Patent Description:
In a refrigeration cycle device, a multi-cylinder rotary compressor having high compression performance is utilized. A multi-cylinder rotary compressor includes a plurality of compression mechanism units, a shaft, and a plurality of eccentric parts. The plurality of eccentric parts are provided on the shaft and are disposed in each of the plurality of compression mechanism units. Directions of eccentricity of the plurality of eccentric parts differ in a circumferential direction of the shaft. When the plurality of eccentric parts rotate together with the shaft, the rotary compressor vibrates. A rotary compressor in which vibration can be suppressed is required.

Prior art constituting technological background to the invention is disclosed in <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

A problem to be solved by the present invention is to provide a rotary compressor and a refrigeration cycle device in which vibration can be suppressed.

A rotary compressor according to the invention includes a shaft, a plurality of compression mechanism units, a plurality of eccentric parts, a first balancer, and a second balancer. The shaft is rotatable around a central axis. The plurality of compression mechanism units includes a first compression mechanism unit, a second compression mechanism unit, and a third compression mechanism unit disposed to be aligned from one side to the other side in a central axis direction of the shaft. The plurality of eccentric parts are provided on the shaft and include a first eccentric part, a second eccentric part, and a third eccentric part disposed in corresponding to the first compression mechanism unit, the second compression mechanism unit, and the third compression mechanism unit. The first balancer rotates together with the shaft. The second balancer is disposed on the other side of the first balancer and rotates together with the shaft. Angles between a direction of eccentricity of the first balancer with respect to the central axis of the shaft and directions of eccentricity of the plurality of eccentric parts with respect to the central axis of the shaft are configured to increase in an order of the third eccentric part, the second eccentric part, and the first eccentric part. Angles between a direction of eccentricity of the second balancer with respect to the central axis of the shaft and directions of eccentricity of the plurality of eccentric parts with respect to the central axis of the shaft are configured to increase in an order of the first eccentric part, the second eccentric part, and the third eccentric part.

Hereinafter, a rotary compressor and a refrigeration cycle device of an embodiment will be described with reference to the drawings.

<FIG> is a schematic configuration view of a refrigeration cycle device including a cross-sectional view of a rotary compressor according to the embodiment. In the present application, a Z direction, an X direction, and a Y direction of an orthogonal coordinate system are defined as follows. The Z direction is a central axis direction of a shaft <NUM>. A +Z direction (one side) is a direction from a compression mechanism unit <NUM> toward an electric motor unit <NUM>, and a -Z direction (the other side) is a side opposite to the +Z direction. For example, the Z direction is a vertical direction, and the +Z direction is vertically upward. The X direction and the Y direction are radial directions of the shaft <NUM>. The X direction is a direction of eccentricity of a third eccentric part <NUM> with respect to the central axis of the shaft <NUM>. For example, the X direction and the Y direction are horizontal directions.

A refrigeration cycle device <NUM> will be briefly described.

The refrigeration cycle device <NUM> includes a rotary compressor <NUM>, a radiator (for example, a condenser) <NUM> connected to the rotary compressor <NUM>, an expansion device (for example, an expansion valve) <NUM> connected to the radiator <NUM>, and a heat absorber (for example, an evaporator) <NUM> connected to the expansion device <NUM>. The refrigeration cycle device <NUM> contains a refrigerant such as carbon dioxide (CO<NUM>). The refrigerant circulates in the refrigeration cycle device <NUM> while changing its phase.

The rotary compressor <NUM> is a so-called rotary type compressor. The rotary compressor <NUM> compresses a low-pressure gaseous refrigerant (fluid) taken into the inside into a high-temperature and high-pressure gaseous refrigerant. A specific configuration of the rotary compressor <NUM> will be described later.

The radiator <NUM> dissipates heat from the high-temperature and high-pressure gaseous refrigerant discharged from the rotary compressor <NUM> to convert the high-temperature and high-pressure gaseous refrigerant into a high-pressure liquid refrigerant.

The expansion device <NUM> reduces a pressure of the high-pressure liquid refrigerant sent from the radiator <NUM> to convert the high-pressure liquid refrigerant into a low-temperature and low-pressure liquid refrigerant.

