JP3924995B2 - Power transmission device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power transmission device that transmits rotational power from a driving source to a rotating shaft of a rotating device, and in particular, when transmission torque exceeds a set value, the transmission of rotating power from the driving source to the rotating shaft of the rotating device is interrupted. The present invention relates to a power transmission device including a limiter mechanism.
[0002]
[Prior art]
Conventionally, in a refrigeration cycle provided with a variable capacity refrigerant compressor, a clutch mechanism for intermittently transmitting the rotational power from the engine to the refrigerant compressor is not required. However, when the clutch mechanism is abolished, if the drive shaft of the refrigerant compressor is locked due to a burn-in failure of the refrigerant compressor, the pulley for driving the drive shaft of the refrigerant compressor stops, and the belt Wear may occur and break.
[0003]
Therefore, a pulley device having a limiter mechanism that shuts off a power transmission path from the engine to the drive shaft of the refrigerant compressor when an overload such as locking of the drive shaft of the refrigerant compressor has been proposed. As this pulley device, there is a pulley device provided with a rubber type limiter mechanism or a pulley device provided with a friction type limiter mechanism.
[0004]
The rubber-type limiter mechanism includes an iron pulley that is belt-driven by an engine, an iron hub that is coupled to the drive shaft of the refrigerant compressor, and a convex concave portion that is fixed to the outer peripheral side of the hub, A rubber-based elastic body sandwiched between the convex and concave portions on the outer peripheral side of the hub is provided, and is configured to block the engagement state between the pulley and the hub when the drive shaft of the refrigerant compressor is locked. .
[0005]
The friction type limiter mechanism includes an iron pulley driven by an engine belt, an iron outer hub fixed to the pulley, an iron flange member connected to the outer hub via a rubber member, a refrigerant compression An inner hub made of iron connected to the drive shaft of the machine, and a multi-plate friction member provided between the flange member and the inner hub, and when the drive shaft of the refrigerant compressor is locked, the inner hub and the outer hub are engaged. It is configured to block the state.
[0006]
[Problems to be solved by the invention]
However, in the pulley apparatus having the conventional limiter mechanism, the ratio of the limiter mechanism is large in the entire pulley apparatus, and the number of parts is large and the number of assembling steps is large, resulting in an increase in product cost. Yes. Further, most of the main parts are made of an iron-based metal material, and there is a problem that even if the limiter mechanism has a simple structure, the weight cannot be reduced.
[0007]
Here, in recent years, in the automobile field, there has been a demand for lower fuel consumption due to environmental problems and the like, and miniaturization and weight reduction of automobile parts have been demanded. This also applies to automotive engine accessories, and in order to meet this demand, it is an effective means to use a lightweight material. For this reason, also in the pulley apparatus as described above, it is conceivable to change the main parts (for example, pulleys and hubs) from a metal material such as iron to a resin material.
[0008]
OBJECT OF THE INVENTION
An object of the present invention is to provide a power transmission device including a limiter mechanism that can be reduced in weight at a low cost by changing a main part from an iron-based metal material to a resin material.
[0009]
[Means for Solving the Problems]
According to the first aspect of the present invention, the convex engagement portion of the resin driven side rotary body is pressed against the concave engagement portion of the resin drive side rotary body by the pressing portion of the elastic body made of resin or metal. ing. As a result, when rotational power is transmitted from the drive source to the drive-side rotator, the driven-side rotator fitted to the drive-side rotator also rotates following the drive-side rotator and rotates the drive source. Power is transmitted to the rotating shaft of the rotating device.
[0010]
When the limiter is actuated, for example, when an overload occurs, such as when the rotation shaft of the rotating device is locked, the driven side rotating body continues to rotate while the driven side rotating body stops rotating. Then, along with the rotation of the driving side rotating body, the convex engaging portion of the driven side rotating body comes out of the concave engaging portion of the driving side rotating body. As a result, the convex engagement portion of the driven-side rotator comes out of the pressing portion of the elastic body and reaches the notch portion of the elastic body. At this time, since the pressing portion of the elastic body closes the concave engaging portion of the driving side rotating body, the convex engaging portion of the driven side rotating body again engages with the concave engaging portion of the driving side rotating body. Absent.
