JPH0233876B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a compressor, and more particularly to a balance device for a compressor operated at a rated speed or higher.

(b) Prior art To explain the conventional example based on FIG.
This is a rotary compressor in which a rotary compression element 4 driven via a rotary compressor element 4 and a rotary compressor element 4 are arranged in a closed container 5. The electric element 2 includes a stator 7 containing a winding 6 and a rotor 8 provided within the stator.
The rotary compression element 4 includes a cylinder 9, a rolling piston 11 that rotates within the cylinder 9 by an eccentric portion 10 of the rotating shaft 3, and a vane 12 that comes into contact with the rolling piston and divides the inside of the cylinder 9 into a high pressure area and a low pressure area. and bearings 13 and 14 that close the opening of the cylinder 9. 15,1
6 is a balance weight that balances the unbalanced force generated by the rotation of the rolling piston 11 of the rotary compression element 4 and the eccentric part 10, and this balance weight is attached to both the upper and lower ends of the rotor 8 of the electric element 2.
They are installed with a rotation angle of 180° shifted.

In this compressor balance device, when the rotary compression element 4 is driven by the electric element 2, the unbalanced force generated by the rotational movement of the rotary compression element for suction and compression is applied to both upper and lower ends of the rotor 8 of the electric element 2. It is balanced by the unbalanced force of balance weights 15 and 16 attached to the parts.

However, the centrifugal force of the balance weights 15 and 16 increases in proportion to the square of the rotational speed.
Further, the amount of deflection of the rotating shaft 3 increases in proportion to the cube of the distance from the fixed portion on which the centrifugal force acts.

Therefore, when the rotational speed of the electric element 2 exceeds the rated rotational speed, the deflection of the rotating shaft 3 due to the centrifugal force of the balance weight increases rapidly. , the contact between the stator 7 and rotor 8 and the rotating shaft 3
This caused galling between the bearings 13 and 14.

(c) Purpose of the invention In view of the above points, the object of the present invention is to reduce the deflection of the rotating shaft due to the bending moment generated by the centrifugal force of the balance weight.

(d) Structure of the Invention This invention constitutes an electric element by housing an electric element that rotates at a rated rotation speed or higher in a closed container, and a rotary compression element that is driven by an eccentric portion of the rotating shaft of this electric element. Two balance weights are installed at both ends of the rotor to balance the unbalanced force of the rotating compression element, shifted by 180 degrees, and the balance weight on the side far from the rotating compression element is placed on the same side as the eccentric part of the rotating shaft.
In a compressor where the balance weight on the near side is placed on the opposite side of the eccentric part, the balance weight on the side far from the rotating compression element is made sufficiently smaller than the balance weight on the near side, and the weight of the balance weight on the far side is is lighter than the weight that balances the unbalanced force of the rotating compression element.

By configuring this invention as described above,
The weight of the balance weight on the side far from the rotary compression element is made lighter than the weight that balances the unbalanced force of the rotary compression element, so as to reduce the deflection of the rotating shaft due to the centrifugal force acting on the balance weight on the far side. This is what I did.

(E) Embodiment The present invention will be explained below based on the embodiment shown in FIG.

Incidentally, parts that are the same or equivalent to those of the conventional example shown in FIG.

In the balance device of the present invention, the balance weight 17 attached to the end of the rotor 8 on the side far from the rotary compression element 4 is made sufficiently smaller than the balance weight 18 attached to the end of the rotor 8 on the near side, In addition, the weight of the balance weight 17 on the far side is distributed between the rolling piston 11 of the rotary compression element 4 and the eccentric portion 1.
It is lighter than the weight that balances the unbalanced force with zero.

In the compressor balance device configured in this manner, the rotary compression element 4 driven by the electric element 2 operated at a frequency of 30Hz to 120Hz is a rolling piston that rotates within the cylinder 9 together with the eccentric portion 10 of the rotating shaft 3. 11, an unbalanced force is generated during suction and compression. This unbalanced force is the rotor 8
balance weights 17 attached to both the upper and lower ends of the
It is designed to become smaller at 18.

By making the balance weight 17 on the side far from the rotary compression element 4 lighter than the weight that balances the unbalanced force of the rotary compression element 4, even if the rotation speed of the electric element 2 exceeds the rated rotation speed, This prevents centrifugal force from acting on it. and,
The balance weight 17 is designed so that even if it is a centrifugal force acting on itself, a bending moment large enough to cause the rotating shaft 3 to deflect is not applied to the shaft. Therefore, the rotating shaft 3 is prevented from tilting toward the stator 7.

Furthermore, by providing the balance weight 18 on the side closer to the rotary compression element 4 around the bearing 13, the bending moment that deflects the rotary shaft 3 can be substantially ignored, and the weight can be reduced by the unbalanced weight of the rotary compression element 4. The weight is the same as the force and balance.

Figure 3 shows the change in the deflection state of the upper end of the rotating shaft with respect to the change in power frequency when the weight of the balance weight W attached to the upper end of the stator is changed.The diameter of the rotating shaft is 19.2 mm.
It can be seen from this figure that the higher the power frequency, the greater the difference in the amount of deflection due to the difference in the weight of the balance weight W.

(f) Effects of the Invention As described above, according to the present invention, the balance weight on the side far from the rotary compression element is made smaller than the balance weight on the near side, and the weight of the balance weight on the far side is reduced to the weight of the balance weight on the side far from the rotary compression element. Since the weight is lighter than the weight that balances the unbalanced force of This reduces the deflection of the rotating shaft due to the weight, and prevents contact between the stator and rotor of the electric element and galling between the rotating shaft and the bearing.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional rotary compressor, and FIG. 2 is a sectional view of a rotary compressor showing an embodiment of the present invention.
FIG. 3 is a characteristic diagram showing changes in deflection of the rotating shaft with respect to frequency. 1... Rotary compressor, 2... Electric element, 3... Rotating shaft,
4... Rotating compression element, 5... Sealed container, 17, 18...
balance weight.

Claims (1)

[Claims] 1 An electric element that rotates at a rated rotation speed or higher and a rotary compression element that is driven by the eccentric part of the rotating shaft of this electric element are housed in a closed container, and a rotary compression element is installed at both ends of the rotor that constitutes the electric element. Two balance weights are installed 180 degrees apart to balance the unbalanced force of the element.The balance weight on the side far from the rotary compression element is on the same side as the eccentric part of the rotating shaft, and the balance weight on the near side is on the opposite side of the eccentric part. In a compressor placed on the side, the balance weight makes the side far from the rotary compression element sufficiently smaller than the side close to it, and balances the weight of the balance weight on the far side with the unbalanced force of the rotary compression element. A compressor balance device characterized by being lighter than its weight.