JPH0281978A - Closed type scroll compressor - Google Patents

Abstract

PURPOSE:To contrive the improvement of reduction of mechanical loss in a main bearing and reliability of the bearing by forming a structure fixing by shrinkage fit one of the frames to a closed chamber and fixing a frame side, provided with a main shaft principal part, to the frame by a stopper bolt. CONSTITUTION:An Oldham's frame 4 is fixed by a barrel part 1b and a contact surface 49 by shrinkage fit, and a fixed scroll 5 is fixed by a stopper bolt 50 and spaced from the barrel part 1b through a clearance 53. While a frame 11 is arranged in the bottom of the Oldham's frame 4, and both the frames are integrally formed with the Oldham's frame 4 by two or more stopper bolts 56. The frame 11 is isolated from the barrel part 1b through a clearance 54. By the structure thus obtained, the deformation of a closed chamber 1b and the Oldham's frame 4 by the shrinkage fit is prevented from giving an influence to a driving system of a compressor particularly a gap in the diametric direction of a rolling bearing in a main bearing. That is, in assembly of the compressor, no burden is applied to a rolling bearing part.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hermetic scroll compressor used as a refrigerant compressor for refrigeration and air conditioning or a helium compressor, and particularly relates to a hermetic scroll compressor used as a refrigerant compressor for refrigeration and air conditioning or a helium compressor. It is about the method.

[Conventional technology]

The hermetic scroll compressor is disclosed in Japanese Patent Application Laid-Open No. 62-129595.
As disclosed in the above issue, the refrigerant gas compressed by the scroll compression mechanism reaches the motor room from the upper discharge chamber through the communication path. The refrigerant gas then flows around the motor and out of the compressor discharge pipe.

In the conventional example described above, a rolling bearing is used as the main bearing. The rolling bearing is fixed to the frame supporting it by shrink fit (press fit). On the other hand, the frame has a structure in which it is fixed to the sealed chamber (casing body) by shrink fit (press fit).

[Problem to be solved by the invention]

In the above conventional technology, the method of fixing the frame and the rolling bearing and the method of fixing the frame and the sealed chamber are shrink fit (press fit).
Because of this method, shrink fitting causes radial deformation on the frame side, resulting in a narrowing of the rolling bearing gap. The gap of the main bearing changes greatly depending on the shrinkage fit at the two locations described above, and in some cases, the gap (radial gap) of the rolling bearing may become zero.

As described above, when the gap of the rolling bearing (main bearing) becomes small, the mechanical loss in this part becomes large, which causes a problem of degrading the performance of the compressor. Depending on the size of the shrinkage fit, the main bearing gap also varies, which has a large effect on the variation in compressor performance. Also,
When the bearing gap becomes extremely small, the contact between the rollers and the inner and outer rings becomes strong, resulting in a reliability problem in which the life of the main bearing is shortened.

An object of the present invention is to reduce the mechanical loss of a main bearing and to improve the reliability (life) of the bearing.

[Means to solve the problem]

The above purpose is to divide the frame into two parts and fix one part to the sealed chamber (casing body) by shrink fitting (pressure).
This is achieved by fixing the frame side, which includes the main shaft main part, to the frame using fixing bolts. In other words, the amount of radial deformation and contraction due to the shrink fit (press fit) between the chamber body and the Oldham frame member is prevented from affecting the bearing clearance of the compressor drive system, especially the main bearing using rolling bearings. It is something to do.

That is, this is achieved by making the frame a two-part structure so that deformation due to shrink fitting with the sealed chamber has as little effect on the drive system of the compressor as possible.

[Effect]

The Oldham frame section, which has a key groove that engages with the Oldham mechanism, and the sealed chamber body are fixed by shrink fit (press fit). Since the fixing method is by tightening, radial deformation of the Oldham frame member during shrink fitting is caused by compressor drive system 1. In particular, it will not directly affect the main bearing side. Therefore, by configuring as described above, no extra burden is placed on the rolling portion of the main bearing portion, and an appropriate bearing clearance can always be ensured.

〔Example〕

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

In FIG. 1, a compressor section 100 is located above inside the closed container 1.
However, the electric motor section 3 is housed below.

Inside the sealed container 1 are an upper chamber 2a (discharge chamber), a motor chamber 2b,
It is divided into 2c.

The compressor section 100 has a fixed scroll member 5 and an orbiting scroll member 6 that are engaged with each other to form a compression chamber (sealed space) 7. The fixed scroll member 5 consists of a disk-shaped end plate 5a and a wrap 5b standing upright thereon and formed into an involute curve or a curve similar to this, and has a discharge port 10 at its center. A suction port 16 is provided on the outer periphery. The orbiting scroll member 6 includes a disc-shaped end plate 6a, and stands upright on this,
It consists of a wrap 6b formed in the same shape as the wrap of the fixed scroll, and a boss 6c formed on the surface opposite to the wrap of the end plate. The frame 11 forms a bearing part in the center,
A rotating shaft 14 is supported by this bearing portion, and an eccentric shaft 14a at the tip of the rotating shaft is inserted into the boss 6C so as to be able to rotate.

