JPH0579476A - Scroll compressor - Google Patents

Abstract

PURPOSE:To improve durability of a bearing by providing one of bearings with an automatic aligning function, and also forming this bearing of a carbon material in a device to effect support by means of bearings located on both sides of an electric motor for a crank shaft for revolving a turning scroll. CONSTITUTION:A compression mechanism part 2 contained in the inner upper part of a closed case 1 has a compression chamber 5 partitioned trough engagement of helical laps 3b and 4b of fixed and revolving scrolls 3 and 4, respectively, with each other. The turning scroll 4 is turned through a crank shaft 6 through rotation of an electric motor 10. The crank shaft 6 is supported by a main bearing 8 supported to a frame 7 against which the fixed scroll 3 is fastened, and a lower bearing 9 positioned on the opposite side to the main bearing 8. In this case, the lower bearing 9 forms a plain bearing having a bore surface formed in an automatic aligning shape (approximately in a spherical shape) 9a and is formed of a carbon material. This constitution absorbs deformation of the crank shaft 6 under operation and prevents the occurrence of abnormal one-sided contact.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor, and more particularly to a scroll compressor suitable for use in an air conditioner, a refrigerator, etc., for improving reliability by an inexpensive means. Is.

[0002]

2. Description of the Related Art The arrangement and structure of a bearing for supporting a crankshaft in a conventional scroll compressor is described in, for example, Japanese Patent Application Laid-Open No. 2-125986. Figure 3
FIG. 3 is a vertical sectional view of a conventional scroll compressor disclosed in the publication. The scroll compressor shown in FIG. 3 is a closed case.
The compression mechanism section 2 and the electric motor section 10 are housed in the space 1, the fixed scroll 3 is a spiral wrap 3b standing upright on the end plate 3a, and the swivel scroll 4 is A spiral wrap 4b is erected on the end plate 4a, and the wraps 3b and 4b are inwardly meshed with each other to form a compression chamber 5. The electric motor 10 comprises a stator 11 and a rotor 12.

Reference numeral 6 denotes a crankshaft for transmitting the rotational force of the electric motor 10 to revolve the swivel scroll 4, and reference numeral 7 denotes a frame having a main bearing 15 for supporting and rotating the crankshaft 6.
The lower bearings 16 are provided in a bearing housing 17 fixed to the closed case 1. The crankshaft 6 coupled to the rotor 12 is a main bearing 1 provided on both sides of the electric motor 10.
5 and the lower bearing 16 are supported, and the main bearing 15 and the lower bearing 16 are fixed straight slide bearings.

[0004]

The above prior art is shown in FIG.
As shown in FIG.
However, since it is housed and fixed in the bearing housing 17 fixed to the closed case 1, the coaxiality between the axis of the crankshaft 6 and the axis of the lower bearing 16 is strictly required during assembly.
Therefore, there is a problem in that the mounting accuracy of the frame 7 to the closed case 1 and the assembly accuracy of the bearing housing 17 to the closed case 1 must be strictly controlled.

When the scroll compressor is operated at high speed, centrifugal force is exerted by the balance weight 14 attached to the lower end of the rotor 12, and the crankshaft 6 is pulled in the balance weight direction, whereby the crankshaft 6 is pulled. 6 is bent, and at the lower end of the crankshaft 6, above the lower bearing 16,
As a result, a large amount of stress is applied to the lower two points, and the amount of wear increases with ordinary bearing metal, resulting in a significant increase in input. Furthermore, in order to maintain accuracy, it is necessary to press-fit the lower bearing 16 into the bearing housing 17 and then perform finishing with high accuracy, resulting in an increase in processing cost.

The present invention has been made to solve the above-mentioned problems of the prior art, and absorbs the inclination of the crankshaft during assembly to improve the coaxiality, improve the assemblability, and improve the assemblability during operation. It is an object of the present invention to provide a scroll compressor that prevents input increase due to bending of the lower end of the crankshaft, improves reliability, and has low noise. Another object of the present invention is to provide a scroll compressor capable of preventing the microscopic image sticking phenomenon that occurs under the condition that the supply state of the lubricating oil deteriorates and further improving the reliability.

