JP3155594B2 - Fully sealed electric compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetically sealed electric compressor generally used for refrigeration and cooling equipment, and more particularly to a hermetically sealed electric compressor having a two-bearing structure for avoiding concentration of sliding load. Related to the auxiliary bearing part.

[0002]

2. Description of the Related Art The structure of a sub-bearing in a conventional hermetic electric compressor having a two-bearing structure is disclosed in, for example,
As described in Japanese Patent No. 0774, there is an example in which a general ball bearing in which a sphere is freely fitted between an inner ring and an outer ring is press-fitted into a boss hole of a support leg formed by cast iron or forging.

[0003]

However, such a conventional mounting structure for a sub-bearing of an all-enclosed electric compressor has the following problems. That is, cast iron or forged material is inferior in molding accuracy, and when such cast iron or forged material having inferior molding accuracy is used as a constituent material of the support legs, equipment and processing costs for machining these are required. This leads to a rise in manufacturing costs.

Further, in order to secure the inner diameter of the case and the accuracy of the center of the auxiliary bearing which require precise centering during assembly, the concentricity between the annular outer diameter of the support leg and the boss hole into which the ball bearing is pressed is ensured. Needless to say, the case is inferior in rigidity and deforms when the stator of the electric motor is fitted, but even in this case, the inner surface of the case is further machined to increase the accuracy of the combination of the case and the support legs. There are many disadvantages in terms of manufacturing costs, including assembling, such as the necessity of processing.

Further, in the above-described conventional hermetic electric compressor, a ball rolling bearing is used as an auxiliary bearing.
For products such as household room air conditioners that use such hermetic electric compressors, the operating noise is a crucial factor in determining the quality, and rolling bearings should avoid hitting caused by ball rolling. Not be able to
Become a customer complaint who wants to reduce noise.

An object of the present invention is to solve such a problem, and
An object of the present invention is to provide a completely hermetic electric compressor that can easily and highly accurately center a bearing and is excellent in quality.

[0007]

To achieve the above object of the Invention The present invention includes a case the motor unit and one of the lid member in the closed container formed by the lid which is welded to the both ends the support legs of the sub-bearing of the rotational shaft is provided, the annular wall and extending life and death the rotating shaft one opposite the lid member from the annular wall on the inner diameter side of the case to be joined to the inner surface of the case between the Let through
Consists of a flat portion having a hole, a flat portion as a support sub bearing, the sub bearing said rotary shaft is mounted, said
It is assumed that the support leg is welded and fixed to the flat portion of the support leg at a position adjusted for centering with respect to the rotation axis in the flat portion.

Further, the present invention provides a spherical bearing having an inner surface on which the rotating shaft is slidably fitted and a smooth spherical outer surface, and a slidable outer surface of the spherical bearing. An outer ring having a spherical inner surface opposed to the outer ring and having an annular concave portion on a part of the inner surface; and an outer ring press-fitted into the concave portion of the outer ring to firmly contact the outer ring, and The outer surface and the inner ring having a spherical inner surface slidably opposed to each other are formed, and the spherical bearing is slidably included by the outer ring and the inner ring.

[0009]

[Function] The auxiliary bearing faces away from the motor of the support leg.
Alignment of the auxiliary bearing is easy because it is fixed to the flat part by welding.
And high accuracy, and the secondary bearing has a high mounting
It will be firmly held with accurate accuracy.

[0010] Not only is the inner surface of the spherical bearing slidable with the rotating shaft, but also the outer surface of the spherical bearing is slidable with the outer ring and the inner ring. And a smooth sliding bearing action is realized.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing one embodiment of a hermetic electric compressor according to the present invention, wherein 1 is a compressor body, 1a is a compression chamber, 2 is a frame, 3 is a main bearing, 4 is a rotary shaft, 4a is a main shaft portion, 4b is an eccentric portion, 4c is a sub shaft portion, 5 is a revolving scroll, 5a is a boss portion, 5b is a wrap, 6 is a fixed scroll, 6a is a wrap, 6b is a discharge port, 7 is a suction pipe, 8 is an Oldham ring, 9 is a bolt, 10 is a motor, 10a is a rotor, 10b is a stator, 11 is a sub-bearing, 11a is a spherical bearing, 11b is an outer ring, 11c is an inner ring, and 12 is a supporting leg of a sub-bearing. , 13 is a closed container, 13a is a case, 13b
Is a lid chamber, 13c is a bottom chamber, and 14 is lubricating oil.

