An electric machine includes a stator assembly defining a longitudinal axis. The stator assembly includes a substantially cylindrical stator core that is concentric with and extends longitudinally along the longitudinal axis. The stator core includes a stator pole having an inner surface spaced radially outward from the longitudinal axis. The stator pole includes a first aperture extending radially outward from the inner surface of the stator pole. The electric machine also includes a rotor assembly rotatable about the longitudinal axis. The rotor assembly includes a rotatable shaft and a rotor core. The rotor core is concentric with and extends longitudinally along the longitudinal axis. The rotor core also includes a rotor pole including an outer surface spaced radially outward from the longitudinal axis. The outer surface is spaced radially inward from the stator pole inner surface.

An electric machine includes a stator assembly defining a longitudinal axis. The stator assembly includes a substantially cylindrical stator core that is concentric with and extends longitudinally along the longitudinal axis. The stator core includes a stator pole having an inner surface spaced radially outward from the longitudinal axis. The stator pole includes a first aperture extending radially outward from the inner surface of the stator pole. The electric machine also includes a rotor assembly rotatable about the longitudinal axis. The rotor assembly includes a rotatable shaft and a rotor core. The rotor core is concentric with and extends longitudinally along the longitudinal axis. The rotor core also includes a rotor pole including an outer surface spaced radially outward from the longitudinal axis. The outer surface is spaced radially inward from the stator pole inner surface.

A control device to control a motor includes a stator including a coil, a rotor including a permanent magnet, a detector that detects a rotational position of the rotor at every predetermined angle and outputs a position signal indicating the detected rotational position, and a controller that receives the position signal output by the detector and adjusts a duty ratio of a driving signal of the rotor by a pulse width modulation scheme based on the received position signal to control rotation of the rotor. The controller raises the duty ratio from a first duty ratio, starting from a point in time at which the position signal is received, and returns the raised duty ratio to the first duty ratio when a next position signal has been received.

A motor includes a shaft member in which at least a part of an outer peripheral surface is made of metal, a magnet unit which is configured by integrating a plurality of magnets and in which a press-fit hole into which the shaft member is press-fitted is formed, a substrate which is disposed at a predetermined distance from the magnet unit in an extending direction of the shaft member and to which electric power is supplied, and a protective member in which a through-hole into which the shaft member is inserted is formed and which is disposed between the magnet unit and the substrate in the extending direction of the shaft member. In the motor, the protective member is in contact with at least a part of the outer peripheral surface of the shaft member.

In described examples of methods and control systems to control a position and/or velocity of a machine, control circuitry is coupled to receive and dither a control signal, and to compute a control output value according to the dithered control signal and a control function. An inverter is coupled to the control circuitry, to control the position and/or velocity according to the control output value.

In described examples of methods and control systems to control a position and/or velocity of a machine, control circuitry is coupled to receive and dither a control signal, and to compute a control output value according to the dithered control signal and a control function. An inverter is coupled to the control circuitry, to control the position and/or velocity according to the control output value.

Some embodiments of the invention include a surveying apparatus that includes an optoelectronic distance measuring device having a measuring beam path, a base for placing the surveying apparatus, a support which is mounted on the base such that it is rotatable about a vertical axis, a beam directing unit which is mounted in the support such that it is rotatable about a tilting axis, an angle measurement system for measuring the axial positions, and an actuatable positioning device driving the beam directing unit or the support. In some embodiments the positioning device may include a plurality of coils which are arranged in a positionally fixed manner in the form of a ring about the tilting axis and/or vertical axis, with winding axes which are axially parallel to the tilting axis or vertical axis.

Some embodiments of the invention include a surveying apparatus that includes an optoelectronic distance measuring device having a measuring beam path, a base for placing the surveying apparatus, a support which is mounted on the base such that it is rotatable about a vertical axis, a beam directing unit which is mounted in the support such that it is rotatable about a tilting axis, an angle measurement system for measuring the axial positions, and an actuatable positioning device driving the beam directing unit or the support. In some embodiments the positioning device may include a plurality of coils which are arranged in a positionally fixed manner in the form of a ring about the tilting axis and/or vertical axis, with winding axes which are axially parallel to the tilting axis or vertical axis.

A motor assembly that includes a motor (102) having a rotatable shaft, a hub coupled to the rotatable shaft, the hub having a propeller indexer to receive a propeller (104), when the propeller is present, a sensor trigger rotatable with the shaft (100) and positioned at a propeller offset angle ?.sub.PROP from the propeller indexer, and a sensor coupled to the motor and positioned to detect the sensor trigger so that the propeller indexer may be positioned at the propeller offset angle ?.sub.PROP from the sensor through rotation of the shaft so that said sensor is proximate to the sensor trigger.

A motor assembly that includes a motor (102) having a rotatable shaft, a hub coupled to the rotatable shaft, the hub having a propeller indexer to receive a propeller (104), when the propeller is present, a sensor trigger rotatable with the shaft (100) and positioned at a propeller offset angle ?.sub.PROP from the propeller indexer, and a sensor coupled to the motor and positioned to detect the sensor trigger so that the propeller indexer may be positioned at the propeller offset angle ?.sub.PROP from the sensor through rotation of the shaft so that said sensor is proximate to the sensor trigger.