JP2719819B2 - Hermetic electric compressor - Google Patents

Description

The present invention relates to a hermetic electric compressor used for a refrigerator, an air conditioner and the like.

(Prior art)

A conventional hermetic electric compressor will be described with reference to FIGS.

In FIG. 5, reference numeral 11 denotes a sealed case, 12 denotes a compression mechanism such as a scroll mechanism, and 15 denotes an electric motor unit including a stator 16 and a rotor 17. 13 is a compression mechanism 12 and a motor 15
Is fixedly supported on the closed case 11 in an inelastic manner. As shown in FIG. 6, the fixing between the stator 16 and the support frame 13 is performed by using bolts 18 inserted into bolt holes 2 drilled at four peripheral edges of the stator core 1, as shown in FIG. It is screwed and fastened to a screw hole 20 provided in the mounting leg 14 and fixed.

The stator core 1 generally has a shape as shown in FIG. 7, but when a thin iron plate forming the stator core 1 is punched, each of the two in the material width direction and the material feeding direction is used. The cut portions 21 are provided at three places to improve the material yield. Since the magnetic path area is reduced near the cut portion 21 so that there is no room for the space, the bolt holes 2 are drilled near the four arc-shaped outer edge portions 22 where there is relatively room for the space. This stator core 1
The end face of the support frame 13 and the mounting surface of the mounting leg 14 of the support frame body 13 are generally fixed by full contact or two-part contact,
8 and 9 show the contact areas 7a, 7b, 7c of the stator core 1 in the case of full contact and two-part contact, respectively, by hatching.

[Problems to be solved by the invention]

In the hermetic electric compressor having the configuration as shown in FIG. 5, since the support frame 13 and the hermetic case 11 are inelastically fixed, vibration and noise are particularly problematic.
That is, when the stator core 1 is excited by the electromagnetic exciting force, the support frame 13 fixed to the stator core 1 also vibrates at the same time, and this vibration is further transmitted to the sealed case 11 fixed to the support frame 13. And it propagates into the air as noise.

Among the respective modes of the natural frequency that generate the vibration and the noise, the secondary mode, in particular, of the secondary mode, generates a jarring noise because it exists in the audible frequency range, and this is a serious problem. Since the stator core 1 and the support frame 13 fixed by four-point bolting have shapes symmetrical with respect to the second mode, for example, as shown by a broken line in FIG. The arc-shaped outer edge portion of the iron core 1 is defined as abdomen 8a, 8b, 8c, 8d, and the cut portion is defined as nodes 9a, 9b, 9
It is configured to easily generate the secondary mode deformation modes c and 9d, and the vibration and noise generated due to the secondary mode are problematic.

[Means for solving the problem]

According to the present invention, a stator core of an electric motor unit is fixed to a support frame by four-point bolt fastening, and three contact areas and three separate areas are alternately provided between the support frame and the stator core. It is. The three contact areas are adjacent two of the four abdominal portions of the stator core deformation second mode.
One abdomen is provided in the vicinity of each of the abdomen, and one is provided in the vicinity of a node located in the middle of the other two abdomen.

The contact area and the separation area are configured by appropriately setting the shape of the facing surface of the stator core or the support frame, and as a result of setting the shape of the facing surface, in the contact area or the One or several minute separation areas or contact areas may be mixed in the separation area.

[Action]

Rigidity is concentrated in three contact areas between the stator core and the support frame, the symmetry of the vibration with respect to the second mode is broken, and the deformation mode of the second mode is suppressed. As a result, in the audio frequency range, Vibration and noise are reduced.

Embodiment An embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 to 4 show the contact areas between the support frame and the stator cores with the stator cores 1a, 1b, 1c, 1d indicated by oblique lines. In FIG. 1, the stator core 1a has an abdomen 8c in the deformation mode and an abdomen adjacent to the abdomen 8c in the deformation mode, as apparent from comparison with the deformation mode in the secondary mode shown by a broken line in FIG.
Contact areas 4 and 5 are respectively provided in the vicinity of each of 8d, and a node 9 located in the middle of the other two abdominal parts 8a and 8b
A contact area 3 is provided in the vicinity of a. A separation area 6 exists between the contact areas 3, 4, and 5.

As shown in FIG. 1, the contact area 3 preferably has a configuration in which the bolt holes 2 on both sides come into contact with each other up to a substantially central portion as long as the fastening strength by the bolt is maintained. As indicated by reference numeral 3d, there is no problem even if the bolt hole 2 is widened to such an extent as to slightly cover the peripheral edge thereof. Further, the contact areas 3 may be provided in a dispersed manner as shown by reference numerals 3a, 3b, and 3c in FIG. Contact areas 4 and 5
Is located in the portion of the bolt hole 2, the fastening strength of the bolt is maintained without any trouble. As a result, the rigidity is concentrated on these three contact areas 3, 4, and 5, and a beam portion is formed between the abdominal portions 8c and 8d in the secondary mode, thereby suppressing the deformation in the secondary mode.

The stator core 1d shown in FIG. 4 is provided with cutout grooves 10 that open to the outer diameter portion in the bolt holes 2a on both sides of the contact area 3e. The difference between the action due to the contact and the action due to the separation becomes remarkable at the center of the area, and the effect of the present invention is promoted.

In forming the contact area between the support frame and the stator core, the mounting surface such as the mounting legs of the support frame, or the end face of the stator core, or both opposing surfaces are formed by forming irregularities. . Therefore, as a result of the setting of the shape of the facing surface, a minute separation area may be generated in the contact area, or a minute contact area may be generated in the separation area, as shown in FIG. The contact state between the support frame and the stator core was comprehensively viewed so that the area where the contact areas 3a, 3b, 3c existed plays the role of the contact area 3 shown in FIG. In this case, the present invention does not depart from the present invention as long as the rigidity is concentrated in three basic contact areas.

〔The invention's effect〕

FIG. 11 shows the frequency response characteristics of the mutually fixed stator core and the support frame in the audible frequency range. In FIG. 11, a broken line 23 indicates a structure according to the present invention, and a solid line 24 indicates a solid line.
Indicates the conventional configuration. As is apparent from FIG. 11, the inertance with respect to the excitation frequency is reduced by the configuration of the present invention, and the peak value 23p of the inertance at the resonance point of the secondary mode is reduced by 5 to 10 dB as compared with the conventional peak value 24p. I was able to.

As described above, according to the present invention, the rigidity is concentrated on the three contact areas between the stator core and the support frame, so that the deformation mode of the secondary mode of vibration is suppressed, and the four-point bolt having a good yield is obtained. Vibration and noise of the hermetic electric compressor using the tightened stator core can be greatly reduced.

[Brief description of the drawings]

1 to 4 show an embodiment of the present invention, in which a plan view of a stator core for explaining a contact area with a support frame, respectively, and FIGS. 5 to 9 show a conventional example. Fig. 6 is a front sectional view of the hermetic electric compressor, Fig. 6 is a perspective view for explaining the fixing of the stator and the support frame, Fig. 7 is a plan view of the stator core, Figs. FIG. 10 is a plan view of a stator core illustrating a contact area with a support frame, FIG. 10 is a view illustrating a secondary mode of vibration of the stator core, and FIG. 11 is a stator core and a support fixed to each other; It is a frequency response characteristic figure in the audio frequency domain of a frame. 1,1a, 1b, 1c, 1d …… stator core, 2,2a …… bolt hole, 3,3a, 3b, 3c, 3d, 3e, 4,5,7a, 7b, 7c …… abutment area, 6
... Separated area, 8a, 8b, 8c, 8d ... Abdominal part of modified secondary mode, 9a, 9b, 9c, 9d ... Node part of modified secondary mode, 10 ... Notch groove, 11 ... Closed case, 12 ... compression mechanism, 13 ... support frame, 15 ... motor, 19 ... stator coil.

Claims (2)

(57) [Claims] 1. A hermetic electric compressor in which a stator core of a motor section is fixed to a support frame fixed to a closed case by four-point bolting, wherein a gap between the support frame and the stator core is provided. An abutment area and a separation area are provided alternately, and a neighborhood area of each of two adjacent abdominal parts of the four abdominal parts of the deformed secondary mode of the stator core and two other abdominal parts are provided. A hermetic electric compressor, wherein an area in the vicinity of a node located in the middle of the above-mentioned section is defined as the contact area. 2. The hermetic electric compressor according to claim 1, wherein a notch groove that opens to an outer diameter portion is provided in a bolt hole portion of the stator core.