[0007]

In order to achieve the above object, the structure of the first invention relating to the scroll compressor of the present invention is an electric motor and a compression mechanism connected to the electric motor in a closed container. The compression mechanism section has a spiral wrap on each end plate, and a fixed scroll and a swivel scroll that mesh with each wrap to form a compression chamber. A rotation preventing means for the orbiting scroll, a crankshaft for transmitting the rotational force of the electric motor to revolve the orbiting scroll, and a frame having a bearing for rotating the crankshaft, and supporting the crankshaft. In a scroll compressor in which bearings are provided on both sides of the electric motor, one of the bearings is a bearing having a self-centering function, and the material of the bearing is a carbon material.

In order to achieve the above object, the structure of the second invention relating to the scroll compressor of the present invention includes an electric motor and a compression mechanism portion connected to the electric motor in a closed container. The compression mechanism section has a spiral wrap on each end plate, and a fixed scroll and a swirl scroll that mesh with each wrap to form a compression chamber, and the swirl. A scroll rotation preventing means, a crankshaft for transmitting the rotational force of the electric motor to revolve the orbiting scroll, and a frame having a bearing for rotating the crankshaft are provided. The bearing for supporting the crankshaft is the electric motor. In scroll compressors installed on both sides of
One of the bearings has a self-aligning function, and the gap between the bearings is 0.008 to 0.030.
mm.

[0009]

The function of the above technical means is as follows. For the lower bearing that supports the lower end of the crankshaft, the shape of the inner surface of the lower bearing that contacts the outer diameter surface of the crankshaft is self-centering (almost spherical or with tapered shape), or the outer circumference of the bearing is spherical. Therefore, the crankshaft can freely change its posture in the lower bearing. Therefore, even if the crankshaft is tilted during assembly, or the centrifugal force of the balance weight at the lower end of the rotor acts on the crankshaft during operation, resulting in deformation of the crankshaft, the self-aligning function causes abnormalities. This has the effect of preventing unbalanced contact. Further, by using a carbon material for the lower bearing, it is possible to prevent a microscopic seizure phenomenon that occurs under the condition that the supply state of the lubricating oil deteriorates, and it is possible to improve reliability.

Further, the clearance between the lower bearings is 0.008 to
By setting the thickness to 0.030 mm, it is possible to reduce the noise value in the low frequency band generated between the lower bearings due to the contact with the crankshaft.

[0011]

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2. [Embodiment 1] FIG. 1 is a longitudinal sectional view of a scroll compressor according to an embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 3 indicate the same or corresponding portions as those in the conventional technique.
In FIG. 1, 1 is a hermetic case, 2 is a compression mechanism portion housed in the upper part of the hermetic case 1, and 3 is a fixed scroll in which a spiral wrap 3b is upright on an end plate 3a. 4 is
A spiral wrap 4b is upright on the end plate 4a, which is a swivel scroll, and the fixed scroll 3 and the swivel scroll 4 engage the respective laps 3b and 4b toward the inside to compress the compression chamber 5. Is formed.

Reference numeral 6 denotes a crankshaft, the eccentric portion 6a of which is fitted into the boss portion of the turning scroll 4 to transmit the rotational force of the electric motor 10 to revolve the turning scroll 4. The turning scroll 4 is prevented from rotating by the action of an Oldham ring (not shown). Reference numeral 7 denotes a fixed frame for accommodating the turning scroll 4 and fastening the fixed scroll 3.
Reference numeral 8 is a main bearing that is provided on the frame 7 and rotatably supports the crankshaft 6, 9 is a lower bearing located on the side opposite to the electric motor (lower side of the electric motor 10) with respect to the main bearing 8, and 13 is A bearing holder for the lower bearing 9.

The electric motor 10 includes a stator 11 and a rotor 12.
And the crankshaft 6 connected to the rotor 12,
It is configured to be supported by a main bearing 8 and a lower bearing 9 provided on both sides of the electric motor 10. The main bearing 8 is a plain slide bearing having a general inner diameter surface, and the lower bearing 9
Is a slide bearing whose inner diameter surface has a self-centering shape (substantially spherical shape) 9a. The material of the lower bearing 9 is a carbon material.

According to this embodiment, since the crankshaft 6 can freely change its posture in the lower bearing 9 by the self-aligning function, the inclination of the crankshaft 6 at the time of assembly can be absorbed and the assemblability can be improved. Can be improved. Similarly, it is possible to absorb the deflection of the crankshaft 6 during operation, prevent abnormal one-sided contact, and improve the reliability of the scroll compressor. Further, by using a carbon material as the material of the lower bearing 9, it is possible to prevent a microscopic seizure phenomenon that occurs under the condition that the supply state of the lubricating oil deteriorates, and further improve the reliability of the scroll compressor. be able to.