The heat absorber <NUM> evaporates the low-temperature and low-pressure liquid refrigerant sent from the expansion device <NUM> to convert it into a low-pressure gaseous refrigerant. In the heat absorber <NUM>, evaporation of the low-pressure liquid refrigerant takes evaporation heat from the surroundings, and thus the surroundings are cooled. The low-pressure gaseous refrigerant that has passed through the heat absorber <NUM> is taken into the rotary compressor <NUM> described above.

As described above, a refrigerant serving as a working fluid circulates while changing its phase between a gaseous refrigerant and a liquid refrigerant in the refrigeration cycle device <NUM> of the present embodiment. The refrigerant dissipates heat in the process of changing phase from the gaseous refrigerant to the liquid refrigerant and absorbs heat in the process of changing phase from the liquid refrigerant to the gaseous refrigerant. Heating, cooling, or the like is performed by utilizing such heat dissipation and heat absorption.

The rotary compressor <NUM> will be described.

The rotary compressor <NUM> includes an accumulator <NUM> and a compressor main body <NUM>. The accumulator <NUM> separates the refrigerant sent from the heat absorber <NUM> into a gaseous refrigerant and a liquid refrigerant. The gaseous refrigerant is taken into the compressor main body <NUM> through a suction pipe.

The compressor main body <NUM> includes a case <NUM>, the shaft <NUM>, the electric motor unit <NUM>, and a plurality of compression mechanism units <NUM>.

The case <NUM> is formed in a cylindrical shape with both end portions closed. The case <NUM> houses the shaft <NUM>, the electric motor unit <NUM>, and the plurality of compression mechanism units <NUM>. The case <NUM> includes a discharge unit <NUM> at an upper end portion. The discharge unit <NUM> supplies the gaseous refrigerant inside the case <NUM> to the radiator <NUM>.

The shaft <NUM> is disposed along the central axis of the compressor main body <NUM>. The shaft <NUM> includes a plurality of eccentric parts <NUM>. Details of the plurality of eccentric parts <NUM> will be described later.

The electric motor unit <NUM> is disposed in the +Z direction of the shaft <NUM>. The electric motor unit <NUM> includes a stator 15a and a rotor 15b. The stator 15a is fixed to an inner circumferential surface of the case <NUM>. The rotor 15b is fixed to an outer circumferential surface of the shaft <NUM>. The electric motor unit <NUM> rotationally drives the shaft <NUM>.

The plurality of compression mechanism units <NUM> compress the gaseous refrigerant by rotation of the shaft <NUM>. The plurality of compression mechanism units <NUM> are disposed in the -Z direction of the shaft <NUM>. The plurality of compression mechanism units <NUM> include a set of three compression mechanism units <NUM> including a first compression mechanism unit <NUM>, a second compression mechanism unit <NUM>, and a third compression mechanism unit <NUM>. The first compression mechanism unit <NUM>, the second compression mechanism unit <NUM>, and the third compression mechanism unit <NUM> are disposed to be aligned in that order from the +Z direction to the -Z direction. Hereinafter, a configuration of the first compression mechanism unit <NUM> will be described as a representative. Configurations of the second compression mechanism unit <NUM> and the third compression mechanism unit <NUM> are the same as that of the first compression mechanism unit <NUM> except for a direction of eccentricity of the eccentric parts <NUM>.

The first compression mechanism unit <NUM> includes a first eccentric part <NUM>, a roller <NUM>, and a cylinder <NUM>.

The first eccentric part <NUM> has a columnar shape and is integrally formed with the shaft <NUM>. When viewed from the +Z direction, a center of the first eccentric part <NUM> is eccentric from the central axis of the shaft <NUM>.

The roller <NUM> is formed in a cylindrical shape and is disposed along an outer circumference of the first eccentric part <NUM>.

The cylinder <NUM> is fixed to a frame <NUM>. An outer circumferential surface of the frame <NUM> is fixed to an inner circumferential surface of the case <NUM>. The cylinder <NUM> includes a first cylinder chamber 21c, a vane (not illustrated), and a suction hole <NUM>. The first cylinder chamber 21c is formed to penetrate a center of the cylinder <NUM> in the Z direction. The first cylinder chamber 21c houses the first eccentric part <NUM> and the roller <NUM> therein. The vane is housed in a vane groove formed in the cylinder <NUM> and can advance into and retreat from the inside of the first cylinder chamber 21c. The vane is urged so that a distal end portion thereof is brought into contact with an outer circumferential surface of the roller <NUM>. The vane, together with the first eccentric part <NUM> and the roller <NUM>, partitions the inside of the first cylinder chamber 21c into a suction chamber and a compression chamber. The suction hole <NUM> takes the gaseous refrigerant into the suction chamber of the first cylinder chamber 21c from the accumulator <NUM>.

