Valve assembly for scroll compressor

A scroll compressor has a reed valve mounted on a central discharge port. The reed valve has a valve portion at a first end and a pin holding the reed valve onto a non-orbiting scroll member at a second end. The reed valve extends along a plane which is non-perpendicular to a drive axis of a drive shaft such that the second end, which receives the pin, is further removed from the compression chambers than is the first end of the reed valve, which covers the central discharge port.

BACKGROUND OF THE INVENTION

This application relates to a discharge valve assembly for a scroll compressor wherein reed valves are pinned to a non-orbiting scroll body at one end, and have a flexible opposed end which can move away a discharge port. The valve body is positioned at an angle, such that the opposed end is closer to the compression chambers than is the one end of the body.

Scroll compressors are known, and have become widely accepted in the refrigerant compression art. In a typical scroll compressor, first and second scroll members orbit relative to each other. Each of the two scroll members have a base and a generally spiral wrap extending from the base. The wraps interfit to define compression chambers. One of the two scroll members is caused to orbit relative to the other, and as the orbiting relative movement occurs the size of the compression chambers is decreased. Eventually, the compression chambers communicate with a discharge port near a center of the scroll members.

The discharge port may be provided with a discharge valve, to control the discharge pressure which is delivered downstream into a discharge plenum.

Another feature of the scroll compressors is the provision of over pressure control valves. These control valves may be positioned slightly radially outwardly of the central discharge port. If the pressure becomes too high, these valves open and allow the high pressure refrigerant to enter the discharge plenum.

In scroll compressors, volumes in discharge ports, which are upstream of the valves, can cause gas re-expansion and associated re-expansion losses.

With scroll compressors there is a phenomenon known as “reverse rotation”. Reverse rotation can occur when a scroll compressor stops being driven to orbit. A previously compressed refrigerant which is in the discharge port, and upstream of the discharge valve can re-expand and drive one scroll member in a reverse direction. This creates unwanted noise.

One way to minimize reverse rotation and re-expansion losses is to minimize the volume of the discharge port which is upstream of the valve. Various discharge valve types have been utilized. However, when a reed valve is utilized it is typically pinned to the base of a scroll member. A minimum thickness of material is required to receive the pin to hold the reed valve firmly.

SUMMARY OF THE INVENTION

In the disclosed embodiment of this invention, a reed valve for a discharge port in a scroll compressor extends on a plane which is at an angle which is non-perpendicular to a drive axis of a drive shaft for the scroll compressor. A pin for the reed valve is received at one end of the reed valve which is spaced further from the compression chambers, while the valve body itself is spaced closer to the compression chambers, to minimize the volume of refrigerant upstream of the valve body.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A scroll compressor20as known in the art is shown inFIG. 1. A non-orbiting scroll member24is associated with an orbiting scroll member22. The orbiting scroll member22is driven by a shaft25to cause the orbiting scroll member22to orbit relative to the non-orbiting scroll member24. As known, a non-rotation coupling100constrains the orbiting scroll member24to orbit. In this manner, compression chambers27between the two become smaller, and an entrapped refrigerant is compressed and moves towards a discharge port40. A valve32is shown on the discharge port40. The above discussed scroll compressor is a generally known in the art.

FIG. 2shows a non-orbiting member124. In the non-orbiting scroll member124the discharge port40is formed at a central location relative to the wrap41of the non-orbiting scroll member. In addition, two over pressure ports42are also shown.

FIG. 3shows a valve arrangement50on the non-orbiting scroll124. As shown, a plurality of valve stops52receive pins54. Reed valves58include holes60to receive the pins54. A remote end62of the valve covers the ports40and42.

Now, as the orbiting scroll member orbits relative the non-orbiting scroll member, should the pressure become unduly high prior to reaching the central discharge port40, then the ports42will open with their valve body62moving away from the ports42and allowing the refrigerant to enter a discharge plenum19(FIG. 1), before the refrigerant would normally exit through the central discharge port40.

FIG. 4shows an inventive feature in which the pin54is formed through a relatively thick portion72of the base of the non-orbiting scroll member124. The valve body58extends downwardly at a plane along a face70which extends towards the compression chambers27. The plane is non-perpendicular to a drive axis X of the driveshaft25. Preferably, the angle θ is between 0 and 60 degrees. In this manner, the volume of the discharge port40is smaller than if the disk valve58were to extend perpendicular to the drive axis of the drive shaft25. The same is true of the valves on discharge ports42. As is clear from theFIGS. 2 and 4, the discharge port40extends along an axis which is parallel to the drive axis X. The valve body58, and the face70, are non-perpendicular to the center of the discharge port. Thus, the magnitude of reverse rotation and re-expansion losses which can be expected will be reduced.