JPS58133494A - Rotary compressor - Google Patents

Abstract

PURPOSE:To reduce the clearance between a roller and an eccentric section, by making a V-shaped groove equipped with an inverting section in the radial direction sliding face at the eccentric section of a crank shaft and utilizing the oil pressure produced in the groove. CONSTITUTION:At the starting, the low pressure side is evacuated to attract a roller 4 to the inner wall 3a of a cylinder while when the centrifugal force is applied on the roller 4 the combined force will function such that even if the roller 4 moves in the centrifugal direction, the clearance between the roller 4 and the eccentric section 5d is reduced considerably by the oil pressure in a V-shaped groove 5d. Consequently the efficiency can be improved because the top clearance is not required to be increased in order to prevent the collision between the roller 4 and the cylinder 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotary compressor used in refrigerators and the like, and its purpose is to reduce noise.

When a conventional rotary compressor is used in a refrigerator or the like, a vacuum is created on the suction side when the compressor is started up, and during that time the roller collides with the cylinder, which can cause a strong collision noise. That is, in FIGS. 1 and 2, 1 is a closed case, 2 is an electric motor section, and the lower part thereof includes a cylinder 3, a roller 4, a crankshaft 5, a vane 6, an upper bearing 7,
A compression element 1o constituted by a lower bearing 8 and a cover 9 is fixed. Further, a compression chamber 11 is formed inside the cylinder 3 by the roller 4 and the vane 6. Further, the page 76 is pressed against the roller 4 by the vane spring 12 on its opposite side to the roller 4 .

The cylinder 3 has a suction hole 13, and the lower bearing 8 has a discharge hole 1.
4 is drilled. 16 is a discharge valve, 16 is a cover 9
17 is a hole that communicates between the discharge chamber 16 and the interior space 18 of the case 1. 19 is refrigerating machine oil.

In this configuration, while the compressor is stopped, the refrigerant dissolves in the refrigerating machine oil 19, and when the compressor is started, the system temporarily runs out of refrigerant gas and the suction pressure becomes vacuum. Therefore, after the top part 4a of the roller 4 passes the vane, the roller 4 moves in the normal direction due to the centrifugal force during rotation by the clearance between the roller 4 and the eccentric part 6a, and collides with the inner wall 3a of the cylinder, causing unpleasant discomfort. Collision noise may occur. In order to avoid this collision, the top clearance between the cylinder 3 and roller 4 must be made large so that the roller 4 and cylinder 3 do not collide, but this will significantly reduce compression efficiency and from the viewpoint of energy efficiency. It's not a good thing.

The present invention solves these problems and aims at reducing noise without reducing compression efficiency.

An embodiment of the present invention will be described in detail below with reference to FIGS. 3, 4, and 5. In order to avoid duplication of explanation, the same parts as in the conventional example are given the same reference numerals, and the explanation will be omitted. In the radial sliding surface 6b of the eccentric portion 5a of the crankshaft 5, a large number of extremely shallow substantially V-shaped grooves 6d having an inverted portion in the counter-rotation direction are formed over the entire circumference by, for example, etching.

Further, FIG. 6 shows another embodiment in which the groove 5d is removed on a surface located within ±200 from the line portion 5C of the maximum eccentricity.

Refrigeration oil is sucked toward the center of the sliding surface 5b by the groove 6d, but since the groove 5d is V-shaped, the oil becomes compressed and presses the roller 4 outward in the normal direction. exert great pressure. Therefore, at startup, when the low pressure side becomes a vacuum, the roller 4 is attracted to the cylinder inner wall 3a side, and a centrifugal force is applied to the roller 4, even if the roller 4 tries to move in the centrifugal direction due to the resultant force, The roller 4 and the eccentric part 5d are moved by the hydraulic pressure of the V-shaped groove 6d.
The clearance between the two appears to be extremely small,
Furthermore, if a groove is formed excluding the maximum eccentric part, the roller 4
This means that the hydraulic pressure applied to the minimum eccentricity portion is greater than that applied to the maximum eccentricity portion, thereby further preventing the roller 4 from moving in the centrifugal direction.

Therefore, there is no need to increase the top clearance to avoid collision between the roller 4 and the cylinder 6, and efficiency can be improved.

As described above, the present invention includes a crankshaft,
A compression element consisting of a roller and a cylinder, and an electric motor directly connected to the crankshaft are housed, and a substantially V-shaped groove having an inverted part in the counter-rotational direction is provided on the radial sliding surface of the eccentric part of the crankshaft. The hydraulic pressure generated in this groove is used to obtain the same effect as if the clearance between the roller and the eccentric part were reduced, and the roller is constantly affected by the combined force of centrifugal force and differential pressure caused by the difference in outer peripheral pressure. The amount of movement in the centrifugal direction of the cylinder can be reduced, and the top clearance between the roller and cylinder can be reduced, improving efficiency.

Furthermore, if the grooves are formed in the eccentric part so as to exclude the largest eccentric part, the movement of the roller in the centrifugal direction can be further reduced. Therefore, the noise of the rotary compressor, especially the noise at startup, can be reduced without reducing efficiency.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a conventional example of a rotary compressor, Fig. 2 is a sectional view taken along line nn' in Fig. 1, and Fig. 3 is a sectional view of a rotary compressor showing an embodiment of the present invention. 4 is a sectional view along the mV-TV' line in FIG. 3, FIG. 6 is a front view of the crankshaft seen from the maximum eccentricity side of the crank part, and FIG. It is a front view of the crankshaft which shows the Example. 141111@el+case, 5,,,,,, crankshaft, 4...Roller, 2...
Electric motor part - %3...Cylinder 10...
・Compression element S5a...Eccentric part, s d 8. ,
,,,groove. Name of agent: Patent attorney Toshio Nakao and 1 other person! l
A1511 et al. Figure 3 Figure 4 Figure 5 Figure 16

Claims (2)

[Claims] (1) Inside the case, the crankshaft, rollers,
and a compression element constituted by a cylinder, and an electric motor unit directly connected to the crankshaft, and an extremely shallow approximately V-shaped groove having an inverted portion in the counter-rotation direction is formed on the radial sliding surface of the eccentric portion of the crankshaft. Rotary compressor installed. (2) The rotary compressor according to claim 1, wherein the groove is provided except for the largest eccentric portion of the radial sliding surface of the eccentric portion.