JPS6311353Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rotary compressor having vanes, and is effective for use as a refrigerant compressor in, for example, an automobile air conditioner.

Conventionally, rotary compressors have been known in which a rotor is rotatably housed in a housing, slits are formed in the rotor, and vanes are slidably disposed in the slits (for example, Japanese Patent Publication No. 51-30284 Publication No.). In this type of compressor, sliding support between the inner surface of the slit formed in the rotor and the side surface of the vane becomes a problem. Usually, the inner surface of the slit and the side surface of the vane are directly opposed to each other, and lubricating oil is interposed between the two to provide sliding support.

However, in this type of structure, the sliding area between the inner surface of the slit and the side surface of the vane is large, so the shear stress of the oil due to sliding of the vane becomes extremely large, which in turn causes the rotation of the compressor. There was a problem that it led to loss of power.

It is also known that a bearing mechanism such as a roller is disposed within the slit in order to reduce the sliding resistance between the slit of the rotor and the vane.
In this case, there was a problem in that the arrangement of the bearing mechanism was extremely complicated, making it impossible to provide a practical compressor.

The present invention has been devised in view of the above points. That is, an object of the present invention is to reduce the friction loss of the vanes sliding within the slits in a rotary compressor in which the vanes slide within the slits, without requiring a special bearing mechanism.

Embodiments of the present invention will be described below based on the drawings.
FIG. 1 is a longitudinal section of a rotary compressor according to the present invention. In the figure, reference numeral 2 denotes a rotor made of iron, and a vane 3 made of aluminum alloy is slidably inserted into a rotor slit 2a provided in the rotor. Both ends of the vane 3 are in sliding contact with the inner surface 1a of the housing 1, and the sliding position is regulated by the shape of the inner surface 1a. Further, since the rotor 2 is eccentrically installed in the housing 1 so that its outer circumferential surface is in sliding contact with a part of the inner surface 1a of the housing, as the rotor 2 rotates in the direction of arrow n as shown in the figure, the outer circumference of the rotor 2 The compression chamber A formed by the vane 3 and the inner periphery of the housing 1 expands and contracts, thereby allowing refrigerant from an evaporator (not shown) to enter the compression chamber A through the suction pipe 4 and the suction port 5. inhale,
After being compressed, it is discharged through a discharge communication port 7 of the discharge port 6 and a discharge pipe 8 to a condenser (not shown). In addition, as shown in Fig. 2, the center part of the vane 3 is removed to form a concave shape as shown in the figure in order to prevent interference between the movements of the vanes, and the two vanes 3 alternately intersect this concave part 3a. In this state, the rotating shaft 9 is inserted into the rotor slit 2a in the rotor 2, and after the insertion, the rotating shaft 9 is fixed to the rotor 2 with a bolt 10.

In the present invention, a portion of the slit 2a that slidably accommodates the vane 3 on the rotor center side is enlarged in width to form a stepped portion 2b. That is, in the slit 2a on the rotor peripheral surface side, the width diameter of the slit 2a is made to be approximately the same as the width diameter of the vane 3 so that the refrigerant in the compression chamber A does not flow into the slit 2a. Although the gap between 3 and 3 is made very narrow (for example, 20
~30μm) This slit 2a in the stepped part 2b
The gap between the vane 3 and the vane 3 has become larger. (For example, about 0.5 to 1.0 mm). Further, in the present invention, by forming the stepped portion 2b in the slit 2a as described above, the frictional resistance accompanying the sliding of the vane 3 can be reduced as described below.

In other words, compressors generally use oil to improve the lubricity and sealing properties of sliding parts, but especially in rotary compressors used for this type of refrigerant compression, oil is mixed into the refrigerant. Therefore, oil with a fairly high viscosity is now used. As described above, the vanes 3 slide within the rotor slit 2a as the rotor 2 rotates, and the shearing stress r that shears the oil adhering to the rotor slit 2a at this time is expressed by r=μV/X. Here μ is the viscosity coefficient, V is the vane 3
, and X represents the clearance between the vane 3 and the rotor slit 2a. This shear stress acts as a torque, and the torque T is expressed as T=rSV/2π. Here, S represents the sliding area of the portion where the vane 3 and the lotus slit 2a slide.

