Hermetic compressor and refrigerator

• US 10,352,312 B2
• Filed: 01/20/2014
• Issued: 07/16/2019
• Est. Priority Date: 01/22/2013
• Status: Active Grant

• Current Assignee: Panasonic Appliances Refrigeration Devices Singapore (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Appliances Refrigeration Devices Singapore (Panasonic Holdings Corporation)
• Inventors: Inagaki, Ko, Kobayashi, Masanori, Haraki, Yu, Ishida, Yoshinori
• Primary Examiner(s): Bertheaud, Peter J
• Application Number:
  US14/655,663
• Publication Number:
  US 20150354552A1
• Time in Patent Office: 2,003 Days
• Field of Search: 417415, 92179
• CPC Class Codes: F04B 35/04 the means being electric
• CPC Class Codes: F04B 39/0005 adaptations of pistons
• CPC Class Codes: F04B 39/0022 piston rods
• CPC Class Codes: F04B 39/023 Hermetic compressors
• CPC Class Codes: F04B 39/0238 with oil distribution channels
• CPC Class Codes: F04B 39/0246 in the rotating shaft
• CPC Class Codes: F04B 53/14 Pistons, piston-rods or piston-rod connections
• CPC Class Codes: F16J 1/08 Constructional features providing for lubrication
• CPC Class Codes: F25B 1/02 with compressor of reciprocating-piston type F25B1/005, F25B1/10 take precedence
• CPC Class Codes: F25B 2500/13 Vibrations
• CPC Class Codes: F25B 2600/021 Inverters therefor
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

A hermetic compressor (100) includes an electric element (110), a compression element (112), and a hermetic container (102). The compression element includes a shaft (118), a cylinder block (124), a piston (136), a connection section (144), and an oil supply mechanism (130). The piston has a columnar seal section (160) in sliding contact with an inner peripheral face of the cylinder, two extension sections (162) that have circular arc faces each having the same radius as a radius of the seal section and extend from the seal section to the bottom dead center side in the axial direction with a circumferential gap therebetween, and a columnar capture section (164) that extends further toward the bottom dead center side than the extension section and has a smaller radius than the radius of the seal section.

Claims

1. A hermetic compressor comprising:

an electric element including a stator and a rotor that rotates relative to the stator;

a compression element driven by the electric element; and

a hermetic container that stores the electric element and the compression element, and accommodates lubricating oil, wherein

the compression element includes;

a shaft including a principal shaft to which the rotor is fixed and an eccentric shaft that is eccentric with respect to the principal shaft;

a cylinder block including a bearing that rotatably supports the principal shaft and a cylinder having an inner space;

a piston that reciprocates in the inner space; and

a connection section that couples the piston to the eccentric shaft, and the piston includes;

a seal section in sliding contact with an inner peripheral face of the cylinder;

two extension sections that have respective circular arc faces having the same radius as a radius of the seal section, are spaced in the circumferential direction, and extend from the seal section toward a crank shaft side in the axial direction; and

a capture section that further extends toward the crank shaft side than the extension sections, the capture section including a portion formed around the entire circumference of the piston and having a radius that is smaller than the radius of the seal section.

2. The hermetic compressor according to claim 1, wherein

when the piston is located at a bottom dead center, at least a part of the capture section is exposed outside of the cylinder.

3. The hermetic compressor according to claim 1, wherein

an axial length of each respective extension section of the two extension sections is within a range of one third to three times of a circumferential width of the respective extension section.

4. The hermetic compressor according to claim 3, wherein

a length of each respective extension section of the two extension sections is equal to the width of the respective extension section.

5. The hermetic compressor according to claim 1, further comprising a pin that connects the connection section to the piston, wherein

a length of each respective extension section of the two extension sections is within a range of one half to three over two of a diameter of the pin.

6. The hermetic compressor according to claim 1, wherein

a length of each respective extension section of the two extension sections is larger than a length of the seal section, and

a central angle of a circular arc of each respective extension section of the two extension sections is within a range of 40 degrees to 90 degrees.

7. The hermetic compressor according to claim 1, wherein

a direction in which the piston is pushed toward the inner peripheral face of the cylinder by the connection section when the piston moves toward a top dead center is a load side, and a direction opposite to the load side is a non-load side,

a width of one extension section of the two extension sections, which is located on the load side, is 1.2 times as much as a width of the other extension section located on the non-load side.

8. The hermetic compressor according to claim 1, wherein

the piston further includes a lubricating oil lead-in section formed as an inclined face between each respective extension section of the two extension sections and the capture section.

9. The hermetic compressor according to claim 1, wherein

a corner that connects a circumferential edge of each respective extension section of the two extension sections to an edge on the crank shaft side of the seal section is a rounded section curved like a circular arc.

10. The hermetic compressor according to claim 9, wherein

a radius of the rounded section is within a range of 25% to 50% of a width of each respective extension section of the two extension sections.

11. The hermetic compressor according to claim 1, wherein

the seal section is provided with an annular groove.

12. The hermetic compressor according to claim 1, wherein

the piston is subjected to a surface treatment with a synthetic resin.

13. The hermetic compressor according to claim 1, wherein

an axial length of a portion of the inner peripheral face of the cylinder, which is opposed to a respective extension section of the two extension sections, is larger than a remaining portion of the inner peripheral face.

14. The hermetic compressor according to claim 1, wherein

at least a part of the inner peripheral face of the cylinder is tapered such that a radius on the crank shaft side is larger than a radius on a load side.

15. The hermetic compressor according to claim 1, wherein

the electric element is driven by an inverter circuit with a plurality of rotation speeds.

16. A refrigerator comprising the hermetic compressor according to claim 1.