JPH09287585A - Enclosed electric compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a centering hole at the same time of forming a first housing while suppressing deformation of the first housing after shrink-fitting. SOLUTION: A clearance C is formed on a first housing 11 on the side of an opening 11c at a fitting portion between the first housing 11 and a stator 42. A press-fit fixing portion for the first housing 11 and the stator 42 is formed on the first housing 11 on the side of a bottom surface 11b. Force applied from the stator 42 in a radially outer direction of the first housing 11 can be decreased. Widening in a radially outer direction is reduced at the end surface of the first housing 11 on the side of the opening 11c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic electric compressor used as a refrigerant compressor in a refrigeration system, and more particularly to an electric scroll compressor having an electric drive source built therein.

[0002]

2. Description of the Related Art FIG. 9 is a sectional view of a conventional electric scroll compressor. In FIG. 9, reference numeral 1 denotes an aluminum housing that forms a case of an electric scroll compressor. The housing 1 includes a first housing 11, a second housing 12,
It also comprises a third housing 13. And the third,
A fixed scroll portion 21 and an orbiting scroll portion 22 as the compression portion 2 are provided in the second housings 13 and 12, and a main shaft 3 and an electric motor portion 4 for driving the main shaft 3 are provided in the first housing 11. The rotor 41 and the stator 42 made of iron are provided.

The main shaft 3 is rotatably held by a first bearing 5 provided in the second housing 12 and a second bearing 6 provided in the first housing 11. In addition, the first housing 11 and the second housing 12,
The second housing 12 and the third housing 13 are fastened and fixed by bolts (not shown). In addition, the first bearing 5 supporting the main shaft 3 and the second bearing 5
In order to align the center with the bearing 6, the first housing 1
1 and the second housing 12 are centered.

Specifically, the end face 11a of the first housing 11 on the second housing 12 side (opening 11c side) and the end face 1 of the second housing 12 on the first housing 11 side.
The outer peripheral portion of 2a is integrally formed with four protrusions extending outward in the radial direction of these end faces, and these protrusions have four bolt holes through which the bolts pass and a core. There are two outlet holes.

The centering holes are provided at a predetermined distance from the centers of the bearing hole 121 and the bearing hole 114 and on the diagonal line, and pins are inserted in the centering holes. Insert and insert the first and second housings 11,
By assembling 12, the bearing hole 121 is centered.
And the bearing hole 114 are aligned with each other. As a result, the main shaft 3 can smoothly rotate.

[0006]

By the way, as a method of fixing the stator 42 to the first housing 11 constituting the compressor, shrink fitting is generally used. The shrink fitting fixing means that the inner diameter of the first housing 11 is made slightly smaller (about several hundreds of μm) than the outer diameter of the stator 42, and the first housing 11 is heated to a high temperature to heat the first housing 11. The first housing 1 which is expanded and thermally expanded
By fitting the stator 42 at room temperature into the first housing 1, the first housing 11 contracts and the stator 42 is fastened and fixed.

However, in the prior art, since the first housing 11 is made of aluminum and the stator 42 is made of iron, when the stator 42 at room temperature is fitted into the thermally expanded first housing 11, the first housing 11 is Although the portion of the stator 42 into which the stator 42 is fitted can return only to the shape of the stator 42 made of iron, which is more rigid than aluminum, the portion of the first housing 11 into which the stator 42 is not fitted is heated. It tries to return to the shape of the first housing 11 before the expansion.

Then, from the entire outer peripheral surface of the stator 42 to the first
The force is applied to the housing 11, and moreover,
Since the first housing 11 is a tubular member having a bottom surface portion 11b at one end and an opening portion 11c at the other end, the first housing 11 is in a state in which the opening portion 11c side of the first housing 11 is expanded. It will be greatly deformed.
Specifically, the inner diameter of the left side portion of the first housing 11 in FIG. 9 expands by about 60 μm (0.06 mm).
On the other hand, since the second housing 12 does not need to be shrink-fitted and fixed, no deformation occurs. Therefore, if the centering hole is formed in advance and then the shrink fitting is performed, the position of the hole of the second housing 12 and the position of the hole of the first housing 11 are largely displaced.

