ROTARY COMPRESSOR
A rotary compressor 100 of the present invention includes a compression mechanism 3 , a motor 2 , a suction path 14 , a communication passage 16 and an on-off valve 32 as a control mechanism 30 . The rotary compressor 100 further includes an interior space 28 , a first check valve 35 a and a second check valve 35 b . If the on-off valve 32 opens, a volume of the operation chamber 25 is reduced and with this reduction in the volume, the first check valve 35 a opens. Pressure in the operation chamber 25 does not rise. At this time, the rotary compressor 100 is operated with substantially zero suction volume. If the on-off valve 32 is closed, the rotary compressor 100 is operated with a normal suction volume.
1 . A rotary compressor in which a compression mechanism comprises:
a cylinder;
a piston disposed in the cylinder;
a frame which rotatably holds a shaft, which covers both upper and lower sides of the cylinder, and which forms an operation chamber between the frame and an inner peripheral surface of the cylinder; and
a vane which partitions the operation chamber into a suction chamber and a compression-discharge chamber, and in which
a motor operates the piston through the shaft, wherein
the rotary compressor comprises:
a hermetic container in which the compression mechanism and the motor are accommodated;
a suction path for guiding working fluid to be compressed to the suction chamber;
a discharge port which is provided in the frame, and through which compressed working fluid flows out from the operation chamber;
an interior space which is partitioned from an interior of the hermetic container and the operation chamber;
a communication passage between the interior space and the suction path;
a first passage between the discharge port and the interior space;
a first check valve which prohibits working fluid passing through the first passage from returning from the interior space to the discharge port;
a second passage between the interior space and the interior of the hermetic container;
a second check valve which prohibits working fluid passing through the second passage from returning from the interior of the hermetic container to the interior space; and
a control mechanism which is provided in the communication passage and which controls pressure in the interior space.
2 . The rotary compressor according to claim 1 , wherein an on-off valve is used as the control mechanism.
3 . The rotary compressor according to claim 1 , further comprises, as the control mechanism, a three-way valve and a high pressure path for supplying pressure which is equal to that of compressed working fluid, wherein, the three-way valve connects one of the suction path and the high pressure path to the interior space.
4 . The rotary compressor according to claim 1 , wherein the first check valve and the second check valve are configured in a direction of an end surface of the piston.
5 . The rotary compressor according to claim 1 , wherein a cross-sectional area of the second passage is greater than that of the first passage.
6 . The rotary compressor according to claim 1 , wherein the first check valve and the second check valve are composed of reed valves.
7 . The rotary compressor according to claim 1 , wherein the second check valve is composed of a plunger and a plunger spring.
8 . The rotary compressor according to claim 1 , wherein if the cylinder is defined as a first cylinder and the piston is defined as a first piston and the vane is defined as a first vane and the operation chamber is defined as a first operation chamber and the compression mechanism is defined as a first compression mechanism,
the rotary compressor includes a second cylinder, a second piston, a second vane and a second operation chamber, and the rotary compressor further comprises a second compression mechanism in which the second piston is moved by the motor which is common with the first compression mechanism, and
the interior space defines the interior of the hermetic container, the first operation chamber and the second operation chamber.
9 . The rotary compressor according to claim 8 , wherein the first operation chamber is located in a vertical direction with respect to the second operation chamber.
10 . The rotary compressor according to claim 1 , further comprising an inverter which drives the motor with an arbitrary number of rotations, and a control unit which controls the inverter.
11 . The rotary compressor according to claim 1 , wherein refrigerant as the working fluid is high density refrigerant such as R410A, carbon dioxide, R32, R407C, HFO-1234yf and R134a.