An actuator is driven by a brushless motor having a rotor with axially extended magnets, permitting axial movement of the rotor while maintaining overlap between the magnets and a stator secured in a fixed position. The rotor is engaged with a fixed structure by a connection such as a ramp or thread that translates rotation into axial movement of the rotor along a rotational axis of the actuator. A valve member coupled to the rotor moves axially between a closed position and a range of positions that regulate fluid flow through a valve. A motor control circuit applies power to the stator coils to rotate the rotor and coupled valve member to a desired axial position and maintain the rotor and valve member at the selected position. The rotor and valve member may be biased toward a rotational position corresponding to a closed position of the valve member.

A hot gas exhaust recirculation valve includes a housing containing a duct for conducting gases, a drive chamber, and a valve stem which is mounted in the housing. The valve stem can be displaced in its longitudinal direction thereof and extends from the drive chamber into the duct. The end of the valve stem that is situated in the drive chamber is coupleable to a drive device. A closing body is fastened to the other end of the valve stem. The closing body is situated in the duct and has a closed position in which it separates an upstream section of the duct from a downstream section of the duct. A sealing ring surrounds the valve stem and is arranged between the duct and the drive chamber. The valve stem is supported within two bearing bushings that are spaced apart from each other, between which the sealing ring is arranged.

A throttle valve device includes a body, a valve, a motor, a speed reducer, and a cover. The body that defines a passage and a motor space therein. The motor includes a motor yoke, a magnet, a motor shaft, a pair of motor bearings, an armature core, a commutator, a brush, and a brush holder. The motor yoke is made of a magnetic material. The brush holder holds the brush. The motor yoke has an open end that is covered by the brush holder.

Provided is an exhaust valve device 1 for a vehicle in which a valve element 7 is supported to be able to be opened and closed in an exhaust passage 4 by a rotating shaft 5 axially supported by a valve body 3, a motor unit 13 is attached to the valve body 3 via a thermal insulation bracket 11, and an output shaft 13a of the motor unit 13 is coupled to the rotating shaft 5, the exhaust valve device 1 including: an outer circumferential, guide surface 10a provided at the valve body 3 and having an arc shape around an axial line C of the rotating shaft 5 at the center; and an inner circumferential guide surface 12a provided at the thermal insulation bracket 11 and brought into slide contact with the outer circumferential guide surface 10a to guide the thermal insulation bracket 11 to be secured at a prescribed securing angle to the valve body 3 around the axial line C of the rotating shaft 5 at the center.

Provided is an exhaust valve device 1 for a vehicle in which a valve element 7 is supported to be able to be opened and closed in an exhaust passage 4 by a rotating shaft 5 axially supported by a valve body 3, a motor unit 13 is attached to the valve body 3 via a thermal insulation bracket 11, and an output shaft 13a of the motor unit 13 is coupled to the rotating shaft 5, the exhaust valve device 1 including: an outer circumferential, guide surface 10a provided at the valve body 3 and having an arc shape around an axial line C of the rotating shaft 5 at the center; and an inner circumferential guide surface 12a provided at the thermal insulation bracket 11 and brought into slide contact with the outer circumferential guide surface 10a to guide the thermal insulation bracket 11 to be secured at a prescribed securing angle to the valve body 3 around the axial line C of the rotating shaft 5 at the center.

A valve of a drive unit of a motor vehicle, having a valve housing that is thermally decoupled from a motor housing. Components of an electric-motor drive and of a transmission that are arranged in the motor housing are thus protected against thermal loads. The valve can be manufactured inexpensively and has a particularly small installation space.

A control device for an internal combustion engine includes an air intake channel, an exhaust gas recirculation channel which enters into the air intake channel, a valve seat formed at an opening at an end of the exhaust gas recirculation channel, and an elastic valve disk which is placeable on the valve seat via an actuator so that the opening of the exhaust gas recirculation channel can be closed. A plane spanned by the valve seat and/or by the valve disk forms an at least single-curved concave surface.

An engine system includes a throttle device, an EGR valve, and an ECU. The ECU diagnoses foreign-matter lodging abnormality of the EGR valve and the foreign-matter diameter based on intake pressure. When the existence of the abnormality and the foreign-matter diameter are determined, the ECU calculates a difference between a foreign-matter diameter and a predetermined learning determination value as a foreign-matter diameter difference. If this difference is larger than an abnormality determination value, the foreign-matter diameter is judged to be excessive and the throttle device is controlled to avoid engine stall. If the foreign-matter diameter difference is equal to or larger than a normality determination value and also equal to or less than the abnormality determination value, engine deceleration is continued. If the foreign-matter diameter difference is less than the normality determination value, the foreign-matter diameter is judged to be minute and the learning determination value is updated.

An EGR device includes an EGR flow path, an EGR valve, a stepping motor, a motor driver, a return spring, a speed detector, and an opening degree estimator. The EGR flow path conveys exhaust gas from an exhaust flow path of an engine to an intake flow path. The EGR valve is disposed on the EGR flow path. The stepping motor drives the EGR valve to open to close. The motor driver supplies driving power to the stepping motor. The return spring urges the EGR valve in a valve closing direction. The speed detector detects an output shaft rotation speed of the engine. The opening degree estimator estimates an opening degree of the EGR valve. The motor driver changes a drive frequency of the stepping motor according to variations of the output shaft rotation speed detected by the speed detector and the opening degree estimated by the opening degree estimator.

An EGR device includes an EGR flow path, an EGR valve, a stepping motor, a motor driver, a return spring, a speed detector, and an opening degree estimator. The EGR flow path conveys exhaust gas from an exhaust flow path of an engine to an intake flow path. The EGR valve is disposed on the EGR flow path. The stepping motor drives the EGR valve to open to close. The motor driver supplies driving power to the stepping motor. The return spring urges the EGR valve in a valve closing direction. The speed detector detects an output shaft rotation speed of the engine. The opening degree estimator estimates an opening degree of the EGR valve. The motor driver changes a drive frequency of the stepping motor according to variations of the output shaft rotation speed detected by the speed detector and the opening degree estimated by the opening degree estimator.