An encoder including a rotary disc that rotates around a rotating shaft, and a sensor that detects a rotational position of the rotary disc, in which the rotary disc is provided with first patterns and second patterns, the first patterns are arranged at positions obtained by equally dividing a first circumference which is a circumference of a first circle into M (M is natural number of 2 or more) at intervals, the second patterns are arranged at positions obtained by equally dividing a second circumference which is a circumference of a second circle which is a concentric circle of the first circle and has a different radius from that of the first circle into N (N is natural number of 2 or more) at intervals, and M and N are different from each other and a greatest common divisor of M and N is 1.

A printing apparatus according to the present disclosure includes a biasing member that applies a force in a −Y direction, a motor supporting member including a reference surface and an inclined surface inclined so that a distance between the reference surface and the inclined surface gradually decreases in the −Y direction, and a motor including an abutting member configured to abut on the reference surface and the inclined surface. By applying the force in the −Y direction from the biasing member to the motor, the abutting member abuts on the reference surface and the inclined surface.

A composite motor having high-precision positioning, comprising: a housing (1), a rough positioning assembly, a hollow output shaft (2), a fine positioning assembly, a power switching apparatus and a controller (6). A stepper motor (3) in the rough positioning assembly is responsible for rough positioning of the composite motor, an annular travelling wave ultrasonic motor in the fine positioning assembly is responsible for tail end fine positioning of the composite motor, and the controller (6) implements power output switching between the annular travelling wave ultrasonic motor and the stepper motor (3). The composite motor effectively solves the problem that annular travelling wave ultrasonic motors which operate continuously for a long time have a short service life, and ensures high-precision positioning while also extending motor service life.

An elevator includes at least one elevator shaft and at least one elevator car traveling in the elevator shaft. The elevator has at least one elevator motor including at least one linear stator located vertically along the elevator shaft and at least one mover located in connection with the elevator car and co-acting with the stator. The elevator includes a vertical stator beam supporting at least one stator, which stator beam has at least one side face carrying ferromagnetic poles of said stator spaced apart by a pitch. The mover includes at least one counter-face facing the side face(s) of the stator beam, in which electro-magnetic components of the mover are located.

An elevator includes at least one elevator shaft and at least one elevator car traveling in the elevator shaft. The elevator has at least one elevator motor including at least one linear stator located vertically along the elevator shaft and at least one mover located in connection with the elevator car and co-acting with the stator. The elevator includes a vertical stator beam supporting at least one stator, which stator beam has at least one side face carrying ferromagnetic poles of said stator spaced apart by a pitch. The mover includes at least one counter-face facing the side face(s) of the stator beam, in which electro-magnetic components of the mover are located.

A stepping motor control device is provided, which controls a stepping motor including a rotor position detector by micro-step driving. The control device has a plurality of operation modes including an adjustment mode and a use mode. In the adjustment mode, the control device generates control data for a closed loop control for controlling the winding current of the stepping motor based on the detection value of the rotor position detector, and performs a stepping motor acceleration operation and a stepping motor deceleration operation according to the control data. In the use mode, the control device performs the stepping motor acceleration operation and the stepping motor deceleration operation so that a winding current observed in the adjustment mode is reproduced by an open loop control for controlling the winding current of the stepping motor based on the control data generated in the adjustment mode.

A stepping motor control device is provided, which controls a stepping motor including a rotor position detector by micro-step driving. The control device has a plurality of operation modes including an adjustment mode and a use mode. In the adjustment mode, the control device generates control data for a closed loop control for controlling the winding current of the stepping motor based on the detection value of the rotor position detector, and performs a stepping motor acceleration operation and a stepping motor deceleration operation according to the control data. In the use mode, the control device performs the stepping motor acceleration operation and the stepping motor deceleration operation so that a winding current observed in the adjustment mode is reproduced by an open loop control for controlling the winding current of the stepping motor based on the control data generated in the adjustment mode.

A composite motor having high-precision positioning, comprising: a housing (1), a rough positioning assembly, a hollow output shaft (2), a fine positioning assembly, a power switching apparatus and a controller (6). A stepper motor (3) in the rough positioning assembly is responsible for rough positioning of the composite motor, an annular travelling wave ultrasonic motor in the fine positioning assembly is responsible for tail end fine positioning of the composite motor, and the controller (6) implements power output switching between the annular travelling wave ultrasonic motor and the stepper motor (3). The composite motor effectively solves the problem that annular travelling wave ultrasonic motors which operate continuously for a long time have a short service life, and ensures high-precision positioning while also extending motor service life.

A magnetic resonance (MR) system may include a MR device and a MR-compatible drive. The MR device may include a scanner with a basic magnet for generating a homogeneous basic magnetic field. The MR-compatible drive may include an electric motor with a stator. The stator of the electric motor may include a dominant component of the basic magnetic field of the basic magnet.

In a motor, a magnet is configured so that four pairs of S-poles and N-poles are formed at equal angular intervals, and a stator core has six salient poles formed thereon. Of the plurality of salient poles, when the first salient pole or the second salient pole faces a position between an S-pole and an N-pole, the other salient pole faces the center of an S-pole or the center of an N-pole. The radial-direction lengths of the first salient pole and the second salient pole among the plurality of salient poles are longer than the other salient poles, and the radial-direction length of the portion of the first coil wound around the first salient pole and the radial-direction length of the portion of the second coil wound around the second salient pole are longer than the radial-direction lengths of the other salient poles.