A method for reducing stress concentration on a rotor sleeve during balance cutting comprising: providing an axial protrusion to an outer diameter of a first end cap and a second end cap of a rotor assembly; and radially cutting at least one of the sleeve or the axial protrusion to balance the rotor assembly.

To provide an electric motor enabling easy and high-precision balance correction, and a machine toll including this electric motor. An electric motor (1) includes: a cylindrical stator (2); a rotor (3) having a rotary shaft part (31) inserted inside of the stator (2); a housing (4) installed to both ends in an axial direction of the stator (2); an opening (51a) provided in at least one outer peripheral lateral face of the housing (4), and disposed to be separated from an internal space (S) of the stator and a ventilation passage (9) formed in the stator (2); and a balance correction component (6, 61) that is installed to the rotary shaft part (31), and corrects balance of the rotor (3), in which the balance correction component (61) is exposed to outside from the opening (51a); and a machine tool (10) includes this electric motor (1).

The present invention relates to a slotless motor including a thin-walled hollow rotor body 100, and methods of manufacture of such rotors, the methods including hot forming and machining steps. The rotor body has a rotational axis 102 and comprises a first cylindrical portion 104 having a first diameter, a second cylindrical portion 106 having a second diameter, larger than the first diameter and a third cylindrical portion 108 having a third diameter, smaller than the second diameter, the third cylindrical portion located at a second end of the rotor body 100. A first end cap 110 joins the first and second cylindrical portions together, and a second end cap 112 joins the first and second cylindrical portions together. The first, second and third cylindrical portions are all arranged coaxially with the rotational axis 102 of the rotor 100 such that the second cylindrical portion 108 and the first and second end caps collectively define a hollow cavity 114 in the rotor body 100. The rotor body 100 may be provided with a Halbach array.

A rotor (10) of an electric machine has a shaft (11) a laminated core (12) arranged on the shaft (11) and balancing bodies (13) arranged on the shaft (11). The balancing bodies (13) have an aperture (15) situated outside the center of gravity. Each balancing body (13) is mounted by way of the aperture (15) on the shaft (11) of the rotor (10) in a defined angular position. Positioning sleeves (20) are arranged on the shaft (11) to define a distance between bearings (16, 17) of the shaft (11) and the laminated core (12) or the balancing bodies (13) and to provide an anti-rotational safeguard for the balancing bodies (13).

The invention relates to a conveyor roller for conveyor systems for conveying containers, pallets, piece goods, and the like. The invention further relates to a method for producing and balancing, in particular dynamic balancing, such a conveyor roller. The conveyor roller comprises a roller body having a roller axle, the outside circumferential surface thereof being a contact surface for conveyed goods or being wrapped about by conveyed goods, and a head element (100), an insertion section (110) thereof being inserted into a hollow end of the roller body, wherein a groove (200) is formed on an end face (120) of the head element (100) facing away from the insertion section (110), in order to receive at least one balancing weight (301-304).

Provided is a motor rotor which, without changing an integral fastening structure relying on swage pins, increases resistance to the excessive excitation force of the motor rotor and which can easily prevent decreases in fastening strength; a motor that uses the motor rotor, and an electric compressor are also provided. This motor rotor is provided with a cylindrical rotor core comprising multiple laminated magnetic steel sheets, end plates and balance weights laminated on both ends of the rotor core, and multiple headed swage pins which are inserted from one side and which integrally fasten the rotor core, the end plates and the balance weights. The material of the balance weight arranged to the head of the swage pin is harder than that of the swage pin, and the material of the balance weight arranged to the swage part of the swage pin is softer than that of the swage pin.

A rotor including: a shaft; a structure comprising at least one end ring and rotor bars, wherein at least the end ring comprises a material subject to expansion or movement radially outward from the shaft upon a rotor balancing process that involves spinning of the structure; a core that at least partially encloses the rotor bars; and means for limiting the expansion or movement of the structure radially outward. A method including: providing a structure comprising at least one end ring and rotor bars, wherein at least the end ring comprises a material subject to expansion or movement radially outward from the shaft upon spinning of the structure; assembling a rotor from the structure and a core, the core at least partially enclosing the rotor bars; spinning the rotor in a rotor balancing process; and limiting the expansion or movement of the structure radially outward in the rotor balancing process.

The present invention is an electrical machine comprising a stator and a rotor (10). The rotor is formed with a rotor body comprising a stack of laminations placed on a rotor shaft. The rotor includes at least one cavity with at least one arm for retaining at least one balancing weight.

Provided is a brushless direct currency (BLDC) motor and a manufacturing method thereof, and more particularly, a brushless direct currency (BLDC) motor including a rotor rotated to drive an impeller and capable of reducing a defective rate of the motor due to a rotational imbalance by controlling a shape of a magnet portion included in the rotor, and a manufacturing method thereof.

A rotor for connection to a stationary member for use in an electric machine is provided. The rotor includes a body defining a center of rotation of the body. The body further defines a first surface extending in a direction generally perpendicular to the center of rotation. The rotor also includes a magnet connected to the body and an adhesive. The adhesive is positioned between the magnet and the body. The adhesive is adapted to assist in securing the magnet to the body. The first surface of the body is adapted to permit removal of material from the body and to assist in balancing the rotor.