Hydraulic servo for a gear change

A hydraulic servo (1) for a gear change provided with a control shaft (2);

• the servo (1) comprising:
• a frame (4) having a first plane connection wall (30);
• a first hydraulic actuator (5), which is carried by the frame (4) and comprises two first chambers (7), which are alternatively filled with a pressurized fluid for displacing the control shaft (2) axially in two directions;
• two first solenoid valves (26), which control filling of the two first chambers (7) of the first hydraulic actuator (5);
• a second hydraulic actuator (6), which is carried by the frame (4) and comprises at least one second chamber (14), which is filled with a pressurized fluid for rotating the control shaft (2) about a central axis (3);
• a second solenoid valve (27), which controls filling of the second chamber (14) of the second hydraulic actuator (6);
• and
• a supporting body (25), which is fixed to the frame (4), has a second plane connection wall (29) set in contact with the first connection wall (30) of the frame (4), houses the solenoid valves (26, 27), and has inside it a series of hydraulic circuits (31, 40) that connect the solenoid valves (26, 27) themselves both to the chambers (7, 14) of the actuators (5, 6) and to a supply of the pressurized fluid;
• the servo (1) is characterized in that:
• passing through the second connection wall (29) of the supporting body (25) is a pair of actuation pipes (31), each of which connects a first solenoid valve (26) to a first chamber (7) of the first hydraulic actuator (5);
• in a position corresponding to the second connection wall (29) of the supporting body (25) there gives out a number of exhaust pipes (32), each of which originates in an exhaust manifold (33) of the fluid at ambient pressure;
• and
• made in a position corresponding to the second connection wall (29) is a recovery channel (34), which traverses and joins the exhaust pipes (32) and extends at least partially around the actuation pipes (31).