Further, a fixed scroll member 5 is fixed to the Oldham frame 4 by a plurality of bolts 50, an orbiting scroll member 6 is supported on the frame L-frame 4 by an Oldham mechanism 38 consisting of an Oldham frame and an Oldham key, and the orbiting scroll member 6 is fixed. Does it rotate without rotating relative to the scroll member 5? , 11) It is formed to do +.

A swing bearing 30 is provided inside the swing boss portion 6c, and a main bearing 31, a lower shaft bearing 32, and a seal bearing 33 are provided at the center of the frame 11. The main bearing 31 uses a rolling bearing (cylindrical roller bearing) that is highly reliable in terms of lubrication. As shown in detail in FIG. 3, 31a is, for example, a cylindrical roller portion, and 31b is an outer ring portion that is fixed to the inner peripheral surface of the frame by shrink fit. On the other hand, 31c is an inner ring portion that is fixed to the main shaft side through an intermediate fit with the main shaft 14.

A back pressure chamber 47 surrounded by the end plate 6a of the orbiting scroll 6, the frame 11, and the Oldham frame 4 communicates with the compression chamber 7 through a back pressure hole 61 provided in the end plate 6a.
The pressure within this back pressure chamber 47 becomes an intermediate pressure between the suction pressure and the discharge pressure. A motor shaft 14b fixed to the rotor 3b is integrally connected to the rotating shaft 14 at the lower part thereof, and the motor section 3
are directly connected. A vertical suction pipe 17 is connected to the suction port 16 of the fixed scroll member 5 through the closed container 1, and the upper chamber 2a in which the discharge port 10 is open is connected to passages 18a and 18b as shown in FIG. Upper motor room 2b via
It communicates with The upper motor chamber 2b communicates with the lower motor chamber 2c via a passage 45 between the motor stator 3a and the side wall of the sealed container 1. Further, the upper motor chamber 2b communicates with a discharge pipe 19 passing through the closed container 1.

Note that llf is a frame pedestal portion for fixing the electric motor 3 to the frame side. Reference numeral 43 indicates a hermetic terminal portion, and reference numeral 22 indicates an oil reservoir at the bottom of the closed container. In the figure, solid line arrows indicate the flow direction of refrigerant gas, and broken line arrows indicate the flow direction of oil. In addition, 2
0 and 21 are first and second balance weights for canceling the centrifugal force accompanying the orbiting motion of the orbiting scroll 6.

The airtight container 1 is formed of an upper end plate 1a, a J5i body portion 1b, and a lower end plate 1c.

FIG. 2 shows the Oldham frame 4 contacting the body portion 1b with the contact surface 4.
9 is a perspective view showing a state in which the parts are fixed by shrink fitting (press fitting). The fixed scroll 5 is fixed with a stop bolt 50 and is separated from the body portion 1b via a gap 53. Further, a frame 11 is arranged below the Oldham frame 4, and both of them are integrated with the Oldham frame 4 by a plurality of stop bolts 56. The frame 11 is separated from the body portion 1b via a gap 54.

FIG. 3 is a plan view when the Oldham frame 4 and the frame 11 are combined. The Oldham frame 4 is provided with a pair of fan-shaped boss portions 4f each having an Oldham keyway 4a. Further, the upper end surface 4c of the Oldham frame 4 has a screw hole 4e for fixing the fixed scroll. On the other hand, there is also a screw hole 4p in the lower end surface 4n for fixing the frame 11 from below. FIG. 4 is an external view of the anti-rotation member (Oldham ring) 38.

The Oldham ring 38 has a ring portion 38a and a key portion 38.
b, and are engaged with the key groove portion on the orbiting scroll 6 side and the key groove portion 4a on the Oldham frame 4 side, respectively. The roller bearing portion 37 of the main bearing is arranged at the center of the frame 11.

In this way, the Oldham frame portion 4 that joins the sealed chamber and the frame ]-1 of the roller bearing portion 31 are constructed as separate bodies. With the above structure, deformation (impact g on the amount of contraction in the radial direction) caused by the shrink fit (press fit) between the sealed chamber 1b and the Oldham frame 4 is reduced in the radial direction of the compressor drive system, especially the rolling bearing of the main bearing. It will no longer affect the gap.

In other words, no load is placed on the rolling bearing during assembly of the compressor.

In addition, in the method of fixing the Oldham frame 4 and the body portion 1b by shrink fitting, the shrink fit allowance δ0 between the two is practically given by the following equation when expressed as a non-dimensional shrink fit allowance δ0−.

