JPS63297777A - Enclosed motor-driven compressor - Google Patents

Abstract

PURPOSE:To reduce improper air gap by providing plural through holes which are scattered nearly on the same circle centering around the axis of a cylindrical hole of a stator core, in the vicinity of a bolt inserting hole on each corner part of the stator core for housing a rotor. CONSTITUTION:A cylindrical hole 14, bolt inserting holes 15, and slots 16 for housing a winding are formed on a stator core 12 for housing the rotor of a compressor. And, plural through holes 1 which are scattered nearly on the same circle centering around the axis of the cylindrical hole 14 are provided inside each bolt inserting hole 15 on the corner parts of the stator core 12. Thereby, improper air gap at the time fastening a bolt or at the time of conveying a compressor can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a hermetic electric compressor, and particularly to a hermetic electric compressor in which a frame body and a stator core are fastened and fixed with bolts.

(b) Conventional technology Conventionally, this type of hermetic electric compressor was disclosed in Japanese Patent Application Laid-Open No. 58-159
As described in Publication No. 644, etc., a frame body having mounting legs and a stator core having a cylindrical hole for housing the rotor are connected through bolt insertion holes drilled in the corners of the core. The mounting leg is secured by tightening with a bolt that is screwed into the bolt hole of the mounting leg.

(C) Problems to be Solved by the Invention However, since the above-mentioned structure is such that the frame body and the stator core are connected with bolts, there may be problems when the flatness of the joint surface of the mounting leg or the end surface of the stator core is not precisely achieved. The problem is that when tightening bolts, tightening stress acts unevenly on the frame and core, leading to a defective core gap in the motor and increased distortion in the inner diameter of the frame's bearing, resulting in failure to start the compressor and increased input power. was there. Additionally, since the frame and stator core are connected only by tightening bolts as mentioned above, if the frame or stator core collides with the sealed case during transport of the compressor, the frame or the core is likely to shift laterally. However, there is a problem in that it promotes air gap defects in the electric motor.

The present invention has been developed in view of these points, and does not require high precision in machining the joint surfaces of mounting legs, etc., and reduces air gap failures during bolt tightening, compressor transportation, etc. It is an object of the present invention to provide a hermetic electric compressor that promotes the cooling effect of an electric motor and has good starting characteristics and a good coefficient of performance.

(d) Means for Solving the Problems The present invention provides a frame body having mounting legs, a stator core having a cylindrical hole for storing the rotor inside, and bolt insertion holes drilled in the corners of the core. In the case where the stator core is tightened and fixed by bolts that are screwed into the bolt holes of the mounting leg through A plurality of through holes are provided, which are scattered on approximately the same circle.

(*) Effect The hermetic electric compressor of the present invention has the above-mentioned configuration, which uses a plurality of through holes to reduce the uneven tightening stress that occurs when bolts are tightened due to poor flatness at the joint surfaces of the mounting legs and stator core. It is possible to equalize the tightening stress applied to the frame and stator core, reduce deformation of the frame and the core, and maintain an appropriate air gap dimension of the electric motor. In addition, the airtight case and frame during transportation of the compressor, etc.
Alternatively, the stress caused by the collision between the sealed case and the core can be absorbed by the plurality of through holes, and the lateral displacement between the frame and the stator core can be reduced to ensure the air gap size. Furthermore, since the stator core is provided with the plurality of through holes mentioned above, the oil that scatters from the upper end of the rotating shaft and falls on the stator core can be returned to the bottom of the sealed case through the through holes, which improves the cooling effect of the electric motor. It can promote

(f) Example Embodiments of the present invention will be described below based on the drawings.

1 has a compressor section 3 attached to the upper part of a frame body 2 and an electric motor section 4 attached to the lower part thereof, and connects the inner parts 3 and 4 with a rotating shaft 5 to form a compressor main body 6, and this main body is enclosed in a sealed case. This is a hermetic electric compressor housed in a 7. The frame body 2 integrally forms a bearing portion 8 for a rotating shaft 5 and a mounting leg 11 having a bolt hole 10 for a bolt 9, which will be described later. 12 is a stator core that constitutes the electric motor section 4, and this core includes:
A cylindrical hole 14 for storing the rotor 13, a bolt insertion hole 15, and a slot 16 for storing the winding wire are formed. 17
are a plurality of through holes scattered on the inside of the bolt insertion holes 15 at three corners of the stator core 12 on substantially the same circle around the axis of the cylindrical hole 14 of the core. The frame body 2 and the stator core 12 are fastened and fixed by bolts 9 which are threaded into bolt holes 1° of the mounting legs 11 through bolt insertion holes 15 of the core.

In the hermetic electric compressor configured in this way, since the plurality of through holes 15 described above are formed in the stator core 12, the flatness of the joint surfaces of the mounting legs 11 and the joint surfaces of the stator core 12 may be slightly different. Even if there is no screw, the through holes 15 can alleviate the uneven tightening stress that occurs when bolts are tightened, equalize the tightening stress applied to the frame 2 and stator core 12, and reduce deformation of the frame and core. However, the air gap size of the electric motor section 4 can be maintained appropriately. Here, since the through hole 15 is formed at the corner of the core 12, it does not deteriorate the characteristics of the electric motor.
In addition, when transporting the compressor, etc., the airtight case 7 and frame body 2
Alternatively, when the sealed case 7 and the stator core 12 collide, the stress at the time of the collision can be absorbed by the through hole 15, and the lateral displacement between the frame body 2 and the stator core 12 is reduced to ensure the air gap size. be able to.

Furthermore, since the stator core 12 is provided with the plurality of through holes 15 described above, the heat dissipation area of the core can be increased, and the heat dissipated from the upper end of the rotating shaft 5 can be scattered from the stator core 12.
The oil that falls on the motor can pass through the through hole and be returned to the bottom of the sealed case 7 while cooling the core, thereby promoting the cooling effect of the motor.

(G) Effects of the Invention As described above, according to the present invention, the characteristics of the electric motor are not significantly deteriorated, and the joint surfaces of the mounting legs do not require high precision in machining, and the bolt tightening and compressor It is possible to provide a hermetic electric compressor that can reduce air gap defects during transportation etc., promote the cooling effect of the electric motor, and have good starting characteristics and coefficient of performance.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a hermetic electric compressor showing an embodiment of the present invention, and FIG. 2 is a plan view of a stake core. 2... Frame body, 9... Bolt, 10... Bolt hole, 11... Mounting leg, 12... Stator core, 14... Cylindrical hole, 15... Bolt insertion hole, 17. ...Through hole.

Claims (1)

[Claims] (1) A frame body having mounting legs and a stator core having a cylindrical hole for storing the rotor inside are screwed into the bolt holes of the mounting legs through bolt insertion holes drilled in the corner corners of the core. In the case where the stator core is tightened and fixed by bolts that fit together, a plurality of holes are scattered on the same circle around the axis of the cylindrical hole of the stator core near the bolt insertion holes at each corner of the stator core. A hermetic electric compressor characterized by having through holes.