JPS61229988A - Rotary type compressor - Google Patents

Abstract

PURPOSE:To prevent rotation and vibration of a crankshaft for noise reduction purpose in a closed type rotary compressor by having the upper end part of the crankshaft supported by a bearing which is attached to a motor stator. CONSTITUTION:The upper end part of the crankshaft 13 of a rotary compressor mechanism which stands fixedly inside a closed case 2 is supported by an upper end part bearing 14 which is coaxially fixed to a motor stator 10. The crankshaft 13 has the opposed ends thereof supported by the upper end part bearing 14 and the upper and lower bearing 4 and 5 so that the electromagnetic vibration of the crankshaft 13 and vibration generated by virtue of the presence of eccentric load can be restrained and noise production can be prevented.

Description

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

Conventional configuration and its problems In general, in such a rotary compressor, due to the influence of motor electromagnetic vibration, electromagnetic noise occurs at a frequency of 2n times the power supply frequency, rotational imbalance due to eccentricity of the flank shaft, and Vibration occurs due to uneven rotation due to load fluctuations due to compression, which generates noise.

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

1 is a rotary compressor, 2 is a sealed case, and 3 is a cylinder, whose outer periphery is welded and fixed to the sealed case 2. 4 is an upper bearing, and 5 is a lower bearing, which supports a crankshaft 6. 9 is an eccentric portion of the crankshaft 6, and a rotor 28 is rotatably arranged on the circumference of the eccentric portion. 9 is a rotor of a single-phase induction motor, which is press-fitted and fixed to the crankshaft 6.

1o is a stator, 10a and 10a' are a pair of motor main windings, and 10b and 10b' are motor auxiliary windings. 11 is a lower balance weight, and 12 is an upper balance weight.

In this configuration, the electromagnetic attractive force exerted by the motor is applied to the rotor in an elliptical distribution, with a maximum at the center of the motor main windings 10a, 10a' and a minimum at the center of the motor auxiliary windings 10b, 10b'.

The rotor vibrates due to motor electromagnetic vibration caused by this electromagnetic attraction force, and electromagnetic noise is generated at a frequency 2n times the power supply frequency. Furthermore, the eccentric load caused by the crankshaft eccentric portion 7 causes rotational imbalance. This rotational imbalance is almost eliminated by the lower and upper balance ways) 11.12, but it is difficult to achieve perfect dynamic balance due to variations in eccentric loads and installation errors of the lower and upper balance ways) 11.12. Therefore, there have been problems in that vibrations are generated due to unbalance, noise is generated, and noise is also generated due to uneven rotational vibrations caused by compression load fluctuations.

OBJECT OF THE INVENTION An object of the present invention is to reduce vibrations caused by unbalanced rotation of electromagnetic vibrations, uneven rotational vibrations, and noise generated thereby. According to the invention, a bearing is also provided at the end of the crankshaft opposite to the compression element, so that the crankshaft is supported at both ends.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. 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.

13 is a crankshaft to which a rotor 9 of a single-phase induction motor is press-fitted and fixed. Reference numeral 14 denotes an upper end bearing which is fixed to the stator 1o by fixing bolts 16.

In such a configuration, the upper end bearing 14 is configured in advance to
The fixing bolt 16 is aligned with the stator 10 and
Fixed by Therefore, during assembly, the upper end bearing 14. Stator 10. Upper bearing 4. There is no need to align the axes of the lower bearing 6 and assemble the stator 10. Upper bearing 4. By only considering the axial center of the lower bearing 6, the axial center of the upper end bearing 14 can be aligned and assembled.

With the above configuration, the crankshaft 13 is supported at both ends by the upper end bearing 14 and the upper and lower bearings 4 and 6, so that vibrations of the rotor 9 excited by electromagnetic vibration due to the electromagnetic attraction force of the motor are suppressed. suppressed, making it difficult for electromagnetic noise to occur. Furthermore, vibrations that could not be suppressed by the balance weights 11 and 12, such as the rotor 9 swinging around the compression element due to the unbalanced rotation caused by the eccentric load caused by the crankshaft eccentric part 7, also cause the upper end of the crankshaft 13 to vibrate. By supporting the upper end bearing 14, noise caused by the vibration is suppressed and less likely to occur. In addition, uneven rotational vibrations caused by compression load fluctuations are also suppressed because the crankshaft 13 is supported at both ends.
Therefore, noise is also less likely to be generated. Therefore, the rotary compressor can be made quiet.

Effects of the Invention As described above, the present invention provides a bearing at the end opposite to the compression element and fixes the bearing to the stator in advance to support the crankshaft at both ends, thereby reducing the electromagnetic attraction of the motor. A quiet rotary compressor can be obtained by suppressing vibrations due to unbalance of one rotation of electromagnetic vibration caused by force and uneven rotational vibrations, and reducing noise generated thereby.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a rotary compressor showing a conventional example, and FIG. 2 is a sectional view taken along line nn' in FIG. 1. FIG. 3 is a longitudinal cross-sectional view of a rotary compressor showing an embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along the line ■-■' in FIG. 5...Lower bearing, 1o...Stator, 1
3... Crankshaft, 14... Upper end bearing 0 Name of agent Patent attorney Toshio Nakao and 1 other person Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A rotating motor comprising a closed case housing an electric compression element, a lower bearing and an upper end bearing at the ends of the compression element side and the anti-compression element side of the crankshaft, respectively, and the upper end bearing is fixed to the stator of the motor. mold compressor.