JP2012002091A - Rotary compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary compressor that can avoid burning of an inner periphery of a sub bearing and a shaft without reducing a sliding area between an end surface at a compression chamber side of the sub bearing and a piston or a shaft.SOLUTION: There is provided the rotary compressor that can avoid burning of the sub bearing by elastic deformation of a shaft by forming a groove 15 of the shaft over a fixed angle range at less than 360° in a circumferential direction near an angle position where a bearing load becomes maximum while the shaft rotates once between a sliding surface between the shaft and the inner periphery of the sub bearing, and a hole arranged in the shaft center axis direction.

Description

  The present invention relates to a rotary compressor provided in an outdoor unit or the like of an air conditioner.

  Generally, a rotary compressor is known as a compressor used for an air conditioner, a refrigerator, or the like. The rotary compressor includes an electric motor part and a compression mechanism part connected to the electric motor part in a hermetic container, and the compression mechanism part includes a cylindrical cylinder, a main bearing and a sub-bearing that form compression chambers at both end surfaces of the cylinder. It comprises a bearing, a piston that revolves in the compression chamber, and a shaft that is coupled to the electric motor that revolves the piston, and a ring-shaped groove is formed on the end surfaces of the main bearing and the sub-bearing on the compression chamber side. Has been. As a result, shaft seizure is avoided by elastic deformation of the inner circumference of the bearing (see, for example, Patent Document 1).

Japanese Utility Model Publication No. 01-036692

  However, by forming a ring-shaped groove on the end surface of the secondary bearing on the compression chamber side, the sliding area with the piston or shaft decreases, resulting in increased surface pressure and abnormal wear on the end surface of the secondary bearing on the compression chamber side. There is a problem that is likely to occur.

  The present invention solves the above-mentioned conventional problem, and avoids seizure between the inner circumference of the auxiliary bearing and the shaft without reducing the sliding area between the piston and the shaft on the end surface of the auxiliary bearing on the compression chamber side. Objective.

  In order to solve the above-mentioned conventional problems, the rotary compressor of the present invention has a circumferential direction in the vicinity of an angular position where the bearing load between the sliding surface of the shaft and the inner bearing of the shaft and the shaft center hole becomes the largest. Are provided with grooves or holes distributed at less than 360 degrees.

  As a result, seizure between the inner circumference of the auxiliary bearing and the shaft can be avoided by elastic deformation of the shaft without reducing the sliding area with the piston or the shaft on the end surface of the auxiliary bearing on the compression chamber side.

  As described above, according to the present invention, it is possible to avoid seizure between the inner circumference of the auxiliary bearing and the shaft without reducing the sliding area between the piston and the shaft on the end surface of the auxiliary bearing on the compression chamber side in the rotary compressor. it can.

Schematic of the compressor in Embodiment 1 of the present invention Sectional drawing of the shaft in Embodiment 1 of this invention Sectional drawing of the shaft in Embodiment 2 of this invention Sectional drawing of the shaft in Embodiment 3 of this invention

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The rotary compressor in the embodiment of the present invention will be described by taking a two-stage rotary compressor as an example. However, the rotary compressor is not limited to this, and a single-stage rotary compressor or a multistage compressor having three or more stages may be used. Needless to say, the present invention is not limited to this embodiment.

(Embodiment 1)
FIG. 1 shows a schematic diagram of a compressor according to Embodiment 1 of the present invention.

  FIG. 1 is a cross-sectional view of a rotary compressor according to the present invention. In FIG. 1, an electric motor part and a compression mechanism part are accommodated in the sealed container 1 below. The electric motor unit includes a stator 14 and a rotor 13. The compression mechanism is composed of two cylindrical upper cylinders 5 and lower cylinders 7 and upper partition cylinders 6, intermediate partition plates 6 partitioning the lower cylinders 7, and both end surfaces of the cylindrical upper cylinders 5 and lower cylinders 7. It comprises a main bearing 4 and a sub-bearing 8 constituting a compression chamber, a piston 10 revolving within the compression chamber, and a shaft 9 coupled to the electric motor that gives the piston 10 a revolving motion.

  FIG. 2 shows a cross-sectional view of the shaft according to the first embodiment of the present invention. Within a certain angular range of less than 360 degrees in the circumferential direction near the angular position where the bearing load becomes maximum during one rotation of the shaft between the sliding surface of the shaft and the inner periphery of the sub-bearing and the shaft center hole. A shaft groove 15 is provided, and the shaft is elastically deformed by the groove.

  As described above, in the present embodiment, by forming a groove in a certain angle range of less than 360 degrees in the circumferential direction between the sliding surface of the shaft and the inner periphery of the auxiliary bearing and the shaft center hole, Seizure with the inner periphery of the auxiliary bearing can be avoided by elastic deformation of the shaft. Further, since no groove is formed on the end surface of the auxiliary bearing on the compression chamber side, the sliding area with the piston or the shaft is not reduced, and abnormal wear can be avoided.

(Embodiment 2)
FIG. 3 shows a cross-sectional view of the shaft according to the second embodiment of the present invention. Thus, by providing the circular hole 16 of the shaft near the angular position where the bearing load is maximum during one rotation of the shaft between the sliding surface of the shaft and the inner periphery of the auxiliary bearing and the center hole of the shaft, Seizure with the inner periphery of the auxiliary bearing can be avoided by elastic deformation of the shaft.

(Embodiment 3)
FIG. 4 shows a cross-sectional view of the shaft according to the third embodiment of the present invention. Thus, by providing the polygonal hole 17 of the shaft near the angular position where the bearing load becomes maximum during one rotation of the shaft between the sliding surface of the shaft and the inner periphery of the auxiliary bearing and the center hole of the shaft. The seizure with the inner circumference of the auxiliary bearing can be avoided by the elastic deformation of the shaft.

  As described above, the rotary compressor according to the present invention can avoid seizure between the inner circumference of the auxiliary bearing and the shaft without reducing the sliding area between the piston and the shaft on the end surface of the auxiliary bearing on the compression chamber side. Therefore, in addition to fields such as air-conditioning equipment and refrigerators, it can also be applied to heat pump application equipment such as dehumidifiers and water heaters.

DESCRIPTION OF SYMBOLS 1 Airtight container 4 Main bearing 5 Upper cylinder 6 Intermediate partition plate 7 Lower cylinder 8 Sub bearing 9 Shaft 10 Piston 13 Rotor 14 Stator 15 Shaft groove 16 Shaft circular hole 17 Shaft polygonal hole

Claims (4)

An airtight container is provided with an electric motor part and a compression mechanism part connected to the electric motor part. The compression mechanism part includes a cylindrical cylinder, a main bearing and a sub-bearing constituting compression chambers on both end surfaces of the cylinder, and the compression A rotary compressor having, as constituent elements, a piston that revolves in a room and a shaft that is coupled to the electric motor that imparts a revolving motion to the piston, wherein the shaft has a sliding surface with an inner periphery of a secondary bearing and a shaft center hole Rotary compressor with a circumferential groove in between. The rotary compressor according to claim 1, wherein a hole having a constant depth is provided instead of a circumferential groove between a sliding surface of the shaft with respect to the inner periphery of the auxiliary bearing and a center hole of the shaft. The rotary compressor according to claim 2, wherein the shaft has a circular hole. The rotary compressor according to claim 2, wherein the hole of the shaft has a polygonal shape.