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US 5,703,419 AGranted
Stepper motor with shortened axial length
AssigneeNippondenso Co., Ltd.
InventorTakashi Mizutani
Life of this patent
Estimating the term…
Abstract
A stepper motor comprises a rotor assembly, two bobbin assemblies and two stator assemblies. The stator assemblies are located to sandwich the rotor assembly radially therebetween. Each stator assembly includes upper and lower yokes, columnar cores and a bobbin assembly.
Claims14
A stepper motor comprising:
- a cylindrical magnet rotor supported rotatably and having a plurality of magnetic poles arranged on a circumferential periphery in a circumferential direction;
- two pairs of cores wound with respective coils thereon around central axes thereof, the central axes being in parallel with a rotary axis of the magnet rotor;
- and
- a pair of rectangular stators located along the circumferential periphery of the magnet rotor and having respective openings which face radially each other to receive the magnet rotor therein, each of the stators having first and second pole teeth facing radially the circumferential periphery of the rotor magnet, and each of the stators respectively supporting axial ends of one pair of the cores at angled corners of said stators sandwiching the cores therebetween so that the first and second pole teeth are magnetized in the opposite polarities.
1 more element
A stepper motor comprising:
- a magnet rotor rotatably supported and having a plurality of magnetic poles arranged circumferentially on a circumferential surface thereof, each of said magnetic poles being in a single magnetic pole in an axial direction;
- a first stator group located in a first space radially adjacent to the magnet rotor and having a first pair of rectangular yokes formed with a semicircular opening and with a pair of angled corners, said first pair of rectangular yokes respectively including first pole teeth and second pole teeth arranged alternately in a circumferential direction to face radially the magnetic poles of the magnet rotor;
- a second stator group located in a second space radially adjacent to the magnet rotor and having a second pair of rectangular yokes formed with a semicircular opening and with a pair of angled corners, said second pair of rectangular yokes respectively including third pole teeth and fourth pole teeth arranged alternately in the circumferential direction to face radially the magnetic poles of said magnet rotor;
- a first pair of cores located to have central axes thereof different from that of the magnet rotor and wound with a first pair of coils thereon to magnetize the first and second pole teeth of the first stator group into opposite magnetic polarities by magnetic fluxes flowing axially between the first and second pole teeth, said first pair of cores being respectively located at said angled corners of said first pair of rectangular yokes of said first stator group;
- and
- a pair of second cores located to have a central axes thereof different from that of the magnet rotor and wound with a second pair of coils thereon to magnetize the third and fourth pole teeth of the second stator group into opposite magnetic polarities by magnetic fluxes flowing axially between the third and fourth pole teeth, said second pair of cores being respectively located at said angled corners of said second pair of rectangular yokes of said second stator group,
- wherein the first and second pole teeth of the first stator group and the third and fourth pole teeth of the second stator group are spaced a predetermined distance apart from each other, and the first and second stator groups are located to radially face each other.
4 more elements
Dependencies are inferred from the claim text.