Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K1/00—Details of the magnetic circuit
  • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
  • H02K1/22—Rotating parts of the magnetic circuit
  • H02K1/27—Rotor cores with permanent magnets
  • H02K1/2706—Inner rotors
  • H02K1/272—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis
  • H02K1/274—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets
  • H02K1/2753—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets the rotor consisting of magnets or groups of magnets arranged with alternating polarity
  • H02K1/276—Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM]
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K15/00—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
  • H02K15/16—Centering rotors within the stator; Balancing rotors
  • H02K15/165—Balancing the rotor
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
  • H02K7/04—Balancing means

Definitions

• the present invention relates to the direct current electric motor of a variable capacity hermetic compressor wherein the permanent magnets of the rotor thereof are fixed at a plurality of planes.
• the present invention more particularly relates to the magnet-rotor of the BLDC electric motor.
• the variable capacity hermetic refrigeration compressor generally comprises a BLDC electric motor which includes a magnet-rotor and a stator.
• the stator of the BLDC electric motor is produced by placing coils composed of conductive wires into the slots in the stator packet.
• the rotor which is placed at the center of the motor without any contact with the stator, is composed of the packet containing magnetic plates placed one above the other, magnets placed into the gaps formed at certain intervals in said packet, sheet metal plates which are fixed onto the lower and upper surfaces of the rotor packet via a connector element in order to prevent the falling off of the magnets, and weights fixed onto the lower and upper surfaces of said plates.
• a metal compressor body is placed onto the stator, and the compressor body supports basic mechanical components such as cylinder, piston, crank and connecting rod, crankpin, etc.
• the rotor is mounted snap-fittingly onto the crank.
• the rotor By means of the effect of the magnetic field generated by the electric current passing through the windings of the stator of the motor, the rotor, which is positioned at the center of the magnetic field and which is mounted snap-fittingly to the crank, is enabled to be rotated.
• the rotating rotor rotates the crank and moves the connecting rod connected to the crank, thus compressing the refrigerant fluid received into the compressor body.
• weights in the form of half rings are asymmetrically placed onto the lower and upper surfaces of the rotor packet in order to balance the unbalanced force generated by the movement of the crank, the connecting rod, piston and the crankpin.
• the weights placed onto the lower and upper surfaces of the rotor packet in order to balance the unbalanced force generated by the movable components of the compressor limit the design of other components of the compressor due to the space occupied.
• connector elements are used to fix the weights onto the rotor, thus increasing the costs.
• the mounting of the weights onto the rotor requires an additional operation during the production of the compressor.
• US2012269667 discloses a design for separating the compressor lubricant and the pressurized refrigerant fluid from each other in a compressor rotor with an additional weight thereon.
• US2008267799 discloses a design for decreasing the frictional resistance of the refrigerant fluid acting on the additional weight placed onto the compressor rotor during the rotational movement.
• the aim of the present invention is the realization of a BLDC electric motor rotor wherein the disadvantages occurring while balancing the unbalanced force generated by the movable components of the compressor with additional weights in the state of the art embodiments are eliminated in a cost-effective manner, thus providing an improved production and improved assembly and decreasing the design limitations of other components positioned in the vicinity of the compressor rotor.
• the rotor of the present invention comprises a rotor packet composed of magnetic sheet metal plates; sheet metal caps which cover the lower and upper surfaces of the rotor packet; slots which start from the lower or upper surface of the rotor packet, at least one thereof from a different surface and wherein the permanent magnets are placed in the magnetic sheet metal plates; and gaps which remain in said slots after the placement of the permanent magnets.
• the main advantage of the present invention is that by placing some of the permanent magnets into the slots opened on the lower surface of the rotor packet and some into the slots opened on the upper surface of the rotor packet and by means of the gaps left by the permanent magnets, the weight distribution of the rotor packet is changed without using any additional weights, thus balancing the unbalanced forces of the compressor. Balancing of the forces decreases the vibration level of the compressor.
• the elimination of the requirement for additional weights and connector elements used for fixing said weights provides advantage in costs and assembly. Moreover, since the volume occupied by the weights added onto the rotor is freed, the design limitations of the components in the vicinity of the rotor are decreased.
• the mass distribution of the rotor can be optimized by changing the heights of the gaps on the rotor packet according to the magnitude of the unbalanced force which changes depending on the mass of the movable components of the hermetic compressor such as crank, connecting rod and piston.
• the depths of the slots opened on the lower and upper surfaces of the rotor packet in order to improve the vibration absorption efficiency can be different from each other.
• said magnets are fixed to the rotor packet by means of adhesion or any connection methods such as snap-fitting, etc.
• Figure 1 is the cross-sectional view of the hermetic compressor.
• Figure 2 is the cross-sectional view of the rotor of the present invention.
• Figure 3 is the top view of the rotor of the present invention.
• the weight balancing rotor (1) is suitable for use in a brushless DC electric motor (12) of a hermetic compressor (2).
• the brushless DC electric motor (12) comprises a stator (13) and a weight balancing rotor (1).
• the weight balancing rotor (1) is composed of a rotor packet (7), an even number of permanent magnets (3) which are disposed into the rotor packet (7), rotor caps (4) which are fixed onto the lower and upper surfaces of the rotor packet (7) by means of connector elements, and gaps (5) provided between the permanent magnets (3) and the rotor caps (4).
• the weight balancing rotor (1) is fixed snap-fittingly onto a crankshaft (15) placed to a body (17) having a bearing (16).
• the weight balancing rotor (1) which rotates in the magnetic field generated by the electric current passing through the stator (13) of the brushless DC electric motor (12), rotates the crankshaft (15) as well.
• the connecting rod (20) connected to the crankshaft (15) converts the rotational movement into axial movement and moves the piston (18) whereto the connecting rod (20) is connected via a pin (21).
• the weight balancing rotor (1) balances the unbalanced force generated by the movable components, that is the crankshaft (15), the connecting rod (20), the pin (21) and the piston (18), in order to eliminate high level of vibrations.
• the peripheral mass distribution of the weight balancing rotor (1) can be changed.
• the unbalanced forces in the compressor (2 ) can be balanced without using any additional weight.
• the required force is provided by changing the volume of the gap (5) between the rotor caps (4) by changing the dimensions of the permanent magnets (3) fixed onto the rotor packet (7) and/or the height of the rotor packet (7).
• the vibrations in the compressor (2) are reduced without requiring any additional structure providing weight and the assembly of this structure.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
• Compressor (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=67513520

Family Applications (1)

Country Status (2)

Families Citing this family (1)

Family Cites Families (7)

• 2019
  • 2019-07-30 WO PCT/EP2019/070496 patent/WO2020057822A1/en unknown
  • 2019-07-30 EP EP19748524.6A patent/EP3853973A1/de not_active Withdrawn

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