The rotary compressor <NUM> includes a first bearing <NUM>, a second bearing <NUM>, a first partition part <NUM>, a second partition part <NUM>, a first muffler <NUM>, and a second muffler <NUM>.

The first bearing <NUM> is disposed in the +Z direction of the plurality of compression mechanism units <NUM> and supports the shaft <NUM>. The second bearing <NUM> is disposed in the -Z direction of the plurality of compression mechanism units <NUM> and supports the shaft <NUM>.

The first partition part <NUM> is disposed between the first compression mechanism unit <NUM> and the second compression mechanism unit <NUM>. The second partition part <NUM> is disposed between the second compression mechanism unit <NUM> and the third compression mechanism unit <NUM>.

The first muffler <NUM> forms a first muffler chamber 27c between itself and the first bearing <NUM>. The gaseous refrigerant compressed by the first compression mechanism unit <NUM> is discharged to the first muffler chamber 27c. The gaseous refrigerant discharged to the first muffler chamber 27c is discharged to the inside of the case <NUM>.

The second muffler <NUM> forms a second muffler chamber 28c between itself and the second bearing <NUM>. The gaseous refrigerant compressed by the third compression mechanism unit <NUM> is discharged to the second muffler chamber 28c. The second muffler chamber 28c communicates with the first muffler chamber 27c via a passage between muffler chambers (not illustrated).

The gaseous refrigerant compressed by the second compression mechanism unit <NUM> is discharged to a partition part passage <NUM> formed in the second partition part <NUM>. The partition part passage <NUM> communicates with the passage between the muffler chambers described above.

A region between a center of gravity <NUM> of the first eccentric part <NUM> and a center of gravity <NUM> of the second eccentric part <NUM> is a first region R1. A region between the center of gravity <NUM> of the second eccentric part <NUM> and a center of gravity <NUM> of the third eccentric part <NUM> is a second region R2. A distance of the second region R2 in the Z direction is larger than a distance of the first region R1 in the Z direction. An intermediate bearing <NUM> that supports the shaft <NUM> is disposed in the second region R2. The second partition part <NUM> described above is disposed in the second region R2. The second partition part <NUM> includes a partition member <NUM> and the intermediate bearing <NUM>. The partition member <NUM> is disposed in the -Z direction, and the intermediate bearing <NUM> is disposed in the +Z direction. An enlarged diameter part <NUM> of the shaft <NUM> is formed at a position in the Z direction at which the intermediate bearing <NUM> is disposed. A through hole <NUM> formed at a center of the intermediate bearing <NUM> supports the enlarged diameter part <NUM> of the shaft <NUM>.

The plurality of compression mechanism units <NUM> are disposed between the first bearing <NUM> and the second bearing <NUM>. Bending of the shaft <NUM> increases between the first bearing <NUM> and the second bearing <NUM>. The intermediate bearing <NUM> is disposed near a center of the plurality of compression mechanism units <NUM> in the Z direction. The intermediate bearing <NUM> suppresses the bending of the shaft <NUM>. Thereby, the rotary compressor <NUM> having low vibration, high reliability, and high performance can be provided.

The plurality of eccentric parts <NUM> will be described.

The plurality of eccentric parts <NUM> include the first eccentric part <NUM>, the second eccentric part <NUM>, and the third eccentric part <NUM>. The first eccentric part <NUM>, the second eccentric part <NUM>, and the third eccentric part <NUM> are disposed in the first compression mechanism unit <NUM>, the second compression mechanism unit <NUM>, and the third compression mechanism unit <NUM>, respectively.

<FIG> is a bottom view of the plurality of eccentric parts. The plurality of eccentric parts <NUM> are eccentric with respect to the central axis of the shaft <NUM>. Directions of eccentricity of the plurality of eccentric parts <NUM> are different from each other in a circumferential direction of the shaft <NUM>. It is desirable that the directions of eccentricity of the plurality of eccentric parts <NUM> be at equiangular intervals in the circumferential direction of the shaft <NUM>. The directions of eccentricity of the first eccentric part <NUM>, the second eccentric part <NUM>, and the third eccentric part <NUM> are at equiangular intervals of <NUM>° in the circumferential direction of the shaft <NUM>.

