JP2001355583A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable clutchlessness by providing a clutch function to a scroll compressor. SOLUTION: In this scroll compressor 10, a turning scroll 13 engaged with a fixed scroll 12 is prevented from rotating and revolves, it is brought into contact with a plurality of contact points to form a crescent compression chamber, the compression chamber is inward moved while reducing its capacity from the outer peripheral side, and suction, compression and discharge are simultaneously performed. An electromagnetic expansion valve 1 for controlling fluid pressure to be sucked to the compression chamber is provided, and an elastic member such as a spring for always providing force in the direction to separate the turning scroll 13 from the fixed scroll 12 is provided on a suitable part of a variable radius turning mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor suitable for use as a refrigerant compressor for a vehicle air conditioner or the like.

[0002]

2. Description of the Related Art Conventionally, a scroll-type fluid machine such as a scroll-type compressor has a scroll-type compression mechanism provided with a fixed scroll, an orbiting scroll, and a rotation preventing mechanism. In this scroll-type compression mechanism, one fixed scroll is an immovable scroll fixedly supported in a housing to which the suction pipe and the discharge pipe are connected. The other orbiting scroll is arranged so as to mesh with the fixed scroll in the up-down or left-right direction. On the other hand, revolving motion is performed. The fixed scroll and the orbiting scroll are meshed with a phase difference of 180 degrees while being eccentric by a predetermined distance from each other. As a result, the orbiting scroll is in line contact with the fixed scroll at a plurality of contact points to form a plurality of crescent-shaped compression chambers. By moving inward, suction, compression, and discharge can be performed simultaneously.

When such a scroll compressor is used as a refrigerant compressor for a vehicle air conditioner, the orbiting scroll is usually driven by an engine for driving the vehicle. The rotary shaft on the scroll compressor side driven by the engine is provided with a power interrupting means such as a clutch in order to enable selective operation of the compressor. An electromagnetic clutch is provided inside the pulley so as to connect or disconnect the motor and the crankshaft.

[0004]

By the way, when the above-mentioned electromagnetic clutch is used, the size of the pulley of the scroll type compressor is increased due to the presence of the electromagnetic clutch, so that the compressor having the same cannot be avoided. There's a problem. In addition, there is a problem that the high-speed operation of the scroll compressor is restricted due to an increase in the diameter of the pulley, or power is required for operation of the electromagnetic clutch, which is disadvantageous for power saving. Against this background, the need for an electromagnetic clutch between the engine and the scroll compressor has been eliminated to reduce the size of the scroll compressor, simplify the structure, and reduce the cost and weight of the compressor. Is desired.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a scroll compressor in which the compressor itself has a clutch function, thereby enabling a so-called clutchless operation.

[0006]

The present invention employs the following means in order to solve the above-mentioned problems. The scroll compressor according to claim 1, wherein the fixed scroll and the orbiting scroll engaged with the fixed scroll and prevented from rotating with respect to the fixed scroll to perform a revolving orbiting motion contact at a plurality of contact points and have a crescent shape. A scroll compressor in which the compression chamber moves inward while reducing the volume from the outer peripheral side to perform suction, compression, and discharge simultaneously,
Suction pressure control means for controlling the pressure of the fluid sucked into the compression chamber; and separation force applying means for applying a force in a direction to separate the orbiting scroll from the fixed scroll. Things.

According to such a scroll compressor, when the clutch is turned off during operation, when the suction pressure is reduced by operating the suction pressure control means, the gas compression force is reduced and applied by the separation force applying means. The orbiting scroll is separated from the fixed scroll and enters an idling state that cannot be compressed. When the clutch is turned on from the above-mentioned idling state (clutch off), if the suction pressure is increased by operating the suction pressure control means, the gas compression force increases with the increase of the pressure loss, and the separation force is eventually applied. The orbiting scroll contacts the fixed scroll in excess of the force provided by the means. As a result, the sucked fluid can be compressed, and the normal compression operation is continued thereafter.

In this case, when the scroll compressor has a slider type variable turning radius mechanism, the separating bush is interposed between the drive bush and the drive pin to urge the drive bush. An elastic member may be used to apply a force in a direction to separate the orbiting scroll from the fixed scroll, or by over-balancing a balance weight provided for the purpose of canceling the centrifugal force generated by the orbiting of the orbiting scroll, A centrifugal force may be applied in a direction to separate the orbiting scroll from the fixed scroll. In addition, as the above-mentioned elastic member, an elastic body such as rubber can be adopted in addition to a spring member such as a disc spring, a plate spring, and a coil spring.

