A working machine, in which a detection device for detecting a swing position of a supported member is prevented from being damaged, includes a support member pivotally supporting the supported member via a pivot, and a cylinder telescopically moved by extension and contraction movement of its piston rod with respect to its cylinder tube by hydraulic fluid flowing through a fluid passage formed in the piston rod. The cylinder tube is pivotally supported by a first end portion of the support member, and the piston rod is pivotally supported by a second end portion of the support member. The detection device for detecting a telescopic movement state of the cylinder is provided between the cylinder and the support member.

A milling machine has a frame, ground engaging tracks that support the frame, a first actuator connecting the frame to a first track of the ground engaging tracks and a second actuator connecting the frame to a second track from the ground engaging tracks. The milling machine has an orientation sensor that determines an orientation of the frame. The milling machine has a controller that operates the first and second actuators to raise or lower the frame. The controller determines the frame orientation using the orientation sensor. The controller also determines a velocity error between actuator velocities of the first and second actuators based on the frame orientation and a target orientation of the frame. The controller determines a control parameter for the second actuator based on the velocity error and operates the second actuator using the determined control parameter.

A plurality of detection valves (12 and 13) are provided to a housing (1), and at least one air passage (14 and 15), which communicatively connects the detection valves (12 and 13) to each other in series, are provided to the housing (1). One or some of the detection valves (12 and 13) are each configured as a throttle detection valve (13) including a throttle passage (56a).

An abnormality detecting system and an abnormality detecting method acquires a stroke of a piston as input from outside, calculates a travel time of the piston based on the results of sensing obtained by a first sensor and a second sensor, calculates a total travel distance of the piston using the number of operations and the stroke of the piston, and detects an abnormality of the actuator based on the travel time and the number of operations or the total travel distance of the piston.

An air cylinder includes a tubular cylinder and a piston which is moved by pressure of a fluid supplied to a chamber provided inside the cylinder. A monitoring device includes a heat flux sensor and a detection part. The heat flux sensor is provided to the cylinder and detects heat flux that flows between inside and outside of the cylinder due to compression or expansion of the fluid in the chamber caused in accordance with the movement of the piston. The detection part detects the moving state of the piston based on the output signal of the heat flux sensor.

In a hydrostatic pressure cylinder, a holding member which holds a magnet is mounted on a piston unit to rotate together with a cylinder tube. The cylinder tube is capable of rotating with respect to a rod cover and a head cover. It is thereby possible to change an attachment position of a magnetic sensor by rotating the cylinder tube.

A gas cylinder actuator with overtravel indicator device, which includes a tubular containment jacket, an end face, an opposite annular guiding portion, a stem-piston arranged so as to pass through the annular guiding portion, wherein the stem-piston protrudes from the jacket in an axial direction, a chamber for pressurized gas being defined between the tubular jacket, the end face, the annular guiding portion for the stem-piston, an indicator device for indicating that overtravel for the stem-piston has occurred; and an annular body, which is inserted partially into a corresponding seat between the jacket and an annular portion so as to surround the outer lateral surface of an end portion of the annular guiding portion; the annular body rests in an axial direction on an element that protrudes radially within the jacket and is integral with the jacket.

A fluid pressure cylinder is provided with a cylinder tube having a sliding hole internally; a piston unit disposed along the sliding hole so as to be capable of moving back and forth, and a piston rod projected in the axial direction from the piston unit. The piston unit can shorten the axial dimension of a piston body by mounting a wear ring to an outer circumferential section of a ring-shaped magnet attached to an outer circumferential section of the piston body.

A hydraulic rotary drive includes a first rotary drive element and at least two annular pistons connected to the first rotary drive element in a rotationally fixed manner and configured to be axially movable on the first rotary drive element between two end positions. Each annular piston has two annular spur serrations directed away from one another. The hydraulic rotary drive includes a second rotary drive element with ring type serrations that are complementary to the spur serrations of the annular pistons. The hydraulic rotary drive includes a control unit that is configured to control supply of hydraulic fluid to the annular pistons to cause a reciprocating movement of the annular pistons on a shaft in accordance with an operating signal. The hydraulic rotary drive includes a sensor arrangement communicatively coupled to the control unit and arranged to detect the positions of the annular pistons along respective sliding paths.

The invention relates to a linear drive device having a housing element in which at least one drivable actuating element is arranged, a guide unit which is coupled to the actuation element and moves relative to the housing element between two stroke end positions in linear direction, a stroke limiting device, by means of which a first stroke end position and a second stroke end position of the guide unit are adjustable, wherein the stroke limiting device has a first stop and a first counterstop for setting a limit of the first stroke end position and a second stop and a second counterstop for setting a first limit of the second stroke end position, wherein the stroke limiting device has a third stop which is adapted to set a second limit of the second stroke end position adjusted with the first counterstop.