In the present application, a θ direction is a rotation direction of a right-hand screw traveling in the +Z direction.

As described above, the direction of eccentricity of the third eccentric part <NUM> is the X direction. A direction of eccentricity of the second eccentric part <NUM> is in a direction of <NUM>° in the θ direction from the X direction which is the direction of eccentricity of the third eccentric part <NUM>. A direction of eccentricity of the first eccentric part <NUM> is in a direction of <NUM>° in the θ direction from the direction of eccentricity of the second eccentric part <NUM>.

When the shaft <NUM> rotates, a centrifugal force F acts on the centers of gravity of the plurality of eccentric parts <NUM>. Magnitudes of the centrifugal forces F acting on the plurality of eccentric parts <NUM> are the same. An X-direction component of the centrifugal force acting on the center of gravity <NUM> of the third eccentric part <NUM> is F, and a Y-direction component thereof is <NUM>. An X-direction component of the centrifugal force acting on the center of gravity <NUM> of the second eccentric part <NUM> is -F/<NUM>, and a Y-direction component thereof is -√<NUM>·F/<NUM>. An X-direction component of the centrifugal force acting on the center of gravity <NUM> of the first eccentric part <NUM> is -F/<NUM>, and a Y-direction component thereof is √<NUM>·F/<NUM>. A moment (swinging moment, rotational moment) of force acts on the shaft <NUM> due to the centrifugal force F acting on the plurality of eccentric parts <NUM>.

The rotary compressor <NUM> illustrated in <FIG> includes a balancer (counter balancer) that suppresses the moment of force acting on the shaft <NUM>. The rotary compressor <NUM> includes a first balancer <NUM> and a second balancer <NUM>. The first balancer <NUM> and the second balancer <NUM> rotate together with the shaft <NUM>. The second balancer <NUM> is disposed in the -Z direction of the first balancer <NUM>. The plurality of eccentric parts <NUM> are disposed between the first balancer <NUM> and the second balancer <NUM> in the Z direction.

The first balancer <NUM> is disposed in the +Z direction of the plurality of eccentric parts <NUM>. The first balancer <NUM> is disposed in the +Z direction of the electric motor unit <NUM>. The first balancer <NUM> is fixed to an end surface of the rotor 15b of the electric motor unit <NUM> in the +Z direction. The first balancer <NUM> rotates together with the rotor 15b and the shaft <NUM>.

The second balancer <NUM> is disposed in the -Z direction of the plurality of eccentric parts <NUM>. The second balancer <NUM> is disposed inside the second muffler <NUM> in the -Z direction of the second bearing <NUM>. The second balancer <NUM> is formed separately from the shaft <NUM>. The second balancer <NUM> is fixed to the shaft <NUM> by a fixing means such as a screw. The second balancer <NUM> rotates together with the shaft <NUM>.

<FIG> is a schematic front view of the shaft. <FIG> is a schematic side view of the shaft. <FIG> and <FIG> schematically illustrate shapes and positions of the shaft <NUM>, the first balancer <NUM>, and the second balancer <NUM> for ease of understanding. A first distance in the Z direction between the center of gravity <NUM> of the first eccentric part <NUM> and the center of gravity <NUM> of the second eccentric part <NUM> is L. A second distance in the Z direction between the center of gravity <NUM> of the second eccentric part <NUM> and the center of gravity <NUM> of the third eccentric part <NUM> is kL. k is a ratio of the second distance to the first distance. A distance in the Z direction between a center of gravity <NUM> of the first balancer <NUM> and a center of gravity <NUM> of the second balancer <NUM> is B.

Using <FIG>, an X-direction component Fbx of a centrifugal force acting on the first balancer <NUM>, in which a moment of force acting on the shaft <NUM> around a Y axis is <NUM>, is obtained. For example, the center of gravity <NUM> of the third eccentric part <NUM> is used as a reference point. A moment of force My acting on the shaft <NUM> around the Y axis due to the X-direction component of the centrifugal force F acting on the plurality of eccentric parts <NUM> is expressed by mathematical expression <NUM>.