[0011]
Accordingly, the convex engagement portion of the driven-side rotator loses the pressing force into the concave engagement portion of the drive-side rotator, so that the limiter operation is instantaneously completed, and the drive-side rotator to the driven-side rotator is completed. Power transmission is interrupted instantly. As a result, the rotation of the drive-side rotator does not stop, and the power transmission member such as a belt does not wear. And by changing the material used for the main parts such as the driving side rotating body and the driven side rotating body from iron-based metal materials to inexpensive resin materials, the power transmission device with the limiter mechanism is reduced in weight and cost. Can be realized. Moreover, since the number of parts of the limiter mechanism can be reduced and the number of assembly steps can be reduced, the product price can be further reduced.
[0012]
According to the second aspect of the present invention, the fitting portion such as the concave portion or the convex portion provided on the inner periphery of the cylindrical wall portion of the driving side rotating body is fitted to the cover such as the convex portion or the concave portion provided on the outer periphery of the elastic body. By fitting the fitting portions, the elastic body also rotates following the driving side rotating body as the driving side rotating body rotates. Thereby, when the limiter is operated, the elastic body also rotates following the driving side rotating body, so that the convex engagement portion of the driven rotating body that does not rotate can easily come out from the pressing portion of the elastic body to the notch portion. it can.
[0013]
According to the third aspect of the present invention, when the limiter is operated, the drive-side rotator continues to rotate while the rotation of the driven-side rotator is stopped. Then, with the rotation of the driving side rotating body, the plurality of convex portions of the driven side rotating body come out from the plurality of concave portions of the driving side rotating body, respectively. As a result, the plurality of convex portions of the driven-side rotator come out of the pressing portions of the elastic body and reach the notches of the elastic body. At this time, since the plurality of pressing portions of the elastic body respectively close the plurality of concave portions of the driving-side rotator, one of the plurality of convex portions of the driven-side rotator again has a concave shape of the driving-side rotator. It does not engage the part.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
[Configuration of Example]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the invention will be described based on examples with reference to the drawings. Here, FIG. 1 is a diagram showing a normal movement range of the shoe, and FIGS. 2 and 3 are diagrams showing a pulley apparatus provided with a limiter mechanism.
[0015]
The pulley apparatus according to the present embodiment is a refrigerant that is disposed in an engine room of a vehicle such as an automobile on which an engine (corresponding to a drive source of the present invention) is mounted, and constitutes one component of the refrigeration cycle of the vehicle air conditioner. A power transmission device that transmits the rotational power of the engine to a compressor (hereinafter referred to as a compressor) 1. When an overload such as locking of the drive shaft 2 of the compressor 1 occurs, the transmission torque to the drive shaft 2 of the compressor 1 exceeds a set value. Then, a limiter mechanism that cuts off the power transmission path from the engine to the drive shaft 2 of the compressor 1 is provided.
[0016]
The compressor 1 corresponds to the rotating device of the present invention, and is a variable capacity refrigerant compressor capable of changing the refrigerant discharge capacity up to 0% capacity. By rotating the drive shaft 2, the evaporator 1 is used. The refrigerant sucked in is compressed, and a high-temperature and high-pressure refrigerant gas is discharged by a condenser.
[0017]
Here, the pulley device is a multi-stage V-belt (not shown) and other engine accessories (for example, an alternator, an engine cooling device) that are stretched around a crank pulley (not shown) attached to the crankshaft of the engine. (Water pump, hydraulic pump of power steering device) and the V pulley.
[0018]
When a transmission torque from the engine to the compressor 1 exceeds a set value, a pulley device having a limiter mechanism that blocks transmission of rotational power from the engine to the compressor 1 is a V-ribbed pulley (hereinafter referred to as a V pulley) that is belt-driven by the engine. 3, a hub 4 that transmits rotational power from the V pulley 3 to the drive shaft 2 of the compressor 1, and a plurality of shoes 5 that are extended from the outer periphery of the hub 4. And a spring 7 that urges the groove 7 in the direction of pressing.
[0019]
The V pulley 3 of the present embodiment corresponds to the driving side rotating body of the present invention, and is integrally formed into a predetermined shape by a thermosetting resin such as a phenol resin, for example. The V pulley 3 has a substantially cylindrical cylindrical wall portion (pulley portion) 11 that is always driven by the engine, and an annular side wall portion 12 that extends radially inward from the cylindrical wall portion 11. is doing.
