JP2615231B2 - Electric compressor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electric compressor.

(Prior Art) One example of a conventional electric compressor is shown in FIG. 3 and FIG.

Inside the closed casing 1, a rotary compression mechanism 3 and a motor 2 for driving the rotary compression mechanism 3 via a crankshaft 4 are accommodated.

The stator 2a of the motor 2 is fixed to the casing 1 by shrink fitting, and the rotor 2b is fixed to the upper part of the crankshaft 4.

The rotary compression mechanism 3 includes a rolling piston 6 fitted to a crank pin 5 of a crankshaft 4 and a cylinder block 7 fixed to the casing 1 by plug welding.
An upper bearing 8 for closing an upper end opening of the cylinder block 7; a lower bearing 9 for closing a lower end opening of the cylinder block 7; a blade 10 supported so as to be able to protrude and retract from the cylinder block 7; And a presser spring 11 for pushing the presser spring.

Rolling piston 6 in cylinder chamber 12 bounded by cylinder block 7, upper bearing 8 and lower bearing 9
The tip of the blade 10 is brought into contact with the outer peripheral surface of the rolling piston 6 so that the blade
The suction chamber 13 is limited on one side of the compression chamber 10, and the compression chamber 14 is limited on the other side.

The crankshaft 4 is supported by an upper bearing 8 and a lower bearing 9 respectively.

When the crankshaft 4 is driven to rotate by the motor 2, the rolling piston 6 eccentrically rotates in the direction indicated by an arrow in the cylinder chamber 12, and at the same time, the suction pipe is inserted into the suction chamber 13.
Gas is sucked in from 20 and the gas in the compression chamber 14 is compressed.

The compressed gas is discharged from the upper bearing 8 through a discharge port
After passing through 22, a discharge valve (not shown) is pushed up to enter a discharge muffler chamber 27 limited by the upper bearing 8 and a cover 26 covering the upper surface of the upper bearing 8, and its pulsating component is removed. Next, the motor 2 is passed through a hole (not shown) formed in the cover 26.
The pulsatile component is further removed by expanding into the first expansion chamber 28 limited below. Next, the air gap between the stator 2a and the rotor 2b and the stator 2a
The pulsation component is further removed by expanding into the second expansion chamber 15 limited above the motor 2 through the gas passage 29 formed between the discharge pipe and the discharge pipe. It is discharged outside through 16.

A lubricating oil 17 is stored in the inner bottom of the casing 1. The lubricating oil 17 is pumped up by a centrifugal oil pump 18 incorporated in the crankshaft 4, and is passed through an oil supply passage 19 formed in the crankshaft 4. 4 and sliding surface between upper bearing 8 and lower bearing 9, sliding surface between crankpin 5 and rolling piston 6, rolling piston 6
The oil is supplied to the sliding surface between the cylinder and the cylinder 7.

(Problems to be Solved by the Invention) In the above-mentioned conventional electric compressor, the crankshaft 4 is supported by an upper bearing 8 and a lower bearing 9 arranged at a small interval at a lower portion thereof, and is mounted on an upper portion thereof. Since the rotor 2b of the motor 2 is supported in a cantilever manner, if the rotor 2b has a slight unbalanced weight, the upper part of the crankshaft 4 whirls as the rotation speed of the motor 2 increases,
In severe cases, there is a problem that the rotor 2b comes into contact with the stator 2a and cannot rotate.

(Means for Solving the Problems) The present invention was invented to solve the above problems, and the gist of the present invention is to drive a compression mechanism inside a casing via a crankshaft. In an electric compressor containing a motor, a rotating body composed of the crankshaft and a rotor of the motor fixed to the crankshaft is fixed to the casing via bearing metals provided at both ends of the rotor. An electric compressor characterized by being rotatably mounted on a stator of a motor.

(Operation) In the present invention, since the above configuration is provided, even if the rotor of the motor has a slight unbalanced weight, it does not swing around and contact the stator.

(Embodiment) One embodiment of the present invention is shown in FIG. 1 and FIG.

Bearing metal 30 is provided on the outer periphery of both upper and lower ends of rotor 2b of motor 2.
The outer peripheral surface of the bearing metal 30 is buried at predetermined intervals on the inner periphery of the upper and lower ends of the stator 2a, and a plurality of (four in the figure) extending toward the center through the air gap δ. The inner peripheral surface of the bearing metal 31 is slidably contacted. The lubricating oil from the oil supply passage 19 is provided on these sliding contact surfaces with an oil supply hole 32 formed in the crankshaft 4 and a rotor 2b.
Oil is supplied through an oil supply passage 33 buried therein and an oil supply hole 34 penetrating through the bearing metal 30.

The upper end opening of the cylinder block 7 is
The lower end opening is closed by a lower end plate 91.

The other structure is the same as the conventional one shown in FIGS. 3 and 4, and the corresponding members are denoted by the same reference numerals.

When the motor 2 is driven, the rotating body composed of the crankshaft 4 and the rotor 2b fixed to the crankshaft 4 rotates while being supported by the bearing metals 30 and 31.
Lubricating oil is supplied to the sliding contact surface between 30 and 31 from the oil supply passage 19 through an oil supply hole 32, an oil supply passage 33, and an oil supply hole. Then, the gas from the first expansion chamber 28 flows between the adjacent bearing metals 31 and flows through the air gap δ.

Thus, since the rotating body is supported by the bearing metals 30 and 31 at both ends of the rotor 2b, even if there is a slight eccentric load on the rotor 2b, the rotor 2b does not whirly,
Therefore, even if the rotation speed of the motor 2 increases, the rotor 2b does not slide on the stator 2a.

In addition, since the crankshaft 4 does not need to be supported by the rotary compression mechanism 3, the upper end plate 81 and the lower end plate 81 are not required.
It suffices that the upper and lower ends of the cylinder block 91 are closed at the upper and lower ends of the cylinder block.

Although the embodiment in which the present invention is applied to the electric hermetic rotary compressor has been described above, the casing may not be hermetically sealed, and the compression mechanism is not limited to the rotary type but may be any other type of compression mechanism. May be.

(Effects of the Invention) In the present invention, the rotating body including the crankshaft and the motor rotor fixed to the crankshaft is rotated by the motor stator fixed to the casing via bearing metals disposed at both ends of the rotor. Because it is freely supported,
Even if the rotor has some unbalanced weight, it will not wobble and contact the stator. In addition, since it is not necessary to support the crankshaft by the compression mechanism, it is possible to manufacture light and inexpensively.

[Brief description of the drawings]

1 and 2 show one embodiment of the present invention. FIG. 1 is a longitudinal sectional view, and FIG. 2 is a transverse sectional view taken along the line II-II in FIG. 3 and 4 show an example of a conventional electric compressor, FIG. 3 is a longitudinal sectional view, and FIG. 4 is a transverse sectional view taken along line IV-IV in FIG. Casing 1, Compression mechanism 3, Crankshaft 4, Motor 2, Stator 2a, Rotor 2
b, bearing metal ... 30, 31

Claims (1)

(57) [Claims] An electric compressor in which a compression mechanism and a motor for driving the compression mechanism via a crankshaft are housed inside a casing, wherein a rotary body comprising the crankshaft and a rotor of the motor fixed to the crankshaft. An electric compressor wherein a rotor is rotatably supported on a stator of a motor fixed to the casing via bearing metals provided at both ends of the rotor.