For example, the center of gravity <NUM> of the second balancer <NUM> is used as a reference point. The X-direction component of the centrifugal force acting on the first balancer <NUM> due to rotation of the shaft <NUM> is assumed to be Fbx. A moment of force Mby acting on the shaft <NUM> around the Y axis due to the X-direction component Fbx of the centrifugal force acting on the first balancer <NUM> is expressed by mathematical expression <NUM>.

When the following mathematical expression <NUM> is established, the moment of force acting on the shaft <NUM> around the Y axis is <NUM>.

Fbx satisfying mathematical expression <NUM> is expressed by mathematical expression <NUM>.

A mass, a position, and a shape of the first balancer <NUM> are set so that the X-direction component Fbx of the centrifugal force acting on the first balancer <NUM> satisfies mathematical expression <NUM>.

An X-direction component of the centrifugal force acting on the second balancer <NUM> due to rotation of the shaft <NUM> is -Fbx. -Fbx is expressed by mathematical expression <NUM>.

A mass, a position, and a shape of the second balancer <NUM> are set so that the X-direction component -Fbx of the centrifugal force acting on the second balancer <NUM> satisfies mathematical expression <NUM>.

Using <FIG>, a Y-direction component Fby of the centrifugal force acting on the first balancer <NUM>, in which a moment of force acting on the shaft <NUM> around an X axis is <NUM>, is obtained. For example, the center of gravity <NUM> of the third eccentric part <NUM> is used as a reference point. A moment of force Mx acting on the shaft <NUM> around the X axis due to the Y-direction component of the centrifugal force F acting on the plurality of eccentric parts <NUM> is expressed by mathematical expression <NUM>.

For example, the center of gravity <NUM> of the second balancer <NUM> is used as a reference point. The Y-direction component of the centrifugal force acting on the first balancer <NUM> due to rotation of the shaft <NUM> is assumed to be Fby. A moment of force Mbx acting on the shaft <NUM> around the X axis due to the Y-direction component Fby of the centrifugal force acting on the first balancer <NUM> is expressed by mathematical expression <NUM>.

When the following mathematical expression <NUM> is established, the moment of force acting on the shaft <NUM> around the X axis is <NUM>.

Fby satisfying mathematical expression <NUM> is expressed by mathematical expression <NUM>.

A mass, a position, and a shape of the first balancer <NUM> are set so that the Y-direction component Fby of the centrifugal force acting on the first balancer <NUM> satisfies mathematical expression <NUM>.

A Y-direction component of the centrifugal force acting on the second balancer <NUM> due to rotation of the shaft <NUM> is -Fby. -Fby is expressed by mathematical expression <NUM>.

A mass, a position, and a shape of the second balancer <NUM> are set so that the Y-direction component Fby of the centrifugal force acting on the second balancer <NUM> satisfies mathematical expression <NUM>.

<FIG> is a bottom view of the first balancer. As described above, the X-direction component Fbx of the centrifugal force acting on the first balancer <NUM>, in which the moment of force acting on the shaft <NUM> is <NUM>, is expressed by mathematical expression <NUM>, and the Y-direction component Fby is expressed by mathematical expression <NUM>. An angle θ1(rad) of a direction of eccentricity of the center of gravity <NUM> of the first balancer <NUM> from the central axis of the shaft <NUM> with respect to the +X direction in the θ direction is expressed by mathematical expression <NUM>.

Angles between the direction of eccentricity of the center of gravity <NUM> of the first balancer <NUM> with respect to the central axis of the shaft <NUM> and directions of eccentricity of the centers of gravity of the plurality of eccentric parts <NUM> with respect to the central axis of the shaft <NUM> are defined as follows. The angle with respect to a direction of eccentricity of the center of gravity <NUM> of the first eccentric part <NUM> is θ11. The angle with respect to a direction of eccentricity of the center of gravity <NUM> of the second eccentric part <NUM> is θ12. The angle with respect to a direction of eccentricity of the center of gravity <NUM> of the third eccentric part <NUM> is θ13. The angles between the direction of eccentricity of the center of gravity <NUM> of the first balancer <NUM> with respect to the central axis of the shaft <NUM> and the directions of eccentricity of the centers of gravity of the plurality of eccentric parts <NUM> with respect to the central axis of the shaft <NUM> satisfy mathematical expression <NUM>.

