JPH0428912B2 - - Google Patents

Description

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

Recently, small hermetic electric compressors used in refrigerators and the like have started to use crankshafts that are made by plastically working steel pipes and only grinding the sliding parts.

This has the advantage of simplifying the machining process and making it cheaper, but due to the 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 raises the temperature of the oil and lowers the viscosity of the oil, resulting in a reduction in the amount of oil pumped up and a disadvantage in that the amount of oil supplied to the sliding parts becomes insufficient. The reason for this lack of oil supply is that the amount of slip between the oil and the inner surface of the oil pump, which has a tapered hollow opening at the lower end of the crankshaft, decreases in proportion to the decrease in the viscosity of the oil. This is because as the size increases, the centrifugal pump action becomes smaller.

Hereinafter, the conventional one 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 includes a crank pin part 1a at the top, a crank journal part 1b in the middle,
It has an oil supply pump 1c at the bottom. Since this oil supply pump 1c is made of a steel pipe, due to the restriction on the drawing ratio during plastic working, it is necessary to utilize the viscosity of the oil.It is a viscous type oil supply pump with a circular, gently tapered inner surface 1d as shown in Fig. 1. Become. Next, this viscous oil supply pump will be explained. This oil supply pump 1c is immersed in oil 2, as shown in FIG. When crankshaft 1 rotates,
Since oil is attached to the inner surface 1d of the oil supply pump 1c due to the viscosity of the oil 2, the attached oil 2 rotates together with the oil 2. 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. It is transmitted like an arrow and rises. The viscous oil pump mentioned above utilizes the viscosity of oil, so as mentioned above, when the load becomes heavy, the heat generated at this time increases the temperature of the oil, causing the viscosity of the oil to decrease. However, since the amount of oil adhering to the inner surface 1d decreases and the amount of slip between the inner surface 1d and the oil 2 increases, the amount of oil pumped up decreases, and the amount of oil supplied to the sliding parts becomes insufficient. There is a drawback that it does.

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 lower the viscosity of oil, and this type of oil pump has become a major obstacle to power saving.

However, in order to solve this problem with a steel pipe crankshaft, it is possible to solve this problem by changing the circular cross section of the oil supply pump to an extremely elliptical shape and incorporating elements of an eccentric pump. However, in this case, the reduction ratio during plastic working becomes even higher, resulting in an increase in the number of processing steps and
Moreover, since cracks occur, special materials must be used, resulting in a significant increase in costs, which negates the merits of the steel pipe crankshaft.

In view of the above, the purpose of the present invention is to improve such drawbacks, and to invent an inexpensive auxiliary piece that has a simple structure and good insertability, and which can be inserted into a fuel pump. This was done so that the advantages of the steel tube crankshaft were not lost.

That is, in a viscous oil pump, the amount of oil adhering to the inner surface of the oil pump decreases when the viscosity decreases, and the amount of oil supplied decreases, so this can be prevented. Therefore,
The present invention includes a crankshaft having a hollow portion with a tapered opening at its lower end, which is located in oil stored at the bottom of a chamber, and an oil supply piece inserted and attached into the hollow portion. (referred to as peace)
is a contact portion that contacts the inner surface of the tapered hollow portion, and a wall portion (hereinafter referred to as “wall”) that rises from the contact portion in the axial direction of the crankshaft.
and a latching part that is latched to the lower end surface of the crankshaft, and a latching part that extends from a position away from the latching part toward the latching part (hereinafter referred to as the folded part) and of the abutting part. This oil supply device for a compressor is composed of a foot portion (hereinafter referred to as a foot) that comes into elastic contact with a tapered inner surface facing the contact position.

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 from a spring plate, and the contact part 3f
The cross section is formed into a U-shape 3d by two walls 3e that stand up at approximately right angles from the wall, and a folded part 3a is provided at one end, and the upper part of the U-shape is provided at the other end. From this point, strip-shaped legs 3b and 3c extend upward in the U-shape.

Figure 3 shows the oil supply pump 1 of the crankshaft 1.
This shows an assembly method for attaching the auxiliary piece 3 to the part c. Simply insert the auxiliary piece 3 into the fuel pump 1c as shown by the arrow.
It is mounted in the oil supply pump 1c as shown by the dashed line by the folded portion 3a and the legs 3b and 3c having spring properties.