Therefore, the stator 42 must be shrink-fitted and fixed in the first housing 11 and then the centering hole must be cut. That is, the first housing 11
Since the centering hole cannot be formed at the same time when the core is formed, the stator 42 is fixed in the first housing 11 and then the centering hole is processed. Since it is difficult to handle, the process of forming the electric scroll compressor is complicated and the cost is high.

[0010] The present invention has been made in view of the above points,
It is an object of the present invention to suppress deformation of the first housing after shrink fitting and to form the centering hole at the same time when the first housing is formed.

[0011]

In order to achieve the above object, the present invention employs the following technical means. In the invention described in claims 1 to 5, one end of the shaft member (3) is located at the central portion (114) of the first housing (11) and the other end is located at the central portion (121) of the second housing (12). A hermetically sealed type in which a stator (42) is shrink-fitted and fixed to a cylindrical first housing (11) that is rotatably supported and has a bottom surface portion (11b) at one end and an opening portion (11c) at the other end. In the electric compressor, a gap (C) is provided in a part of the fitting portion between the first housing (11) and the stator (42) in the axial direction so that the first housing (11) and the stator (42). It is characterized in that the axial length of the shrink fitting press-fitting fixing portion (116, 116a, 116b) is shortened.

According to this technical means, at the time of shrink fitting, part of the outer peripheral surface of the stator (42) is crimped to the inner peripheral surface of the first housing (11), so The force applied outward in the radial direction of the one housing (11) is smaller than in the conventional case. Therefore, the outward spread in the radial direction of the end surface (11a) of the first housing (11) on the opening (11c) side is reduced, and the warp of the end surface (11a) of the first housing (11) is also reduced. .

Therefore, at the time of forming the first housing (11), the end surface (11) of the first housing (11) is
Even if the hole (113) for centering is formed at the same time in (a) and then shrink fitting is performed, the positions of the hole (113) of the first housing (11) and the hole of the second housing (12) are not changed. Since the deviation is small, the first housing (11) and the second housing (12) can be reliably centered according to the initial design. Therefore, unlike the conventional case, it is not necessary to form the centering hole (113) after shrink fitting,
The process for forming the hermetic electric compressor is simplified, and the hermetic electric compressor can be formed at low cost.

According to the second aspect of the invention, the gap (C) is the opening (11c) of the first housing (11).
The shrink-fitting press-fitting fixing portion (116) provided on the side is the first
It is characterized in that it is provided on the bottom surface portion (11b) side of the housing (11). Therefore, at the time of shrink fitting, the force applied from the stator (42) outward in the radial direction of the first housing (11) becomes smaller, so that the radial direction at the end face (11a) of the first housing (11) is reduced. The outward spread becomes smaller, and the warp of the end surface (11a) of the first housing (11) becomes smaller. Therefore, the hole (113) of the first housing (11)
With this, the positional deviation from the hole of the second housing (12) can be further reduced, and the centering can be performed more reliably.

Further, in the invention described in claim 4, the gap (C) is provided in a portion of the stator (42) corresponding to the central portion in the axial direction, and the shrink fitting press-fitting fixing portion (116, 1).
16a and 116b) are provided on the one end (42a) side in the axial direction and the other end (42b) side in the axial direction of the stator (42). According to this technical means, by providing the gap (C), the hole (113) of the first housing (11) and the second housing (12) are provided.
The stator (42) while keeping the positional deviation from the hole of the
By press-fitting and fixing both ends (42a, 42b) of the first
It can be more securely fixed in the housing (11).

