JP2001124177A - Clutchless compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clutchless compressor capable of surely cutting off the transmission of rotational motive power to a rotary shaft of the compressor from a pulley at preset overload time without making the hub side heavy and large. SOLUTION: In a clutchless compressor having a hub 20 integrally arranged on a driving shaft 2 and a damper holding plate 50 for holding an elastic body for transmitting torque, when an overload is applied to an engaging mechanism 70 composed of a hole 56 formed in the damper holding plate 50 and a projecting part 25 formed in the hub 20, the damper holding plate 50 rotates against engaging force of the projecting part 25 and the hole 56, engagement of the projecting part 25 and the hole 56 is released, and the damper holding plate 50 runs on the projecting part 25 while pushing up a disc spring 60. When the damper holding plate 50 rotates by a prescribed quantity or more, a projecting part formed in the hole 56 and a pin 41 engage with each other, and the pin 41 rotates in the direction for loosening a nut 40 to reduce pressing force 60 of the disc spring 60 for energizing the damper holding plate 50 to idly rotate a pulley 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutchless compressor in which a driving force of an external driving source is transmitted to a driving shaft housed in a housing via a pulley.

[0002]

2. Description of the Related Art In a compressor with a clutch, the driving force of an engine is transmitted to a drive shaft of the compressor via an electromagnetic clutch.

[0003] In this compressor with a clutch, when an abnormality such as seizure occurs inside the compressor, the electromagnetic clutch is disengaged based on the temperature and pressure in the compressor to prevent engine stall due to excessive load on the engine. ing.

On the other hand, in a clutchless compressor that does not use an electromagnetic clutch, when an abnormality such as seizure occurs inside the compressor, the compressor is connected to the pulley by a pulley to prevent the engine from stalling due to an excessive load on the engine. A mechanism for interrupting power transmission to the drive shaft is required.

As this mechanism, the flange of the inner holding member fixed to the pulley is brought into contact with the arc-shaped projection of the flange of the hub via a washer, and the flange of the inner holding member fixed to the pulley is connected to the flange. When the load torque on the compressor side is within the set value, the rotational force of the pulley is applied via the washer and the flange of the washer and the hub when the load torque on the compressor side is within the set value. When the load is transmitted to the drive shaft and the load torque on the compressor side exceeds the set value, slippage occurs between the washer and the arc-shaped protrusion on the flange of the hub, and the washer is inserted into the notch of the hub. There is known a configuration in which the pulley is displaced in the axial direction to reduce the pressing force of the disc spring, and the pulley idles (Japanese Patent Laid-Open No. 10-313399).

[0006]

However, in this mechanism, torque transmission is performed by a frictional force between a washer having a small coefficient of friction and an arc-shaped projection on a flange portion of a hub. Even when the torque variation is within the range, the frictional portion between the washer and the arc-shaped projection may slip.

Further, in order to prevent the friction portion from slipping, it is necessary to increase the load for pressing the washer. Therefore, a coned disc spring having a large spring force is required, and the hub receiving the disc spring's load also increases the strength. Therefore, it becomes heavy and large.

Further, since the torque is detected by the frictional force, the friction coefficient may change due to the environment such as temperature and humidity or the invasion of foreign matter, and the intended torque may not be detected.

The present invention has been made in view of such circumstances, and an object thereof is to reliably transmit rotational power from a pulley to a rotary shaft of a compressor at a set overload without making the hub side heavy and large. To provide a clutchless compressor that can be disconnected.

[0010]

According to a first aspect of the present invention, there is provided a clutchless compressor having a hub integrally provided on a drive shaft and an elastic body for transmitting torque. A nut that is screwed into the hub and presses the holding plate against the hub via a disc spring.
Engagement means for engaging the flange portion of the hub and the holding plate, and attached to the nut,
A pin that engages with the holding plate and loosens the nut when the engagement by the engagement means is released.

Since the holding plate is pressed by the nut with a predetermined force via the disc spring by the nut, the load torque of the compressor is equal to or more than a set value, that is, the holding plate is rotated when the load is overloaded and the engaging means is rotated. Is released, the pin attached to the nut is rotated in a direction in which the nut is loosened, the spring force of the disc spring pressing the holding plate against the hub is weakened, and the holding plate runs idle. Also,
Since the overload state is detected by the engagement means, a disc spring having a large spring force is not required.

A clutchless compressor according to a second aspect of the present invention is the clutchless compressor according to the first aspect, wherein the engaging means is formed on a projection formed on a flange of the hub and on the holding plate. And a hole facing the projection.

