Rotary compressor

• US 10,436,199 B2
• Filed: 12/15/2016
• Issued: 10/08/2019
• Est. Priority Date: 12/21/2015
• Status: Active Grant

• Current Assignee: Fujitsu General Company Limited (Fujifilm Holdings Corporation)
• Original Assignee: Fujitsu General Company Limited (Fujifilm Holdings Corporation)
• Inventors: Morishita, Taku, Morozumi, Naoya
• Primary Examiner(s): Wan, Deming
• Application Number:
  US15/380,325
• Publication Number:
  US 20170175742A1
• Time in Patent Office: 1,027 Days
• Field of Search: 418 11, 418 13, 418 60, 418 63, 418 96, 418 94
• CPC Class Codes: F04C 18/3564 the surfaces of the inner and outer member, forming the working space, being surfaces of revolution
• CPC Class Codes: F04C 2240/20 Rotors
• CPC Class Codes: F04C 2240/30 Casings or housings
• CPC Class Codes: F04C 2240/60 Shafts
• CPC Class Codes: F04C 23/001 of similar working principle
• CPC Class Codes: F04C 23/008 Hermetic pumps
• CPC Class Codes: F04C 27/001 Radial sealings for working fluid
• CPC Class Codes: F04C 29/025 using a lubricant pump
• CPC Class Codes: F04C 29/065 Noise dampening volumes, e.g. muffler chambers
• CPC Class Codes: F04C 29/12 Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet
• CPC Class Codes: F04C 29/124 with inlet and outlet valves specially adapted for rotary or oscillating piston pumps

Abstract

In a rotary compressor, a protruding portion which protrudes downward from a bottom end of a rotation shaft and in which an outer diameter is smaller than an outer diameter of a sub-bearing unit is formed on the sub-bearing unit which is provided on a lower end plate, a step portion is formed between the protruding portion and the sub-bearing unit, and a center hole of a lower end plate cover is caused to mate with the protruding portion and is caused to come into close contact with the step portion.

Claims

1. A rotary compressor comprising:

a sealed vertically-placed cylindrical compressor housing in which a discharge pipe which discharges a refrigerant is provided on a top portion and an upper inlet pipe and a lower inlet pipe which suck in the refrigerant are provided on bottom portions of side surfaces;

an accumulator which is fixed to a side portion of the compressor housing and which is connected to the upper inlet pipe and the lower inlet pipe;

a motor which is disposed inside the compressor housing; and

a compressing unit which is disposed beneath the motor inside the compressor housing, is driven by the motor, sucks in the refrigerant from the accumulator via the upper inlet pipe and the lower inlet pipe, compresses the refrigerant, and discharges the refrigerant from the discharge pipe,

wherein the compressing unit includes

an upper cylinder and a lower cylinder which are formed in ring shapes;

an upper end plate which blocks a top side of the upper cylinder and a lower end plate which blocks a bottom side of the lower cylinder;

an intermediate partition plate which is disposed between the upper cylinder and the lower cylinder and blocks a bottom side of the upper cylinder and a top side of the lower cylinder;

a rotation shaft which includes, in an inner portion thereof, an oil feeding vertical hole into which an oil feeding impeller is press-fitted and an oil feeding horizontal hole which communicates with the oil feeding vertical hole, whose main shaft unit is supported by a main bearing unit provided on the upper end plate, whose sub-shaft unit is supported by a sub-bearing unit provided on the lower end plate, and which is driven by the motor;

an upper eccentric portion and a lower eccentric portion which are provided on the rotation shaft with a mutual phase difference of 180′

;

an upper piston which mates with the upper eccentric portion, revolves along an inner circumferential surface of the upper cylinder, and forms an upper cylinder chamber inside the upper cylinder;

a lower piston which mates with the lower eccentric portion, revolves along an inner circumferential surface of the lower cylinder, and forms a lower cylinder chamber inside the lower cylinder;

an upper vane which protrudes into the upper cylinder chamber from an upper vane groove which is provided in the upper cylinder, comes into contact with the upper piston, and partitions the upper cylinder chamber into an upper inlet chamber and an upper compression chamber;

a lower vane which protrudes into the lower cylinder chamber from a lower vane groove which is provided in the lower cylinder, comes into contact with the lower piston, and partitions the lower cylinder chamber into a lower inlet chamber and a lower compression chamber;

an upper end plate cover which covers the upper end plate to form an upper end plate cover chamber between the upper end plate cover and the upper end plate, and includes an upper end plate cover discharge hole which communicates with the upper end plate cover chamber and an inner portion of the compressor housing;

a lower end plate cover which covers the lower end plate and forms a lower end plate cover chamber between the lower end plate cover and the lower end plate;

an upper discharge hole which is provided in the upper end plate and which communicates with the upper compression chamber and the upper end plate cover chamber;

a lower discharge hole which is provided in the lower end plate and which communicates with the lower compression chamber and the lower end plate cover chamber;

a refrigerant path hole which penetrates the lower end plate, the lower cylinder, the intermediate partition plate, the upper end plate, and the upper cylinder, and communicates with the lower end plate cover chamber and the upper end plate cover chamber; and

a reed valve type upper discharge valve which opens and closes the upper discharge hole, and a reed valve type lower discharge valve which opens and closes the lower discharge hole,

wherein a protruding portion which protrudes downward from a bottom end of the rotation shaft and in which an outer diameter D2 of the protruding portion is smaller than an outer diameter D1 of the sub-bearing unit, is formed on the sub-bearing unit which is provided on the lower end plate and a step portion includes a lower surface and is formed between the protruding portion and the sub-bearing unit, and

wherein the lower end plate cover has a center hole that extends through a thickness of the lower end plate cover, the center hole defined by a peripheral portion of the lower end plate cover that extends along only the lower surface of the step portion, wherein the center hole of the lower end plate cover is caused to mate with the protruding portion, such that an entire inner circumferential surface of the center hole along the entire thickness of the lower end plate cover is in face-to-face contact with an outer circumferential surface of the protruding portion and an upper surface of the peripheral portion of the lower end plate cover is in face-to-face contact with an entirety of the lower surface of the step portion, and the protruding portion protrudes downward beyond a lower surface of the peripheral portion of the lower end plate cover, such that a lower surface of the protruding portion is lower than the lower surface of the peripheral portion of the lower end plate cover.

2. The rotary compressor according to claim 1, wherein an outer diameter of the sub-shaft unit of the rotation shaft, is smaller than an outer diameter of the main shaft unit.

3. The rotary compressor according to claim 1, wherein the lower surface of the protruding portion is lower than the lower surface of the peripheral portion of the lower end plate cover by an amount that is larger than or equal to the thickness of the lower end plate cover.

4. The rotary compressor according to claim 1, wherein an opening at a bottom end of the oil feeding vertical hole of the rotation shaft is open inside the sub-bearing unit.