[Embodiment 2] FIG. 2 is a vertical sectional view of a scroll compressor according to another embodiment of the present invention. In the figure, those having the same reference numerals as those in FIG. In FIG. 2, the electric motor 1
The lower bearing 9A arranged on the lower side of 0 is a self-aligning bearing in which the outer peripheral portion of the bearing has a substantially spherical shape 9b, and the bearing housing 9c having an inner peripheral surface having a substantially spherical shape. Of 0.008 to 0.
It is 030 mm. The material of the lower bearing 9A is preferably a carbon material, but is not limited thereto.

In this embodiment, by setting the clearance between the lower bearings 9A to 0.008 to 0.030 mm, the noise value in the low frequency band generated between the lower bearings as the crankshaft 6 touches is reduced. can do. For example, 50
A reduction of 10 dB could be realized at 0 Hz to 630 Hz.
As described above, according to the embodiment of FIG. 2, the same effect as that of the embodiment of FIG. 1 can be obtained, and the assembling property of the scroll compressor can be improved and the reliability can be improved.

[0017]

As described above in detail, according to the present invention, the inclination of the crankshaft during assembly is absorbed to improve the coaxiality and improve the assemblability, and the lower end of the crankshaft during operation is improved. It is possible to prevent an increase in input due to bending, improve reliability, and provide a low-noise scroll compressor. Further, in particular, it is possible to provide a scroll compressor capable of preventing the microscopic image sticking phenomenon that occurs under the condition that the supply state of the lubricating oil deteriorates and further improving the reliability.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a scroll compressor according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a scroll compressor according to another embodiment of the present invention.

FIG. 3 is a vertical sectional view of a conventional scroll compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealed case 2 Compression mechanism part 3 Fixed scroll 4 Swing scroll 3a, 4a End plate 3b, 4b Wrap 5 Compression chamber 6 Crankshaft 7 Frame 8 Main bearing 9,9A Lower bearing 9a Self-aligning shape 9b Spherical shape 9c Bearing housing 10 Electric motor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigenya Kawaminami 800 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Hitachi Tochigi Plant (72) Inventor Atsushi Shimada 800, Tomita, Ohira-machi, Shimotsuga-gun, Tochigi Stock Company Hitachi Co., Ltd. Tochigi factory (72) Inventor Masanori Sudo 800 Tomita, Ohira-machi, Shimotsuga-gun, Tochigi Prefecture Hitachi Co., Ltd. Tochigi factory (72) Inventor Akio Machida, Ohira-machi, Shimotsuga-gun, Tochigi 800 Tomita Co., Ltd. Hitachi Ltd. Tochigi factory (72) Inventor Tatsuya Wakana 2 709 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Prefecture 2 Hitachi Tochigi Electronics Co., Ltd.

Claims (3)

[Claims] 1. A hermetically-sealed container for accommodating an electric motor and a compression mechanism portion connected to the electric motor, wherein the compression mechanism portion has a spiral wrap on each end plate. Fixed scroll and orbiting scroll that form a compression chamber by meshing the wraps, rotation preventing means of the orbiting scroll, and a crankshaft that revolves the orbiting scroll by transmitting the rotational force of the electric motor. In a scroll compressor having a frame having a bearing for rotating a crankshaft, the bearings supporting the crankshaft being provided on both sides of the electric motor, one of the bearings having a self-aligning function. At the same time, the scroll compressor is characterized in that the bearing material is a carbon material. 2. A hermetically-sealed container for accommodating an electric motor and a compression mechanism portion connected to the electric motor, wherein the compression mechanism portion has a spiral wrap on each end plate, Fixed scroll and orbiting scroll that form a compression chamber by meshing the wraps, rotation preventing means of the orbiting scroll, and a crankshaft that revolves the orbiting scroll by transmitting the rotational force of the electric motor. In a scroll compressor having a frame having a bearing for rotating a crankshaft, the bearings supporting the crankshaft being provided on both sides of the electric motor, one of the bearings having a self-aligning function. In addition, the clearance between the bearings of the bearing is 0.008 to 0.030.
A scroll compressor characterized by having a size of mm. 3. The scroll compressor according to claim 2, wherein the bearing material having a self-aligning function is a carbon material.