JPH0214560B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vane-type rotary compressor, in which the vane back pressure is reduced by reducing the clearance of the throttle ring, especially during high-speed rotation when the discharge temperature of gas etc. is high. This prevents abnormal wear of the vanes.

Vane-type rotary compressors are used in car cooler compressors, etc. When the rotor is rotated by the rotating shaft, the vanes attached to the rotor slide while being pressed against the inner peripheral surface of the cam ring. By changing the volume between each vane, refrigerant gas, etc. is introduced into the pump chamber via the suction passage.
It is designed to be pressurized and discharged to the outside through a discharge passage. Such a vane-type rotary compressor is generally provided with an oil reservoir connected to the discharge passage, and the oil in the oil reservoir is introduced into the bottom of the vane receiving hole of the rotor by the discharge pressure of gas or the like. Back pressure is applied to the vane, and the back pressure presses the vane against the inner peripheral surface of the cam ring.

However, if the discharge pressure is directly introduced into the bottom of the vane receiving hole, the back pressure may be too strong and cause abnormal wear of the vanes. Therefore, a vane-type rotary compressor has been developed that uses a so-called throttle ring to reduce discharge pressure and apply appropriate back pressure to the vane. Since the rotating shafts to which the aperture ring is attached are both made of a material with the same coefficient of thermal expansion, such as carbon steel, there are the following drawbacks.

(1) The clearance (orifice) formed between the throttle ring and the rotating shaft is approximately the same even when the discharge pressure and discharge temperature are low when starting the compressor, and when the discharge pressure and discharge temperature are high during steady operation. If the above-mentioned clearance is set based on normal temperature operation in order to maintain the same value, the back pressure at the time of startup will be insufficient, resulting in insufficient vane ejection force and causing noise.

(2) The disadvantage of item (1) above can be overcome by setting the clearance based on the starting time, that is, by setting the clearance so that sufficient back pressure can be obtained at the starting time, but if you do this, Back pressure becomes too high during steady operation, causing abnormal wear of the vanes.

The present invention has been made with the aim of eliminating the above-mentioned conventional drawbacks, and its gist is that the aperture ring is made of a material with a smaller coefficient of thermal expansion than the rotating shaft, and the coefficient of thermal expansion of both is made smaller. Due to the difference,
The purpose is to prevent abnormal wear of the vanes by reducing the clearance between the throttle ring and the rotating shaft during steady operation when the discharge pressure and temperature are high.

Next, the present invention will be explained based on the drawings. 1 is a rotating shaft, 2 is a rotor rotated via the rotating shaft 1,
3...3 is a large number of vanes attached to the rotor 2 so as to be freely protrusive and retractable approximately in the radial direction; 4 is a cam ring that accommodates the rotor 2 to which the vanes 3...3 are attached; 5;
and 6 sandwich the cam ring 4 and hold the cam ring 4.
8 is a housing housing the side plates 5, 6 and the rotor 2;
9 and 10 are a suction passage and a discharge passage provided in the housing 8; 11 is an oil reservoir provided in the housing 8 in communication with the discharge passage 10; and 12 is accommodated in the oil reservoir 11. Oil 13 is an aperture ring installed between the rotating shaft 1 and the side plate 6, and the aperture ring 1
3 is made of a material with a coefficient of thermal expansion smaller than that of the rotating shaft 1, such as ceramic or carbon, and the clearance C with the rotating shaft 1 is based on the time when the compressor is started, when the discharge pressure and discharge temperature are low. It is formed in a size that can introduce necessary and sufficient back pressure at the time of startup. In the figure, 14 is a radial bearing, and 15 is a radial bearing 14.
The spring that presses the aperture ring on, 16
is a thrust bearing, and 17 is an oil and gas separator.

Next, we will discuss its effect. When the rotor 2 is rotated via the rotating shaft 1, the vanes 3...3 attached to the rotor 2 slide while being pressed against the inner peripheral surface of the cam ring 4, and the volume change between each vane 3 at that time. A working gas (refrigerant gas) (not shown) is introduced into the pump chamber 7 via the suction passage 9, pressurized, and discharged to the outside via the discharge passage 10, as well as an oil reservoir 1 connected to the discharge passage 10.
The oil 12 of No. 1 is introduced into the bottom of the vane receiving hole 2a through the clearance C by the gas discharge pressure, and applies back pressure to the vanes 3. However, as mentioned above, the aperture ring 13 is made of a material with a smaller coefficient of thermal expansion than the rotating shaft 1, so as time passes from the time of startup and the rotational speed of the rotor 2 increases. As the discharge pressure and discharge temperature become higher, the clearance C decreases, and the back pressure is lowered than at the time of starting, thereby preventing abnormal wear of the vanes 3...3 during steady operation.

As explained above, the present invention includes a rotating shaft, a rotor that is rotated via the rotating shaft, a large number of vanes that are attached to the rotor so as to be freely retractable in a substantially radial direction, and a rotor that houses the vanes. A cam ring, a side plate that holds the cam ring and forms a pump chamber on the inner periphery of the cam ring, and a housing that accommodates the side plate or rotor, and when the rotor is rotated, it is attached to the rotor. The vanes in the cam ring slide while being pressed against the inner circumferential surface of the cam ring, and the volume change between the vanes at that time introduces working gas into the pump chamber through the suction passage, pressurizes it, and sends it outside through the discharge passage. At the same time, oil, etc. in an oil reservoir connected to the discharge passage is introduced into the bottom of the vane receiving hole of the rotor through a throttle ring installed between the rotating shaft and the side plate by the gas discharge pressure. In the vane type rotary compressor,
The aperture ring is made of a material with a coefficient of thermal expansion smaller than that of the rotating shaft, so during steady operation with high discharge pressure, the clearance is small and back pressure is lowered to prevent abnormal vane wear and reduce the discharge pressure at startup. When the vane is low, the clearance is increased, the back pressure is increased, and the flying force of the vane can be increased, which is an excellent practical effect.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view taken along the line -- in FIG. 2 of the vane type rotary compressor of the present invention, FIG. 2 is a cross-sectional view taken along the line -- in FIG. . 1... Rotating shaft, 2... Rotor, 2a... Vane receiving hole, 3... Vane, 4... Cam ring, 5, 6
... side plate, 7 ... pump chamber, 8 ... housing, 9 ... suction passage, 10 ... discharge passage,
11... Oil reservoir, 12... Oil, 13...
aperture ring.

Claims (1)

[Claims] 1. A rotating shaft, a rotor rotated via the rotating shaft, a number of vanes attached to the rotor so as to be able to protrude and retract in a substantially radial direction, a cam ring that accommodates the rotor with the vanes attached, and a cam ring that holds the cam ring in place. The cam ring has a side plate that forms a pump chamber on the inner periphery of the cam ring, and a housing that accommodates the side plate or rotor. The vanes slide while being pressed against the surface, and the volume change between the vanes at that time introduces the working gas into the pump chamber through the suction passage, pressurizes it, and discharges it to the outside through the discharge passage. A vane-type rotary compression system that uses gas discharge pressure to introduce oil, etc. from the oil reservoir connected to the rotor into the bottom of the vane receiving hole of the rotor through a throttle ring installed between the rotating shaft and the side plate. A vane type rotary compressor, characterized in that the aperture ring is formed of a material having a smaller coefficient of thermal expansion than the rotating shaft.