A torque motor includes a large area rotor, a stator surrounding at least a portion of the rotor, and a small air gap separating the rotor from the stator to allow frictionless thermal coupling between the rotor and the stator. Heat from the rotor is transferred to the stator by conduction. The stator contacts an inner surface for a housing of the torque motor for conductively coupling to a cold environment air flow exterior to the torque motor housing. The air gap may have a dimension of about 0.002 to 0.003 inches. The stator may be conductively coupled to the torque motor housing by one of a thermal gap pad or high conductivity thermal gap filling compound. Heat conduction from the rotor to the stator preferably occurs without rotation of the rotor.

A torque motor includes a large area rotor, a stator surrounding at least a portion of the rotor, and a small air gap separating the rotor from the stator to allow frictionless thermal coupling between the rotor and the stator. Heat from the rotor is transferred to the stator by conduction. The stator contacts an inner surface for a housing of the torque motor for conductively coupling to a cold environment air flow exterior to the torque motor housing. The air gap may have a dimension of about 0.002 to 0.003 inches. The stator may be conductively coupled to the torque motor housing by one of a thermal gap pad or high conductivity thermal gap filling compound. Heat conduction from the rotor to the stator preferably occurs without rotation of the rotor.

An apparatus includes a first platform and a second platform configured to rotate relative to the first platform about an axis. A magnet ring is mounted to the first platform and centered around the axis. The magnet ring includes four or more magnetized poles positioned such that each respective boundary between neighboring poles is shifted relative to a corresponding nominal boundary defined by a uniform spacing of boundaries of the poles around the magnet ring. The shifted boundaries of the poles define a characteristic shift pattern for the magnet ring. A magnetic field sensor is connected to the second platform. Circuitry is configured to (i) determine a magnetic field pattern generated by the poles based on data generated by the sensor and (ii) determine a rotational position of the first platform relative to the second platform by correlating the magnetic field pattern to the characteristic shift pattern.

An apparatus includes a first platform and a second platform configured to rotate relative to the first platform about an axis. A magnet ring is mounted to the first platform and centered around the axis. The magnet ring includes four or more magnetized poles positioned such that each respective boundary between neighboring poles is shifted relative to a corresponding nominal boundary defined by a uniform spacing of boundaries of the poles around the magnet ring. The shifted boundaries of the poles define a characteristic shift pattern for the magnet ring. A magnetic field sensor is connected to the second platform. Circuitry is configured to (i) determine a magnetic field pattern generated by the poles based on data generated by the sensor and (ii) determine a rotational position of the first platform relative to the second platform by correlating the magnetic field pattern to the characteristic shift pattern.

The invention relates to a torque motor comprising a stator and a rotor that extend along a common central axis. The stator includes an integral magnetic body and at least one pair of radial teeth that extend along the central axis and define slots for receiving stator windings, and at least one permanent magnet supported by the integral magnetic body. The torque motor also includes a winding support for the stator windings that has a hollow body that extends along the central axis and that delimits a chamber for receiving the rotor, and cavities for receiving the stator windings. In this way, the stator windings are integrated in the stator by the winding support, fitted with the stator windings, being axially inserted into the integral magnetic body.

The invention relates to a torque motor comprising a stator and a rotor that extend along a common central axis. The stator includes an integral magnetic body and at least one pair of radial teeth that extend along the central axis and define slots for receiving stator windings, and at least one permanent magnet supported by the integral magnetic body. The torque motor also includes a winding support for the stator windings that has a hollow body that extends along the central axis and that delimits a chamber for receiving the rotor, and cavities for receiving the stator windings. In this way, the stator windings are integrated in the stator by the winding support, fitted with the stator windings, being axially inserted into the integral magnetic body.

A direct drive brushless motor including a plurality of rotational components and a plurality of non-rotational components. Ones of the pluralities of rotational and non-rotational components form a dual magnetic circuit. The plurality of rotational components includes a center rotation shaft circumscribed by a plurality of coils and a coil termination plate configured to support the plurality of coils. The plurality of non-rotational components includes a plurality of outer magnets arranged around the plurality of coils in a Halbach configuration and a plurality of inner magnets arranged in a Halbach configuration between the coils and the shaft. A flex cable having one or more leads provides electrical current to the plurality of coils without the use of brushes.

A direct drive brushless motor including a plurality of rotational components and a plurality of non-rotational components. Ones of the pluralities of rotational and non-rotational components form a dual magnetic circuit. The plurality of rotational components includes a center rotation shaft circumscribed by a plurality of coils and a coil termination plate configured to support the plurality of coils. The plurality of non-rotational components includes a plurality of outer magnets arranged around the plurality of coils in a Halbach configuration and a plurality of inner magnets arranged in a Halbach configuration between the coils and the shaft. A flex cable having one or more leads provides electrical current to the plurality of coils without the use of brushes.

A torsion bridge for use in a servovalve includes a body extending along and adapted to rotate about a first axis; a passage extending through the body along a second axis substantially perpendicular to the first axis, the passage defining a first cylindrical surface having a radius R.sub.1; an annular groove formed in the first cylindrical surface. The annular groove includes: a second cylindrical surface extending substantially in the direction of the second axis, the second cylindrical surface having first and second ends and a radius R.sub.2, where R.sub.2 is greater than R.sub.1; a first annular surface joining the first cylindrical surface to the first end of the second cylindrical surface; and a second annular surface joining the second end of the second cylindrical surface to the first cylindrical surface.

A torsion bridge for use in a servovalve includes a body extending along and adapted to rotate about a first axis; a passage extending through the body along a second axis substantially perpendicular to the first axis, the passage defining a first cylindrical surface having a radius R.sub.1; an annular groove formed in the first cylindrical surface. The annular groove includes: a second cylindrical surface extending substantially in the direction of the second axis, the second cylindrical surface having first and second ends and a radius R.sub.2, where R.sub.2 is greater than R.sub.1; a first annular surface joining the first cylindrical surface to the first end of the second cylindrical surface; and a second annular surface joining the second end of the second cylindrical surface to the first cylindrical surface.