In FIG. 1, a closed container 13 is formed by welding a lid chamber 13b to one side of a cylindrical case 13a and a bottom chamber 13c to the other side. This closed container 13
Inside, an electric motor 10 and a compressor main body 1 are connected by a rotating shaft 4 and provided. The rotary shaft 4 is composed of a main shaft 4a and the eccentric portion 4b and the auxiliary shaft portion 4c, the central portion of the main shaft 4a is pressed or Shohama the rotor 10a of the electric motor 10, a stator 10b of the motor 10 Case 13a Are joined by shrink fitting or the like. Also, the main shaft portion 4a of the rotary shaft 4
Is slidably supported by a main bearing 3 integrated with a frame 2 provided above the electric motor 10, and a sub shaft portion 4 c of the rotary shaft 4 is connected to a case 13 a below the electric motor 10.
Is slidably supported by a sub-bearing 11 welded and attached to a sub-bearing support leg 12 in a state of being press-fitted and welded.

The sub bearing 11 includes a spherical bearing 11a having a cylindrical inner diameter into which the sub shaft portion 4c of the rotating shaft 4 is slidably fitted.
An outer ring 11b having an inner spherical surface slidably with the outer spherical surface of the spherical bearing 11a and an annular projection on the outer diameter side, and an inner ring having an outer diameter portion and an inner spherical surface press-fitted into the inner diameter of the annular projection. And a ring 11c.

The compressor body 1 is mounted above the frame 2 and mainly comprises a revolving scroll 5 and a fixed scroll 6. A boss 5a is formed in the center of the lower surface of the orbiting scroll 5, and the boss 5
a eccentric part 4b above the rotary shaft 4
Is inserted. As a result, the orbiting scroll 5 rotates eccentrically with the rotation of the rotating shaft 4, but the orbiting scroll 5 is provided by the Oldham ring 8 provided on the upper surface of the frame 2.
Is prevented from rotating and moves on a circular orbit about the central axis of the rotating shaft 4. However, in the following description, this movement of the orbiting scroll 5 is referred to as orbit. Fixed scroll 6
Are fixed to the frame 2 by bolts 9.

A spiral wrap 5b is provided on the upper surface of the orbiting scroll 5, and a spiral wrap 6a is also provided on the lower surface of the fixed scroll 6 disposed on the upper portion of the orbiting scroll 5. 5b and the wrap 6a of the fixed scroll 6 fit each other. The spiral shapes of the wraps 5b and 6a are different, and the tip ends of the spirals of the wraps 5b and 6a and the wraps 5b and 6a are different from each other.
The wall surfaces a contact each other at two points. These wraps 5
The compression chamber 1a is formed by the wall surfaces of b and 6a, their tip portions, and the contact points of these wall surfaces. When the orbiting scroll 5 revolves, these contact points on the wall surfaces of the wraps 5b and 6a move along the trajectory of the spiral, and the contact of the tips of the wraps 5b and 6a does not change, so that the compression chamber 1a becomes narrow. To go.

A discharge port 6b is provided near the center of the fixed scroll 6, and a suction pipe 7 communicates with a compression chamber 1a formed by a wrap 5b of the orbiting scroll 5 and a wrap 6a of the fixed scroll 6. .

The compressor main body 1 is configured as described above. The compressor main body 1 is inserted into a case 13a to which a bottom chamber 13c is attached, and the center of the compressor main body 1 and the inner diameter of the case 13a are determined. After the centering, the outer peripheral surface of the frame 2 and the inner surface of the case 13a are fixed by spot welding.