Therefore, in order to reduce this torque loss, since the vane speed V and the viscosity coefficient μ are constant, the gap between the slit 2a and the vane 3 described above can be widened or the sliding area can be reduced.
There are also problems with the sealing between the rotor slit 2a and the rotor slit 2b, making it difficult to increase the size.

Based on the above reasons, the present invention expands a part of the rotor slit 2a to provide a stepped portion as shown in FIGS. The reduction in torque loss can be achieved without making any material changes or increasing weight. Further, since the machining of the stepped portion 2b does not require high-precision machining unlike the rotor slit 2a, it has the advantage that polishing of the rotor slit 2a can be easily performed.

Next, the deflection of the vane 3 in the compressor having the above configuration will be explained according to the diagram. First, when the compressor operates under low load, the vane 3 does not bend much in this case, so its support point is at the outer diameter portions A and B of the rotor slit 2a as shown in FIG. This is supported by two points. However, as the load on the compressor increases, one of the support points, ie, point B in FIG. 3, shifts to the right side of the figure due to the deflection of the vane 3. As a result, as shown in FIG. 3, in the slit 2a without the stepped part 2b, considering the balance of forces, when supporting at point CA, the distance between the supporting points becomes > compared to when supporting at point BA, and the distance between the supporting points becomes shorter.
As a result, the drag force acting on each support point increases.
On the other hand, in the compressor of the present invention, the slit 2a is provided with the stepped portion 2b, so that the support point is not only the support point at low load but also the support point at high load.
By limiting the distance to the DA point, it is possible to increase the distance between the support points, thereby suppressing an increase in drag due to the shift of the support points and reducing torque loss due to frictional force.

As explained above, in the compressor of the present invention, the slits provided in the rotor have a stepped shape with a larger width diameter on the rotor center side, so the shear stress generated by shearing the oil mixed in the compressor It has the excellent effect of being able to reduce the torque loss and, as a result, reducing the torque loss. This torque loss reduction effect is particularly effective when the oil is of high viscosity during low-temperature startup. Furthermore, the compressor of the present invention has a stepped shape of the slit, so that
Even during high-load operation of the compressor, the distance between the vane support points of the slit can be increased, thereby reducing the drag force acting on the support points and reducing friction loss at the support points. It also has excellent effects.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the rotary compressor of the present invention, Fig. 2 is a perspective view showing the rotor section of the rotary compressor shown in Fig. 1, and Fig. 3 is a slit with no stepped portion. Explanatory diagram showing the support position of the vane, No. 4
The figure is an explanatory view showing the supporting positions of the rotor and vanes in the slit of the configuration according to the present invention. 1...Housing, 2...Rotor, 2a...Slit, 2b...Stepped portion, 3...Vane.

Claims (1)

[Scope of utility model registration request] A cylindrical housing, a rotor rotatably disposed within the housing, a plurality of slits formed in the diametrical direction of the rotor and also opening on one end surface of the rotor, and a rotor that slides into the slits. a plurality of vanes that are freely arranged and have both ends protruding from the slit and slidingly contacting the inner surface of the housing;
a rotating shaft fixed to one end surface side of the rotor and closing the opening of the slit, the slit of the rotor has a stepped shape with a width diameter larger on the rotor center side than on the rotor peripheral surface side, and the vane is in sliding contact with the slit with surface contact only at the small diameter portion of the slit on the rotor peripheral surface side, and in the large width portion of the slit on the center side, there is a predetermined gap between the vane and the slit. A rotary compressor, wherein a gap is provided between the vanes, and each end surface of the plurality of vanes is slidable with respect to a surface of the rotating shaft and the rotor.