Device for supplying and modifying a cylinder cubic capacity of a hydraulic motor

A device for supplying and modifying a cylinder cubic capacity of a hydraulic motor, comprising:

• a first conduit (1) for supplying and discharging an operating fluid to a first side of the hydraulic motor (M);
• a second conduit (2) for supplying and discharging an operating fluid to a second side of the hydraulic motor (M);
• an actuator (3), suitable for modifying a cubic capacity of the motor (M);
• an increase conduit (31) for increasing the cubic capacity of the motor (M), connected to the actuator (3) for supplying operating fluid to a side of the actuator (3) which produces an increase of the cubic capacity of the motor (M);
• a reduction conduit (32) for reducing the cubic capacity of the motor (M), connected to the actuator (3) for supplying operating fluid to a side of the actuator (3) which produces a reduction of the cubic capacity of the motor (M);
• characterised in that:
• the device comprises a first piloting conduit (41);
• the device comprises a bistable valve (5), connected at the inlet to the first conduit (1) and to the second conduit (2) and at the outlet to the first piloting conduit (41);
• the device comprises a third conduit (11), connected at the inlet to the first conduit (1) and at the outlet to a union (12);
• the device comprises a fourth conduit (21), connected at the inlet to the second conduit (2) and at the outlet to the union (12);
• the union (12) is connected to the increase conduit (31);
• the device comprises a first valve (6) and a second valve (7), connected to one another;
• the first valve (6) can take a first operating position, in which the first valve (6) sets the union (12) in communication with the second valve (7), and a second operating position, in which the first valve (6) occludes the union (12), wherein the first piloting conduit (41) is connected to the first valve (6) so as to displace the first valve (6) from the second position towards the first position;
• the second valve (7) can take a first operating position, in which the second valve (7) occludes the union (12), and a second operating position, in which the second valve (7) sets the union (12) in communication with the reduction conduit (32), wherein a second piloting conduit (42) is connected to the union (12) and the second valve (7) so as to displace the second valve (7) from the second operating position to the first operating position.