JPH09144679A - Rotary compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the rigidity of a crank shaft and eliminate a noise caused by the contact of a stator with a rotor in starting of a compressor, and enhance the reliability. SOLUTION: In a rotary compressor formed of a sealed vessel 1 for housing an electric motor part and a compressing mechanism part and a crank shaft 4a for connecting the electric motor part to the compressing mechanism part, a hollow part is provided in the shaft center part of the crank shaft 4a made of casting material, and a highly rigid member is fixed to the hollow part by press-in or shrinkage fitting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary compressor that prevents noise generated due to contact between the inner diameter of a stator of an induction motor and the outer diameter of a rotor when the rotary compressor is started.

[0002]

2. Description of the Related Art Generally, a rotary compressor has a structure as described in, for example, Japanese Patent Laid-Open No. 62-67292. The structure and operation of the rotary compressor will be described with reference to FIG. FIG. 5 is a vertical sectional view of a conventional rotary compressor. The rotary compressor shown in FIG. 5 accommodates an induction motor including a rotor 2 and a stator 3 in an upper part of a closed container 1, and is connected to an induction motor in a lower part of the closed container 1 via a crankshaft 4. Contains the compression mechanism. The induction motor and the compression mechanism are connected to each other, and the air gap distance between the rotor 2 and the stator 3 forming the induction motor is arranged in the vicinity of 0.4 mm to 0.6 mm in consideration of the efficiency of the induction motor. The crankshaft 4 is formed by cutting a casting as shown in the crankshaft 4 in FIG.

[0003]

As described above, the conventional crankshaft 4 is a machined casting, and the rotor 2 connected to the crankshaft 4 when the induction motor of the rotary compressor is started.
The amount of deflection of the upper end of the crankshaft 4 in the outer radial direction is increased by the force of pulling the outer radial direction, that is, the magnetic attraction force.
There is a problem that the inner diameter of the stator 3 and the outer shape of the rotor 2 are repeatedly contacted with each other by a distance larger than the gap between the stator 3 and the stator 3, and noise is generated.

In order to solve this problem, if a highly rigid material such as steel is used as the material of the crankshaft 4, there is a problem that the machinability is deteriorated and the mass productivity is deteriorated.

An object of the present invention is to prevent noise generated by contact between the inner diameter of the stator 3 of the induction motor and the outer diameter of the rotor 2 at the time of starting the rotary compressor.

[0006]

In order to achieve the above object, the rotary compressor of the present invention accommodates an induction motor composed of a rotor 2 and a stator 3 in the upper part of a closed container 1 of FIG. An induction motor is provided at the bottom of the closed container 1 and a crankshaft 4 is provided.
It houses the compression mechanism section connected via. The crankshaft 4a of FIG. 4 for connecting the compression mechanism portion and the induction motor portion is provided with a hollow portion 13 at the crankshaft axis as shown in FIG. Separately, the member 12 having a high rigidity is fixed by press fitting or shrink fitting as shown in FIG.

The operation of the above technical means will be described below.

