JPH056036B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in hermetic compressors used, for example, in refrigeration cycle devices.

[Prior Art] FIG. 1 shows a conventionally used hermetic compressor. This is an electric compressor main body 4 in which an electric motor section 2 and a compressor section 3 are arranged in series in a closed container 1. Both the electric motor section 2 and the compressor section 3 are provided on the rotating shaft 5. In the compressor section 3, an eccentric crank 6 is provided on the rotating shaft 5, and the gas to be compressed can be compressed with this eccentric rotational movement.

To further explain the rotating shaft 5, for example, as shown in FIG. 2A, an eccentric crank 6 may be formed integrally with casting, forging, or pipe material by bulging or other means, or as shown in FIG. 2B. There is one in which the rotating shaft 5 and the eccentric crank 6 are manufactured separately and press-fitted to form them.

[Problems to be Solved by the Invention] However, in either structure, all diameters except for the rotating shaft 5 and the eccentric crank 6 are the same. Minimum dimensional difference W between rotating shaft 5 and eccentric crank 6
has been determined and must be ensured.
Therefore, the diameter of the eccentric crank 6 is determined from the diameter of the rotating shaft 5. If this is made smaller, the diameter of the compressor section 3 becomes smaller, and the compressor itself can be made smaller. At present, it is not possible to reduce the diameter of the eccentric crank 6 in order to ensure the minimum dimensional difference W, and it is impossible to downsize the compressor.

Note that FIG. 3 shows an oil supply structure in a conventional compressor. That is, the oil suction hole 7 is vertically provided in the rotating shaft 5 from the bottom surface to the middle part thereof.
and a pair of oil guide holes 8a, 8b provided on the peripheral surface.
and communicates with an oil guide hole 8c provided on the circumferential surface of the eccentric crank 6. The reason why the two oil guide holes 8a and 8b are necessary in the rotating shaft 5 is to supply oil to the main bearing 9 and the sub-bearing 10 that pivotally support the rotating shaft 5, as shown in FIG.

This structure has good refueling efficiency, but
On the other hand, drilling and deburring are troublesome, and there is a risk of accidents such as galling of sliding parts due to residual chips.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to reduce the diameter of the eccentric crank as much as possible to downsize the compressor section, thereby reducing the overall size and ensuring smooth sliding. The present invention aims to provide a hermetic compressor that secures dynamic performance and improves oil supply efficiency.

[Means for Solving the Problems] The present invention provides an electric compressor main body in which a rotary compressor section is provided at a lower part of a rotating shaft and an electric motor section is provided at an upper part thereof is housed in an airtight container.
The rotating shaft has a stepped portion facing the compressor portion, and an eccentric crank made of a cylindrical body is provided on the small diameter portion of the rotating shaft, and the compressor portion is immersed in a reservoir of lubricating oil collected at the inner bottom of the closed container. and an oil guide path is provided in the small diameter portion of the rotating shaft to suck up lubricating oil from the reservoir,
This hermetic compressor is characterized in that it communicates with an oil groove provided on the inner circumferential surface of the eccentric crank.

[Operation] The diameter of the eccentric crank is reduced, making the compressor section and compressor smaller.

Furthermore, the oil guide path and the oil groove do not directly face the sliding portion, ensuring smooth sliding and sufficient oil supply efficiency.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. Figure 4 shows a hermetic compressor. 11 in the diagram
is a sealed container, and the electric compressor body 1 is installed inside this container.
2 is accommodated, and the inner bottom has an oil reservoir 13 for lubricating oil.
is formed. The electric compressor main body 12 has an electric motor section 14 in the upper part and a compressor part 15 in the lower part. The electric motor section 14 includes a rotor 17 fitted onto a rotating shaft 16, and a stator 18 fitted into the closed container 11 with a narrow gap between the rotor 17 and the rotor 17. The compressor section 15 includes a main bearing 19 and a sub-bearing 20 that pivotally support the rotating shaft 16, a cylinder 21 provided between the main bearing 19 and the sub-bearing 20, and an eccentric cylindrical body provided on the rotating shaft 16. It consists of an eccentric crank 22, a roller 23 that fits into the eccentric crank 22, and the like.

As shown in FIGS. 5A and 5B, the rotary shaft 16 is provided with a stepped portion 16a on its lower side, and has a small diameter portion 16b at its lower end. This small diameter portion 16
The eccentric crank 22 is fitted to b. The minimum dimensional difference W between the small diameter portion 16b and the eccentric crank 22 is determined from the viewpoint of strength and safety, as in the prior art. Moreover, these eccentricities are the same eccentricity dimension e as in the conventional case.

By energizing the electric motor section 14, the rotating shaft 16 rotates, and the eccentric crank 22 and the roller 23 rotate eccentrically. Gas to be compressed is sucked into the cylinder 21, compressed, and discharged. Although the diameter of the eccentric crank 22 is smaller than before, its function and effect are the same.