That is, the angle increases in an order of θ13, θ12, and θ11 from the smallest.

The plurality of eccentric parts <NUM> and the first balancer <NUM> are set to satisfy mathematical expression <NUM>. Even when the directions of eccentricity of the plurality of eccentric parts <NUM> are not at equiangular intervals, the moment of force of the shaft <NUM> is suppressed when mathematical expression <NUM> is satisfied. Even when the centrifugal force acting on the first balancer <NUM> does not satisfy mathematical expression <NUM> or <NUM>, the moment of force of the shaft <NUM> is suppressed when mathematical expression <NUM> is satisfied.

<FIG> is a bottom view of the second balancer. As described above, the X-direction component -Fbx of the centrifugal force acting on the second balancer <NUM>, in which the moment of force acting on the shaft <NUM> is <NUM>, is expressed by mathematical expression <NUM>, and the Y-direction component -Fby is expressed by mathematical expression <NUM>. An angle θ2(rad) of a direction of eccentricity of the center of gravity <NUM> of the second balancer <NUM> from the central axis of the shaft <NUM> with respect to the +X direction in the θ direction is expressed by mathematical expression <NUM>.

Angles between the direction of eccentricity of the center of gravity <NUM> of the second balancer <NUM> with respect to the central axis of the shaft <NUM> and the directions of eccentricity of the centers of gravity of the plurality of eccentric parts <NUM> with respect to the central axis of the shaft <NUM> are defined as follows. The angle with respect to the direction of eccentricity of the center of gravity <NUM> of the first eccentric part <NUM> is θ21. The angle with respect to the direction of eccentricity of the center of gravity <NUM> of the second eccentric part <NUM> is θ22. The angle with respect to the direction of eccentricity of the center of gravity <NUM> of the third eccentric part <NUM> is θ23. The angles between the direction of eccentricity of the center of gravity <NUM> of the second balancer <NUM> with respect to the central axis of the shaft <NUM> and the directions of eccentricity of the centers of gravity of the plurality of eccentric parts <NUM> with respect to the central axis of the shaft <NUM> satisfy mathematical expression <NUM>.

That is, the angle increases in an order of θ21, θ22, and θ23 from the smallest.

The plurality of eccentric parts <NUM> and the second balancer <NUM> are set to satisfy mathematical expression <NUM>. Even when the directions of eccentricity of the plurality of eccentric parts <NUM> are not at equiangular intervals, the moment of force of the shaft <NUM> is suppressed when mathematical expression <NUM> is satisfied. Even when the centrifugal force acting on the second balancer <NUM> does not satisfy mathematical expression <NUM> or <NUM>, the moment of force of the shaft <NUM> is suppressed when mathematical expression <NUM> is satisfied.

<FIG> is a graph illustrating a relationship between a deviation angle of the balancer and a vibration amplitude of the compressor main body. The horizontal axis of <FIG> represents a deviation angle (°) of the angles θ1 and θ2 of the balancers <NUM> and <NUM> described above. The vertical axis of <FIG> is a vibration amplitude (µm) of the compressor main body <NUM>. As the deviation angles of the angles θ1 and θ2 of the balancers <NUM> and <NUM> increase, the vibration amplitude of the compressor main body <NUM> becomes larger. When the deviation angles of the angles θ1 and θ2 are in a range of ±<NUM>° (± π/<NUM> rad), the vibration amplitude of the compressor main body <NUM> is <NUM> or lower. It is desirable that the angles θ1 and θ2 satisfy mathematical expressions <NUM> and <NUM>, respectively, with A = √<NUM>/(<NUM>+<NUM>). <MAT> <MAT>.

As described in detail above, the rotary compressor of the embodiment includes the shaft <NUM>, the plurality of compression mechanism units <NUM>, the plurality of eccentric parts <NUM>, the first balancer <NUM>, and the second balancer <NUM>. The plurality of eccentric parts <NUM> include the first eccentric part <NUM>, the second eccentric part <NUM>, and the third eccentric part <NUM> disposed to be aligned from the +Z direction to the -Z direction in the central axis direction of the shaft <NUM>. The second balancer <NUM> is disposed in the -Z direction of the first balancer <NUM>. Angles between the direction of eccentricity of the first balancer <NUM> and the directions of eccentricity of the plurality of eccentric parts <NUM> satisfy mathematical expression <NUM>. Angles between the direction of eccentricity of the second balancer <NUM> and the directions of eccentricity of the plurality of eccentric parts <NUM> satisfy mathematical expression <NUM>.

