A throttle valve for an internal combustion engine provided with a valve body, a tubular feeding duct defined in the valve body, a throttle plate, and an actuating device which controls rotation of the throttle plate. The actuating device includes an electric motor and an actuating device conditioning circuit defined in the valve body. The conditioning circuit includes a tube made of a first material able to conduct heat, and the valve body is entirely made of a second metal material and is provided with a seat for housing the tube, in which is provided a layer of a structural and heat-conducting resin, interposed between the seat and the tube.

An apparatus for the actuation of a throttle valve, in particular a throttle valve arranged in an intake system of an internal combustion engine, uses a servomotor, in which apparatus at least one device for thermal decoupling is arranged between the throttle valve and servomotor. A shaft of the servomotor is coupled to a shaft of the throttle valve via a torque-transmitting coupling element with a definedly low heat transfer capability.

A method of manufacturing a butterfly member of an exhaust brake valve assembly. The method includes providing a metal material, machining the metal material to form a body, and drilling a through bore in a central portion of the body, thereby delimiting a first side of the body from a second side of the body that is opposite the first side. The through bore is configured to receive a shaft for pivoting movement of the body in a valve housing of the exhaust brake valve assembly. The method further includes positioning the body for a single machining operation and machining the body to form a first sealing face on the first side of the body and a second sealing face on the second side of the body. The first sealing face defines a first plane and the second sealing face defines a second plane spaced from the first plane.

Proposed is a butterfly valve for minimizing leak of exhaust gas from an exhaust pipe even under high back pressure. The butterfly valve may include a valve plate provided in the exhaust pipe, a valve shaft crossing the exhaust pipe and holding the valve plate, and a bearing unit slidably supporting the valve shaft and including an annular sealing bush and an annular support bush into which the valve shaft 120 is inserted. The valve may also include a housing attached to the exhaust pipe and accommodating the bearing unit. The support bush is arranged between the housing and the sealing bush and contacts the housing on an outer peripheral surface of the support bush. The sealing bush contacts the housing on an outer peripheral surface of the sealing bush and contacts a flange of the valve shaft on a valve shaft opposing surface of the sealing bush.

In a throttle device including: a throttle shaft to which a throttle valve is secured; a motor; and a deceleration mechanism decelerating rotation of a drive shaft of the motor and transmitting the rotation to the throttle shaft, the deceleration mechanism includes a throttle gear secured to the throttle shaft, the throttle gear includes a tubular ring into which the throttle shaft is detachably inserted and a gear main body including a gear portion, and the gear main body is formed of a resin by insert processing including the ring.