Motor-driven throttle valve for an exhaust duct

A motor-driven throttle valve (1) for an exhaust duct and comprising:

• a tubular duct (2), which is designed so that exhaust gases can flow through the tubular duct (2);
• a throttle shutter (3), which is arranged inside the tubular duct (2) and is mounted so as to rotate around a rotation axis (4);
• a first shaft (5), which is mounted so as to rotate around the rotation axis (4) and supports the throttle shutter (3);
• an electric actuator (6), which is provided with a second shaft (52) and is designed to rotate the first shaft (5) around the rotation axis (4);
• a first support bearing (9), which supports the first shaft (5) in a through manner and is arranged on a first side of the tubular duct (2);
• a first spring (11), which applies an elastic force to the first shaft (5), said elastic force being oriented in an axial manner and pushing the first shaft (5) along an axially oriented pushing direction (D);
• a first plate (53), which is integral to the first shaft (5), is arranged on the outside of the tubular duct (2) more externally than the first support bearing (9) and constitutes a striker against which the first spring (11) is compressed;
• and
• a second plate (56), which is integral to the second shaft (52) of the electric actuator (6), is arranged on the outside of the tubular duct (2) more externally than the first support bearing (9), is arranged between the first support bearing (9) and the first plate (53), is crossed without contact by the first shaft (5) and constitutes a striker against which the first spring (11) is compressed;
• wherein the first spring (11) is configured to transmit a rotary motion around the rotation axis (4) from the second shaft (52) of the electric actuator (6) to the first shaft (5) supporting the throttle shutter (3).