JPH018701Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement in a device for attaching a rotor of an electric motor that drives a compression element to a crankshaft. Fig. 1 is a partial sectional view of a conventional semi-hermetic compressor, where 1 is a partition wall of the crankcase body that divides it into a compression element chamber A that houses a compression element and an electric element chamber B that houses an electric motor, which will be described later. . 2 shows the main bearing metal press-fitted into the bulkhead 1 of the crankcase body. 3 is a crankshaft supported by the main bearing metal 2; 3a is the main bearing part of the crankshaft 3;
Similarly, 3c is a circumferential groove for attaching a shaft retaining ring 4, and is provided between the main bearing part 3a and the rotor insertion part 3b. 3d indicates a thrust receiving portion, and 5 indicates a thrust receiving metal fixed to the partition wall 1 of the crankcase body with a spring pin 6. Reference numeral 7 designates the rotor of the electric motor that is attached to the stator (not shown) fixed to the wall of the electric element chamber B, and the bolt 9 that is attached to the end face of the crankshaft 3 on the rotor insertion side via the rotary retainer 8. By tightening, one end surface of the rotor 7 is pressed, and the other end surface contacts the shaft retaining ring 4, so that the rotor 7 is attached to the crankshaft 3. 10 is a key provided between the crankshaft 3 and the rotor 7. Conventionally, in this type of compressor, as shown in Fig. 2 (partially enlarged view of the retaining ring for the shaft), the rotor 7 and the shaft retaining ring are When the retaining ring 4 was pressed, the corner 30c of the circumferential groove 3c on the side opposite to the rotor insertion side was plastically deformed and became larger than the outer diameter of the main bearing part 3a. When the crankshaft 3 is removed from the compression element chamber A side, the inner surface of the main bearing metal 2 is damaged, which causes a metal burnout accident when the crankshaft 3 is reassembled. Furthermore, conventionally, the main bearing part 3a and the thrust bearing part 3d of the crankshaft 3 are polished at the same time in order to shorten the machining time, but since the length of the main bearing part 3a differs depending on the size of the compressor capacity. The length of each polishing whetstone is different, and during polishing, it is necessary to replace the whetstone with a grindstone that corresponds to the length of the main bearing portion 3a. As a result, it took a long time to prepare before processing, resulting in a compressor that was expensive to manufacture. This invention eliminates the above-mentioned drawbacks by providing a relief part in the vicinity of the circumferential groove for inserting the retaining ring, which serves as a fixing tool for the rotor, that is smaller than the shaft diameter of the main bearing part and the rotor insertion part. This is what I am trying to do. An embodiment of this invention will be described below with reference to FIG. 3 (enlarged view of the retaining ring for the shaft). That is, as shown in the same figure, the shaft diameter of the crankshaft 3 including the circumferential groove 3c is determined by the main bearing portion 3.
a and a relief portion 11 formed smaller than the shaft diameter of the rotor insertion portion 3b of the motor. Due to the existence of this relief part, even if plastic deformation occurs at the corner 30c of the circumferential groove 3c when the rotor 7 is assembled, this will be absorbed by the relief part 11 and the outer diameter will be increased from the main bearing part 3a. Almost nothing stands out. Therefore, the inner surface of the main bearing metal 2 is not damaged when the crankshaft 3 is removed, and it is possible to prevent metal burnout of the compressor during reassembly. Furthermore, when simultaneously polishing the main bearing part 3a and the thrust bearing part 3d, the crank with the longest main bearing part 3a does not have to be replaced with a grindstone according to the length of the main bearing part 3a before polishing as in the conventional case. If you prepare one grindstone for polishing the shaft 3, the main bearing part 3
If the length a is shorter than that, the main bearing part 3
Even if the grindstone protrudes beyond the point a, the relief part 11 absorbs it, so that the rotor insertion part 3b of the electric motor will not be scraped.

As described above, according to the configuration of this invention, a relief part is provided in which the diameter of the shaft in the vicinity of the groove including the insertion groove for the retaining ring, which is a fixing tool for the rotor, is smaller than the shaft diameter of the main bearing part and the rotor insertion part. Therefore, it is possible to avoid the diameter expansion of the shaft due to the plastic deformation of the corners of the circumferential groove mentioned above, eliminate the risk of metal burnout of the main bearing part when reassembling the compressor, and reduce the polishing work time mentioned above. This has the effect of shortening the time.

[Brief explanation of the drawing]

Figure 1 is a partial sectional view of a conventional semi-hermetic compressor.
FIG. 2 is a partially enlarged view of a conventional retaining ring for a shaft, and FIG. 3 is a partially enlarged view of a retaining ring for a shaft that is an embodiment of this invention. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. In the figure, 1 is the bulkhead of the crankcase body, 2
is the main bearing metal, 3 is the crankshaft, 3a is the main bearing part, 3b is the rotor insertion part, 3c is the circumferential groove, 4
7 is a retaining ring for the shaft, 7 is a motor rotor, and 9 is a bolt.

Claims (1)

[Scope of utility model registration request] The shaft diameters of the main bearing part 3a of the crankshaft 3 supported by the main bearing of the crankcase and the rotor insertion part 3b of the electric motor are formed to be the same diameter, and there is a space between the main bearing part 3a and the rotor insertion part 3b. One end surface of the rotor 7 is pressed against the retaining ring 4 fitted in the provided circumferential groove 3c by tightening a bolt 9 screwed into the end surface of the rotor insertion portion of the crankshaft; In the case where the rotor 7 is fixed to the rotor insertion portion 3b of the crankshaft by abutting the other end surface, the shaft diameter in the vicinity of the circumferential groove including the circumferential groove is adjusted between the main bearing portion and A refrigerant compressor characterized in that a relief part 11 is provided with a diameter smaller than the shaft diameter of a rotor insertion part.