[0013] Since the engaging means is constituted by a projection formed on the flange of the hub and a hole formed on the holding plate and opposed to the projection, the projection is dropped into the hole so that the flange of the hub is formed. And the holding plate can be engaged.

According to a third aspect of the present invention, there is provided the clutchless compressor according to the first or second aspect, wherein the protrusion is formed in a circumferential direction of the flange of the hub. Features.

Since the projection is formed in the circumferential direction of the flange of the hub, the projection easily falls into the hole.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of a clutchless compressor according to an embodiment of the present invention, FIG. 2 is a view taken in the direction of arrow A in FIG. 1, and FIG. 3 is an exploded perspective view of a power transmission device of the clutchless compressor in FIG. FIG.

The clutchless compressor includes a pulley 10 rotatably supported by a boss 1a of a housing 1 via a radial bearing 5 and rotating by a rotational force from an engine (not shown) about a drive shaft 2 as a rotation center. ,
A center bolt 6 and a hub 20 fixed by a stopper 30 also serving as a washer are provided at an end of the drive shaft 2 protruding from the housing 1.

The hub 20 comprises a flange portion 21 and a cylindrical portion 22.

An annular concave portion 23 is formed at the center of the front end face of the flange portion 21.

The annular portion 24 connected to the concave portion 23 is formed with projections 25 having a rectangular shape in plan view and a trapezoidal shape in side view at intervals of 120 ° in the circumferential direction.

On the outer peripheral surface of the cylindrical portion 22, a male screw 22a which can be screwed with the female screw 40a of the nut 40 is formed.
When the male screw 22a rotates in the same direction as the rotation direction of the pulley 10, the nut 40 is reverse-threaded so as to be loosened. Further, a through hole 26 through which the center bolt 6 passes is formed on the central axis of the cylindrical portion 22.

An outer peripheral edge of an annular damper holding plate (holding plate) 50 is fixed to a pulley 10 fixed to an outer ring 5 a of the radial bearing 5 by a screw 51. The inner ring 5b of the radial bearing 5 is fixed to the boss 1a of the housing 1.

The pulley 10 is formed of a thermosetting resin. The pulley 10 is insert-molded with a nut portion 15 into which a screw 51 is screwed and a radial bearing 5. A belt (not shown) is wound around the outer peripheral surface of the pulley 10, and the pulley 10 is connected to a crankshaft of an engine (not shown) via the belt.

The damper holding plate 50 includes an outer holding plate 52 and an inner holding plate 53 which is arranged on the inner peripheral side of the outer holding plate 52 with a space therebetween. The outer holding plate 52 and the inner holding plate 53 are connected by an elastically deformable damper rubber 55, and torque (driving force) is transmitted through the damper rubber. The damper rubber 55 is fixed to the outer holding plate 52 and the inner holding plate 53 by an adhesive while being urged in the axial direction (the direction away from the hub 20).

The damper holding plate 50 (inner holding plate 53) is formed with a rectangular hole 56 which can be engaged with the projection 25 of the hub 20. Projection 25 and hole 56
These form an engaging mechanism (engaging means) 70.

A substantially circular opening 57 is formed in the center of the damper holding plate 50 to allow the cylindrical portion 22 of the hub 20 to escape. The opening 57 is formed with two projections 58 projecting inward in the radial direction so as to face each other.

The nut 40 is provided with a pin 41 whose one end is engaged with the projection 58 of the damper holding plate 50. Therefore, when the pulley 10 (damper holding plate 50) rotates, the pin 41 connects the nut 40 to the cylindrical portion 22.
Bias in a direction away from The other end of the pin 41 is prevented from coming off by the stopper 30.

A disc spring 60 for pressing the damper holding plate 50 against the hub 20 by the tightening force of the nut 40 is provided between the nut 40 and the damper holding plate 50. At this time, the pressing force of the damper holding plate 50 against the hub 20 is determined by the amount of tightening of the nut 40 with respect to the cylindrical portion 22.

The pulley 10, the hub 20, the damper holding plate 50, the disc spring 60, the nut 40, the pin 41, and the center bolt 6 constitute a power transmission device of a clutchless compressor. .

When the load torque on the compressor side is within the set value, the projection 25 and the hole 56 are engaged, and the driving force of the pulley 10 is controlled by the damper holding plate 50, the hole 56, the projection 25 and the hub. The power is transmitted to the drive shaft 2 through the drive shaft 20, and the drive shaft 2 rotates (see FIG. 1).

When the load torque on the compressor side becomes excessively larger than the set value, the load torque is applied to the engagement mechanism 70 composed of the hole 56 and the projection 25. for that reason,
The damper holding plate 50 rotates against the engaging force between the projection 25 and the hole 56, and the engagement between the projection 25 and the hole 56 is released. At this time, the damper holding plate 50 rides on the projection 25 while pushing up the disc spring 60.