When the scroll compressor has a swing link type variable turning radius mechanism, the separating force applying means biases a pin of the swing link mechanism to separate the orbiting scroll from the fixed scroll. A direction in which the orbiting scroll is moved away from the fixed scroll by using an elastic member that imparts a force in the direction, or by overbalancing a balance weight provided for the purpose of canceling the centrifugal force generated by the orbiting of the orbiting scroll. Centrifugal force may be applied. In addition, as the above-mentioned elastic member, besides a spring member such as a disc spring, a plate spring and a coil spring, an elastic body such as rubber or an O-ring can be adopted.

In the scroll compressor, it is preferable that an electromagnetic expansion valve is adopted as an expansion valve mechanism required for a refrigeration cycle, and this is used as the suction pressure control means.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the scroll compressor according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing an internal structure of a scroll compressor used in a refrigeration cycle of a vehicle air conditioner as a first embodiment of the present invention, and reference numeral 1 in the drawing denotes electromagnetic expansion provided as an expansion mechanism. Valves 2, evaporators 3, refrigerant pipes 10, scroll compressors. The high-temperature and high-pressure gas refrigerant sent from the scroll compressor 10 circulates through the refrigerant pipe 3 in the order of the condenser, the electromagnetic expansion valve 1 and the evaporator 2 (not shown), and repeats a state change.

The scroll compressor 10 includes a housing 11
The fixed scroll 12 is fixedly installed therein, and the orbiting scroll 13 meshed with the fixed scroll 12 is prevented from rotating with respect to the immobile fixed scroll 12 to perform a revolving orbiting motion. The orbiting scroll 13 is eccentric with the fixed scroll 12 by a predetermined distance, and meshes with a phase difference of 180 degrees. As a result, the orbiting scroll 13 is in line contact with the fixed scroll 12 at a plurality of contact points to form a plurality of crescent-shaped compression chambers. -It is configured to perform ejection at the same time. In the drawing, reference numeral 14 denotes a suction port for the fluid to be compressed, and 15 denotes a discharge port for the compressed fluid.

The orbiting scroll 13 includes a rotating shaft 17 that rotates integrally with a pulley 16 that is driven by a belt from a drive source (not shown), and a drive pin 18 that is eccentrically protruded from the center of the rotating shaft 17. And a drive bush 20 having a through hole 19 through which the drive pin 18 slidably passes. When the rotating shaft 17 rotates, the drive bush 20 and the orbiting scroll 13 pass through the through hole 19 (see FIG.
) To change its turning radius. Such a variable turning radius mechanism is a “slider type”.
It is a well-known thing called.

The orbiting scroll 13 performs a revolving orbiting motion in a state in which the orbiting scroll 13 is prevented from rotating with respect to the immovable fixed scroll 12 by a rotation preventing mechanism 21 having a known Oldham link. Further, the orbiting scroll 13 has a balance weight 22 which orbits integrally with the drive bush 20. The balance weight 22 is a substantially semi-disc-shaped member extending in the radial direction, and acts in a direction opposite to the force of the orbiting scroll 13 performing the revolving orbiting motion while changing the orbital radius against the fixed scroll 12 by centrifugal force. To generate a turning reaction force Fc. Such a balance weight 22
The effect of (1) can prevent an increase in the frictional force generated when the orbiting scroll 13 is pressed against the fixed scroll 12 more strongly than necessary. That is, the orbiting scroll 1
An excessive frictional force that promotes abrasion is prevented from being generated between the fixed scroll 3 and the fixed scroll 12, and an appropriate sealing force is obtained between the two so that the orbiting scroll 13 can smoothly orbit. It was made.

When the rotary shaft 17 is driven to make the orbiting scroll 13 revolve orbit, a gas compression force Fg is generated as shown in FIG. In FIG. 2,
The orbiting scroll 13 is a fixed scroll 12 on the left side of the drawing.
The right side of the drawing shows the clutch-off state in which the orbiting scroll 13 is separated from the fixed scroll 12 and the gap S is formed.
The gas compression force Fg generated in the clutch-on state acts as a radial component (hereinafter, radial force Fn) and a tangential component (hereinafter, tangential force Ft). This tangential force Ft automatically acts as a force pressing the orbiting scroll 13 in the direction of the fixed scroll 12.
The tangential force Ft is equal to the balance weight 2 described above.
Since the turning reaction force Fc in the opposite direction due to the action of 2 is received, the force that actually presses the turning scroll 13 against the fixed scroll 12 is approximately (Ft−Fc). Therefore, by adjusting the turning reaction force Fc, the pressing force between them during normal operation is changed, and an appropriate sealing force can be given.

