JP2005248843A - Enclosed type compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem: when a rare earth magnet is used and the thickness of a magnetic-steel sheet laminate of a rotor is small, a weight increment in the rotor itself is small, and the inertia force in rotation is small, consequently fluctuation of the rotational load has a great effect. <P>SOLUTION: The enclosed type compressor is a rotary compressor mounted with a rare earth magnet motor used in a refrigeration circuit. A balance weight 5 is attached to the rotor 3b. In the rotor 3b, an inertia part 5a has a specified thickness so that the thickness of the magnetic-steel sheet laminate becomes equal to that of a rotor mounted with a ferrite magnet. The balance weight 5 has an inertia function of a non-magnetic body in which inertia-part mass is heavier than the mass of the balance-weight part. Thus, the weight of the rotor 3b itself becomes heavy to make the inertia force large, effect of rotation load fluctuation can be made small, performance is improved, and noise and vibration are reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rare earth magnet motor-equipped hermetic compressor used in a refrigeration circuit such as an air conditioner, and in particular, a balance weight attached to a rotor of an electric motor unit used for balancing a rotating system balance. It is about.

Conventionally, in order to balance the rotation system balance of a hermetic compressor, for example, the following has been performed.
An upper balance weight eccentric in the eccentric direction of the eccentric part is attached to the end face of the rotor far from the compression mechanism part, and the end face near the compression mechanism part of the rotor is opposite to the eccentric direction of the eccentric part via a spacer. By attaching a lower balance weight that is eccentric to the center and inserting a spacer, the lower balance weight is moved away from the rotor end face, thereby canceling the unbalanced force even in the case of an upper balance weight with a small mass and suppressing vibration. The bending of the rotating shaft during rotation is prevented (see Patent Document 1).
JP 2002-213357 A (page 4, FIG. 1)

  By the way, in a hermetic compressor mounted with a rare earth magnet motor used in a refrigeration circuit, since the rare earth magnet is used for the rotor of the motor section, the magnetic force is stronger than the rotor using a ferrite magnet, and the same output When it is necessary, the lamination thickness of the electromagnetic steel sheets can be reduced. Therefore, there is an advantage that the hermetic compressor itself can be reduced in weight, size, and cost, and the degree of freedom of unit mounting is increased.

  However, in the case of an electric motor using a rare earth magnet, since the laminated thickness of the electromagnetic steel sheets is reduced, the weight of the rotor itself is reduced, and the inertial force during rotation is reduced. is there. As a result, the performance may be degraded, and noise and vibration may be increased.

  Even in the hermetic compressor described in Patent Document 1, when a rare earth magnet is used and the laminated thickness of the electromagnetic steel sheet of the rotor is small, the spacer of the material having a light specific gravity has a small weight increment of the rotor itself, Since the inertial force is small, there is a problem that it is greatly influenced by fluctuations in rotational load.

The present invention has been made to solve the above-described problems, and uses rare earth magnets to reduce the cost by reducing the size of the magnets, and even if the laminated thickness of the electromagnetic steel sheets of the rotor is reduced. An object of the present invention is to obtain a hermetic compressor that is not greatly affected by fluctuations in rotational load.
In addition, a rare earth magnet is used to reduce the cost of the magnet and reduce the cost, and even if the laminated thickness of the electromagnetic steel sheet of the rotor is reduced, a hermetic compressor that has low vibration and ensures bearing reliability. The purpose is to obtain.
In addition, the use of rare earth magnets and the miniaturization of the magnets will reduce costs, and even if the laminated thickness of the electromagnetic steel sheets of the rotor is reduced, the bending deformation of the rotating shaft is reduced so that it does not sway during rotation. Thus, an object is to obtain a hermetic compressor that prevents metal contact with the bearing.

  In the hermetic compressor according to the present invention, the compression mechanism unit and the motor unit are connected and accommodated in a hermetic container by a rotating shaft, and a rare earth magnet is used for the rotor of the motor unit, and the upper and lower end faces of the rotor. A non-magnetic balance weight with inertia function is provided on the tip side of the balance weight part and the end face side is an inertia part, and the unbalanced force generated by the rotational movement of the eccentric part of the compression mechanism is balanced statically and dynamically. In addition, the sum of the mass of the rotor and the mass of the inertia part of the balance weight with the inertia function is equal to or greater than a predetermined mass that reduces the influence of the rotational load fluctuation.