[0020]
A plurality of V-shaped groove portions 13 corresponding to the plurality of V-shaped groove portions formed on the inner peripheral surface of the V-belt are formed on the outer periphery of the cylindrical wall portion 11. Further, a substantially semicircular recess (corresponding to the fitting portion of the present invention) 14 in which the outer peripheral portion of the spring 7 is fitted is formed on the inner periphery of the cylindrical wall portion 11.
[0021]
The side wall portion 12 is rotatably supported via a bearing 15 on the outer periphery of the cylindrical portion 9 of the compressor housing 8 that rotatably supports one end portion of the drive shaft 2 of the compressor 1. A plurality (six in this example) of concave grooves 6 are formed on the side surface of the side wall portion 12 opposite to the compressor 1 side.
[0022]
The plurality of concave grooves 6 correspond to the concave engaging portions and concave portions of the present invention, each having a substantially semicircular hollow portion (dented portion), and the like in the circumferential direction on the side surface of the side wall portion 12. It arrange | positions so that it may become a space | interval (for example, 60 degree space | interval).
[0023]
The hub 4 of the present embodiment corresponds to the driven side rotating body of the present invention, and is integrally formed into a predetermined shape by a thermoplastic resin such as 66 nylon resin. The hub 4 includes a boss portion 21 fitted to the outer periphery of the tip end portion of the drive shaft 2 of the compressor 1, an annular plate-shaped side wall portion 22 extending radially inward and outward from the boss portion 21, In addition, it has a plurality of (six in this example) leg portions 23 that are extended from the outer periphery of the side wall portion 22 and can be elastically deformed.
[0024]
A spline that engages with a spline formed at the tip of the drive shaft 2 of the compressor 1 is formed on the inner periphery of the boss portion 21. In addition, an insertion hole 24 through which the shaft portion of the fixing bolt 10 screwed into the inner peripheral screw portion formed at the distal end portion of the drive shaft 2 is formed in the inner periphery of the side wall portion 22. Thereby, the hub 4 and the drive shaft 2 are fixed by the inner peripheral portion of the side wall portion 22 being fastened to the distal end portion of the drive shaft 2 by the head (hexagonal portion) of the fixing bolt 10.
[0025]
Each of the plurality of leg portions 23 has an axial portion 25 that extends substantially in the axial direction from the outer periphery of the side wall portion 22, and a tip portion 26 that extends radially outward from the end portion of the axial portion 25. is doing. A plurality of (six in this example) (six in the present example) engagement (concave fitting) with the plurality of concave grooves 6 of the V pulley 3 are formed on the side surfaces of the V pulley 3 of the tip portions 26 of the plurality of leg portions 23. Each shoe 5 is provided.
[0026]
The plurality of shoes 5 correspond to the convex engaging portions and convex portions of the present invention, and, like the concave grooves 6 of the V pulley 3, equidistant in the circumferential direction on the outer periphery of the side wall portion 22 (for example, 60 ° interval). These shoes 5 have a substantially semicircular cross section corresponding to the hollow shape of the concave groove 6.
[0027]
The spring 7 corresponds to the elastic body of the present invention, and is integrally formed into a predetermined shape by a thermoplastic resin such as 66 nylon resin. The spring 7 includes a cylindrical tube wall portion 31 fitted to the inner periphery of the tube wall portion 11 of the V pulley 3, and a plurality of (six in this example) projecting radially inward from the tube wall portion 31. ) Protrusion 32.
[0028]
On the outer periphery of the cylindrical wall portion 31, a convex portion (corresponding to the fitted portion of the present invention) 33 that is fitted into the concave portion 14 formed on the inner periphery of the cylindrical wall portion 11 of the V pulley 3 is provided. Yes. The convex portion 33 has a substantially semicircular cross section, and is provided in the same number (six) as the concave portion 14 of the V pulley 3 at positions corresponding to the shoe 5, the concave groove 6 and the protruding portion 32. By such concave-convex fitting of the plurality of concave portions 14 of the V pulley 3 and the plurality of convex portions 33 of the spring 7, it becomes possible to always follow the rotation of the V pulley 3. It is comprised so that it may always drive by an engine via.