For example, the diameter of the rotating shaft 16 is 20 m/m, the diameter of the small diameter portion 16b is 14 m/m, and the minimum dimensional difference W is
2m/m and the eccentricity e is 4m/m, the diameter of the eccentric crank 22 is 26m/m. However, the minimum dimensional difference W and the amount of eccentricity e must be ensured even in the past, and the conventional rotating shaft 5 has no small diameter part and is straight, so if this diameter is set to 20 m/m,
The diameter of the eccentric crank 6 is 32 m/m. Therefore, if configured as in the present invention, the diameter of the rotating shaft 16 is the same as the conventional one, and the small diameter portion 16
By providing b, the diameter of the eccentric crank 22 can be made smaller than that of the conventional crank.

In addition, as shown in FIGS. 6A and 6B, the rotating shaft 16 may be formed so that the small diameter portion 16b is obtained from a pipe material. The eccentric crank 22 is press-fitted into this small-diameter portion 16b, or loosely fitted thereinto, and then fixed by appropriate means. When the oil guide hole 25 is bored in a portion of the small diameter portion 16b facing the eccentric crank 22, an oil guide path 26 is formed between this hole and the hollow portion of the rotating shaft 22. An oil groove 27 is provided on the inner circumferential surface of the eccentric crank 22 at a portion facing the oil guide hole 25 . Here, the oil groove 27 is different from the portion forming the minimum dimensional difference W previously explained in FIG. 5B on the eccentric crank 2.
The position is set on the inner circumferential surface of the thick eccentric portion on the opposite side via the axis of the eccentric crank 22, and is carved from the upper end surface to the lower end surface of the eccentric crank 22. The lower end of the rotating shaft 16 is immersed in the reservoir 13 .

As the rotating shaft 16 rotates, lubricating oil is sucked up along the oil guide path 26. Furthermore, the lubricating oil flows from the oil groove 27 to the small diameter portion 16b and the stepped portion 1.
6a, the oil is guided to the outer peripheral surface of the eccentric crank 22, and each sliding portion is supplied with oil. From this, the conventional 3
Instead of the oil holes 8a, 8b, 8c, only the oil groove 27 provides sufficient oil supply efficiency. Moreover, the oil groove 27
is provided on the inner peripheral surface of the eccentric crank 22, and the oil guide hole 25 is provided on the small diameter portion 16b of the rotating shaft 16, so that neither the oil groove 27 nor the oil guide hole 25 directly faces the sliding portion. Therefore, there is no occurrence of galling accidents due to poor finishing accuracy during deburring.

By configuring as shown in FIG. 6, reliable oil supply efficiency can be obtained with simple machining. However, if the eccentric crank 22 is formed by sintered alloy or forging, for example, the oil groove 27 may affect the cost. You can prepare without having to do anything.

Note that the step portion may be formed in multiple steps.

[Effects of the Invention] As explained above, in the present invention, the rotary shaft is stepped at the part facing the compressor part, and the eccentric crank made of a cylindrical body is provided in the small diameter part, so that the diameter of the eccentric crank can be reduced. The compressor section can be made smaller,
Therefore, the hermetic compressor can be made smaller.

In addition, since the oil guide path was provided on the small diameter part of the rotating shaft and communicated with the oil groove provided on the inner peripheral surface of the eccentric crank made of a cylindrical body, the oil guide path and oil groove do not directly face the sliding part. Therefore, there is no occurrence of galling accidents due to the finish accuracy of the deburring process, and sufficient oil supply efficiency can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of a conventional hermetic compressor according to the present invention, Fig. 2 A and B are front views of the rotating shaft, and Fig. 3
The figure is a front view of the main parts of the rotating shaft showing the oil supply groove structure, FIG. 4 is a longitudinal sectional view of a hermetic compressor showing an embodiment of the present invention, and FIG. 5A is an exploded view of the rotating shaft and eccentric crank. , FIG. 6B is a cross-sectional view thereof, FIG. 6A is a vertical cross-sectional view of a main part of a rotating shaft according to an embodiment of the present invention, and FIG. 6B is a cross-sectional view thereof. 16... Rotating shaft, 15... Compressor section, 14...
Electric motor section, 12...Electric compressor main body, 11...Airtight container, 16b...Small diameter section, 22...Eccentric crank, 13...Sump portion, 26...Oil guide path, 27...
...oil groove.

Claims (1)

[Claims] 1. An electric compressor main body, which has a rotary compressor section at the bottom and a motor section at the top, is housed in a sealed container, and the rotating shaft has a stepped section facing the compressor section. , an eccentric crank made of a cylindrical body is provided in the small diameter part of the compressor part, and the compressor part is immersed in a reservoir of lubricating oil collected at the bottom of the closed container, and the lubricating oil is supplied from the reservoir to the small diameter part of the rotating shaft. A hermetic compressor characterized by being provided with an oil guide path for sucking up oil, which communicates with an oil groove provided on the inner circumferential surface of the eccentric crank.