When the damper holding plate 50 rotates by a predetermined amount or more, the projection 58 and the pin 41 engage, and the pin 41 rotates in a direction to loosen the nut 40. As a result, the pressing force of the disc spring 60 biasing the damper holding plate 50 decreases and eventually becomes zero, the pulley 10 idles, and the transmission of the rotational force from the pulley 10 to the drive shaft 2 is interrupted. Dripping.

According to the clutchless compressor of this embodiment, the following effects can be obtained.

The rotational force of the pulley 10 is transmitted to the drive shaft 2 via the damper holding plate 50, the hole 56, the projection 25, and the hub 20, and the drive force is transmitted by the friction between the washer and the hub as in the conventional example. The nut 40 is loosened by the driving force within the allowable range, and the pulley 1
The transmission path of the rotational force from 0 to the drive shaft is not interrupted.

Further, since the driving force is not transmitted by the frictional force between the washer and the hub as in the conventional example, it is not necessary to apply a large load to the hub 20 by the disc spring 60, and the hub side is reduced in weight and size. Can be achieved.

Further, the damper holding plate 50 is pressed to the hub 20 via the disc spring 60 by the nut 40 screwed to the hub 20 to transmit the driving force from the pulley 10, and the nut 40 is loosened to transmit the driving force. , The timing of interruption of the transmission path caused by a change in the coefficient of friction due to the environment (temperature and humidity) or the invasion of foreign matter does not vary, and fluctuations in detection accuracy are reduced.

When the nut 40 is loosened, the damper holding plate 50 is moved in the axial direction by the urging force of the damper rubber 55 in the axial direction, and the projection 25 and the damper holding plate 50 are separated from each other. Generation of sound due to contact with the damper holding plate 50 is prevented.

Further, since the pulley 10 is molded using a thermosetting synthetic resin, the weight of the pulley 10 can be reduced and the moment of inertia can be reduced.

Further, since the nut portion 15 and the like are insert-molded, the number of manufacturing steps can be reduced, and the manufacturing cost of the clutchless compressor can be reduced.

In this embodiment, the number of pins 41 for urging the nut 40 in the direction away from the cylindrical portion 22 is four. However, the number is not limited to four and may be two, for example.

Although the pulley 10 is molded using a thermosetting synthetic resin, it may be manufactured by forging or machining using iron as in the conventional case.

Further, in this embodiment, the projection 25 is formed on the hub 20 and the hole 56 is formed on the damper holding plate 50. However, the hole is formed on the hub 20 and the damper holding plate 5 is formed.
A protrusion may be formed at 0.

The projections 25 are formed on the flange 21 at intervals of 120 ° in the circumferential direction.
The protrusions 25 may be continuously formed in the circumferential direction of the flange portion 21 so that any one of the protrusions 25 can be engaged with the hole 56 of the damper holding plate 50.

[0045]

As described above, according to the clutchless compressor of the first aspect of the present invention, the transmission of rotational power from the pulley to the drive shaft of the compressor can be reliably cut off by the set overload. it can. Further, the hub side receiving the load due to the spring force can be made small and light.

According to the clutchless compressor of the second aspect of the present invention, the engagement means can be configured with a simple configuration.

According to the third aspect of the present invention, it is possible to more reliably cope with an overload state.

[Brief description of the drawings]

FIG. 1 is a sectional view of a clutchless compressor according to one embodiment of the present invention.

FIG. 2 is a view taken in the direction of arrow A in FIG. 1;

FIG. 3 is an exploded perspective view of a power transmission device of the clutchless compressor of FIG. 1;

[Explanation of symbols]

 2 Drive shaft 20 Hub 21 Flange 25 Projection 40 Nut 41 Pin 50 Damper holding plate (holding plate) 55 Damper rubber (elastic body) 56 Hole 60 Disc spring

Claims (3)

[Claims] 1. A clutchless compressor comprising: a hub integrally provided on a drive shaft; and a holding plate for holding an elastic body for transmitting torque. A nut for pressing the hub through a disc spring; engaging means for engaging the flange portion of the hub with the holding plate; attaching to the nut and engaging with the holding plate; And a pin for loosening the nut when the engagement state of the clutch is released. 2. The device according to claim 1, wherein said engaging means comprises a projection formed on a flange of said hub and a hole formed on said holding plate, said hole facing said projection. 2. The clutchless compressor according to 1. 3. The clutchless compressor according to claim 1, wherein the protrusion is formed in a circumferential direction of the flange of the hub.