摘要:
A spindle motor for a machine tool is required to operate at a low rotational speed and to deliver a high output in a machining mode, and is required to operate at a high rotational speed and to deliver a high output in another machining mode. An AC motor employing a winding arrangement of the present invention meets those operating conditions for different machining modes, in that the coils (X1, X2; X1', X2') of each winding for a phase are divided into a plurality of sets of coils, and the plurality of sets of coils are held in a slot (SL). The connection of terminals (U1, U2; V1, V2; W1, W2) for phase dividing the coils into the sets is changed selectively by switching unit (SW, SW') such as an electromagnetic relay, to thereby supply power selectively to the coils for the output regulation.
摘要:
The stator of a built-in motor must be firmly and accurately mounted on the spindle head housing or the like of a machine tool. A stator core (10), i.e., a principal component of the stator is welded partially at the circumference (14) thereof, and then the circumference of the stator core (10) held by a mandrel is finished to an accurate outside diameter by grinding. The stator core (10) thus constructed is subjected to a deformation with a lapse of time after the mandrel has been removed. To solve this problem, each lamination (12) of the stator core (10) is coated with a thermosetting adhesive, to be thereby joined together, and each lamination (12) is provided with a plurality of pressed projections (22) to be joined together by weld portions (20) on the circumference of the stator core (10), or each lamination (12) is joined together by pressing a serrated bar (26) into a bore (24) thereof, without a pressed projection (22).
摘要:
An ac spindle motor (10) for driving a spindle motor of a machine tool provided with a rotor (14) having an output shaft (12) connected to the spindle, and a stator (16) surrounding the rotor and having a laminated core (20) serving as a yoke, and stator winding assemblies of three phases (U-phase, V-phase, W-phase). The stator winding assembly of each phase (18u, 18v, 18w) has: windings (C.sub.2, C.sub.4) of a first group which are energized for a rotation of the spindle in both a low-speed range not higher than a given speed, and a high-speed range above the given speed; windings (C.sub.1, C.sub.3) of a second group energized only for a rotation of the spindle in the low-speed range; and electrical contact means (S1, S2, S3, S4) controlled so that the windings (C.sub.1, C.sub.2, C.sub.3, C.sub.4) of the first and second groups are energized to generate a first multipolar revolving magnetic field for the rotation of the spindle in the low-speed range, and so that only the windings (C.sub.2, C.sub.4) of the first group are energized to generate second multipolar revolving magnetic field having magnetic poles less than those of the first multipolar revolving magnetic field for the rotation of the spindle in the high-speed range. The operating mode of the ac spindle motor is changed between a high-speed mode and a low-speed mode by changing the ampere-turn of the windings and the number of poles of the revolving magnetic field.
摘要:
The stator of a built-in motor must be firmly and accurately mounted on the spindle head housing or the like of a machine tool. A stator core (10), i.e., a principal component of the stator is welded partially at the circumference (14) thereof, and then the circumference of the stator core (10) held by a mandrel is finished to an accurate outside diameter by grinding. The stator core (10) thus constructed is subjected to a deformation with a lapse of time after the mandrel has been removed. To solve this problem, each lamination (12) of the stator core (10) is coated with a thermosetting adhesive, to be thereby joined together, and each lamination (12) is provided with a plurality of pressed projections (22) to be joined together by weld portions (20) on the circumference of the stator core (10), or each lamination (12) is joined together by pressing a serrated bar (26) into a bore (24) thereof, without a pressed projection (22).
摘要:
A rotor 14 for a high speed induction type ac motor having a construction such that the rotor is provided with an iron core 20 provided, at the periphery thereof, with a plurality of through-bores 22 in which electro-conductive rods 24 made of aluminum rod members are forcibly inserted in a press-fitting manner so as to form opposite projections from the axial opposite ends of the iron core 20, electro-conductive end rings 26 connected to the projections of the electro-conductive rods 24, and slitted pins 30 press-fit in small blind bores 32 formed in the projections of the electro-conductive rods 24 to thereby fixedly attach the electro-conductive rings 26 to the opposite end faces of the iron core 20.
摘要:
A method of producing a squirrel-cage rotor for an induction motor, which includes a plurality of secondary conductors arranged respectively in through holes (16) of a laminated core (14), and a pair of end rings connecting the secondary conductors with one another at both axial ends of the laminated core (14). Each of a pair of reinforcing members (22) includes a cylindrical wall (26), an annular multi-aperture wall (28) provided with apertures (32) and extending in a radial inward direction from one edge of the cylindrical wall (26), and an annular end wall (30) extending generally parallel to the multi-aperture wall (28) in a radial inward direction from another edge of the cylindrical wall (26). Each reinforcing member (22) is arranged in a manner in which the multi-aperture wall (28) is brought into contact with one of the axial end faces of the laminated core (14) while the apertures (32) communicate with the through holes (16). In this state, the laminated core (14) and the pair of reinforcing members (22) are fixedly supported by a jig (34) and placed in a mold (36). In the casting process, molten metal is poured into a continuous cavity from a center opening (31) of the end wall (30) of one reinforcing member (22a) disposed near a gate (58), while gas in the cavity is discharged through a center opening (31) of the end wall (30) of another reinforcing member (22b).
摘要:
A squirrel-cage rotor (10) includes a laminated core (14) fixed to a rotor shaft (12), a plurality of secondary conductors (18) arranged respectively in a plurality of through holes (16) formed through the laminated core (14), a pair of end rings (20) connected to the secondary conductors (18) at axial ends of the laminated core (14), and a pair of reinforcing members (22, 23) respectively covering the end rings (20). The secondary conductors (18) and the end rings (20) are integrally formed through a casting process, and are connected with the laminated core (14) and the reinforcing members (22, 23). Each reinforcing member (22, 23) is formed as an annular element of high-rigidity material, and includes a cylindrical wall (26, 27) surrounding the cylindrical outer surface of the end ring (20), a multi-aperture wall (28, 29) provided with a plurality of apertures (32) which communicate respectively with the through holes (16) of the laminated core (14 ) and held between the end ring (20) and the laminated core (14), and an end wall (30, 31) brought into contact with the axial outer surface of the end ring (20).
摘要:
A squirrel-cage rotor 10 includes a plurality of slots 16 for accommodating secondary conductors 18 along the outer circumferential surface of a laminated core 14 fixed to a rotor shaft 12. Each slot 16 is defined by a wall having a generally elliptical profile in which a maximum circumferential distance D is larger than a maximum radial distance d in a given section orthogonal to an axis and axially penetrates near the outer circumferential surface of the laminated core 14. The radial inner profile of the slot 16 has a shape in which the tangents on given two points adjacent to the radial innermost portion of each slot wall do not cross at an acute angle in a section orthogonal to the axis, in order to prevent a stress concentration.
摘要:
An induction motor has a stator formed by inserting and holding piled steel plates (12) between end plates (11a, 11b) and welding support bars (13) consisting of nonmagnetic metal along the external surface of said piled steel plates.
摘要:
A rotor for high speed induction motor, having a stacked-lamination type rotor core (23) provided with axial opposite ends on which aluminum end rings (24) are assembled or fused by die casting, and balancing rings (25) provided as iron coverings enclosing the aluminum end rings (24), the iron balancing ring (25) being assembled or fused together with the above-mentioned end rings on the stacked-lamination type rotor core (23) by die casting.