Here, R: Radius of joint surface 4g (m) δ0: Shrink fit allowance (m) δ0: Non-dimensional shrink fit allowance By setting the non-dimensional shrink fit allowance around the above range, the conventional Also, it is possible to further prevent the gap to the main bearing from decreasing.

In addition, the shrink fit allowance between the outer ring portion 31b of the main bearing 31 and the inner circumferential surface ILm of the frame 11 is also appropriate within the range of formula (1) described above.

As shown in FIGS. 1 and 3, the structure is divided into an Oldham frame 4 and a frame 4, and an Oldham key groove portion 4a is provided on the Oldham frame 4 side.
The size of the balance weight 20 and main bearing 31 arranged in
0 becomes easier to design, and the ease of assembling the main bearing 31 is improved. In the conventional machine, the Dzo dimension is the maximum diameter in the case shown in FIG. Also, the assembly of the main bearing 31 is Dz.

There were drawbacks such as difficulty due to size constraints.

FIG. 5 is an explanatory diagram showing the effect of reducing mechanical loss in the main bearing section according to the present invention in comparison with that of a conventional machine. It can be seen that the conventional machine has a large mechanical loss and its variation is large. On the other hand, in the present invention, the loss is small and the variation is also small, and as a result, the performance of the compressor as a whole can be improved and a compressor with small variation in performance can be achieved. This mechanical loss is N=36
00rp+n, and if the spindle 14 speeds up further,
The difference in performance between the two compressors becomes significant. Therefore, the present invention is suitable for an inverter-controlled scroll compressor in which the compressor rotates at high speed under inverter control.

As described above, in the present invention, the Oldham frame member provided with the Oldham key groove for preventing rotation and the frame member incorporating the rolling bearing are fixed with a locking bolt, and the outer periphery of the Oldham frame member is sealed. It is characterized by being integrated with the container body by shrink fitting.

That is, the deformation caused by the shrink fit between the chamber body and the Oldham frame member does not affect the drive system of the compressor at all.

〔Effect of the invention〕

According to the present invention, there are the following effects.

(1) Mechanical loss in the main bearing is reduced, improving compressor performance.

(2) Since no extra burden is placed on the rolling part of the main bearing during assembly, the life of the rolling part is extended, and
The reliability of the entire compressor is increased.

(3) The effects of items (2) and (3) above become more pronounced as the speed of the compressor increases due to inverter control.

(4) The split structure of the frame simplifies the shape design of the balance weight installed in the back pressure chamber and increases the degree of freedom in selecting the size (outer diameter) of the main bearing 31. be.

[Brief explanation of the drawing]

Figure f51 is a longitudinal sectional view showing the overall structure of the hermetic scroll compressor of the present invention. Figure 2 shows the assembly status of the Oldham frame part.
11 is a perspective view. FIG. 3 is a plan view of the Oldham frame, and FIG. 4 is an external view of the Oldham ring. FIG. 5 is an explanatory diagram of mechanical loss showing the effects of the present invention. 2b...Electric motor room, 3...Electric! l+a, 4... Oldham frame, 5... fixed scroll, 6... orbiting scroll, 11... frame, 17... suction pipe, 19... discharge pipe, 20... balance way l −、
22...Oil. Eku! Mouth 41 Rukum - 10tr to Leh, enter Kuro 'L-7f So', ν Rimi bud map on the buttocks.

Claims (1)

[Claims] 1. A scroll compressor and an electric motor are housed in a sealed container and are connected to each other via a rotating shaft supported on a frame.
A scroll compressor divides a closed container chamber into upper and lower chambers, and a fixed scroll member with a spiral wrap standing upright on a disk-shaped end plate and an orbiting scroll member are engaged with each other with the wrap inside, and the orbiting scroll member is attached to a rotating shaft. The orbiting scroll member is engaged with an eccentric shaft connected to the fixed scroll member, and the orbiting scroll member is engaged with an eccentric shaft portion connected to the fixed scroll member, without rotating on its own axis, and the fixed scroll member has a discharge port that opens at the center and an intake port that opens at the outer periphery. The gas is sucked in from the suction port, moved around the compression space formed by both scroll members to reduce the volume and compress the gas, and the compressed gas is discharged into the upper container chamber from the discharge port, and the passage In a hermetic scroll compressor that leads to the lower container chamber through a pipe and discharges to the outside of the container through a discharge pipe, an Oldham frame member equipped with an Oldham key groove for automatic prevention and a frame member with a built-in rolling bearing are attached to a stop bolt. A hermetic scroll compressor, characterized in that the Oldham frame member is fixed in place, and the outer periphery of the Oldham frame member is integrated with the body of the hermetic container by shrink fitting.