When the rotating shaft 4 is rotated by the electric motor 10, the orbiting scroll 5 revolves as described above, and the volume of the compression chamber 1a is gradually reduced at each revolution. In such an operation, refrigerant gas from an evaporator (not shown) of the refrigeration cycle is supplied to the compression chamber 1a through the suction pipe 7, is gradually compressed, and is discharged from the discharge port 6b into the closed container 13. Thereafter, the refrigerant gas is sent from a discharge pipe (not shown) to a condenser (not shown) of the refrigeration cycle.

On the other hand, the lubricating oil 14
When the rotating shaft 4 rotates, the lubricating oil 14 rises inside the lubrication holes provided along the central axis of the rotating shaft 4, and the inner surface of the main bearing 3, the sub bearing 11, Axis 4
Is supplied between the eccentric portion 4b and the boss portion 5a of the orbiting scroll 5, whereby a smooth operation of the hermetic electric compressor is performed.

The auxiliary bearing 1 in FIG. 1 which characterizes this embodiment.
1, as shown in FIG. 2, a spherical bearing 11a of the auxiliary shaft portion 4c of the rotary shaft 4 (FIG. 1) has an inner surface 11a ₁ and the spherical outer surface 11a ₂ which fits slidably, the spherical Bearing 1
Spherical inner surface 11 to slide freely with the outer surface 11a ₂ of 1a
b ₁ a recess 11b ₂ provided annularly to the inner surface 11b ₁
An outer ring 11b with a, and a inner ring 11c having a spherical inner surface 11c ₁ to slide freely between the outer surface 11a ₂ of the recessed portion 11b ₂ on the indented by spherical bearing 11a. According to the case of assembling the sub-bearing 11, inserts a spherical bearing 11a as the outer surface 11a ₂ spherical to the inner surface 11b ₁ of the outer ring 11b strikes in the outer ring 11b, and thereafter, the recessed portion 11b of the outer ring 11b ₂ inner rings 1
1c is press-fitted. Thus, the auxiliary bearing 11 is configured as shown in FIG. 1, in this case, the outer surface 11a ₂ of the spherical bearing 11a inner surface 11b ₁ of the outer ring 11b, an inner ring 1
1c is freely inside surface 11c ₁ and sliding, thus, each of the ring 11b, a state in which the spherical bearing 11a is slidably contained within the 11c. The spherical bearing 11a and the rings 11b and 11c are made of a steel plate or a steel material, and are formed by plastic working or cutting.

Next, the assembling of the auxiliary bearing 11 and the support leg 12 in FIG. 1 which characterizes this embodiment will be described in more detail with reference to FIG. However, in the figure, 12a is an annular wall, 12b is an outer diameter side flat portion, 12c is an inner diameter side flat portion,
Reference numeral 12d denotes a hole, and a portion corresponding to FIG.

The support leg 12 has an annular wall 12a press-fitted into the case 13a and joined thereto, an outer-diameter side flat portion 12b continuous with the annular wall 12a, and a recess continuously formed in the outer-diameter side flat portion 12b. It consists inner diameter side flat portion 12c which becomes Jo, countershaft axis of rotation 4 in the central portion of the inner diameter side flat portion 12c
A hole 12d having a diameter larger than the outer diameter of the portion 4c and smaller than the outer diameter of the outer ring 11b of the auxiliary bearing 11 is provided.
The countershaft 4c of the rotary shaft 4 is passed through the hole 12d.
The support legs 12 are made of a steel plate, and are formed by cold plastic working of a high-precision steel plate, and can be formed in a short time. To attach the support leg 12 to the inner surface of the case 13a, press the annular wall 12a of the support leg 12 into the inner surface of the case 13a, and then attach the annular wall 12a to the case 13a.
Welded to the inner surface. Thus, the case 1 is
An annular wall 12 having a large area in contact with the inner surface of 3a
a, it is easy to press-fit the support leg 12 into the case 13a and attach it stably.
While the auxiliary bearing 11 is supported at the back of the case 13a, the portion to be welded to the case 13a can be located on the front side of the case 13a, which facilitates the welding operation.

