For rotary protection of an external force piston of a power brake pressure generator of a hydraulic vehicle power braking system, axially parallel rotary protection grooves are provided at a circumference of an external force cylinder bore in a hydraulic block of a hydraulic unit of the vehicle power braking system, and tabs of the external force piston protrude into the rotary protection grooves.

The present patent of invention relates to a hydraulic unit (U) with a pneumatic cylinder (15) that works jointly with a servomotor (M), together with a ball screw (29) to together move a hydraulic piston pump (8), made up of a hydraulic plunger (7), with related sealing elements to prevent oil leaks, noise, metal-on-metal attrition and loss of efficiency, that is moved upwards and downwards using a ball screw (29) and a pneumatic cylinder (15), jointly with a servomotor (M) which, when moved, pushes the pressurized oil outwards while filling the opposite hydraulic chamber with an oil suction movement, the pumped oil entering a hydraulic pressure accumulator (25), where it remains idle to be used when required and being supplied by the up/down movement of the piston, generating continuous pumping, which is automatically stopped when the hydraulic pressure accumulator (25) is full and has reached the predetermined hydraulic pressure.

A pressurizing device includes: a pressurizing unit that pressurizes a pressurized object by supplying a working fluid; a first cylinder mechanism that supplies the working fluid in a first cylinder to the pressurizing unit by output of a first drive source; a second cylinder mechanism that supplies the working fluid in a second cylinder to the pressurizing unit by output of a second drive source; and a control device that controls the first drive source and the second drive source, in which the control device performs transition control to transition to a second supply state of supplying the working fluid from the second cylinder mechanism to the pressurizing unit when satisfying a remaining amount condition of the working fluid in the first cylinder of the first cylinder mechanism in a first supply state of supplying the working fluid from the first cylinder mechanism to the pressurizing unit.

Ball screw rotary actuator with independent ball paths. In one embodiment, a ball screw rotary actuator includes an outer cylinder including a fluid port, a piston configured to translate within the outer cylinder due to fluid pressure, helical grooves disposed between the outer cylinder and the piston, and outer ball bearings configured to travel in the helical grooves to rotate the piston within the outer cylinder as the piston translates. The ball screw rotary actuator also includes an inner shaft situated radially inward of the piston, straight grooves disposed between the piston and the inner shaft, and inner ball bearings configured to travel in the straight grooves, and to rotate the inner shaft as the piston rotates.

The present disclosure relates to a hydraulic-electric coupling driven multi-actuator system and control method, and belongs to technical fields of hydraulic transmission and electro-mechanical transmission. The hydraulic-electric coupling driven multi-actuator system comprises one or more hydraulic-electric hybrid driven actuators, first inverters, control valves, centralized hydraulic units and control units, wherein the number of the first inverters and the number of the control valves are the same as that of the hydraulic-electric hybrid driven actuators; each hydraulic-electric hybrid driven actuator is correspondingly connected with one first inverter and one control valve; the centralized hydraulic units are connected with the control valves and configured to supply oil for the hydraulic-electric hybrid driven actuators and to perform power compensation; and the control units are respectively connected with the hydraulic-electric hybrid driven actuators, and each control unit is configured to control output torque of a first motor of the corresponding hydraulic-electric hybrid driven actuator based on pressure information of the hydraulic-electric hybrid driven actuator, such that pressure of driving cavities of the hydraulic-electric hybrid driven actuators is equal, which greatly reduces throttling loss caused by the load differences of the actuators.

A multistage piston actuator exerts a driving pressure against a spring pressure into pressure chambers of piston bodies, fitted into a cylinder body, to operate the push rod. Each piston body is combined with a partition fitted into the cylinder body. Each piston body includes a pressure receiving plate portion, and an axial rod and a slidable cylindrical guide portion extending concentrically in opposite directions, the axial rod having an axial air passage connected to the pressure chambers. Each partition includes a base plate portion having a through-hole which receives the axial rod of an adjacent piston body, a large-diameter outermost cylindrical portion fitted into the cylinder body, and a slidable cylindrical guide portion slidably fit-engaged with the slidable cylindrical guide portion of the piston body. The axial rods of each piston body are brought into contact to operate the push rod.

An apparatus includes a drive mechanism, a first cylinder comprising a first piston coupled to the drive mechanism, and a second cylinder comprising a second piston. The first cylinder includes a first fluid reservoir and a second fluid reservoir, with the first piston disposed between the first fluid reservoir and the second fluid reservoir. The second cylinder includes a third fluid reservoir and a fourth fluid reservoir, with the second piston disposed between the third fluid reservoir and the fourth fluid reservoir. The apparatus further includes a first fluid line coupling the first fluid reservoir to the fourth fluid reservoir, and a second fluid line coupling the second fluid reservoir to the third fluid reservoir. The first piston comprises a threaded portion disposed in a threaded aperture of the first cylinder.

A cylinder device for a hydraulic lifting device has a housing and a piston rod axially movable relative to the housing. A rotary element is mounted on the housing in such a way that a rotary movement of the rotary element relative to the housing is possible and an axial movement of the rotary element relative to the housing is prevented. The piston rod has a movement transmission element, wherein the movement transmission element translates an axial movement of the piston rod into a rotary movement of the rotary element. A sensor unit is attached to the housing, which detects the rotary movement of the rotary element. Furthermore, a hydraulic lifting device with such a cylinder device, a chassis of a mobile device with a lifting device and a mobile device with a chassis are provided.

A pressurizing device includes: a pressurizing unit that pressurizes a pressurized object by supplying a working fluid; a first cylinder mechanism that supplies the working fluid in a first cylinder to the pressurizing unit by output of a first drive source; a second cylinder mechanism that supplies the working fluid in a second cylinder to the pressurizing unit by output of a second drive source; and a control device that controls the first drive source and the second drive source, in which the control device performs transition control to transition to a second supply state of supplying the working fluid from the second cylinder mechanism to the pressurizing unit when satisfying a remaining amount condition of the working fluid in the first cylinder of the first cylinder mechanism in a first supply state of supplying the working fluid from the first cylinder mechanism to the pressurizing unit.

The present patent of invention relates to a hydraulic unit (U) with a pneumatic cylinder (15) that works jointly with a servomotor (M), together with a ball screw (29) to together move a hydraulic piston pump (8), made up of a hydraulic plunger (7), with related sealing elements to prevent oil leaks, noise, metal-on-metal attrition and loss of efficiency, that is moved upwards and downwards using a ball screw (29) and a pneumatic cylinder (15), jointly with a servomotor (M) which, when moved, pushes the pressurized oil outwards while filling the opposite hydraulic chamber with an oil suction movement, the pumped oil entering a hydraulic pressure accumulator (25), where it remains idle to be used when required and being supplied by the up/down movement of the piston, generating continuous pumping, which is automatically stopped when the hydraulic pressure accumulator (25) is full and has reached the predetermined hydraulic pressure. With regard to the field of application, the invention is intended to be used to move hydraulic actuators in a variety of different machines and equipment.