JPH057557B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a rotary compressor used in refrigeration equipment such as refrigerator-freezers.

Conventional configuration and its problems Generally, in such a rotary compressor,
Due to the influence of motor electromagnetic vibration, electromagnetic noise is generated at a frequency around 500Hz, which can be especially large when the air gap between the rotor and stator is not uniform.

A conventional example will be described below with reference to FIGS. 1, 2, and 3.

1 is a rotary compressor, 2 is a sealed case, and 3 is a cylinder, which is fixed to the sealed case 2 by welding.
The crankshaft 6 is supported by an upper bearing 4 and a lower bearing 5. Reference numeral 7 designates an eccentric portion of the crankshaft 6, on the upper circumference of which a roller 8 is rotatably arranged. Reference numeral 9 denotes a rotor of a single-phase induction motor, to which a crankshaft 6 is press-fitted and fixed. 10
is a stator, 10a and 10a' are a pair of motor main windings, and 10b and 10b' are motor auxiliary windings. Reference numeral 11 indicates an air gap (a gap between the rotor 9 and the stator 10). 12 is a gate valve;
13 is a compression chamber, and 14 is a suction chamber. Reference numeral 15 in FIG. 3 shows the electromagnetic attractive force between the stator 10 and rotor 9 of the motor, which is larger on the main windings 10a, 10a' side and smaller on the auxiliary windings 10a, 10b' side.

In this configuration, when the rotary compressor 1 is in operation, the force that the rotor 9 receives in addition to the rotational force is 2.
There are different types. One is the motor main winding 10a, 10
The electromagnetic attractive force 15 is due to a', and has an elliptical distribution with a maximum at the center of the main winding. The other is the force 16 exerted on the crankshaft eccentric portion 7 due to compression work, as shown in FIG. That is, the gate valve is assumed to be at 0°, and the trajectory of the vector in the shaft eccentric portion 7 is shown, and in one revolution of the crankshaft 6, a substantially water drop-shaped circle is shown. Furthermore, the number in parentheses indicates the rotation angle of the crankshaft 6.
The force 16 applied to the crankshaft eccentric part 7 due to compression work is due to the pressure difference between the compression chamber 13 and the suction chamber 14,
Centrifugal force due to crankshaft rotation, gate valve 12
is the resultant force of the pushing force, etc., which deforms the crankshaft 6 using the upper bearing 4 and lower bearing 5 as fulcrums,
This is a force that acts on the rotor in a direction 180° opposite to this resultant force.

In the above configuration, electromagnetic noise is
Occurs at a frequency 2n times higher, especially in air gap 1.
1 has a minimum air gap 11' in one direction as shown in FIG.
This occurs significantly when the position is eccentric with respect to 0). However, the stator 10 of this rotor 9
It is very difficult to assemble so that the eccentricity is uniform, and in most cases the eccentricity is in a certain direction, but it is possible to specify the direction of eccentricity. Then, as shown in FIG. 3, the rotor 9
When the eccentric direction (minimum air gap direction) is in the motor main winding 10a or 10a' direction, the electromagnetic attraction force 1 of the motor main windings 10a, 10a'
5, the rotor 9 becomes more eccentric (the minimum air gap 11' dimension becomes smaller). In addition, the eccentric direction of the rotor 9 is 180° opposite to the force received by the crankshaft eccentric portion 7.
6, the force applied to the crankshaft eccentric portion 7 causes the crankshaft 6 to
The upper bearing 4 and the lower bearing 5 are deformed as fulcrums, and the rotor 9 is further eccentric in the eccentric direction. Therefore, it has been found that when the rotor is eccentric in either of these directions, electromagnetic noise increases.

OBJECT OF THE INVENTION Therefore, an object of the present invention is to reduce electromagnetic noise caused by motor electromagnetic vibration by specifying the minimum air gap position.

Structure of the Invention In order to achieve this object, the present invention aims to align the minimum dimensional position (rotor eccentricity direction) of the air gap (gap between the rotor and stator) with the direction of the force applied to the eccentric part of the crankshaft due to compression work. direction, and in a direction substantially orthogonal to the motor main winding.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. Incidentally, 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 FIG. 6, 111 is the air gap 11
The position of this minimum air gap 111 (in the eccentric direction of the rotor 9') is
With the gate valve 12 at 0°, the position is set at 145° clockwise to be the center of the force distribution of the force 16 received by the crankshaft eccentric portion 7, and the stator 1
0 is the center A-A' of the auxiliary windings 10d and 10d', with the gate valve 12 at 0°, and the position is 145° clockwise. The direction of the force 16 applied to the eccentric portion of the crankshaft 7 due to work is the same direction and the motor main windings 10c, 10
The position is approximately perpendicular to the direction of c'.

According to this configuration, the motor main windings 10c, 1
Since the position of the minimum air gap 111 is set at the position where the electromagnetic attraction force 15 of 0c' is the minimum, electromagnetic vibration due to the electromagnetic attraction force in the direction of the minimum air gap can be suppressed to a minimum. Furthermore, since the position of the minimum air gap corresponds to the direction of the force 16 applied to the eccentric portion 7 of the crankshaft, the force 16
Therefore, the crankshaft 6 is connected to the upper bearing 4 and the lower bearing 5.
By deforming using the rotor 9' as a fulcrum, the rotor 9' is deformed in the direction opposite to the minimum air gap, and the minimum air gap 111 is not made smaller, but on the contrary, the dimension of the minimum air gap 111 is relaxed. Moreover, since the electromagnetic attractive force in the direction of the minimum air gap is minimized, the effect of mitigating the minimum air gap by the force 16 is maximized, making it possible to equalize the air gap 11 and further reduce electromagnetic vibration.

Effects of the Invention As described above, the present invention makes the direction of the minimum dimension position of the gap (air gap) between the rotor and stator the direction of the minimum electromagnetic attractive force of the motor main winding (motor auxiliary winding direction). In addition to minimizing electromagnetic vibration due to electromagnetic attraction, the direction of the minimum air gap between the rotor and stator (eccentric direction)
By making the direction of the force applied to the eccentric part of the crankshaft due to compression work the same direction, the crankshaft is deformed by the force applied to the eccentric part of the crankshaft, and the minimum air gap is relaxed due to the deformation. Moreover, since the electromagnetic attraction force in the direction of the minimum air gap between the rotor and stator has already been suppressed to the minimum, its mitigation effect is maximized and the air gap can be made uniform, greatly reducing electromagnetic vibration and preventing electromagnetic noise. Quiet operation can be achieved.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the rotary compressor, Figure 2 is the
Figure 3 is a cross-sectional view taken along line -' in Figure 1, Figure 4 is a distribution diagram of the force exerted on the rotor due to compression work, Figure 5 shows the relationship between the rotor and stator. 6 is a sectional view corresponding to FIG. 3 showing an embodiment of the present invention. 6... Crankshaft, 7... Crankshaft eccentric portion, 9'... Rotor, 10... Stator, 10c,
10c'...Motor main winding, 10d, 10d'...Motor auxiliary winding, 11...Air gap, 111...Minimum air gap.

Claims (1)

[Claims] 1 A rotor fixed to a crankshaft, and a stator having a main motor winding and an auxiliary motor winding for rotating the rotor, the minimum dimension position of the gap between the rotor and the stator;
The rotary compressor is arranged such that the direction of the force applied to the eccentric portion of the crankshaft due to compression work is in the same direction and at a position substantially perpendicular to the direction of the main windings of the motor.