The sub-bearing 11 assembled as described above in the state shown in FIG. 3 is mounted on the sub-shaft portion 4c of the rotating shaft 4 and mounted on the inner diameter side flat portion 12c of the support leg 12. Thereafter, the auxiliary bearing 11 is fixed to the support leg 12 by centering and welding the constituent members of the auxiliary bearing 11 .
4 will be described. However, in FIG. 4 , reference numeral 15 denotes a centering device, reference numeral 16 denotes a welding torch, reference numeral 17 denotes an auxiliary bearing temporary fixing jig, and portions corresponding to the above-mentioned drawings are denoted by the same reference numerals.

[0024] The sub-bearing 11, the inner surface of the spherical bearing 11a 11 a 1 as (2) is freely auxiliary shaft portion 4c and the sliding of the rotating shaft 4, the support legs 12 attached to the auxiliary shaft portion 4c
After being installed on the inner diameter side flat portion 12c, the rotating shaft 4 is rotated at a low speed by using the centering device 15 having a function of measuring rotational torque and the like, and the sub shaft portion 4c and the inner surface 11a1 of the spherical bearing 11a of the sub bearing 11 are rotated. The clearance is centered so as to be optimal while adjusting the position of the sub-bearing 11, and when the centering is completed, the sub-bearing 11 is fixed by the jig 17 for temporarily fixing the sub-bearing to the inner surface side portion of the support leg 12. 12c and temporarily fixed. Then, a plurality of welding torches 16 are spot-welded at a plurality of points where the support leg 12 and the sub-bearing 11 overlap. At this time, a non-consumable electrode that does not use a filler is used for welding, and a normal welding state with relatively little spatter can be obtained by joining together.

In this way, the auxiliary bearing 11 is
Although attached to the sub bearing 11, as explained in FIG. 2, on the auxiliary shaft portion 4c of the rotary shaft 4 to the inner surface 11a ₁ of the spherical bearing 11a is slidable, the outer surface 11 of the spherical bearing 11a
inner ring 11c a ₂ is the inner surface 11b ₁ of the outer ring 11b
Because it is slidable in the the inner surface 11c _1, low straightness of the rotary shaft 4 is slightly, even if deformed bending thereto, absorbing the eccentricity of the rotary shaft 4 by the bending deformation at these sliding portions can do. Therefore, the sub bearing 11 becomes a smooth sliding bearing with respect to the sub shaft portion 4c of the rotating shaft 4, and the friction between them can be reduced, and generation of friction noise can be prevented.

In addition, the case 13a is formed by plastic working of a steel plate from the viewpoint of cost. Therefore, the accuracy is inferior. The compressor body 1, the electric motor 10, the rotating shaft 4 and the like are mounted in the case 13a to mount the support legs 12 thereon. When fixed by welding, the concentricity of the compressor main body 1 and the case 13a is hardly obtained, and the case 13
A shift occurs between the center of a and the center of the rotating shaft 4.
However, in the above embodiment, the inner surface side flat portion 1
2c is provided with a hole 12d into which the sub shaft portion 4c of the rotating shaft 4 is fitted with a margin even if the center of the case 13a and the center of the rotating shaft 4 are displaced, and the sub shaft portion passing through the hole 12d is provided. 4c, the auxiliary bearing 11 is centered as described above and fixed to the support leg 12 by welding.
Smooth bearing is possible.

[0027]

As described above, according to the present invention,
The support legs provided between the lid of the electric motor part and the sealed container in the closed container, the flat portion facing the lid member of the support leg and the supporting portion of the sub bearing, the sub-bearing flat portion Since the secondary bearing is fixed by welding, the auxiliary bearing can be easily and accurately centered.
Even if it shifted to bets, so that the mounting accuracy of the sub bearing is stably maintained in a high state.

Further, since the auxiliary bearing is centered with respect to the rotary shaft and fixed by welding to the supporting legs, the case is mounted by a combination of complicated related parts such as mounting of the compressor body, the supporting legs and the like in the case. Even if the center of the rotary shaft is displaced from the center of the rotary shaft, the auxiliary bearing acts as a smooth sliding bearing with respect to the rotary shaft, and can prevent noise from the auxiliary bearing.

