate arms 52 extending in the radial direction from the cylindrical portion 51 fitted to the front end of the drive shaft 16.
The two plate arm portions 52 are linear (18
(An angle position of 0 °), and each arm portion 55 has a distal end portion bent in an L-shape and extends again radially from the lower end.

In the inner concave portion of the pulley 43, two substantially semi-circular leaf springs 61 and 62 as a spring material are disposed. A pair of mounting members 47 are fixed to the inner peripheral wall of the ring-shaped portion 43a of the pulley 43 at positions opposing each other with the bolt 45 interposed therebetween, and the base ends of the leaf springs 61 and 62 are provided on the lower surface of each mounting member 47. It is fixed by rivets 46. Engaging recesses 63 whose upper surfaces are depressed are formed at the distal ends of the leaf springs 61 and 62 in a bent manner.
It is hung with 5. The arm 55 is in surface contact with the engagement surfaces 64 and 65 of the engagement recess 63. In this locked state, the drive shaft 16 is driven by the spring elastic force of the leaf springs 61 and 62.
Is biased to the front side. A solid lubricating layer is formed on the surface of the arm 55.

The coefficient of friction μ is not limited to the range of 0.05 ≦ μ ≦ 0.2. Coefficient of friction between metals (approx. 0.4)
If it is smaller than 0.3, which is smaller than 0.3, the release torque can be stabilized to a desired degree as compared with the related art. When the friction coefficient is 0.2 <μ <0.3, the preload F and the inclination angle θ
Can be set in the target range by appropriately setting the value of. In this case, the separation torque T can be more stable than in the case of metal-to-metal contact.

The number of spring members is not limited to two and can be changed as appropriate. However, the location where the force is transmitted to the rotating body (the place where the arm is attached or the place where the spring material is fixed) is preferably positioned at an equal angular interval with respect to the center of the rotating body. This makes it difficult to apply a biased moment to the axis of the drive shaft.

The present invention is embodied in a power transmission mechanism in which the spring member and the engagement member are engaged without applying a preload. The spring material used in the present specification is not limited to a configuration of only a spring such as a leaf spring, and an engaging member (a plate or the like) is elastically supported by a spring such as a leaf spring.
It includes a component having an engaging member and a spring.

The technical ideas other than the claims that can be grasped from the embodiment and the modified examples are described below. (1) In claim 1, a power transmission surface is formed on at least one of the spring member and the engagement member, and the power transmission surface is inclined at a non-perpendicular angle to a power transmission direction of the connecting means. . According to this configuration, when the operative connection between the spring member and the engagement member is released, the power transmission surface that is inclined at a right angle to the power transmission direction forms a guide surface when the spring member separates from the engagement member. As soon as the load on the driven device reaches a predetermined limit value, the spring member can be smoothly and reliably detached from the engagement member.

(2) In any one of the technical idea of the first aspect and the technical idea of the first aspect, the friction coefficient of a contact surface between the spring member and the engagement member is in a range of 0.05 or more and less than 0.3. Was set to the value. In this case, the detachment torque can be stabilized as compared with the case of contact between metals.

(3) Claim 1 and (1), (2)
In any of the technical ideas described above, the spring material is a leaf spring material that extends in an arc along the rotation direction of the first rotating body.

In this leaf spring material, the arc direction along the rotation direction of the first rotating body is the length direction. Therefore, by setting the arc length, resistance to repeated stress can be secured. For this reason, it is not necessary to make the width of the leaf spring material so large, and since the leaf spring material itself is gathered in an arc shape, attachment to the first rotating body or the second rotating body becomes easy. Further, the spring constant can be set to a desired value by adjusting the thickness of the spring material, and resonance with the drive source and the driven device can be prevented.

(4) In the ninth aspect, at least a portion of the engaging member that comes into contact with the spring material is made of a resin or rubber and a solid lubricating layer provided on the surface of the resin or rubber. In this case, the same effect as the ninth aspect can be obtained.

(5) In the technical concept of the above (4), the resin or rubber is provided so as to cover the surface of the base material of the engaging member.

[0087]

As described above, according to the invention described in each claim, the first rotating body on the driving source side and the second rotating body on the driven equipment side.
The timeliness of the power shut-off operation of each member constituting the connection means for connecting the rotating body so as to be integrally rotatable can be more reliably ensured. Therefore, when the load on the driven device becomes excessive, the engagement between the spring member and the engagement member is released in a timely manner, and the drive source can be reliably protected from excessive load torque.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a variable displacement compressor according to a first embodiment.

FIG. 2 is a front view of the power transmission mechanism during power transmission.

FIG. 3 is a sectional view taken along line X1-X1 in FIG. 2;

FIG. 4 is a front view of the power transmission mechanism when power is cut off.