  The hermetic compressor of the present invention uses a rare-earth magnet for the rotor of the motor part, and has a non-magnetic inertia function in which the tip end side is a balance weight part and the end face side is an inertia part on the upper and lower end faces of the rotor. A balance weight is provided to balance the unbalance force generated by the rotational movement of the eccentric part of the compression mechanism part statically and dynamically, and the total mass of the rotor and the inertia part of the balance weight with inertia function is By reducing the influence of rotational load fluctuations to a predetermined mass or more, cost reduction is achieved by downsizing the magnet, and the rotor and inertia parts of the motor part are heavier and the inertial force is increased. This has the effect of obtaining a hermetic compressor in which the influence of load fluctuation is reduced and performance is improved and noise and vibration are reduced.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing a rotary compressor that is a hermetic compressor according to Embodiment 1 of the present invention, and FIG. 2 is a view for explaining the balance of balance when the rotary compressor rotates.
In FIG. 1, a compression mechanism portion 2 and an electric motor portion 3 are connected and accommodated in a sealed container 1 by a rotating shaft 4. The compression mechanism section 2 includes a cylinder 2a fixed to the sealed container 1, a piston 2e attached to the outer peripheral portion of the eccentric portion 4a of the rotating shaft 4 in the cylinder 2a, and an upper end plate 2b that closes both end faces of the cylinder 2a. And the lower end plate 2c. The electric motor unit 3 includes a stator 3 a fixed to the hermetic container, and a rotor 3 b surrounded by the stator 3 a and fixed to the rotating shaft 4.
In this rotary compressor, after the refrigerant sucked from the suction pipe 11 is compressed in the compression chamber of the cylinder chamber 2d, the compressed refrigerant is discharged into the sealed container 1 and discharged from the discharge pipe 12 to the outside.

The motor unit 3 is a rare earth magnet motor, and a rare earth magnet is used for the rotor 3b.
The structure of the rotor 3b of the electric motor unit 3 is such that a rare earth magnet is inserted into the magnet insertion holes of the laminated electromagnetic steel sheets, and the inserted magnets are not formed on both end faces of the rotor 3b of the electric motor unit 3 in order to prevent the inserted magnets from falling. A balance weight integrated with an end plate of magnetic material is attached. These are caulked with rivets or the like. The balance weight is attached to balance the rotating system, but in the case of an electric motor using rare earth magnets, it is larger than that of an electric motor using ferrite magnets because the laminated thickness of electromagnetic steel sheets is reduced. It is necessary to attach a balance weight and increase the inertial force.

  In the present embodiment, the balance weight 5 with a non-magnetic inertia function is attached above and below the rotor 3b. The balance weight 5 with the non-magnetic inertia function includes an inertia part 5a on the end face side of the rotor 3b, and an upper end (when the rotor 3b is above) or a lower end (when the rotor 3b is below) of the inertia part 5a. The balance weight portion 5b is formed so that the balance weight portion 5b at the upper end is eccentric to the same side as the eccentric portion 4a of the rotating shaft 4, and the balance weight portion 5b at the lower end is eccentric to the opposite side to the eccentric portion 4a. Install as you do. Further, the upper and lower inertia parts 5a are combined to have a predetermined thickness so that the upper and lower inertia parts 5a and the rotor 3b have the same laminated thickness of the electromagnetic steel sheets as the ferrite magnet-mounted rotor. In FIG. 1, the upper and lower thicknesses are made equal. Further, the mass W1 of the inertia part 5a is made larger than the mass W2 of the balance weight part 5b, and the total mass of the mass of the rotor 3b and the mass of the inertia part 5a (both vertically) of the balance weight 5 with an inertia function. Is not less than a predetermined mass, for example, the mass of the ferrite magnet mounted rotor. These are caulked with rivets or the like.

The balance of the rotation system balance will be described with reference to FIG.
When the rotating shaft 4 rotates, the unbalanced force F1 generated by the rotation of the eccentric portion 4a is balanced by the unbalanced forces F3 and F2 of the upper and lower balance weight portions 5b. That is, F1 + F3 = F2 and the static balance is balanced.
Moreover, the rotating shaft 4 is supported and rotated by the upper end plate 2b which also serves as a bearing. At that time, the forces F1, F2, and F3 due to the unbalance between the eccentric portion 4a and the upper and lower balance weights 5b are set so that the moments are balanced with the center of gravity of the compressor as a fulcrum. That is, the distances from the fulcrum to the unbalanced forces F1, F2, and F3 are expressed as shown in FIG. 2, and F1 × L1 + F2 × L2 = F3 × L3, and the dynamic balance (moment) is balanced.
In this way, by balancing the static and dynamic balance, the unbalance of the eccentric portion 4a can be canceled, and the moment force that tries to cause the rotary shaft 4 to perform a sliding motion can also be canceled. Thus, a rotary compressor in which bearing reliability is ensured can be obtained.