In the three-cylinder rotary compressor <NUM>, the moment of force of the shaft <NUM> caused by the three eccentric parts <NUM>, <NUM>, and <NUM> is suppressed by the two balancers <NUM> and <NUM>. Thereby, vibration of the rotary compressor <NUM> is suppressed. Decrease in reliability and deterioration in performance of the rotary compressor <NUM> due to bending of the shaft <NUM> are suppressed. Therefore, the rotary compressor <NUM> having low vibration, high reliability, and high performance can be provided.

An angle in a direction of eccentricity of the first balancer <NUM> with respect to the +X direction is assumed to be θ1(rad). An angle in a direction of eccentricity of the second balancer <NUM> with respect to the +X direction is assumed to be θ2(rad). θ1 and θ2 satisfy mathematical expressions <NUM> and <NUM>.

When θ1 satisfies mathematical expression <NUM> and θ2 satisfies mathematical expression <NUM>, the moment of force of the shaft <NUM> is theoretically <NUM>. When the deviation angle of θ1 from mathematical expression <NUM> and the deviation angle of θ2 from mathematical expression <NUM> are ±<NUM>°, the vibration amplitude of the compressor main body <NUM> is suppressed to <NUM> or lower. Therefore, when mathematical expressions <NUM> and <NUM> are satisfied, the rotary compressor <NUM> with low vibration can be provided.

The plurality of eccentric parts <NUM> are disposed between the first balancer <NUM> and the second balancer <NUM> in the Z direction.

The center of the moment of force acting on the shaft <NUM> due to the centrifugal force of the plurality of eccentric parts <NUM> and the center of the moment of force acting on the shaft <NUM> due to the centrifugal force of the two balancers <NUM> and <NUM> approach each other. Therefore, bending of the shaft <NUM> due to the deviation of the center of the moment of force is suppressed. Therefore, the rotary compressor <NUM> having low vibration, high reliability, and high performance can be provided.

Of the first region R1 between the center of gravity <NUM> of the first eccentric part <NUM> and the center of gravity <NUM> of the second eccentric part <NUM>, and the second region R2 between the center of gravity <NUM> of the second eccentric part <NUM> and the center of gravity <NUM> of the third eccentric part <NUM>, the intermediate bearing <NUM> that supports the shaft <NUM> is disposed in a region in which a distance in the Z direction is larger.

Since the intermediate bearing <NUM> is disposed near the center of the plurality of compression mechanism units <NUM>, bending of the shaft <NUM> or the like is suppressed. Thereby, the rotary compressor <NUM> having low vibration, high reliability, and high performance can be provided.

The rotary compressor <NUM> further includes the electric motor unit <NUM>, the first bearing <NUM>, and the second bearing <NUM>. The first balancer <NUM> is disposed in the +Z direction of the electric motor unit <NUM>. The second balancer <NUM> is disposed in the -Z direction of the second bearing <NUM>.

Since a distance between the balancers <NUM> and <NUM> is large, the mass of each of the balancers <NUM> and <NUM> is suppressed. Thereby, reduction in weight, reduction in size, and resource saving of the rotary compressor <NUM> can be achieved.

The refrigeration cycle device <NUM> of the embodiment includes the rotary compressor <NUM> described above, the radiator <NUM> connected to the rotary compressor <NUM>, the expansion device <NUM> connected to the radiator <NUM>, and the heat absorber <NUM> connected to the expansion device <NUM>.

Thereby, the refrigeration cycle device <NUM> having low vibration, high reliability, and high performance can be provided.

<FIG> is a cross-sectional view of a rotary compressor of a first modified example of the embodiment. The first modified example is different from the embodiment in terms of positions and shapes of the balancers <NUM> and <NUM>.

Similarly to the embodiment, the first balancer <NUM> and the second balancer <NUM> rotate together with the shaft <NUM>. The second balancer <NUM> is disposed in the -Z direction of the first balancer <NUM>. The plurality of eccentric parts <NUM> are disposed between the first balancer <NUM> and the second balancer <NUM> in the Z direction.

