JPS59115491A - Enclosed compressor - Google Patents

Abstract

PURPOSE:To make the diameter of an eccentric crank reducible to the smallest possible extent as well as to aim at the miniaturization of a device as a whole, by installing a stepped rotation shaft in the opposite part to a compressor part, and also installing an eccentric crank in a small diametral part of this rotation shaft, while securing a minimum dimensional difference between the eccentric crank and the rotation shaft. CONSTITUTION:A rotation shaft 16 is provided with a stepped part 16a at its lower side, while the lower end is made up of a small diametral part 16b in which an eccentric crank 22 is fitted. When the diameter of the rotation shaft 16 is set to 20mm., the diameter of the small diametral part 16b to 14mm., a minimum dimensional difference W to 2mm., and an eccentric amount (e) to 4l respectively, the diameter of the eccentric crank 22 comes to 26mm.. However, a conventional rotation shaft has no small diametral part and is of straight in type, so that when its diameter is adjusted to 20mm., the eccentric crank 22 comes to 32mm. in diameter. Like this, without altering the existing diameter of the rotation shaft 16, the diameter of the eccentric crank 22 can be made smaller with the small diametral part 16b installed anew, thus the miniaturization of a device is well promoted.

Description

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

[Technical background of the invention and its problems]

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, FIG. 2 (A
), the eccentric crank 6 is formed by casting, forging, or pipe material integrally formed by Parno processing, or as shown in the same figure (B), the rotating shaft 5 and the eccentric crank 6 There are those that are manufactured separately and press-fitted into shape.

However, regardless of the structure, all the rotating shafts 5 except for the eccentric crank 6 have the same diameter. The minimum dimensional difference W between the rotating shaft 5 and the eccentric crank 6 is 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. Currently, it is impossible to reduce the diameter of the eccentric crank 6 without ensuring 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, an 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 and 8b are provided on the circumferential surface, and an oil guide hole 7 is provided on the circumferential surface of the eccentric crank 6. It communicates with the hole 8c. The reason why the two oil guide holes 81L and 8b are necessary in the rotating shaft 5 is to supply oil to the main bearing 9 and the sub-bearing 1θ that pivotally support the rotating shaft 5, as shown in FIG.

This structure provides good oil supply efficiency, but on the other hand, machining and deburring of holes is troublesome, and there is a risk of accidents such as scratching of sliding parts due to residual chips.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to reduce the size of the compressor section by reducing the diameter of the eccentric crank as much as possible, and to create a hermetic seal that achieves overall miniaturization. The aim is to provide a compact compressor.

[Summary of the invention]

The present invention includes a rotating shaft with a stepped portion facing the compressor section, and an eccentric crank is provided on the small diameter portion of the rotating shaft to ensure a minimum dimensional difference from the rotating shaft.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on the drawings.

Figure 4 shows a hermetic compressor. In the figure, reference numeral 11 denotes a closed container, in which an electric compressor main body 12 is housed, and an oil reservoir 13 for lubricating oil is formed at the inner bottom. The electric compressor main body 12 has an electric motor section 14 at the top and a compressor section 1 at the bottom.
5 in a row. 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, and these main bearings 19 and sub-bearings 20.
It consists of a cylinder 21 provided between the rotary shaft 16, an eccentric crank 22 provided on the rotating shaft 16, a roller 23 fitted to the eccentric crank 22, and the like.

As shown in FIGS. 5(A) and 5(B), the rotating shaft 16 is provided with a stepped portion 16& on its lower side, and the lower end thereof is a small diameter portion 16b. The eccentric crank 22 is fitted into this small diameter portion 16b.

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.

Therefore, by energizing the electric motor section 14, the rotating shaft 1
6 rotates, and together with this, the eccentric crank 22 and roller 23 rotate eccentrically. Gas to be compressed is sucked into the cylinder 21, compressed, and discharged. eccentric crank 22
Although the diameter is smaller than before, its function and effect are the same.