  Further, as shown in FIG. 1, the inertia part 5a has a predetermined thickness so that the magnetic steel sheet laminated thickness is equivalent to that of the ferrite magnet-mounted rotor, and the mass W1 of the inertia part 5a is greater than the mass W2 of the balance weight part 5b. The balance weight 5 with a heavy non-magnetic body inertia function is attached to both ends of the rotor 3b, and the total mass of the mass of the rotor 3b and the mass of the inertia part 5a (both vertically) of the balance weight 5 with the inertia function is Since the predetermined mass, for example, the mass of the ferrite magnet mounted rotor or more is set, the weight of the rotor 3b itself is increased, and the influence of the rotational load fluctuation can be reduced by increasing the inertial force.

As described above, the upper and lower inertia portions 5a and the rotor 3b have a predetermined thickness in combination with the upper and lower inertia portions 5a so that the laminated thickness of the electromagnetic steel sheets is the same as that of the ferrite magnet mounted rotor. The thickness of the inertia part 5a and the rotor 3b may be smaller than the laminated thickness of the electromagnetic steel plates of the ferrite magnet mounted rotor. However, a predetermined weight increase of the upper and lower inertia parts 5a necessary for increasing the inertial force is performed. In addition, L2 and L3 are reduced to balance the static and dynamic balance. In this way, the same effect can be obtained.
Further, in the above, the mass W1 of the inertia part 5a is larger than the mass W2 of the balance weight part 5b, but the mass W1 of the inertia part 5a and the mass of the rotation are combined, regardless of this, A predetermined mass that can reduce the influence of the rotational load fluctuation, for example, the mass of the ferrite magnet mounted rotor or more may be used, and the same effect can be obtained.

Embodiment 2. FIG.
In the first embodiment, the balance weight 5 with a non-magnetic inertia function is added to the rotor 3b, thereby increasing the inertial force, reducing the influence of the rotational load fluctuation, and balancing the static and dynamic balance. In this embodiment, as shown in FIG. 3 which is a sectional view of the rotary compressor, the balance weight 5 with an inertia function is attached to the rotor 3b. It is attached only to the lower end face. That is, in the rotary compressor equipped with the rare earth magnet motor, the inertia part 5a has a predetermined thickness so that the laminated thickness of the electromagnetic steel sheets is equal to that of the ferrite magnet-equipped rotor, and the mass of the inertia part 5a is larger than the mass of the balance weight part 5b. A balance weight 5 with a heavy non-magnetic inertia function is attached only to the lower end surface of the rotor 3b. Therefore, the inertia part 5a on the upper end face of the rotor 3b in FIG. 1 is integrated with the inertia part 5a on the lower end face in the vertical direction, and the upper balance weight part 5b is deleted. The total mass of the mass of the rotor 3b and the mass of the inertia part 5a of the balance weight 5 with the inertia function is set to a predetermined mass, for example, the mass of the ferrite magnet mounted rotor or more. The upper end surface of the rotor 3b prevents the rare earth magnet from falling off by the end plate 9. Others are the same as in the first embodiment.

  In this way, the inertia part 5a has a predetermined thickness so as to be equal to the laminated thickness of the electromagnetic steel plates of the ferrite magnet-mounted rotor, and the balance with the non-magnetic inertia function is larger in the inertia part 5a than the balance weight part 5b. The weight 5 is attached only to the lower end surface of the rotor 3b, and the upper end surface of the rotor 3b is closed by the end plate 9, thereby lowering the center of gravity of the hermetic compressor and reducing the size of the attached balance weight portion. be able to. Further, the inertia force is increased by providing the balance weight 5 with the non-magnetic inertia function. Therefore, the rotation system balance can be maintained without being affected by the reliability due to the swinging, and the cost can be reduced.

In the rotary compressor of the present embodiment, a balance weight 5b may be provided on the same side as the eccentric part 4a of the upper end surface of the rotor 3b in FIG. By attaching the balance weight 5 with the non-magnetic inertia function only to the lower end surface of the rotor 3b, the lower balance weight portion 5b becomes close to the fulcrum of the upper end plate that also serves as a bearing, that is, L2 shown in FIG. Thus, the mass W2 of the upper balance weight portion 5b can be reduced from the above equation of balance between static and dynamic balance. Therefore, by balancing the static and dynamic balance, vibration can be reduced, and by the balance weight 5 with a non-magnetic inertia function, the influence of rotational load fluctuation can be reduced by increasing the inertial force. It is possible to prevent the rotating shaft 4 from being bent and swung, and to prevent metal contact with the bearing and loss of reliability.
In addition, since the amount of bending of the rotating shaft 4 is proportional to the cube of the distance between the portion where the centrifugal force acts and the fulcrum of the upper end plate 2b, the influence of the mass W2 of the upper balance weight portion 5b is particularly large.