The first balancer <NUM> is disposed in the +Z direction of the plurality of eccentric parts <NUM>. The first balancer <NUM> is disposed in the -Z direction of the electric motor unit <NUM>. The first balancer <NUM> is fixed to an end surface of the rotor 15b of the electric motor unit <NUM> in the -Z direction.

The second balancer <NUM> is disposed in the -Z direction of the plurality of eccentric parts <NUM>. The second balancer <NUM> is disposed in the -Z direction of the second bearing <NUM>. A surface of the second balancer <NUM> in the +Z direction is disposed along a surface of the second bearing <NUM> in the -Z direction.

The rotary compressor <NUM> of the first modified example satisfies mathematical expressions <NUM>, <NUM>, <NUM>, and <NUM>. The plurality of eccentric parts <NUM> are disposed between the first balancer <NUM> and the second balancer <NUM> in the Z direction. Thereby, the rotary compressor <NUM> having low vibration, high reliability, and high performance can be provided.

<FIG> is a cross-sectional view of a rotary compressor of a second modified example of the embodiment. The second modified example is different from the embodiment in terms of positions and shapes of the balancers <NUM> and <NUM>.

Similarly to the embodiment, the first balancer <NUM> and the second balancer <NUM> rotate together with the shaft <NUM>. The second balancer <NUM> is disposed in the -Z direction of the first balancer <NUM>.

The first balancer <NUM> is disposed in the +Z direction of the plurality of eccentric parts <NUM>. The first balancer <NUM> is disposed in the +Z direction of the electric motor unit <NUM>. The first balancer <NUM> is fixed to an end surface of the rotor 15b of the electric motor unit <NUM> in the +Z direction.

The second balancer <NUM> is disposed in the +Z direction of the plurality of eccentric parts <NUM>. The second balancer <NUM> is disposed in the -Z direction of the electric motor unit <NUM>. The second balancer <NUM> is fixed to an end surface of the rotor 15b of the electric motor unit <NUM> in the -Z direction.

The rotary compressor <NUM> of the second modified example satisfies mathematical expressions <NUM>, <NUM>, <NUM>, and <NUM>. Thereby, the rotary compressor <NUM> having low vibration, high reliability, and high performance can be provided.

The rotary compressor <NUM> of the embodiment illustrated in <FIG> is a so-called rotary type compressor in which the blade (not illustrated) and the roller <NUM> are separate bodies. On the other hand, the rotary compressor may be a swing type compressor in which the blade and the roller are integrated.

According to at least one embodiment described above, the balancers <NUM> and <NUM> satisfying mathematical expressions <NUM> and <NUM> are provided. Thereby, the rotary compressor <NUM> having low vibration, high reliability, and high performance can be provided.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosure.

Claim 1:
A rotary compressor (<NUM>) comprising:
a shaft (<NUM>) rotatable around a central axis;
a plurality of compression mechanism units (<NUM>) including a first compression mechanism unit (<NUM>), a second compression mechanism unit (<NUM>), and a third compression mechanism unit (<NUM>) disposed to be aligned from one side to the other side in a central axis direction of the shaft;
a plurality of eccentric parts (<NUM>) provided on the shaft (<NUM>) and including a first eccentric part (<NUM>), a second eccentric part (<NUM>), and a third eccentric part (<NUM>) disposed in corresponding to the first compression mechanism unit (<NUM>), the second compression mechanism unit (<NUM>), and the third compression mechanism unit (<NUM>); characterized in
a first balancer (<NUM>) rotating together with the shaft (<NUM>); and
a second balancer (<NUM>) disposed on the other side of the first balancer (<NUM>) and rotating together with the shaft (<NUM>), wherein
angles between a direction of eccentricity of the first balancer (<NUM>) with respect to the central axis of the shaft (<NUM>) and directions of eccentricity of the plurality of eccentric parts with respect to the central axis of the shaft (<NUM>) are configured to increase in an order of the third eccentric part (<NUM>), the second eccentric part (<NUM>), and the first eccentric part (<NUM>), and
angles between a direction of eccentricity of the second balancer (<NUM>) with respect to the central axis of the shaft (<NUM>) and directions of eccentricity of the plurality of eccentric parts (<NUM>) with respect to the central axis of the shaft (<NUM>) are configured to increase in an order of the first eccentric part (<NUM>), the second eccentric part (<NUM>), and the third eccentric part (<NUM>).