US 4,536,141 AGranted

Rotary vane compressor with suction passage changing in two steps

AssigneeMatsushita Electric Industrial Co., Ltd.

InventorTeruo Maruyama

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Abstract

A rotary compressor which includes a rotor into which vanes are slidably provided, the rotor and vanes being rotatably mounted in a non-circular cylinder having side plates fixed to both sides thereof. The rotor, cylinder, and side plates define sealing spaces at respective ends of which are provided suction bores and discharge bores. Between the blades and also bounded by the rotor, side plates and cylinder are blade chambers which rotate with the rotor and vanes across the suction bores and discharge bores so that the pressure in the blade chambers during a suction stroke of the compressor utilizes a suction loss which is lower than the pressure of a refrigerant supply source to carry out suppression of the refrigerating capacity during high speed rotation of the rotor. The passages of communication from the suction bores to the blade chambers have effective areas which are smaller during the second half of each suction stroke than during the first half thereof, thereby obtaining an effective suppression of refrigerating capacity during high speed rotation of the rotor, while maintaining low torque at low speed and a high volumetric efficiency.

A rotary compressor comprising:

a cylinder having a non-circular inner peripheral surface;
side plates fixed to and closing the axial ends of said cylinder;
a rotor, rotatably mounted in said cylinder, having radially extending, equiangularly spaced slots therein;
and
slidable vanes radially slidably mounted in said slots so as to slidably engage said inner surface when rotated with said rotor in a rotational direction in said cylinder, so as to define sealing spaces between the outer periphery of said rotor, said inner peripheral surface of said cylinder, and said side plates, and blade chambers in said sealing spaces respectively bounded on at least one circumferential side by said vanes so as to rotate and vary in volume as said rotor and vanes rotate in said cylinder, said blade chambers having a predetermined maximum value V.sub.0 during said rotation;
said cylinder having suction bores and discharge bores, including a respective suction port and a respective discharge port opening into each of said sealing spaces through said cylinder adjacent respective opposite circumferential ends thereof, said respective discharge port being located downstream of said respective suction port with respect to the rotational direction of said rotor;
said vanes and said blade chambers rotating across said suction bores and discharge bores as they rotate with said rotor, such that each of said suction bores open into said blade chambers as said blade chambers rotate thereacross, and said suction bores communicate with any one of said blade chambers over a continuous total rotational angle of travel .theta..sub.s of said rotor divided into a first angle of travel .theta..sub.A and a second angle of travel .theta..sub.1, such that over said first angle of travel .theta..sub.A, said suction bore has a first effective suction area a.sub.1 of communication with said blade chamber and, over said second angle of travel .theta..sub.1, said suction bore has a second effective suction area a.sub.2 of communication with said blade chamber, wherein:
a.sub.1 >a.sub.2,
.theta..sub.1 /.theta..sub.s >0.170 and
0.025<K.sub.22 <0.055,
wherein K.sub.22 is defined as a.sub.2 .theta..sub.s /V.sub.0.

8 more elements

Abstract

Claims1