JPS63255580A - Crankshaft of electric compressor - Google Patents

Abstract

PURPOSE:To improve the oil rising performance by forming a spiral oil groove through the plastic press working onto the outer peripheral surface of a crankshaft and forming the inner peripheral surface of the crankshaft as oil rising passage. CONSTITUTION:The body 5g of a crankshaft 5 having an oil hole 5a, oil feeding pump part 5b, shaft part 5c, joint part 5d with a rotor, oil holes 5e and 5f is formed by plastic-working a steel pipe. A spiral oil groove 5h is formed by the press-working onto the outer periphery of the shaft part 5c, and a projection part 5i corresponding to the oil groove 5h is formed onto the inner peripheral surface of the shaft part 5c. Therefore, a portion of the oil rising in the oil hole 5a can be introduced into the oil groove 5h, and the rising oil quantity can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to the structure of a crankshaft used in an electric compressor.

(B) Prior Art Conventionally, the crankshaft of this type of electric compressor has been described in Japanese Patent Publication No. 61-27594 and has been formed as shown in FIG. 5 or 6.

What is shown in Fig. 5 is an oil hole 10 and an inverted conical oil pump part 1 made by plastically working a wooden steel pipe material.
1. A main body 15 having a shaft part 12, a rotor joint part 13, and a sleeve hole 14 is formed, and a balancer 16 is installed at the upper end of this main body.
and the crank bin 17 are fixedly attached to each other. Also,
An oil groove 1 is formed on the outer peripheral surface of the shaft portion 12 by cutting.
8 is formed. Also, what is shown in Fig. 6 is the fifth
By plastic working a single steel pipe material as shown in the figure, an oil hole 20, an inverted conical oil supply pump part 21, and a shaft part 2 are formed.
2, a main body 25 having a rotor joint 23 and a sleeve hole 24;
The balancer 26 and the crank bin 27 are fixed to the upper end of the main body, and the oil groove 28 provided in the shaft part 22 is formed by pressing the shaft part from the outside all the way around. It is formed.

In each of the above crankshafts, the oil holes 10 and 20 are
The oil stored at the bottom of the sealed case is pumped up through the
Oil is introduced from the oil chambers 14, 24 to the outer peripheral surface of the shaft and the oil grooves 1B, 28 to lubricate the shaft portions 12, 22, while oil is ejected from the upper end openings of the crank bins 17, 27 to prevent the sliding parts of the crank bins from sliding. It's lubricated.

(c) Problems to be Solved by the Invention However, the above configuration has the following problems, and improvements are desired.

First, according to the configuration shown in FIG. 5, the oil groove 18 is formed by cutting, which is a troublesome work that generates cutting powder, and this part becomes thin, which causes a problem of reducing the strength of the shaft part. Ta.

Further, according to the configuration shown in FIG. 6, since the oil groove 28 is formed by pressing, the wall thickness of the shaft portion 22 is kept uniform, and there is no problem of strength reduction as described above. Since the inner circumferential surface of the shaft portion 22 corresponding to the oil groove 28 protrudes inward over the entire circumference, this protruding portion acts as a resistance when oil rises, reducing the amount of oil rising to the crank bottle 27. There was a problem in that poor lubrication was likely to occur at the sliding part of the pin.

The present invention has been made in view of the above, and an object of the present invention is to provide a crankshaft which has good lubrication characteristics on the outer circumferential surface of the shaft portion and can improve oil flow inside the oil hole without causing a decrease in the strength of the shaft portion. purpose.

(d) Means for Solving the Problems The present invention provides an electric compressor in which an electric motor section and a compressor section are connected by a crankshaft made of a steel pipe with an oil groove provided on the outer circumferential surface of the crankshaft. A spiral oil groove is formed by plastic pressing, and the inner circumferential surface of the crankshaft excluding the protrusion corresponding to the oil groove is used as an oil upstream passage.

(E) Function The crankshaft of the electric compressor of the present invention has the above-mentioned structure, so that an oil groove is formed on the outer peripheral surface of the shaft, and at the same time, the inner peripheral surface of the shaft has a large rotation radius (the maximum rotation radius of the crankshaft). It is possible to form an oil passage (same as the inner diameter), and by pressing the oil groove, the wall thickness of the shaft part is kept uniform, which not only prevents a decrease in the strength of the crankshaft, but also prevents the crankshaft's centrifugal pump action. A part of the oil that rises in the oil hole is led out from the oil chamber to the outside of the shaft and supplied to the oil groove to lubricate the sliding surface of the shaft. The oil can be raised to the upper end of the crankshaft via the spiral oil passage (which has no resistance and has a high oil climbing rate), allowing for an increase in the amount of oil rising and lubrication on the sliding surfaces of both the shaft and crankshaft. It is something that can improve the characteristics.

(f) Example Embodiments of the present invention will be described below based on the drawings.

1 is a sealed case 2 in which lubricating oil is stored at the bottom, a compressor part 3 is housed in the upper part, and an electric motor part 4 is housed in the lower part, and these two parts 3 and 4 are connected by a crankshaft 5. This is an electric compressor.

The crankshaft 5 has an oil hole 5a and an inverted conical oil pump portion 5b formed by plastically working a single steel pipe material.
, a shaft portion 5c corresponding to the bearing 6, a joint portion 5d of the rotor 7,
A main body 5g having oil chambers 5e and 5f provided at the upper and lower ends of the shaft portion 5c is formed, and a balancer 8 is provided at the upper end of this main body.
It is formed by respectively joining crank bins 9 to the upper surface of the balancer. Further, a spiral oil groove 5h is formed on the outer peripheral surface of the shaft portion 5c of the main body 5g by pressing, and at the same time, an oil groove 5h is formed on the inner peripheral surface of the shaft portion 5c.
A protrusion 51 corresponding to h is formed.

Thereby, a spiral oil passage 5j whose radius is equal to the maximum radius of the oil hole 5a is formed between the protrusions 51 on the inner circumferential surface of the shaft portion 5c.

In the electric compressor configured in this manner, the lubricating oil stored at the bottom of the sealed case 2 is transferred to the crankshaft 50.
The oil rises inside the oil hole 5a due to the action of a centrifugal pump due to rotation. A part of the oil rising in the oil hole is guided to the outer peripheral surface of the shaft portion 5c and the oil groove 5h via the oil chamber 5e, and is completely supplied to the sliding surface of the shaft portion. Furthermore, most of the remaining oil rising inside the oil hole 5a rises along the spiral oil passage 5j, which has a large rotation radius and no resistance, and flows between the upper ends of the crank pin 9 [19a The liquid is ejected from the pin and supplied to the sliding portion of the pin.

That is, according to the configuration of the present invention, the oil groove 5h is connected to the shaft portion 5C.
Since the shaft portion 5C is formed by pressing from the outside, the wall thickness of the shaft portion 5C can be maintained uniformly, and a decrease in strength of the crankshaft 5 can be prevented. In addition, part of the oil rising in the oil hole 5a due to the centrifugal pump action of the crankshaft 5 can be guided to the oil groove 5h via the oil fillers 5e and 5f', and the sliding surface of the shaft portion 5C lubrication can be performed. Furthermore, most of the oil rising inside the oil hole 5a can be made to rise along the spiral oil passage 5j, which has a large rotation radius and has no protrusions that create resistance, so that the amount of oil rising can be reduced. As a result, the lubrication characteristics of the sliding surface of the crank pin 9 can be improved.

In addition, since the oil groove 5h is formed at the center position of the shaft portion 5C where surface pressure is applied to the crankshaft 5 (large surface pressure is applied to the upper and lower ends of the shaft portion 5C due to compression load),
Oil supply to the oil groove 5h is performed smoothly, and the lubrication characteristics of the sliding surface of the shaft portion 5C can be improved. The arrows in FIG. 2 indicate the distribution of surface pressure. Furthermore, since the oil groove 5h formed by the pressing process is arranged on the high load side of the outer peripheral surface of the crankshaft 5 (the same direction or opposite to the eccentric direction of the crank bin 9), The surface pressure strength of the crankshaft 5 can be increased, and durability and reliability can be improved.

(G) Effects of the Invention As described above, the present invention provides an electric compressor in which an electric motor section and a compressor section are connected by a crankshaft made of a steel pipe with an oil groove provided on the outer circumferential surface. A spiral oil groove is formed by plastic pressing, and the inner circumferential surface of the crankshaft, excluding the protrusion corresponding to this oil groove, is used as an oil passageway, so the outer circumferential surface of the shaft of the crankshaft At the same time as forming an oil groove in the shaft, a spiral oil flow path with a large rotation radius can be formed on the inner peripheral surface of the shaft, which not only improves the strength of the crankshaft but also increases the amount of oil flow. This can improve the lubrication characteristics on the sliding surfaces of the shaft and crankbin.

[Brief explanation of drawings]

Figures 1 to 4 show embodiments of the present invention, with Figure 1 being a cutaway sectional view of essential parts of an electric compressor, Figure 2 being a front view of the crankshaft, and Figure 3 being a longitudinal sectional view of the crankshaft. , 4th
The figure is a cross-sectional view taken along the line AA' section of the crankshaft shown in FIG. 2, and FIGS. 5 and 6 are vertical cross-sectional views of essential parts of the crankshaft, respectively, showing conventional examples. 5...Crankshaft, 5h...Oil L5i...
・Protrusion, 5j...Oil upstream passage.

Claims (2)

[Claims] (1) In an electric compressor in which an electric motor section and a compressor section are connected by a crankshaft made of a steel pipe with an oil groove provided on the outer circumferential surface, a spiral oil groove is formed on the outer circumferential surface of the crankshaft by plastic pressing. A crankshaft for an electric compressor, characterized in that the inner circumferential surface of the crankshaft, excluding the protrusions corresponding to the oil grooves, is used as an oil upstream passage. (2) A crankshaft for an electric compressor according to claim 1, wherein the oil groove is formed at a position where surface pressure applied to the crankshaft is small.