[0029]
Each of the plurality of protrusions 32 has a substantially U-shaped cross section, and protrudes inward in the radial direction from a portion at an equal interval (for example, 60 ° interval) in the circumferential direction on the inner periphery of the cylindrical wall portion 31. And functions as a closing portion capable of closing the plurality of concave grooves 6 of the V pulley 3 when the limiter is actuated. Further, at the tips of these projecting portions 32, there are provided pressing portions 34 for pressing the plurality of shoes 5 of the hub 4 against the plurality of concave grooves 6 of the V pulley 3 during normal operation.
[0030]
Further, on both sides of the plurality of protrusions 32, notch portions 35 larger than the width of the plurality of shoes 5 of the hub 4 are formed. Thereby, the spring 7 has an annular portion in which the protruding portions 32 and the pressing portions 34 and the notches 35 are alternately provided in the circumferential direction.
[0031]
(Effects of Example)
Next, the operation of the pulley apparatus provided with the limiter mechanism of this embodiment will be briefly described with reference to FIGS. Here, FIGS. 4A to 4C are views showing a state in which the shoe comes out of the concave groove.
[0032]
During normal operation, when the engine is started, the crankshaft rotates, and when the rotational power of the engine is transmitted to the V pulley 3 via the V belt, as shown in FIG. 1 and FIG. The hub 4 in which each shoe 5 is pressed into each concave groove 6 (normal movement range in FIG. 1) by the urging force of the pressing portion 34 of FIG. Thereby, the rotational power of the engine is transmitted to the drive shaft 2 of the compressor 1. For this reason, since the refrigerant sucked by the compressor 1 is compressed and high-temperature and high-pressure refrigerant gas is discharged, the vehicle interior of the vehicle such as an automobile is cooled.
[0033]
During an overload such as the drive shaft 2 of the compressor 1 being locked, the V pulley 3 continues to rotate while the rotation of the hub 4 is stopped. Therefore, the transmission torque from the V pulley 3 to the hub 4 exceeds the set value. That is, when an impact load is applied, for example, when the drive shaft 2 of the compressor 1 is locked, the plurality of shoes 5 of the hub 4 are applied to the urging force of the pressing portion 34 of the spring 7 as shown in FIG. As a result, the V pulley 3 comes out of the plurality of concave grooves 6 and becomes free. At the same time, the plurality of shoes 5 enter the notches 35 of the spring 7.
[0034]
As a result, the plurality of shoes 5 are released from the pressure of the spring 7, so that the plurality of protrusions 32 are elastically deformed (plastically deformed) so that the plurality of shoes 5 are turned up. The shoe 5 is separated from the side wall portion 12 of the V pulley 3 and the engagement state between the V pulley 3 and the hub 4 is instantaneously released.
[0035]
Further, when the V pulley 3 further rotates, since the concave groove 6 is covered by the protruding portion 32 of the spring 7, the plurality of shoes 5 of the hub 4 ride on the protruding portion 32 and the pressing portion 34 of the spring 7. For this reason, the plurality of shoes 5 are not fitted into the plurality of concave grooves 6 again. Thereby, the limiter operation is completed instantaneously, and the power transmission path from the V pulley 3 to the hub 4 is instantaneously completely interrupted.
[0036]
[Effects of Examples]
As described above, in the pulley apparatus equipped with the limiter mechanism of the present embodiment, the material used for the main parts such as the V pulley 3, the hub 4, and the spring 7 is changed to a resin material that is cheaper and lighter than iron-based metal materials. By doing so, weight reduction and cost reduction of the pulley device can be achieved. Moreover, since the number of parts of the limiter mechanism can be reduced and the number of assembly steps can be reduced, the product price can be further reduced.
[0037]
And since the escape of the hub 4 from the concave groove 6 of the shoe 5 is instantaneously performed, it is possible to suppress a decrease in the rotational speed of the V pulley 3 during an overload such as the drive shaft 2 of the compressor 1 being locked. A speed difference does not occur between the V pulley 3 and the V belt. As a result, no slippage occurs between the V pulley 3 and the V belt, and no wear occurs on the V belt.
[0038]
Therefore, the pulley device provided with the limiter mechanism is connected to various engine accessories other than the compressor 1 (for example, an alternator, a water pump for the engine cooling device, a hydraulic pump for the power steering device, etc.) from the engine. Even when the rotational power is configured to be transmitted, the V-belt can be prevented from being worn or broken by instantaneously completing the limiter operation during an overload such as the drive shaft 2 of the compressor 1 being locked. It does not cause a serious failure that the vehicle such as an automobile cannot run.