As a separating force applying means for applying a force in a direction to separate the orbiting scroll 13 from the fixed scroll 12 to the "slider type" variable radius orbiting mechanism provided with such a balance weight 22, In the embodiment, a spring 23 is provided between the drive bush 20 and the drive pin 18. The spring 23 can be a leaf spring, a coil spring, a disc spring, or the like. Specifically, the spring 23 is disposed between the peripheral surface 18a of the drive pin 18 and the end surface 19a of the drive pin 18 in the sliding direction in the through hole 19. hand,
It is urged in a direction to increase the inter-surface distance L between the peripheral surface 18a and the sliding direction end surface 19a. Note that, as the separating force applying means, an elastic body such as rubber can be used in addition to the above-described spring member. Therefore, the drive bush 20
Of the orbiting scroll 13 fitted on the outer peripheral side of the shaft via bearings, in a direction away from the fixed scroll 13 together with the drive bush 20 with the drive pin 18 as a reference, in other words, a force substantially in the same direction as the orbiting reaction force Fc. I have always received it.

For this reason, when the electromagnetic expansion valve 1 is closed and the circulation of the refrigerant is stopped, the tangential force Ft does not act because the gas compression force Fg is not generated. Accordingly, the orbiting scroll 13 during orbiting is in a state of substantially zero balance with the orbiting reaction force Fc of the balance weight 22 and receives a force in the direction away from the fixed scroll 12 by the amount of the bias of the spring 23, and the gap S The orbiting scroll 13 is idled without being compressed since the clutch is kept in the clutch-off state separated only by the distance. That is, the orbiting scroll 1
3 and the balance weight 22 are substantially balanced in their turning moments, so that the turning reaction force Fc is substantially
Does not contribute to the clutch on / off of the orbiting scroll 13. When the electromagnetic expansion valve 1 is opened from the clutch off state,
Since the refrigerant is supplied to the scroll compressor 10 and the suction pressure rises, a relatively small gas compression force fg is initially generated. The tangential force ft acting by this gas compression force fg
Is smaller than the urging force of the spring 23, and the orbiting scroll 13 is still in a clutch-off state separated from the fixed scroll 12.

If the above state continues, the amount of gas in the scroll compressor 10 increases and the pressure loss increases. As a result, the gas compression force fg also increases. And
When the tangential force ft that increases as the gas compression force fg increases becomes larger than the urging force of the spring 23, the orbiting scroll 13 is pressed toward the fixed scroll 12 by the action of the tangential force ft. Thus, the orbiting scroll 13
Is in the clutch-on state, and the gas compression force F in the steady operation is
Since g occurs, the compression operation is performed with an appropriate sealing force of approximately (Ft-Fc).

Next, a case where the clutch is switched from the clutch-on state to the clutch-off state will be described. The trigger of this operation is the operation of the electromagnetic expansion valve 1 as in the above-described switching from the clutch off to the clutch on, and in this case, the electromagnetic expansion valve 1 is closed. As a result, the suction pressure of the scroll compressor 10 decreases, and the gas compression force Fg also decreases. Therefore, when the tangential force Ft decreases and becomes smaller than the urging force of the spring 23, the orbiting scroll 13 becomes fixed scroll. Separated from 12. Thus, the clutch is turned off, and the orbiting scroll 13 idles.

Subsequently, a second separating force applying means for applying a force in a direction for separating the orbiting scroll 13 from the fixed scroll 12 to the "slider type" variable radius orbiting mechanism.
An embodiment will be described. In this embodiment, a balance weight 22 provided as a separating force applying means for the purpose of canceling the centrifugal force generated by the turning of the orbiting scroll 13.
, The centrifugal force acting in a direction to move the orbiting scroll 13 away from the fixed scroll 12 is adopted. That is, the balance weight 22 is overbalanced so that the value of mr obtained by dividing the moment of inertia represented by mr ² by the radius of rotation r is larger in the balance weight 22 than in the orbiting scroll 13.