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention shown in the drawings will be described. (First Embodiment) FIG. 1 is a sectional view of an electric scroll compressor according to the first embodiment. In FIG.
Is a housing that forms the case of the electric scroll compressor,
The housing 1 includes a first housing 11, a second housing 12, and a third housing 13. And the 1st housing 11 and the 2nd housing 12, and the 2nd housing 12 and the 3rd housing 13 are respectively fastened and fixed by the bolt which is not illustrated, and one closed housing 1 is formed as a whole. ing.

The housing 1 is made of an aluminum alloy for the purpose of weight reduction, and is made of a first housing 11
Is a tubular member having a bottom surface portion 11b at one end and an opening portion 11c at the other end. And the second and third housings 1
The fixed scroll portion 2 serving as the compression portion 2 is provided in each of the reference numerals 2 and 13.
1 and the orbiting scroll portion 22 are provided, and in the first housing 11, a main shaft 3, a rotor 41 as an electric motor unit 4 that drives the main shaft 3, and an iron stator 42 are provided.

The first bearing 5 provided in the center of the second housing 12 and the second bearing 6 provided in the center of the first housing 11 serve as a main shaft (shaft member) 3.
Is rotatably held. The first bearing 5 is press-fitted and fixed in a bearing hole 121 formed in the second housing 12, and the second bearing 6 is press-fitted and fixed in a bearing hole 114 formed in the first housing 11. Further, on the inner peripheral surface of the first housing 11, one end 42 a of the stator 42 is
A ring-shaped groove 115 is formed at a position corresponding to the corner of the groove.

By forming the inner diameter of the groove portion 115 larger than the inner diameter of the bottom surface portion 11b side portion of the first housing 11, the shoulder portion on the bottom surface portion 11b side of the groove 115 is formed.
The corner of the one end 42a side of the stator 42 contacts. Further, on the inner peripheral surface of the first housing 11, a portion corresponding to about half of the one end 42a side of the stator 42 is press-fitted and fixed with a press-fitting margin (several hundred μm) so that the stator 42 can be press-fitted and fixed. A fitting press-fitting fixing portion) 116 is formed.

Further, on the inner peripheral surface of the first housing 11, from a position corresponding to a substantially central portion in the axial direction of the stator 42,
A notch 117 is formed to a position corresponding to the end surface 11a on the opening 11c side of the first housing 11 so as to be larger than the outer diameter of the stator 42 by about 0.1 mm. Due to the notch 117, a gap C is formed between the first housing 11 and a portion corresponding to the axial other end 42b side half of the stator 42.

Further, FIG. 2A shows the first housing 11
2B is a front view seen from the side of the opening 11c, and FIG. 2B is a sectional view taken along line AA of FIG. As shown in FIG. 2A, four protrusions 111 are formed on the outer peripheral portion of the end surface 11a of the first housing 11 so as to extend radially outward from the end surface 11a. Part 11
1, a bolt hole 112 is provided, and two diagonally projecting portions 111 are provided with a centering hole 113 (having a diameter of 4 mm).

Similarly, the second housing 12 (see FIG. 1)
Also, four protrusions (not shown) are formed on the outer peripheral portion of the end surface 12a on the first housing 11 side (see FIG. 4). In each protrusion, portions corresponding to the bolt holes 112 and the holes 113 of the first housing 11 are A bolt hole and a centering hole are provided respectively. The centering hole 113 is formed so that the distance B between the center of the bearing hole 114 and the center of the hole 113 becomes a predetermined amount (67 mm) when the first housing 11 is formed. And
The hole for centering the second housing 12 is also formed such that the distance B between the center of the bearing hole 121 and the center of the hole is the predetermined amount when the second housing 12 is formed.

Then, a pin (not shown) slightly smaller than the diameter of the hole 113 is inserted into the hole of the second housing 12 and the hole 113 of the first housing 11, and bolted. As a result, centering is performed, the center of the bearing hole 121 and the center of the bearing hole 114 can be arranged coaxially, and the main shaft 3 can be smoothly rotated.

