Patent ID: 8430656

Claim:
A 2 stage rotary compressor, comprising: a hermetic container; a rotation shaft provided in the hermetic container to transfer a rotation force; a low pressure compression assembly including a low pressure cylinder, a low pressure eccentric portion fixed to the rotation shaft and rotated together with the rotation shaft, a low pressure roller rotatably installed on the outside of the low pressure eccentric portion wherein the low pressure roller is rolled and rotated along an inner wall of the low pressure cylinder due to rotation of the rotation shaft and the low pressure eccentric portion, and a low pressure vane for partitioning off an inner space of the low pressure cylinder; a high pressure compression assembly including a high pressure cylinder, a high pressure eccentric portion fixed to the rotation shaft and rotated together with the rotation shaft, a high pressure roller rotatably installed on the outside of the high pressure eccentric portion wherein the high pressure roller is rolled and rotated along an inner wall of the high pressure cylinder due to rotation of the rotation shaft and the high pressure eccentric portion, and a high pressure vane for partitioning off an inner space of the high pressure cylinder; a middle plate for separating the low pressure cylinder from the high pressure cylinder; and a middle pressure communication hole formed in the middle plate so that refrigerant can flow from the low pressure cylinder to the high pressure cylinder, wherein the low pressure cylinder and the high pressure cylinder further comprise a middle pressure communication hole and a middle pressure inflow groove communicating with the middle pressure communication hole of the middle plate, respectively, and the middle pressure communication hole of the low pressure cylinder and the middle pressure inflow groove of the high pressure cylinder are formed in different positions in an axial direction of the compressor.