In this manner, the balance weight 22
Is generated in a direction in which the orbiting scroll 13 is separated from the fixed scroll 12 by an amount corresponding to the large moment of inertia. That is, in the state where the electromagnetic expansion valve 1 is closed, no gas compressive force is generated, and the turning reaction force Fc becomes larger than the zero balance by the overbalance of the balance weight 22. The clutch-off state in which the gap S is formed by being separated is maintained.

When the electromagnetic expansion valve 1 is opened from the clutch-off state, the refrigerant is supplied to the scroll compressor 10 and the suction pressure rises, so that a relatively small gas compression force fg is generated at first. The tangential force ft exerted by the gas compression force fg is smaller than the force in the separating direction generated by overbalancing, and the orbiting scroll 13 is still in the clutch-off state separated from the fixed scroll 12. If such a state continues, the amount of gas in the scroll compressor 10 increases and the pressure loss increases, so that the gas compression force fg also increases. And
When the tangential force ft that increases as the gas compression force fg increases becomes larger than the force caused by overbalancing, the orbiting scroll 13 is pressed toward the fixed scroll 12 by the action of the tangential force ft. Thus, the orbiting scroll 13 is in the clutch-on state, the gas compression force Fg of the steady operation is generated, and the compression operation is performed.

Next, a case where the clutch is switched from the clutch-on state to the clutch-off state will be described. The trigger of this operation is the operation of the electromagnetic expansion valve 1 as in the above-described switching from the clutch off to the clutch on, and in this case, the electromagnetic expansion valve 1 is closed. As a result, the suction pressure of the scroll compressor 10 decreases, and the gas compression force Fg also decreases. Therefore, when the tangential force Ft decreases and becomes smaller than the force caused by overbalance, the orbiting scroll 13 becomes fixed scroll. Separated from 12. Thus, the clutch is turned off, and the orbiting scroll 13 idles.

The above-mentioned separating force applying means is a "slider type".
In addition to the scroll compressor having the variable radius turning mechanism described above, the present invention is also effective to a scroll compressor having a known variable radius turning mechanism called “swing link type”. As shown in FIG. 3, the “swing link type” variable radius turning mechanism protrudes from the lower surface of the balance weight 22 while the “slider type” drive pin 18 slides in the through hole 19. The pin 24 slides along an arcuate guide groove 25 formed on the distal end surface of the large diameter portion 17a of the rotating shaft 17. In this case, a drive pin 18 is provided at a position eccentric from the rotation center of the rotary shaft 17, and a pin 24 is further provided eccentrically from the drive pin 18. The guide groove 25 is provided on an arc having a radius equal to the distance between the drive pin 18 and the pin 24, as shown in FIG. Note that the pin 24 is
7a, the guide groove 25 may be formed on the lower surface of the balance weight 22. The pin 24 and the guide groove 25 may be provided on the drive bush integrated with the balance weight 22. Is also good.

In the apparatus having such a "swing link type" variable radius turning mechanism, as a third embodiment relating to the separating force applying means, a pin 24 is biased to separate the orbiting scroll 13 from the fixed scroll 12. An elastic member is provided to apply a force in the direction to be squeezed. As the elastic member in this case, for example, there is an O-ring 26 fitted to the pin 24. In this case, the O-ring 26
The ring 26 and the ring 26 are eccentric so that a moment in the direction of expanding the gap S acts on the guide groove 25. In this way, the moment generated by the urging force of the O-ring 26 is superior when the electromagnetic expansion valve 1 is closed and the gas compression force Fg is reduced by the same operation as in the above-described first embodiment. Can be in a clutch-off state in which the clutch is separated from the fixed scroll 12.
Conversely, when the electromagnetic expansion valve 1 is opened and the gas compression force fg increases, the tangential force Ft becomes greater, so that the orbiting scroll 13 can be pressed against the fixed scroll 12 and the clutch can be turned on. The elastic member that can be employed as the separating force applying means includes the O-ring 26 shown here.
In addition, as in the first embodiment, a spring member such as a plate spring, a coil spring, or a disc spring, or an elastic body such as rubber may be employed between the pin 24 and the wall surface of the guide groove 25. Good.

