JPS5825594A - Rotary shaft for totally-closed motor compressor - Google Patents

Abstract

PURPOSE:To check a slippage phenomenon as well as to aim at securing a proper of lubrication, by making up a spiral groove, which makes oil progressively go up in accordance with the rotating direction of a steel pipe shaft, in a bore on top of the shaft in order to continuously feed lubricating oil to the upper part of the said bore by way of the spiral groove. CONSTITUTION:A spiral groove 1i, which makes oil progressively go up in accordance with the rotating direction of a steel pipe shaft 1, is made up in a bore on top of the shaft 1 equal to a shaft part 1a in size. The spiral groove is formed by machining or anelastic working so as to become a section shown in illustration. As a result, lubricating oil being forcibly pressed to the inside wall side by dint of centrifugal force as the steel pipe shaft 1 rotating is scooped up by the spiral groove 1i and continuously fed to the upper part of the steel pipe shaft 1 bore. In consequence, in comparison with the conventional method, a rise in a friction factor between the pipe inside wall and lubricating oil as well as a slippage phenomenon caused by a lowering of viscosity incident to an oil temperature rise by compressor operation can be all checked and, what is more, dropping the amount of lubrication can be obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of an oil supply pump having a shaft portion and an eccentric portion formed by plastic working of a single steel tube.

Fig. 1 shows the form of a general steel pipe shaft made of steel pipe as the basic material. 1 is a rotating shaft, and the rotating shaft 1 is roughly divided into a shaft part 1a that rotates around the axis and an eccentric part 1b, both of which are It is formed from a single steel pipe connected by a stepped bent portion 1C formed by plastic working.

Further, a balance weight 2 is attached to the upper part of the shaft portion 1a to absorb the unbalance caused by the operation of the compression mechanism portion. Further, an oil filler 1d, an oil groove 1e, and an oil reservoir 1f are formed in the shaft portion 1a and the eccentric portion 1b. As shown in the figure, the tip of the steel pipe shaft is formed with an oil supply pump part 1g having a constricted opening, and a flat pressed part 1h for the purpose of preventing a decrease in the amount of oil supplied due to slippage of the lubricating oil with the inner wall of the constricted part. There is.

For the purpose of applying centrifugal force to the lubricating oil, the orifice diameter is usually about 1 h of the inner diameter of the steel pipe shaft, and as the steel pipe shaft rotates, the lubricating oil flows into various parts as shown by the arrows. supplied to However, as shown in Fig. 1, the oil pump structure in which a neck-drawn shape is formed on the steel pipe shaft is not easy to use due to the work hardening of the neck-drawing process, although it varies somewhat depending on the wall thickness and material of the steel pipe itself.
Furthermore, since the flat pressed portion 1h is formed with an unbalanced stress during plastic working, cracks may occur during molding and the intended oil pump function may not be achieved. In addition, since the load required for plastic forming becomes extremely large, when forming this steel pipe shaft using a multi-station transfer press, an imbalance in the forming load may occur and the overall forming accuracy may deteriorate. There is.

Therefore, the present invention aims to compensate for these problems in plastic working and the performance defects caused thereby.

FIG. 2 shows an example of a steel pipe shaft according to the present invention, in which a spiral groove 11 is formed on the inner diameter of the tip end of the steel pipe shaft 1 having the same diameter as the shaft portion 1a in a direction that gradually rises according to the rotational direction of the steel pipe shaft. Shape. Spiral groove machining (tapping method)
Alternatively, it is formed by plastic working so as to have the cross section shown in FIG.

As a result, the lubricating oil that is pressed against the inner wall by the centrifugal force due to the rotation of the steel pipe shaft 1 is scooped up by the spiral groove 11 and continuously supplied to the upper part of the inner diameter of the steel pipe shaft 1 as shown by the arrow. Compared to a method in which lubricating oil is supplied through a slanted internal diameter surface, the coefficient of friction between the inner wall of the steel pipe and the lubricating oil increases, and it is possible to prevent slippage caused by a decrease in viscosity due to increases in oil temperature caused by compressor operation. In other words, Fig. 5 shows an oil supply pump (with a simple Taber neck shape) which is also advantageous for plastic working.
The shape shown in Fig. 1 with the flat pressed part removed) improves the oil supply characteristics with a lower oil temperature. Furthermore, as shown in FIG. 4, the oil supply characteristic, line a, in which oil supply stops or decreases at a certain rotation speed, is improved as shown in line b. From a processing perspective, the processing stress of spiral groove forming using either the cutting method or the plastic processing method is lower than that of either mouth drawing or flat pressing, which sufficiently eliminates manufacturing problems and, of course, causes cracks. danger is avoided. In particular, the spiral groove shown in FIG. 6 formed by plastic working is a highly efficient forming method that does not generate chips, and these patented effects are advantageous in terms of performance improvement and processing characteristics.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of the shape of a conventionally known steel pipe shaft;
Fig. 2 is a perspective view showing an example of a steel pipe shaft according to the present invention, and Fig. 6 is a perspective view showing an example of the shape of a plastic forming groove whose effective diameter is the inner diameter of the steel pipe (dotted line). Cross-sectional view along
4 and 5 are pictorial diagrams showing the oil supply characteristics of a steel pipe shaft according to the present invention and a conventionally known simple Tebaro throttle pump. 1... Steel pipe shaft, 1a... Shaft part of steel pipe shaft 1 ,1
b...Eccentric part of steel pipe shaft 1, 1C...Step bent part, 1d
...? White person, 1e...oil groove, 1f...oil sump part,
1g...Refueling pump. Part, 1 h"...Flat press part, 11...Spiral groove. !34 figure!35 figure crushed-/j!L

Claims (1)

[Claims] The rotating shaft of the compressor is made of a plastically processed steel pipe, and the inner diameter of the steel pipe serves as the oil supply pump.A spiral groove whose bright line rises in the direction of rotation is formed on the inner diameter of the rotating shaft to form a pump function part. A rotary shaft for a completely hermetic electric compressor, which is characterized by: