JPS6338553B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a hermetic compressor, and more particularly to a crankshaft of a hermetic compressor that is provided perpendicularly to a case of the compressor and has a tubular member. The lower end of this tubular section has a plastic tubular neck, the upper part of which snaps into engagement with the tubular part, and the lower part flares upward to pump lubricating oil up from the bottom of the case and into the crankshaft. The lubricating oil is sent up through the lubricating pipe that forms the upper part of the crankshaft.

[Technical background of the invention and its problems]

A typical crankshaft of this type is described in US Pat. No. 4,209,080. According to it,
The plastic neck consists of a tubular section consisting of two parts, an upper and a lower part, between which a hexagonal collar is provided on the outside. The lower part expands upward to form a net.
The upper part is longitudinally divided towards the upper end into two resilient arms, each of which has diametrically opposed teeth on its surface. The color is
It has two diametrically opposed projections on its upper surface.

The tubular shaft portion has a pair of diametrically opposed horizontal holes at a predetermined height for receiving the teeth, and a pair of diametrically opposed notches at the lower end for receiving the projections. There is.

The neck is installed by inserting the resilient arm into the tubular shaft portion and then orienting the neck through the hexagonal collar until the projection is aligned with the notch. During this orientation, the upper part of the neck is pressed fully into the tubular shaft section. Here, the protrusion engages the notch and the teeth snap onto each side, securing the neck.

The above crankshaft has two drawbacks. The first drawback is that three operations are required for the snap connection. The first action is to axially insert the arm into the tubular shaft portion, the second action is to align it with the side hole, and the third action is to further axially insert the arm into the tubular shaft portion to complete the engagement. It may be moved to

A second disadvantage is that a considerable amount of plastic material is required to mold the parts. The upper tubular section needs to be somewhat longer to avoid problems with its sealing, with respect to the hydraulic pressure which is maximum at the level of the lower end of the shaft tubular section.

[Purpose of the invention]

It is an object of the invention that a simple axial movement of the net of plastic material is sufficient for its snap engagement, which reduces labor and equipment costs and reduces the amount of plastic material used in production. Another object of the present invention is to provide a crankshaft for a closed type compressor that does not cause pressure seal problems and can save materials.

[Summary of the invention]

In the crankshaft according to this invention,
The lower end of the tubular portion has an annular groove on its outer surface, and the upper portion of the neck constitutes a tubular sleeve. and the sleeve is elastically expanded and fitted over the lower end of the tubular portion to snap into engagement with a groove in the tubular portion and to form a tubular protruding ring having a lower side that aligns and engages the underside of the groove. It has inside. In addition, in the boundary area between the lower part of the neck and the sleeve, an upwardly inwardly radiating tubular shoulder is provided, which corresponds to the lower end of the tubular part, and at least one lower side radiates upwardly. It is in the shape of a converging truncated cone and, together with the other underside, produces a cam action which converts the elastic contraction force of the sleeve into an axial pressure of the shoulder against the lower end of the tubular part.

That is, the crankshaft according to the invention has a structure that is easy, convenient and economical to manufacture without the disadvantages of similar devices of the prior art.

[Embodiments of the invention]

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

Figure 1 shows Italian patent application 68090-A/81
A closed compressor 1 for a refrigerator is shown, which is similar to the compressor described in .

The compressor 1 has a closed case 2 made of a thin metal plate, and a compressor motor device 3 is provided inside the case 2. The bearing member 4 constitutes the main body of the motor device 3 and is preferably formed by casting iron. The bearing member 4 has a tubular central vertical shaft that acts as a bearing for the crankshaft 5.

As shown in FIG. 2, the crankshaft 5 is
The main parts, continuous from the upper end to the lower end, constitute a crank pin 6, an eccentric 7 forming a flat sector, an intermediate tubular part 8 and a tubular neck 9 which widens upwards. The upper part of the tubular portion 8 is rotatably connected within the bearing member 4 . Furthermore, the lower end face of the eccentric 7 is provided with an annular projection 10 which cooperates with an upper annular raised surface 11 of the bearing member 4 in the form of a thrust bearing.

Although not shown, a rotor 12 of an electric motor is fastened to the lower part of the tubular part 8 , and the starter of the electric motor is fixed at its lower end to the bearing member 4 .

The head of a connecting rod 13 is connected to the crank pin 6, and the other end of the connecting rod 13 is connected to a piston that slides within a cylinder of a compressor located in the upper part of the case 2. The lower end of the neck 9 is immersed in lubricating oil 14 in the lower part of the case 2. During rotation of the shaft, the neck 9 acts as an eccentric shaft pump pumping lubricating oil 14 through the tubular portion 8 to the eccentric 7 and crankpin 6 in the usual manner. In the tubular part 8, the eccentric 7 and the crankpin 6 have a lubrication hole 15 shown in FIGS. 1 and 2.

Typically, the crankpin 6 and the eccentric 7 are formed as a single piece of sintered gold ply. However, the tubular portion 8
are cut from a continuous standard tube made of medium grade mild steel.

The connection of the tubular part 8 to the eccentric 7 and the crankpin 6 is carried out by engaging the upper end of the tubular part 8 in a seat formed by the annular raised part 10. Once this engagement is made, the preferred method of final connection between the two parts is to weld the protrusion or relief. Another connection method is to apply metal adhesive between the parts to bond them.