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 1c. It also has a role to play. To explain this in detail, by providing the legs 3a and 3c extending toward the folded part 3a from a position away from the folded part 3a, the legs 3a and 3c are attached to the crankshaft 1 when inserted.
It easily shrinks to the opening size of the lower end, and the leg 1 extending from a position away from the folded part 3a toward the folded part 3a has elasticity on the tapered inner surface 1d facing the abutting position of the abutting part 3f. Since the legs 1 are in contact with each other, when they are further inserted from the insertion position and the folded portions 3a are hooked to the lower end surface of the crankshaft 1, the legs 1 expand due to elasticity and taper to form the taper of the hollow oil supply pump 1c. Press the shaped inner surface 1d to come into contact. Therefore, the oil supply piece is difficult to come off and has a contact portion 3 on the tapered inner surface 1d.
f is closely attached and installed inside the oil supply pump 1c, which has a tapered opening. Moreover, since the abutting portion 3f is in close contact with the tapered inner surface 1d as described above, the oil is pushed in the rotational direction by the wall 3e, producing centrifugal force and flowing upward along the tapered inner surface 1d. A thrust will be generated, and the oil will surely rise up the inner surface of the crankshaft 1. Also,
Since the auxiliary piece 3 is provided with a wall 3e that rises from the abutment portion 3f in the axial direction of the crankshaft 1, a sufficient height can be easily obtained with a simple structure, and low viscosity oil can be used. Not only can a sufficient amount of oil be supplied even when oil is used, but if low viscosity oil is used, power consumption can be saved. Furthermore, the number of machining steps for the crankshaft 1 does not increase.

As described above, the auxiliary piece 3 of this embodiment has a simple structure and is therefore inexpensive, and at the same time
It has the characteristic that it is very easy to attach to the c.

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

In FIG. 4, N indicates the direction of rotation, and when rotated in the N direction, the U-shaped portion 3d of the auxiliary piece 3 and the oil 2 at the portion received on the outside of the U-shaped portion 3d.
rotates at the same speed as the oil supply pump 1c, so
Sufficient centrifugal force can be obtained. The oil 2 that has obtained this centrifugal force generates an upward thrust along the inner surface 1d of the oil supply pump 1c.

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

As explained above, in this example, oil 2
Since the method for pumping the oil is made to be independent of the viscosity of the oil 2, the viscosity of the oil can be significantly reduced, which has a great effect on power saving.

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

On the other hand, if there is sufficient margin in the pump up amount, as in the auxiliary piece 4 shown in FIG.
By making the cross section L-shaped and providing the wall 4a on the counter-rotation direction side, oil can be received in this L-shaped part, so it is possible to pump up regardless of the viscosity of the oil. Since it is simplified, it can be made cheaper.

Further, if it is desired to further prevent the auxiliary piece from coming off, it is preferable to provide a cut-down portion 5a on the mating part side to increase elasticity, as in the case of the auxiliary piece 5 shown in FIG.

As described above, in the present invention, since the oil supply piece is provided with a wall portion that rises from the abutting portion in the direction of the axis of the crankshaft, a sufficient height can be obtained easily and with a simple structure, resulting in a low cost. Even with oil of high viscosity, a sufficient amount of oil can be supplied, and when low viscosity oil is used, power is saved. Furthermore, there is no need to increase the number of processing steps for the crankshaft. In addition, by providing a foot portion that extends from a position away from the above-mentioned latching portion toward the latching portion, the foot portion can easily be retracted to the opening size of the lower end of the crankshaft during insertion, and the latching portion Since the foot portion extending toward the hook portion from a position away from the above-mentioned contact portion elastically contacts the tapered inner surface facing the contact position of the above-mentioned contact portion, the foot portion is further inserted from the above-mentioned insertion position. When the hook is hooked to the lower end surface of the crankshaft, the foot expands due to its elasticity and comes into contact with the inner surface of the tapered hollow section. Therefore, the oil supply piece is difficult to come out simply by being inserted, and the abutting portion is brought into close contact with the tapered inner surface, so that it can be reliably and easily attached to the tapered hollow portion. Moreover, since the contact portion is in close contact with the tapered inner surface as described above, the oil is pushed in the direction of rotation by the wall surface portion to generate centrifugal force and upward thrust along the tapered inner surface. This ensures that the oil rises up the inner surface of the crankshaft.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of a conventional steel pipe crankshaft, Fig. 2 is a perspective view of an auxiliary piece of the present invention, and Fig. 3 is an explanatory diagram showing a method for inserting the auxiliary piece into the oil supply pump of the crankshaft. , FIG. 4 is a sectional view taken along line A-A' in FIG. 3 with the auxiliary piece inserted into the fuel pump, FIG. 5 is a perspective view of the auxiliary piece of the present invention with a further simplified shape, and FIG. , is a perspective view of an auxiliary piece of the present invention provided with a cut-down portion to prevent it from coming off. 1...Crankshaft, 1a...Crank pin part, 1b...Crank journal part, 1c...
Oil supply pump, 1d...inner surface, 2...oil, 3...auxiliary piece, 3a...folded part, 3b, 3c...
Leg, 3d... U-shaped part, 4... Auxiliary piece, 4a
... Wall, 5 ... Auxiliary piece, 5a ... Cut-down part.

Claims (1)

[Scope of Claims] 1. A crankshaft having a hollow portion whose lower end is tapered and opened in a tapered shape and located in oil stored at the bottom of the chamber; and an oil supply piece inserted and attached into the hollow portion; The piece has a contact portion that contacts the inner surface of the tapered hollow portion, a wall portion that rises from the contact portion in the axial direction of the crankshaft, and a piece that is hooked to the lower end surface of the crankshaft. and a foot portion extending toward the hooking portion from a position away from the hooking portion and elastically contacting a tapered inner surface facing the abutment position of the abutting portion. A compressor oil supply device featuring: