JPS61218785A - Oil supply device of closed-type motor-driven compressor - Google Patents

Abstract

PURPOSE:To make pump up possible regardless of coefficient of viscosity of oil, and to try to simplify the structure and fitting work of a U-shaped auxiliary piece into an oil supply pump by fitting the piece into the pump and giving the oil a centrifugal force with the oil held in the U-shaped part. CONSTITUTION:An auxiliary piece 3 is fitted into an oil supply pump 1c, as shown by one chain line, due to a bent part 3a and legs 3b, 3c having spring feature provided on the auxiliary piece 3 only by fitting the U-shaped 3d auxiliary piece 3 into the oil supply pump 1c as an arrow mark shows. Meanwhile, since acting in the direction opposite to coming out direction, the legs 3b, 3c prevent the auxiliary piece 3 from coming out, and also fix the auxiliary piece 3 into the oil supply pump 1c since having spring feature. In this way, the U-shaped 3d auxiliary piece 3 is fitted into the oil supply pump 1c, the oil is given the centrifugal force, as being held in the U shape 3d, pump up is made to be possible regardless of the coefficient of viscosity of the oil, and the structure is enabled to be simplified as well as fitting the piece 3 into the pump 1c is made to be easy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a viscous oil supply system for a hermetic electric compressor, and it solves the problem of a viscous oil supply system in that when the viscosity of the oil decreases, the amount of oil pumped up decreases. This is an improvement on the defects.

Recently, small hermetic electric compressors used in refrigerators, etc., have been using crankshafts that are made of plastically worked steel pipes and only have their sliding parts ground.

This has the advantage of simplifying the machining process and making it cheaper, but due to limitations on the degree of plastic working, a viscous oil supply pump is required, so when the load becomes heavy and the compression work increases, this The heat generated by the compression work increases the temperature of the oil, which lowers the viscosity of the oil, resulting in a decrease in the amount of oil pumped up, resulting in an insufficient amount of oil supplied to the sliding parts.

Hereinafter, the conventional device will be explained with reference to the drawings.

FIG. 1 is a longitudinal sectional view of the crankshaft.

The crankshaft 1 shown in FIG. 1 is made by plastic working a steel pipe and grinding the sliding parts, and has a crank pin part 1a at the top and a crank journal part 1b in the middle.

It has an oil supply pump 1c at the bottom. This oil pump 1
Since c is made from a steel pipe, it is inevitably a circular, gently tapered viscous oil pump as shown in FIG. 1, which utilizes the viscosity of oil due to restrictions on the drawing ratio during plastic working. Next, this viscous oil supply pump will be explained. This oil supply pump IC is immersed in oil 2, as shown in FIG.

When the crankshaft 1 rotates, oil adheres to the inner surface 1d of the oil supply pump IC due to the viscosity of the oil 2, so the oil 2 that adheres also rotates.

Since centrifugal force is generated in the rotated oil 2 and the inner surface 1d of the oil supply pump 1c is inclined, an upward thrust is generated in the oil 2, and the oil 2 is pushed against the inner surface of the crankshaft 1. The viscous oil pump described above uses the viscosity of the oil, so when the load becomes heavy, the heat generated at this time causes the oil to rise. As the temperature increases, the viscosity of the oil decreases, and the amount of oil adhering to the inner surface 1d decreases, resulting in a decrease in the amount of oil pumped up, which has the disadvantage that the amount of oil supplied to the sliding parts is insufficient. .

In addition, in recent years, it has been confirmed that reducing the viscosity of oil and reducing the viscous resistance of oil in sliding parts has a great effect on power saving. For the above reasons, there has been a trend in recent years to reduce the viscosity of oil, and this type of oil pump has become a major bottleneck in reducing power consumption.

However, to deal with this with a steel pipe crankshaft,
This problem can be solved by changing the circular cross section of the oil pump to an extreme ellipse and incorporating the elements of an eccentric pump. However, in this case, the reduction ratio during plastic working becomes even higher (which increases the number of processing steps, and requires the use of special materials because cracks occur), resulting in a significant cost increase. The problem is that the advantages of the steel pipe crankshaft are lost.

In view of the above, an object of the present invention is to invent an inexpensive auxiliary piece that has a simple structure and good insertability, and to insert this into a fuel pump in order to improve these drawbacks. This is to ensure that the advantages of the steel pipe crankshaft are not lost.

In other words, in a viscous oil pump, when the viscosity decreases, the amount of oil adhering to the inner surface of the oil pump decreases (therefore, the amount of oil supplied decreases), so this can be prevented. Therefore, the present invention involves inserting a U-shaped auxiliary piece into the oil supply pump, allowing oil to flow into the U-shape, applying centrifugal force to the oil, and pumping up the oil regardless of the viscosity of the oil. Moreover, the auxiliary piece has a simple structure, can be easily attached, and has a structure that prevents it from coming off.

An embodiment of the present invention will be described below with reference to FIGS. 2 to 6.

FIG. 2 shows a perspective view of the auxiliary piece of the invention.

The auxiliary piece 3 is made of a spring plate, and has a U-shaped cross section 3d, with a folded part 3a at one end, and the other end is bent at the upper part of the U-shape. Legs 3b and 3C, which are more rectangular, extend upward in the U-shape.

Figure 3 shows the oil supply pump 10 of the crankshaft 1.
This shows an assembly method for attaching the auxiliary piece 3. By simply inserting the auxiliary piece 3 into the fuel pump 1c as shown by the arrow, the folded part 3a provided on the auxiliary piece 3 is attached.
The legs 3b and 3t having spring properties are attached to the oil supply pump lc as shown by the dashed lines.

On the other hand, the legs 3b and 3c act in the opposite direction to the coming off, so they prevent the auxiliary piece from coming off, and at the same time, they have spring properties, so they fix the auxiliary piece 3 in the oil supply pump lc. It also has a role to play.

As described above, the auxiliary piece 3 of the present invention is characterized in that it is simple in structure and therefore inexpensive, and is also very easy to attach to the fuel pump 1c.

Next, the pump action will be explained. FIG. 4 shows a cross section taken along line AA' in FIG. 3 with the auxiliary piece inserted into the oil supply pump.

In FIG. 4, N indicates the rotation direction, and when rotated in the N direction, the U-shaped portion 3d of the auxiliary piece 3 and the U-shaped portion 3
Since the oil 2 shown on the outside of d rotates at the same speed as the oil supply pump IC, sufficient centrifugal force can be obtained.

Therefore, a sufficient pump-up amount can be ensured.

As explained above, in the case of the present invention, the method for pumping up the oil 2 is made so that it is not related to the viscosity of the oil 2, so the viscosity of the oil can be significantly reduced, which has a large effect on power saving. There is.

Furthermore, the auxiliary piece 3 of the present invention has a simple shape and is easy to assemble, so it is inexpensive and does not diminish the advantages of the steel pipe crankshaft.

On the other hand, if there is sufficient margin for the pump-up amount, the cross section should be made into an L-shape as shown in the auxiliary piece 4 shown in Fig. 5, and the wall 4a
If it is provided on the opposite rotation direction side, oil can be collected in this L-shaped part, so it can be pumped up regardless of the viscosity of the oil. Furthermore, the shape is simplified, so it is cheaper. It can be done.

Further, if it is desired to further prevent the auxiliary piece from being pulled out, it is preferable to form a cut-down portion 5a on the side of the mating part, as in the case of the auxiliary piece 5 shown in FIG.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional steel pipe crankshaft;
The figure is a perspective view of the auxiliary piece of the present invention, Figure 3 is an explanatory diagram showing a method for inserting the auxiliary piece into the oil pump of the crankshaft, and Figure 4 shows the auxiliary piece inserted into the oil pump. 3 is a cross-sectional view of person A', FIG. 5 is a perspective view of an auxiliary piece of the present invention whose shape is further simplified, and FIG. It is a perspective view of a piece. 1... Crankshaft, la... Crank bin part, lb... Crank journal part, 1c... Oil supply pump, 1d... Inner surface, 2... Oil, 3... Auxiliary piece, 3 G...Folded part, 3b, 3c...legs, 3d...
... U-shaped part, 4 ... Auxiliary heath, 4a ... Wall, butt ... Auxiliary piece, 5 straight ... Cut-down part.

Claims (1)

[Claims] 1. A viscous oil pump formed by plastically working a steel pipe into a tapered shape, the inside of which has a U-shaped cross section and a part of the end that is folded back. In addition, at the other end, a piece is inserted that is bent at the top of the U-shape and has a strip-like leg extending upwardly from the U-shape. A unique oil supply system for hermetic electric compressors. 2. The oil supply device for a hermetic electric compressor according to claim 1, characterized in that the oil supply device is formed by inserting a piece having an L-shape in cross section. 3. A patent claim characterized in that a piece is inserted into a part of the bottom surface of the piece that comes into contact with the inner surface of the steel pipe, and is opened in the opposite direction of insertion and has a claw that bends toward the contact surface side. A lubricating device for a hermetic electric compressor according to scope 1.