In the present invention, a hollow portion 13 as shown in FIG. 2 is provided at the center of the crankshaft of the crankshaft body, and the hollow portion 13 is provided.
By separately fixing a member 12 made of a material having high rigidity as shown in FIG. 3 by press fitting or shrink fitting as shown in FIG. 4, the rigidity of the crankshaft 4a is increased as shown in FIG. The amount of bending of the upper end of the crankshaft 4a due to the magnetic attraction force is reduced. Therefore, the amount of deflection of the outer diameter of the rotor 2 becomes smaller than the gap distance between the stator 3 and the rotor 2, and the noise generated when the outer diameter of the rotor 2 repeatedly contacts the inner diameter of the stator can be prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will now be described with reference to FIGS.
This will be described with reference to FIGS. 2, 3, 4, 5, and 7. FIG. 1 is a vertical cross-sectional view of a rotary compressor according to an embodiment of the present invention, FIG. 5 is a vertical cross-sectional view of a conventional rotary compressor, and FIG. 2 is a cast crankshaft of the present invention in which a hollow portion 13 is provided. FIG. 3 is a perspective view of a member added to enhance rigidity, and FIG. 4 is a sectional view when the crankshaft 11 of FIG. 2 and the member 12 of FIG. 3 are combined. FIG. 7 is a graph showing a comparison of deflection amounts of the conventional crankshaft and the crankshaft of the present invention. 1, the crankshaft 4a connecting the induction motor housed in the closed container 1 and the compression mechanism portion is a section 16A from the crankshaft upper end 14 to the upper end 5a of the main bearing 5 shown in FIG. As shown in FIG. 2, the hollow portion 13 at the center of the crankshaft 11 has a depth of 16 A or more, and the length of the member 12 in FIG. 5 in the hollow portion 13 is 16 A or more.
By fixing 2 as shown in FIG. 4 by press fitting or shrink fitting, the rigidity of the section 16A of the crankshaft 4a is 17B from the upper end 5a of the main bearing 5 to the lower end 5b of the main bearing 5 in FIG.
The rigidity of the section 16A of the crankshaft 4a is improved with respect to the section 18C from the crankshaft upper end 15 of the crankshaft 4 to the upper end 5a of the main bearing 5 in FIG.
Further, by extending the length of the hollow portion 13 at the center of the crankshaft 11 in FIG. 2 from the crankshaft upper end 14 to the lower end 5b of the main bearing 5 or the lower end 15 of the crankshaft, the range in which the rigidity is improved is sectioned. The rigidity of not only the 16A portion but the entire crankshaft 4a is improved. As shown in the graph of the flexure amount comparison of the crankshaft 4a this time and the flexure amount of the conventional crankshaft in FIG. 7, the set air gap distance between the outer diameter of the rotor 2 and the inner diameter of the stator 3 is 0. 4 mm ~
Even in the vicinity of 0.6 mm, the amount of deflection of the outer diameter of the rotor 2 is smaller than the gap distance between the stator 3 and the rotor 2, and the noise generated when the outer diameter of the rotor 2 repeatedly contacts the inner diameter of the stator 3 is prevented. You can

[0010]

According to the present invention, since the amount of deflection of the upper end of the crankshaft 4a acting at the time of starting the compressor is reduced, the inner diameter of the stator 3 and the outer diameter of the rotor 2 are repeatedly brought into contact with each other. It is possible to provide a highly reliable rotary compressor that can prevent generated noise.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a rotary compressor of the present invention.

FIG. 2 is a sectional view of a crankshaft provided with a cast hollow portion of the present invention.

FIG. 3 is a perspective view of a member added to enhance the rigidity of the present invention.

FIG. 4 is a cross-sectional view of the combination of FIGS. 4 and 5.

FIG. 5 is a vertical cross-sectional view of a rotary compressor having a conventional structure.

FIG. 6 is a sectional view of a crankshaft having a conventional structure.

FIG. 7 is a characteristic diagram for comparing the deflection amounts of a conventional crankshaft and the crankshaft of the present invention.

[Explanation of symbols]

1 ... Airtight container, 2 ... Rotor, 3 ... Stator, 4 ... Crankshaft, 4a ... Crankshaft, 5 ... Main bearing, 5a ... Main bearing upper end, 5b ... Main bearing lower end, 6 ... Cylinder, 7 ... Secondary bearing,
8 ... Vane, 9 ... Spring, 10 ... Roller, 11 ... Cast crankshaft provided with hollow part, 12 ... Additional member, 13 ...
Hollow part, 14 ... crankshaft upper end, 15 ... crankshaft upper end.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukiko Ueoka 800 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Stock Company, Hitachi, Ltd. Cooling & Heat Division (72) Inventor Shin Ishihara 800 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Ceremony company Hitachi Co., Ltd.

Claims (1)

[Claims] 1. In a crankshaft for accommodating an induction motor section and a compression mechanism section connected by a crankshaft in a closed container and rotating the compression mechanism section, an upper deflection amount of the crankshaft causes the induction motor section to move. A rotary compression characterized in that the shaft center of the crankshaft is processed into a hollow shape so that it is smaller than the gap distance between the inner diameter of the stator and the outer diameter of the rotor, and a member having high rigidity is press-fitted into the hollow portion. Machine.