The method of forming the first housing 11 will be described below.
The method of assembling the stator 42 will be described with reference to FIGS. 1 and 2. First, a cup-shaped member having one end closed and the other end opened is formed by casting, and thereafter, as shown in FIGS. 1 and 2, a bearing hole 114, a lead wire outlet 118, a groove 115, a notch portion. 117, bolt holes 112, and centering holes 113 are formed by cutting. The inner peripheral surface of the first housing 11, specifically, the bearing hole 11
4, the inner peripheral surfaces of the press-fitting and fixing portion 116 and the centering hole 113 are subjected to polishing to improve processing accuracy (dimensional accuracy, surface roughness, etc.). Further, the inner diameter of the press-fitting fixing portion 116, which corresponds to the inner peripheral surface of the first housing 11, is formed to be slightly smaller (about several hundred μm) than the outer peripheral surface of the stator 42.

The stator 42 is attached to the first housing 11.
As a method for fixing the, the shrink fitting method is generally used. In this shrink fitting, first, the first housing 11 is placed in a high temperature furnace of about 170 ° C. for about 2 hours to bring the first housing 11 to a high temperature of about 170 ° C. Then, due to thermal expansion, the inner diameter of the press-fitting fixing portion 116 that corresponds to the inner peripheral surface of the first housing 11 becomes slightly larger than the outer diameter of the stator 42. Then, the first housing 11 is taken out from the furnace, and the stator 42 in the room temperature state is fitted into the first housing 11 and naturally cooled. Then, since the first housing 11 contracts, the stator 42 can be tightened and press-fitted and fixed.

The manner in which distortion occurs in this embodiment and the conventional technique will be described below. As shown in FIG. 1, a bearing hole 114 and a lead wire outlet 118 are formed in the bottom surface portion 11b of the first housing 11, but the bottom surface portion is shown in FIGS. 3 (a) and 3 (b). A schematic half sectional view is shown, assuming that 11b is closed. First, in the conventional technique shown in FIG. 3B, the gap C in the present embodiment (see FIG. 1) is not provided, and the first housing 11 has a portion corresponding to the axial length of the stator 42. Is the press-fitting and fixing portion 116 of the first housing 11. For this reason, when the press-fitting fixing portion 116 of the first housing 11 tightens the stator 42 tightly during shrink fitting, as shown by the arrow in FIG. The end surface 11a is deformed outward in the radial direction of the housing 11.

Then, the first housing 11 is shown in FIG.
Deformation such that the entire first housing 11 spreads outward in the radial direction as shown in (a), and in the force direction with the center L of the bottom surface portion 11b as a fulcrum as shown in FIG. 4 (b). It transforms to rotate. As a result, the position of the protruding portion 111 of the first housing 11 is largely displaced outward in the radial direction as compared with that before the shrink fitting, and moreover, the first housing 1
The end surface 11a of No. 1 warps.

On the other hand, in the present embodiment shown in FIG. 3 (a), as described above, the first housing 11 and the stator 4 are
A gap C is formed between the press-fitting and fixing portion 116.
Since the axial length of the stator 42 is smaller than that of the conventional technique, the stator 42 is, as shown by an arrow in FIG.
The force applied from the outer side in the radial direction of the first housing 11 becomes smaller than that in the conventional case.

Moreover, since the press-fitting and fixing portion 116 is provided on the fulcrum L side of the first housing 11, a force is applied to the bottom surface portion 11b (fulcrum) side of the first housing 11 and the radial direction of the first housing 11 is increased. The moment applied outward is reduced. As a result, FIG. 4 (a) and FIG.
Since both the deformations of the first housing 11 as shown in (b) are reduced, it is possible to reduce the displacement of the protruding portion 111 outward in the radial direction, and the first housing 1
The warp of the end surface 11a of No. 1 can be reduced.

