阅读说明：本技术 具有过压补偿的液压致动器 (Hydraulic actuator with overpressure compensation ) 是由 S·阿尔法亚德 M·卡多法基 M·斯莱曼 于 2020-02-25 设计创作，主要内容包括：本发明涉及液压致动器,其包括：可变输送正排量泵(12)；构件(20),该构件允许泵(12)的输送量被连续改变,构件(20)由液压缸(40)致动,液压缸由根据控制致动器(10)运动的命令工作的第一方向控制阀(48)反馈。根据发明,致动器(10)包括根据泵(12)的输出压力(P)被控制的第二方向控制阀(60),第二方向控制阀(60)包括两个位置,其中一者(60a)被称为静止位置,只要泵(12)的输出压力(P)低于预定压力就获得该静止位置,在该静止位置,来自第一方向控制阀(48)的输出被直接传递到双动式液压缸(40),且另一者(60b)被称为工作位置,在该工作位置,泵(12)的输出压力(P)被传递到液压缸(40)而不经过第一方向控制阀(48),以减小泵(12)的输出压力(P)。(The invention relates to a hydraulic actuator comprising: a variable delivery positive displacement pump (12); a member (20) allowing the delivery volume of the pump (12) to be continuously varied, the member (20) being actuated by a hydraulic cylinder (40) fed back by a first directional control valve (48) operating according to a command controlling the movement of the actuator (10). According to the invention, the actuator (10) comprises a second directional control valve (60) controlled according to the output pressure (P) of the pump (12), the second directional control valve (60) comprising two positions, one (60a) of which is called the rest position, which is obtained as long as the output pressure (P) of the pump (12) is below a predetermined pressure, in which rest position the output from the first directional control valve (48) is transmitted directly to the double-acting hydraulic cylinder (40), and the other (60b) is called the working position, in which the output pressure (P) of the pump (12) is transmitted to the hydraulic cylinder (40) without passing through the first directional control valve (48) to reduce the output pressure (P) of the pump (12).)

1. A hydraulic actuator (10), the hydraulic actuator (10) comprising: a variable delivery positive displacement pump (12); a first directional control valve (48), the first directional control valve (48) being commanded based on a motion command of the actuator (10); and a hydraulic cylinder (40), the hydraulic cylinder (40) being supplied by the first directional control valve (48), the pump comprising a moving member (20), the movement of the moving member (20) allowing the delivery volume of the pump (12) to be continuously varied, the moving member (20) being movable by the hydraulic cylinder (40), the first directional control valve (48) being capable of applying, via the position of the moving member (20), a continuous function relating the movement command to the delivery volume of the pump when the moving member is moving, characterized in that the actuator (10) comprises a second directional control valve (60) commanded on the basis of the output pressure (P) of the pump (12), the second directional control valve (60) comprising two positions, one (60a) of which is called a rest position, the rest position being obtained as long as the output pressure (P) of the pump (12) is lower than a predetermined pressure, in this rest position, the output from the first directional control valve (48) is directly transmitted to a double-acting hydraulic cylinder (40), thereby allowing the pump (12) to follow the continuous function, the other position (60b) of the two positions being called a working position, which is obtained when the output pressure (P) of the pump (12) is greater than or equal to the predetermined pressure, in which the output pressure (P) of the pump (12) is transmitted to the hydraulic cylinder (40) without passing through the first directional control valve (48) and without following the continuous function, in order to reduce the output pressure (P) of the pump (12).

2. The hydraulic actuator of claim 1, wherein the predetermined pressure is adjustable.

3. An actuator according to any preceding claim, wherein the moving member (20) is configured to allow the pump (12) to reverse its delivery direction.

4. A hydraulic actuator according to claim 3, characterized in that the hydraulic cylinder (40) comprises two chambers (42, 44) and the actuator (10) comprises a third directional control valve (68), the third directional control valve (68) being configured to transfer the output pressure (P) of the pump (12) to one or the other of the two chambers (42, 44) depending on the delivery direction of the pump (12).

5. A hydraulic actuator according to any one of claims 3 and 4, characterized in that the hydraulic actuator further comprises a set of valves (52) configured to command the second directional control valve (60) by means of the highest output pressure of the pump (12).

6. A hydraulic actuator according to any preceding claim, wherein the hydraulic cylinder (40) comprises a travel rod (46) connected to a body (80) of the first direction control valve (48).

7. Hydraulic actuator according to any of the preceding claims, characterized in that the moving rod (46) is connected to the body (80) of the first direction control valve (48) by means of an end fixed connection.

8. A hydraulic actuator according to any one of the preceding claims, wherein the pump (12) is a piston pump having axial pistons (24), the moving member that allows varying the delivery volume is a swash plate (20), the swash plate (20) having a variable inclination angle (a), the pistons (24) being pressed against the swash plate, varying the inclination angle (a) of the swash plate (20) allowing varying the stroke of the pistons (24), the inclination angle (a) of the swash plate (20) being adjusted by the hydraulic cylinder (40) driven by a micro-actuator (83) that defines a command through the actuator (10) of the first directional control valve (48) as long as the output pressure (P) of the pump (12) is lower than a predetermined pressure.

9. A hydraulic actuator according to any one of the preceding claims, comprising a housing (84) inside which are arranged: the pump (12); a motor (100), the motor (100) allowing actuation of the pump (12); the moving means (20), the moving means (20) allowing the delivery volume of the pump (12) to be continuously varied; the hydraulic cylinder (40), the hydraulic cylinder (40) actuating the moving member (20); the first direction control valve (48), the first direction control valve (48) supplying the hydraulic cylinder (40); a micro-actuator (83), the micro-actuator (83) operating the first directional control valve (48) and the second directional control valve (60), the hydraulic actuator further comprising: at least one electrical connector (106) passing through said housing (84) and allowing said actuator (10) to receive electrical energy for powering said motor (100) and electrical signals for driving said micro-actuator (83); and a hydraulic connector (108), the hydraulic connector (108) passing through the housing (84) and allowing the actuator (10) to deliver hydraulic energy.

10. A hydraulic actuator according to any one of claims 1-8, characterized in that the hydraulic actuator comprises a housing (84) inside which there is arranged: the pump (12); a motor (100), the motor (100) allowing actuation of the pump (12); the moving means (20), the moving means (20) allowing the delivery volume of the pump (12) to be continuously varied; the hydraulic cylinder (40), the hydraulic cylinder (40) actuating the moving member (20); the first direction control valve (48), the first direction control valve (48) supplying the hydraulic cylinder (40); a micro-actuator (83), the micro-actuator (83) operating the first directional control valve (48) and the second directional control valve (60), the hydraulic actuator further comprising: at least one electrical connector (106) passing through said housing (84) and allowing said actuator (10) to receive electrical energy for powering said motor (100) and electrical signals for driving said micro-actuator (83); and a mechanical output (110), the mechanical output (110) passing through the housing (84) and allowing the actuator (10) to deliver mechanical energy.

11. A hydraulic actuator according to any one of claims 9 and 10 when dependent on claim 2, wherein the at least one electrical connector (106) allows the actuator (10) to receive a second electrical signal to drive the adjustment of the predetermined pressure.

12. The hydraulic actuator according to any one of the preceding claims, wherein the first directional control valve (48) comprises a neutral position (48a), in which the moving member (20) is stationary, such that the delivery quantity of the pump (12) is not changed, and two operating positions (48b, 48c), in which the moving member (20) is moved, such that the delivery quantity of the pump (12) is changed, and wherein the first directional control valve (48) is configured in such a way that: such that the change between the neutral position (48a) and one of the operating positions (48b, 48c) is carried out continuously.