In addition, for the "swing link type" variable radius orbiting mechanism, the orbiting scroll 13 is fixed to the fixed scroll 1
As a fourth embodiment of the separating force applying means for applying a force in the direction of separating from the second, the centrifugal force generated by the turning of the orbiting scroll 13 is provided as in the second embodiment described above. A centrifugal force acting in a direction to move the orbiting scroll 13 away from the fixed scroll 12 by overbalancing the balance weight 22 may be adopted. In this way, when the electromagnetic expansion valve 1 is closed and the gas compression force Fg is reduced by the same operation as the above-described second embodiment, the orbiting reaction force Fc due to over-balance becomes large, and the orbiting scroll 1
3 is disengaged from the fixed scroll 12 so that the clutch is in the off state. Conversely, the electromagnetic expansion valve 1 is opened and the gas compression force f
As g increases, the tangential force Ft increases, and the orbiting scroll 13 can be pressed against the fixed scroll 12 to put the clutch on.

As described above, the scroll compressor of the present invention performs the compression operation in which the orbiting scroll 13 is pressed against the fixed scroll 12 by closing the electromagnetic expansion valve 1 or the opening operation of the electromagnetic expansion valve 1. Since a function equivalent to a conventional electromagnetic clutch is provided, such as rotating the orbiting scroll 13 away from the fixed scroll 12 and causing the orbiting scroll 13 to idle, a so-called clutchless operation in which a clutch mechanism such as an electromagnetic clutch is omitted can be realized.

[0028]

According to the scroll compressor of the present invention, a clutch mechanism such as an electromagnetic clutch can be omitted.
The size can be reduced. Further, since the electromagnetic clutch is built in the pulley that normally drives the belt, the diameter of the pulley can be reduced by eliminating the clutch, so that the scroll compressor can be operated at high speed. Further, power consumption can be reduced because the power for operating the electromagnetic clutch becomes unnecessary with the shift to clutchless operation.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a scroll compressor according to the present invention.

FIG. 2 is an explanatory diagram showing a clutchless operation in a “slider type” variable radius turning mechanism.

FIG. 3 is a cross-sectional view illustrating a main part of a “swing link type” variable radius turning mechanism in which clutchless operation is performed.

FIG. 4 is a plan view of the rotating shaft in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electromagnetic expansion valve (suction pressure control means) 2 evaporator 3 refrigerant pipe 10 scroll compressor 12 fixed scroll 13 orbiting scroll 17 rotating shaft 18 drive pin 19 through hole 20 drive bush 21 rotation prevention mechanism 22 balance weight 23 spring (separation force application) Means) 24 pins 25 guide grooves 26 O-ring (separation force applying means)

Claims (6)

[Claims] A fixed scroll and a revolving scroll engaged with the fixed scroll and prevented from rotating with respect to the fixed scroll to perform revolving revolving motion at a plurality of contact points to form a crescent-shaped compression chamber. A scroll compressor in which the compression chamber moves inward while reducing the volume from the outer peripheral side to simultaneously perform suction, compression and discharge, and a suction pressure control means for controlling a pressure of a fluid sucked into the compression chamber; And a separation force applying means for applying a force in a direction for separating the orbiting scroll from the fixed scroll. A drive bush of said orbiting scroll, wherein said drive bush is provided with a slide-type variable turning radius mechanism which slides with respect to a drive pin, and said separating force applying means is interposed between said drive bush and said drive pin. The scroll compressor according to claim 1, wherein the scroll compressor is an elastic member that urges the drive bush and applies a force in a direction that separates the orbiting scroll from the fixed scroll. 3. A swivel-type variable turning radius mechanism in which a drive bush of the orbiting scroll slides with respect to a drive pin, wherein the separating force applying means cancels a centrifugal force generated by the turning of the orbiting scroll. 2. The scroll compressor according to claim 1, wherein the centrifugal force causes the orbiting scroll to move away from the fixed scroll by overbalancing the weights. 3. 4. A swing link type variable turning radius mechanism for sliding a pin provided by the orbiting scroll eccentrically from a drive pin along an arc-shaped guide groove,
2. The separation force applying means is an elastic member which applies a force in a direction for urging the pin to separate the orbiting scroll from the fixed scroll.
2. The scroll compressor according to item 1. 5. A swing link type variable turning radius mechanism for sliding a pin provided eccentrically from a drive pin by the orbiting scroll along an arc-shaped guide groove,
A centrifugal force in which the separating force applying means acts in a direction for separating the orbiting scroll from the fixed scroll by overbalancing a balance weight for canceling a centrifugal force generated by the orbiting of the orbiting scroll. The scroll compressor according to claim 1, wherein: 6. The scroll compressor according to claim 1, wherein said suction pressure control means is an electromagnetic expansion valve provided in a refrigeration cycle.