An experiment in which the amount of displacement of the protrusion 111 is examined will be described below with reference to FIGS. 2 and 5.
First, in FIG. 2, the end surface 11 a of the first housing 11
The axial length from the press fit fixing part 116 to p, the stator 4
5, the axial length of 2 is q, and the distance from the center of the first housing 11 to the center of the centering hole 113 is B.
The horizontal axis of the graph shown in FIG. 2 is p / q, and the vertical axis is the amount of change between the distance B before shrinkage fitting and the distance B after shrinkage fitting, which is plotted as the positional deviation amount ΔB.

In order to perform the above experiment, first, the distance B is set to 6
7 mm, the inner diameter of the notch 117 is made larger than the outer diameter of the stator 42 by about 0.1 mm, and the press-fitting fixing portion 116 is further provided.
A predetermined number of first housings 11 are formed so that the press-fitting margin between the stator 42 and the stator 42 is several hundreds of μm, and the length p of each of the first housings 11 is changed to make the first housing for experiments. It was set to 11.

Then, the first housing 11 placed in a furnace at about 170 ° C. for 2 hours and heated to about 170 ° C.
Then, the stator 42 in the room temperature state was fitted and shrink-fitted as described above. After that, the distance B after shrink fitting was measured using a three-dimensional measuring device. As a result, as shown in the graph of FIG. 5, it has been found that ΔB decreases as p / q increases, that is, the length p increases. When ΔB is 8 μm or less, the bearing hole 121 of the second housing 12 and the bearing hole 114 of the first housing 11 are substantially coaxial with each other, and the spindle 3 held by the bearing holes 121, 114 is substantially coaxial. It has been confirmed by the experiments of the present inventors that the can be smoothly rotated. Therefore, in the graph of FIG. 5, p / q ≧ 0.
If it is 33, ΔB is 8 μm or less, and the compressor can be assembled so that the main shaft 3 can rotate smoothly.

By providing the gap C, the stator 42
Although the press-fitting fixing force of is small, it has been confirmed that there is no practical problem. (Second Embodiment) As shown in FIG. 6A, in the present embodiment, in addition to the press-fitting and fixing portion 116 of the first embodiment, which is provided on the axial end 42a side of the stator 42,
In the first housing 11, the auxiliary press-fitting fixing portion 116a is also provided on the axially other end 42b side of the stator 42. Specifically, by forming the notch 117, the press-fitting fixing portion 116 is crimped to the one end 42a side of the stator 42, and the auxiliary press-fitting fixing portion 116a is crimped to the other end 42b side of the stator 42, and This notch 117 allows the stator 42 and the first
A gap C is formed between the housing 11 and the housing 11.

The auxiliary press-fitting fixing portion 116a is formed so that its length is much smaller than that of the press-fitting fixing portion 116.
Specifically, when the length q of the stator 42 is 103 mm, the length of the press-fitting fixing portion 116 is about 30 mm, and the sub-press-fitting fixing portion 1
The length of 16a is about 5 mm, and the length of the gap C is about 25 mm. Hereinafter, how distortion is generated in the present embodiment and the conventional technique will be described with reference to FIG. It should be noted that FIG. 6B shows a schematic half sectional view on the assumption that the bottom surface portion 11b of the first housing 11 is closed.

First, by shrink fitting, the first housing 1
Since the first press-fitting fixing portion 116 portion receives the force from the stator 42, the end surface 11a side of the first housing 11 slightly expands outward in the radial direction. Therefore, the auxiliary press-fitting fixing portion 116
The press-fitting margin of “a” is smaller than the press-fitting margin of the press-fitting fixing portion 116, and the auxiliary press-fitting fixing portion 116 a is the press-fitting fixing portion 11.
Since the axial length is shorter than 6, the force applied from the stator 42 to the auxiliary press-fitting and fixing portion 116a is very small. That is, the displacement of the protrusion 111 due to the provision of the sub-press-fitting and fixing portion 116a is very small.