FIG. 5 is a sectional view taken along line X2-X2 in FIG. 4;

FIG. 6 is a view for explaining a series of detaching operations of a spring plate member.

FIG. 7 is a sectional view showing a portion where the leaf spring and the engaging member are engaged.

FIG. 8 is a cross-sectional view showing a state when the engaging member comes off the leaf spring.

FIG. 9 is a graph showing a relationship among an inclination angle, a friction coefficient, and a separation torque.

FIG. 10 is a front view of the power transmission mechanism according to the second embodiment when power is transmitted.

11 is a sectional view taken along line X3-X3 in FIG.

FIG. 12 is a cross-sectional view showing a portion where a leaf spring and an engagement member are engaged.

FIG. 13 is a cross-sectional view showing an engagement concave portion of another example leaf spring.

FIG. 14 is a cross-sectional view showing the same hooking portion of another example different from FIG. 13;

FIG. 15 is a cross-sectional view showing the same hooking portion of another example different from FIG. 14;

FIG. 16 is a cross-sectional view showing the same hooking portion of another example different from FIG. 15;

17 is a cross-sectional view showing another example of the same hooking portion different from FIG. 16;

FIG. 18 is a cross-sectional view showing the same hooking portion of another example different from FIG. 17;

FIG. 19 is a front view of another example power transmission mechanism during power transmission.

FIG. 20 is a sectional view taken along line X4-X4 in FIG. 19;

[Explanation of symbols]

10: Compressor as driven equipment, 16: Drive shaft constituting second rotating body, 35: Engine as drive source, 43,
48: pulley as first rotating body, 49: engaging member, 5
0: a receiving member constituting the second rotating body; 61, 62 ... a leaf spring as a spring material which constitutes connecting means;
66 ... engagement concave portion, 64, 74 ... engagement surface, 71, 72, 8
1, 82 ... engaging members constituting the connecting means, 55, 73,
83: arm portion, 75, 76: solid lubricating film as solid lubricating layer, 91: spring material as engaging member.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akifumi Uryu 2-1-1 Toyota-cho, Kariya-shi, Aichi Pref. Inside Toyota Industries Corporation (72) Inventor Hirohiko Tanaka 2-1-1, Toyota-cho, Kariya-shi, Aichi Pref. F-term in Toyota Industries Corporation (reference) 3H076 AA06 BB50 CC07 CC12 CC17 CC20

Claims (11)

[Claims] 1. A first rotating body on a driving source side and a second rotating body on a driven device side are provided so as to be relatively rotatable coaxially, and while the first and second rotating bodies are operatively connected to each other, a driven device is provided. A connection means capable of releasing the operative connection between the two according to the magnitude of the load on the side, wherein the connection means is provided on one of the first and second rotating bodies. A spring member, and an engaging member provided on the other side of the first and second rotating bodies and capable of engaging with the spring member so as to transmit power. And a friction coefficient of a contact surface between the power transmission and the engagement member is set to a value small enough that the two can be stably disengaged with a disengagement torque within a target range in which the operative connection between the two is released. mechanism. 2. The power transmission mechanism according to claim 1, wherein at least one of the spring member and the engagement member has an engagement surface inclined at an acute angle with respect to a power transmission direction. 3. The method according to claim 1, wherein a friction coefficient of a contact surface between the spring member and the engagement member is set to a value within a range of 0.05 to 0.2. Power transmission mechanism. 4. A solid lubricating layer is formed on at least one surface of a contact portion between the spring member and the engagement member. A power transmission mechanism according to the item. 5. The power transmission mechanism according to claim 4, wherein said solid lubrication layer is made of a fluororesin. 6. The power transmission mechanism according to claim 1, wherein the engagement member is made of resin. 7. The power transmission mechanism according to claim 6, wherein the pulley serving as the first rotating body and the engaging member are both made of resin. 8. The first spring member has a flat plate shape, and
When the operative connection of the second rotator is performed, the power transmission from the first rotator to the second rotator is performed mainly in the surface direction of the spring member, and the engagement of the spring member for releasing the operative connection is performed. The power transmission mechanism according to any one of claims 1 to 7, wherein the power transmission mechanism is arranged so that the detachment operation from the joining member is performed mainly in a thickness direction of the spring material. 9. The driven device is a compressor, and the second device is a second device.
The rotator includes a drive shaft of a compressor, and the spring member is disposed so as to bias the drive shaft toward the outside of the compressor when the first and second rotators are operatively connected. The power transmission mechanism according to any one of claims 1 to 8, wherein: 10. The power transmission mechanism according to claim 1, wherein at least a portion of the engagement member that contacts the spring member has elasticity. 11. A compressor, wherein the power transmission mechanism according to any one of claims 1 to 10 is provided on a drive shaft.