For example, if the diameter of the rotating shaft 16 is 20%, the diameter of the small diameter portion 16b is 14%, the minimum dimensional difference W is 2%, and the eccentricity e is 4%, the diameter of the eccentric crank 22 is 26%. However, the minimum dimensional difference W and the amount of eccentricity e have to be maintained as before, and the conventional rotating shaft is straight without a small diameter part, so if the diameter is set to 20~, the diameter of the eccentric crank 22 will be 32%. becomes. Therefore, according to the present invention, the diameter of the eccentric crank 22 can be reduced by providing the small diameter portion 16b without changing the diameter of the rotating shaft 16 from the conventional one.

In addition, as shown in FIGS. 6(A) and (B), the rotating shaft 1
6 may be formed so as to obtain the small diameter portion 16b from the base material. The eccentric crank 22 is press-fitted or loosely fitted into this small-diameter portion 16b, and then fixed by appropriate means. Small diameter part 16
When the oil guide hole 25 is bored in the portion facing the eccentric crank 22 in b, an oil guide path 26 is formed between this hole and the hollow portion of the rotating shaft 22. On the inner peripheral surface of the eccentric crank 22,
An oil groove 27 is provided at a portion opposite the oil guide hole 25 . This oil groove 27 is carved from the upper end surface to the lower end surface of the eccentric crank 22. The lower end portion of the rotating shaft 16 is immersed in the above-mentioned ridge portion 13 .

As the rotating shaft 16 rotates, lubricating oil is sucked up along the oil guide path 26. Furthermore, the lubricating oil is oil groove 2.
7 to the small diameter portion 16b and the step portion 16a, the eccentric crank 2
The oil is guided to the outer peripheral surface of No. 2, and each sliding portion is supplied with oil. From this, instead of the conventional three oil holes 8a, 8b, 8c,
Sufficient oil supply efficiency is obtained using only the oil groove 27. Moreover, oil groove 2
7 and the oil guide hole 25 do not directly face the sliding part, and therefore galling accidents are likely to occur due to poor finishing accuracy during the deburring process.

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.

〔Effect of the invention〕

As explained above, the present invention has a stepped part of the rotating shaft facing the compressor part, and an eccentric crank is provided in the small diameter part, so the diameter of the eccentric crank can be reduced, the compressor part can be downsized, and this Therefore, the hermetic compressor can be made smaller.

Furthermore, since the oil guide path is provided in the small diameter portion of the rotating shaft and communicates with the oil groove provided in the inner circumferential surface of the eccentric crank, sufficient oil supply efficiency can be obtained with a simpler structure than the conventional one.

Furthermore, by molding the rotating shaft from Iso material, it is possible to reduce costs and facilitate step machining.

Furthermore, by forming the eccentric crank using a method such as sintered metal or forging, costs can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of a hermetic compressor showing a conventional example of the present invention, Figs. 2 (A) and (B) are front views of the rotating shaft, and Fig. 3 is a main part of the rotating shaft showing the oil supply structure. A front view, FIG. 4 is a vertical sectional view of a hermetic compressor showing an embodiment of the present invention, and FIG.
) is an exploded view of the rotating shaft and eccentric crank, FIG. 6(B) is a cross-sectional view thereof, and FIG. B) is a cross-sectional view thereof. 16... Rotating shaft, 15... Compressor section, 14... Electric motor section, 12... Electric compressor main body, 1... Sealed container, 16b ... Small diameter part, 22 ... Eccentric crank, 1
3... Reservoir portion, 26... Oil guide path, 27... Oil groove.

Claims (4)

[Claims] (1) In an electric compressor body that is housed in an airtight container and has a rotary compressor section at the bottom of the rotating shaft and an electric motor section at the top, the rotating shaft has a stepped section facing the compressor section. , a hermetic compressor characterized by having an eccentric crank in its small diameter section. (2) The compressor section 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 section of the rotating shaft to suck up the lubricating oil from the reservoir, and the eccentric crank 2. The hermetic compressor according to claim 1, wherein the hermetic compressor communicates with an oil groove provided on an inner circumferential surface of the compressor. (3) The hermetic compressor according to claims 1 and 2, characterized in that the rotating shaft is made of a rubber material. (4) The hermetic compressor according to any one of claims 1 to 3, wherein the eccentric crank is formed using a method such as sintered metal or forging.