Embodiment 3 FIG.
The rotary compressor according to the present embodiment is obtained by changing the shape and mounting method of the balance weight 5 with a nonmagnetic inertia function that is mounted on the lower end surface of the rotor 3b in the second embodiment.
FIG. 4 is a cross-sectional view illustrating a state in which the balance weight 5 with a nonmagnetic inertia function is attached to the rotor 3b. Although not shown, the rotary shaft 4 is arranged so that the rotor 3b is divided into left and right in the vertical direction in FIG. 4, the balance weight portion 5b is on the right, and the nonmagnetic spacer 8 is on the left. .
As shown in FIG. 4, the inertia part 5a has a predetermined thickness so that the rotor 4 has the same magnetic steel sheet lamination thickness as the ferrite magnet-mounted rotor, and the mass of the inertia part 5a is greater than the mass W2 of the balance weight part 5b. Balance weight 5 with non-magnetic inertia function with heavy W1 (the total mass of the rotor 3b and the inertia part 5a is equal to or more than a predetermined mass, for example, the mass of a ferrite magnet-mounted rotor) ) Is attached to the balance weight portion 5b on the opposite side of the lower end surface of the rotor 4 from the eccentric portion 4a of the rotating shaft 4, and the nonmagnetic spacer is provided on the same side as the eccentric portion 4a of the rotating shaft 4. 8 is attached, and the inertia part 5a is attached through these.

By doing in this way, the gravity center position of a hermetic compressor becomes low, and the size of the balance weight part to attach can be made small. Further, the inertia force is increased by providing the balance weight 5 with the non-magnetic inertia function. Therefore, the rotation system balance can be maintained without being affected by the reliability due to the swinging, and the cost can be reduced.
In addition, since the refrigerant gas compressed and discharged by the compression mechanism is discharged to the planar shape side of the balance weight (the balance weight 5 side with the inertia function in FIG. 4), the refrigerating machine oil enclosed in the sealed container is wound up In addition, since the oil separation effect of the discharged refrigerant gas is improved, the amount of oil taken out from the sealed container to the mounting unit is reduced, and the performance when the unit is mounted can be improved.

Embodiment 4 FIG.
As shown in FIG. 5, the present embodiment is the same as in the first to third embodiments. The balance weight 5 with inertia function attached to the rotor 3b of the rare earth magnet motor-equipped rotary compressor is replaced with the inertia portion 5a and the balance weight portion. It is a separate part from 5b and is attached to the rotor 3b in combination.

  By creating a separate part in this manner, the balance weight 5 with inertia function attached to the rotor 3b is changed only in the balance weight portion 5b with respect to the series development when the mass of the eccentric portion 4a is changed. It can be easily handled.

It is sectional drawing which shows the rotary compressor in Embodiment 1 of this invention. It is a figure explaining the balance balance at the time of rotation of the rotary compressor in Embodiment 1 of this invention. It is sectional drawing which shows the rotary compressor in Embodiment 2 of this invention. It is explanatory drawing which shows the state which attached the balance weight 5 with a nonmagnetic body inertia function in Embodiment 3 of this invention to the rotor 3b. It is a figure which shows what used the balance weight with an inertia function in Embodiment 4 of this invention as another component.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airtight container, 2 Compression mechanism part, 3 Electric motor part, 3b Rotor, 4 Rotating shaft, 4a Eccentric part, 5 Balance weight with inertia function, 5a Inertia part, 5b Balance weight part, 8 Spacer.

Claims (4)

The compression mechanism part 2 and the electric motor part 3 are connected and accommodated in the sealed container 1 by the rotating shaft 4,
Moreover, a rare earth magnet is used for the rotor of the electric motor part,
A non-magnetic balance weight with an inertia function is provided on the upper and lower end faces of the rotor, the tip side being a balance weight part, and the end face side being an inertia part, and is generated by the rotational movement of the eccentric part of the compression mechanism part The unbalanced force is statically and dynamically balanced, and the sum of the mass of the rotor and the mass of the inertia part of the balance weight with the inertia function is not less than a predetermined mass that reduces the influence of rotational load fluctuations. A hermetic compressor characterized by   2. The hermetic compressor according to claim 1, wherein the balance weight with the inertia function is provided only on a lower end surface of the rotor, and the lower inertia part is combined with the upper inertia part.   At the lower end face of the rotor, the balance weight part is provided on the opposite side of the eccentric part of the rotating shaft, and a nonmagnetic spacer is provided on the same side as the eccentric part of the rotating shaft, and the The hermetic compressor according to claim 2, further comprising an inertia part. The hermetic compressor according to any one of claims 1 to 3, wherein the balance weight part of the balance weight with inertia function and the inertia part are separate members.

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