Further, since the sub bearing has a separate structure and is provided with a slidable portion inside the sub bearing as well as sliding with the rotary shaft, the rotary shaft is bent and deformed or the above-mentioned core is not formed. Even if there is a slight error in the protrusion, these can be absorbed by the respective sliding portions, and noise can be eliminated as a smooth sliding bearing.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a hermetic electric compressor according to the present invention.

FIG. 2 is an exploded perspective view showing a specific example of a sub bearing in FIG.

FIG. 3 is a longitudinal sectional view showing a specific example of an assembled state of a sub bearing and its support leg in FIG. 1;

FIG. 4 is a longitudinal sectional view showing a specific example of a method of attaching a sub bearing to a support leg in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor main body 3 Main bearing 4 Rotating shaft 4c Subshaft part 5 Orbiting scroll 6 Fixed scroll 10 Electric motor 11 Sub bearing 11a Spherical bearing 11b Outer ring 11c Inner ring 12 Support leg 12aAnnular wall  12b Outer diameter side flat part 12c Inner diameter side flat part 12d Hole 13 Sealed container 13a Case 15 Centering device 16 Welding torch 17 Temporary fixing jig

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masanori Wakaizumi 800, Tomita, Odaimachi, Ohira-machi, Shimotsuga-gun, Tochigi Hitachi, Ltd.Tochigi Plant (72) Inventor Mitsuaki Haneda 502, Kunitachicho, Tsuchiura-shi, Ibaraki Hitachi, Ltd. Inside the Machinery Research Laboratory (72) Inventor Keiji Taguchi 502, Kandachicho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (56) References JP-A-3-217678 (JP, A) JP-A-3-96678 (JP, A) JP-A-3-996 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F04B 39/00 103 F04C 29/00

Claims (4)

(57) [Claims] 1. A compression mechanism in a sealed container formed by welding a first lid to one end of a cylindrical case and a second lid to the other end. And a motor unit connected and accommodated by a rotating shaft, a main bearing of the rotating shaft is disposed near the compression mechanism unit on the first lid side, and the second bearing is arranged so as to sandwich the motor unit with the main bearing . A hermetic electric compressor having a two-bearing structure in which a sub-bearing of the rotary shaft is disposed on the side of the lid, wherein an annular wall joined to the inner surface of the case;
The support leg of the auxiliary bearing having a flat portion provided with a hole through which the rotary shaft is provided at the center and extending to the inner diameter side of the case so as to face the lid of The support leg is fixed to an inner surface of the case by press-fitting and welding the annular wall to the case, and the second lid of the support leg is provided . The flat portion facing the support leg is used as a support portion for the sub bearing, and the sub bearing to which the rotating shaft is attached
A hermetically sealed electric compressor, wherein the compressor is welded and fixed to the flat portion of the support leg at a position where the center of the rotary shaft is adjusted with respect to the rotation axis in the surface portion. 2. The spherical bearing according to claim 1, wherein the auxiliary bearing comprises: a spherical bearing having an inner surface on which the rotating shaft is slidably fitted; and a smooth spherical outer surface. An outer ring having a spherical inner surface freely facing and having an annular recess in a part of the inner surface; and an outer ring press-fit into the recess of the outer ring to slide on the outer surface of the spherical bearing. A hermetically-sealed electric compressor, comprising: an inner ring having a spherical inner surface facing freely; said outer ring and said inner ring slidably enclosing said spherical bearing. . 3. The device according to claim 1, wherein the annular wall of the support leg is fixed to the inner surface of the case and the sub bearing is fixed to the flat portion of the support leg by adjusting the alignment of the auxiliary bearing. A completely hermetic electric compressor characterized by the following. 4. The method according to claim 3, wherein the case is welded to the annular wall of the support leg, and the flat portion of the support leg and the sub-bearing are spotted using a non-consumable electrode. An all-enclosed electric compressor characterized by being welded by welding.