As shown in FIGS. 3 and 4, the tubular portion 8
has an annular groove 16 at its lower end. This groove 16
has a triangular shape and a truncated conical surface 16a that tapers upward on the lower side. The neck 9 has in its lower part a conical part 17 which widens upwards, and its upper part is a sleeve 18. In the boundary area between the conical part 17 and the sleeve 18, the inside of the neck 9 has an annular upwardly directed shoulder 19. Shoulder part 1
The size of 9 corresponds to the size of the lower end surface 20 of the tubular portion 8. The two fins 21 extend axially at diametrically opposed positions within the conical portion 17 of the neck 9. The fins 21 function as vanes that propel the lubricating oil 14 sent from the bottom of the case 2 while the crankshaft 5 is rotating.

This propulsion action acts tangentially to the crankshaft 5 and, together with the enlarged structure of the conical section 17 of the neck 9, pumps up the lubricating oil into the tubular section 8. The arrangement is such that the maximum pressure of the lubricating oil and the boundary area between the conical part 17 and the sleeve 18 are reached.

Sleeve 18 has a notch or slot 22 that extends through sleeve 18.
is divided into a plurality of arch parts (six in the illustrated example) extending perpendicularly from the region connected to the conical part 17. The net 9 is made from a single piece of resilient plastic material such as polyamide. The arched part of the sleeve 18 is elastic and the neck 9 is fitted into the lower end of the tubular part 8. The plurality of sleeve portions 23 have enlarged heads 24 at their free ends.
The inner surface of each free end is provided with a triangular tooth-like protrusion 25 having substantially the same shape as the annular groove 16 . In particular, the lower surface of each protrusion 25 is inclined with respect to the axis of the crankshaft 5, similar to the inclination of the conical portion 16a of the groove 16 of the tubular portion 8.

When the neck 9 is fitted into the lower end of the tubular portion 8, the protrusion 25 snaps into groove 16 and urges the neck 9 upwardly. frustoconical surface 16 in the form of a cam
Collaborate with a. As a result of this biasing force, the surface of the shoulder 19 is pressed against the lower end surface 20 of the tubular portion 8, providing a securely sealed connection between the tubular portion 8 and the neck 9, and dispersing the lubricating oil to the outside. maximum capacity of pump operation is maintained.

An elastic ring 26, for example an open metal ring, surrounds the sleeve 18 at its upper end. The force exerted by the elastic ring 26 is added to the elasticity of the portion 23, causing the protrusion 25 to move into the groove 2.
Increase the radial thrust to 6. Then, the sealing of the lubricating oil conduit in the area where the lubricating oil pressure is at its maximum value is increased. The head 24 of the section 23 is preferably provided with a raised end 27 which acts as a stop to prevent the elastic ring 26 from rising. Further, another protrusion 28 that prevents the elastic ring 26 from lowering projects from the outer surface of the side wall of the sleeve 18.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view showing a closed compressor for a refrigerator equipped with a crankshaft according to an embodiment of the invention, and FIG. 2 is an exploded perspective view of the crankshaft according to an embodiment of the invention. Figure 3 is a vertical sectional view of the lower part of the crankshaft shown in Figure 2 before assembly, Figure 4 is a vertical sectional view of the lower part of the crankshaft shown in Figure 2 after assembly, and Figure 5 is a vertical sectional view of the lower part of the crankshaft shown in Figure 2. FIG. 4 is a diagram showing the configuration of the constituent members shown in FIG. 4; DESCRIPTION OF SYMBOLS 1... Compressor, 2... Case, 5... Crankshaft, 7... Eccentric, 8... Tubular part, 9... Neck, 16... Groove, 18... Sleeve, 19... Shoulder, 2
5...Protrusion, 26...Elastic ring.

Claims (1)

[Scope of Claims] 1. The compressor is provided vertically in the case of the compressor and has a tubular part, and the tubular part has a plastic tubular neck at its lower end, and this neck snaps onto the tubular part. A closed type having an engaged upper part and an upwardly expanding lower part, and this lower part carries lubricating oil up from the bottom of the case and sends the lubricating oil through the crankshaft to a lubricating pipe formed in the upper part of the crankshaft. In the crankshaft of the compressor, the tubular part has an annular groove on the outer surface at its lower end, the upper part of the neck constitutes a tubular sleeve, which elastically expands, and the lower end of the tubular part The upper part of the neck is composed of an annular sleeve that fits into the
a ring projecting inside the sleeve and having a lower side that snaps into engagement with the groove and engages a corresponding lower side of the groove; in the boundary area between the lower part of the neck and the sleeve; having an upwardly facing shoulder engaging the lower end of the tubular portion, at least one underside generally having the shape of an upwardly converging truncated cone and cooperating with the other underside to cause the cam to A crankshaft for a closed compressor, characterized in that the elastic contraction force of the sleeve is converted into axial pressure of the shoulder against the lower end of the tubular part. 2. The crankshaft for a hermetic compressor according to claim 1, wherein an elastic ring is fitted into the sleeve and generates a contraction force that is superimposed on the elastic contraction force of the sleeve. 3. said sleeve has a plurality of axial slots dividing the sleeve into a plurality of elastically bifurcatable parts, at least some of the parts engaging in a tubular groove in a tubular part of the crankshaft; A crankshaft for a closed compressor according to claim 1 or 2, characterized in that the crankshaft has tooth-like protrusions near the free end. 4. At least some of the elastic parts have enlarged heads at their free ends which snap into a tubular groove provided in the tubular part of the crankshaft and whose surface faces inwardly of the sleeve. A hermetic compressor according to claim 3, characterized in that a stop member is provided on the outwardly facing surface of the sleeve for fixing the elastic ring in the axial direction. crankshaft. 5. The crankshaft for a hermetic compressor according to any one of claims 1 to 4, characterized in that the inner surface of the neck is provided with fins for propelling and sending lubricating oil.