Therefore, according to the present embodiment, the protrusion 11
It is possible to more reliably fix the stator 42 in the first housing 11 while suppressing the positional deviation of No. 1 to be small. An experiment in which the amount of positional deviation is examined will be described below with reference to FIGS. First, in FIG. 6A, the length in the axial direction of the auxiliary press-fitting fixing portion 116a is set to r, the horizontal axis of the graph shown in FIG. 7 is r, and the vertical axis is the distance B before shrinkage fitting and after shrinkage fitting. The amount of change from the distance B is plotted as the amount of positional deviation ΔB.

In order to obtain this graph, first, the distance B is set to 67 mm, the inner diameter of the notch 117 is made larger than the outer diameter of the stator 42 by about 0.1 mm, and the press-fitting margin between the press-fitting fixing portion 116 and the stator 42 is set. Is several hundred μm, and the axial length p from the end surface 11a of the first housing 11 to the press-fitting fixing portion 116 is fixed so that p / q = 0.50.
A plurality of housings 11 are formed. Then, the length r in the axial direction of the auxiliary press-fitting and fixing portion 116a of the first housing 11 was changed to obtain the first housing 11 for an experiment.

Then, the first experimental housing 1 was placed in a furnace at about 170 ° C. for 2 hours and heated to about 170 ° C.
1, the stator 42 in the room temperature state was fitted and shrink-fitted as described above. Then, the distance B after shrink fitting was measured using a three-dimensional measuring device. As a result, as shown in the graph of FIG. 7, it was found that ΔB also increased as the length r of the auxiliary press-fitting fixing portion 116a increased. Then, as described above, it has been confirmed by the experiments by the present inventors that the spindle 3 can smoothly rotate if ΔB is 8 μm or less. Therefore, in the graph of FIG.
If ≦ 20 (mm), ΔB is 8 μm or less, and the compressor can be assembled so that the main shaft 3 can rotate smoothly.

(Third Embodiment) As shown in FIG. 8, in this embodiment, in addition to the press-fitting fixing portion 116 and the sub-press-fitting fixing portion 116a in the second embodiment, a press-fitting fixing portion 11 and A sub-press-fitting fixing portion 116b is further provided between the sub-press-fitting fixing portion 116a. The cutout 11
Due to the formation of 7, 117, the notches 117, 1
Due to 17, gaps C and C are formed between the stator 42 and the first housing 11, and the press-fitting fixing portion 116 and the sub-press-fitting fixing portions 116a and 116b are formed.

Then, the auxiliary press-fitting fixing portions 116a, 116b.
Has an axial length much shorter than that of the press-fitting and fixing portion 116. Specifically, the axial length of the press-fitting and fixing portion 116 is about 30 mm, and the sub-press-fitting and fixing portions 116a and 11a.
Since the axial length of 6b is about 5 mm, the force applied from the stator 42 to the auxiliary press-fitting and fixing portions 116a and 116b is very small. Therefore, according to the present embodiment, the protrusion 11
It is possible to more reliably fix the stator 42 in the first housing 11 while suppressing the positional deviation of No. 1 to be small.

In the above embodiment, the press-fitting fixing portion 11 is used.
6 is provided mainly in a portion distant from the opening 11c of the first housing 11, but the present invention is not limited to this, and the press-fitting having a smaller axial length than the stator 42 is provided. The fixing portion 116 is attached to the opening 11 of the first housing 11.
You may provide in the part near c. As a result, the force applied from the stator 42 to the outer side in the radial direction of the first housing 11 becomes small, so that the deformation of the first housing 11 can be suppressed to be small.

Further, in the above embodiment, the notch 117 is provided on the inner peripheral surface of the first housing 11 to form the gap C between the first housing 11 and the stator 42, but the present invention is not limited to this. The present invention is not limited to this, and the gap C may be formed by notching the outer peripheral surface of the stator 42.

[Brief description of drawings]

FIG. 1 is a sectional view of an electric scroll compressor showing a first embodiment of the present invention.

2A is a front view of a first housing in which a stator is shrink-fitted, and FIG. 2B is a sectional view taken along line AA of FIG.

3A is a schematic half sectional view of a first housing of the first embodiment, and FIG. 3B is a schematic half sectional view of a conventional first housing.

FIG. 4A and FIG. 4B are schematic half cross-sectional views showing how the first housing is deformed.

FIG. 5 is a first embodiment of shrink fitting according to the first embodiment.
7 is a graph showing the amount of positional deviation of the centering hole of the housing.

FIG. 6A is a cross-sectional view of an essential part of the second embodiment, and FIG. 6B is a schematic half cross-sectional view showing how the first housing is deformed.

FIG. 7 is a first embodiment of shrink fitting in the second embodiment.
7 is a graph showing the amount of positional deviation of the centering hole of the housing.

FIG. 8 is a main-portion cross-sectional view showing a third embodiment.

FIG. 9 is a cross-sectional view of a conventional electric scroll compressor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Housing, 11 ... 1st housing, 12 ... 2nd housing, 13 ... 3rd housing, 2 ... Compression part, 3 ... Main shaft (shaft member), 4 ... Electric motor part, 41 ... Rotor, 42 ... Stator, 116 ... Press-fitting fixing part (shrink-fitting press-fitting fixing part).

Claims (5)

[Claims] 1. A cylindrical first housing (11) having a bottom surface portion (11b) at one end and an opening portion (11c) at the other end, and an opening portion (11c) of the first housing (11).
A housing (1) having at least a tubular second housing (12) adjacent to the side, and a compression part (2) supported and fixed to the second housing (12) side in the housing (1) to compress a fluid. An electric motor part (4) fixed in the first housing (11) to apply a driving force to the compression part (2), and one end of the central part (114) of the first housing (11).
Is rotatably supported by the second housing (1).
2) A shaft member (3) that is rotatably supported by the central portion (121) and that transmits the driving force of the electric motor unit (4) to the compression unit (2). A stator (42) made of a system material and fixed along the inner peripheral surface of the first housing (11),
Provided in the electric motor section (4), the first housing (11) is made of an aluminum alloy material, and the stator (42) is press-fitted and fixed in the first housing (11) by shrink fitting. Type electric compressor, a gap (C) is provided in a portion of the fitting portion of the first housing (11) and the stator (42) in the axial direction, and the gap is provided between the first housing (11) and the stator (42). A hermetic electric compressor characterized in that the axial length of a press-fitting press-fitting fixing portion (116, 116a, 116b) with a stator (42) is shortened. 2. The gap (C) is provided on the opening (11c) side of the first housing (11), and the shrink fitting press-fitting fixing part (116) is provided in the first housing (11). The hermetic electric compressor according to claim 1, wherein the hermetic electric compressor is provided on the bottom surface portion (11b) side. 3. The hermetic electric compressor according to claim 2, wherein the shrink fitting press-fitting fixing portion (116) is provided from an end surface (11a) on the opening portion (11c) side of the first housing (11).
To p, and the axial length of the stator (42) is q, p / q ≧ 0.33. 4. The stator (42) is provided with the gap (C).
Of the shrink fitting press-fitting fixing portion (116, 116a, 116).
b) is one axial end (42a) of the stator (42)
The hermetic electric compressor according to claim 1, which is provided on the side and the other end (42b) in the axial direction. 5. The hermetic electric compressor according to claim 4, wherein the first housing (11) has an end face (11a) on the opening (11c) side, and the shrink fit press-fitting and fixing on the one end (42a) side. The axial length up to the portion (116) is p, the axial length of the stator (42) is q, and the axial length of the shrink fitting press-fitting fixing portion (116a) on the other end (42b) side. R
Then, p / q ≧ 0.50 and r ≦ 20 (mm), the hermetic electric compressor.