[0039]
[Modification]
In this embodiment, an example in which the present invention is applied to a pulley apparatus that is driven by a belt by an engine mounted on a vehicle such as an automobile has been described. However, a belt is driven by a driving source such as an internal combustion engine or an electric motor that is placed at a fixed position in a factory or the like. You may apply to the pulley apparatus (power transmission device). In the present embodiment, the multi-stage V pulley (V-ribbed pulley) 3 is used, but a V pulley having one V groove may be used. In this case, a V belt having a shape corresponding to the V pulley is used.
[0040]
In the present embodiment, the example in which the present invention is applied to a pulley device (power transmission device) provided with a limiter mechanism that rotationally drives the compressor 1 constituting one component of the refrigeration cycle of the vehicle air conditioner has been described. The invention may be applied to a pulley apparatus provided with a limiter mechanism that rotationally drives another rotating device (for example, an alternator, a water pump, a hydraulic pump, a blower, or a fan).
[0041]
In the present embodiment, the number of convex engaging portions such as the shoe 5 and the concave engaging portions such as the concave groove 6 is six, but the number of convex engaging portions and concave engaging portions is 1 to 5. It may be individual or seven or more. Moreover, the installation intervals of the convex engagement portions and the concave engagement portions may be either equal intervals or random.
[0042]
In the present embodiment, an example in which the spring 7 integrally formed of a resin material is used has been described. However, a leaf spring manufactured of a metal material such as spring steel may be used as the spring. In this embodiment, the V pulley 3 is provided with a plurality of recesses 14, the spring 7 is provided with a plurality of projections 33, and the recesses 14 and the projections 33 are fitted into the recesses and projections. A plurality of fitting portions such as convex portions may be provided, and a portion to be fitted such as a plurality of concave portions may be provided on the spring 7 so that the convex portions and the concave portions are concavo-convexly fitted. Moreover, the installation interval of the recessed part 14 and the convex part 33 may be either equal intervals or random.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a normal movement range of a shoe (Example).
FIG. 2 is a cross-sectional view showing a pulley apparatus provided with a limiter mechanism (Example).
FIG. 3 is a plan view showing a pulley apparatus provided with a limiter mechanism (Example).
4A to 4C are cross-sectional views taken along the line AA in FIG. 3 (Example).
[Explanation of symbols]
1 Compressor (Rotating device)
2 Drive shaft (rotary shaft)
3 V pulley (drive side rotating body)
4 Hub (driven rotor)
5 Shoe (convex engagement part, convex part)
6 concave groove (concave engagement part, concave part)
7 Spring (elastic body)
11 Cylinder wall part 14 Recessed part (fitting part)
23 Leg 32 Protrusion 33 Protrusion (Fitted part)
34 Pressing part 35 Notch part

Claims (3)

(A) a resin-made drive-side rotating body that has a concave engagement portion and is rotationally driven by a drive source;
(B) A leg portion that is superimposed on the drive-side rotating body and extends so as to protrude radially outward from the outer periphery, and a protrusion that is provided at the distal end of the leg portion and engages with the concave engagement portion. A resin-made driven rotating body connected to the rotating shaft of the rotating device,
(C) a pressing portion that is superimposed on the side wall portion of the driven-side rotating body, presses the convex engaging portion against the concave engaging portion, and closes the concave engaging portion; A power transmission device comprising: a resin or metal elastic body provided adjacent to the portion and having a notch portion larger than the width of the convex engagement portion. The power transmission device according to claim 1,
The driving side rotating body has a cylindrical wall portion disposed on the outer peripheral side, and a fitting portion such as a concave portion or a convex portion on the inner periphery of the cylindrical wall portion,
The elastic body has a fitting portion such as a convex portion or a concave portion fitted on the fitting portion on the outer periphery. In the power transmission device according to claim 1 or 2,
The concave engaging portions are a plurality of concave portions disposed at predetermined intervals in the circumferential direction on the annular side wall portion of the driving-side rotator.
The convex engagement portions are a plurality of convex portions arranged to engage with the plurality of concave portions in the circumferential direction on the annular side wall portion of the driven side rotating body,
The power transmission device according to claim 1, wherein the elastic body is an annular spring in which the pressing portions and the notches are alternately provided in a circumferential direction.

Images