A power transmission device with a clutch plate wear sensor system includes a power transmission shaft configured to transmit torque and a clutch configured to selectively deliver power into or out of the power transmission shaft. The clutch includes a clutch stack and clutch piston that moves to selectively actuate the clutch stack between an engaged state to deliver power through the clutch and a disengaged state to not deliver power through the clutch. The clutch stack wear sensor system includes at least one detectable element arranged for movement in unison with the clutch piston and a sensor arranged to detect the detectable element and provide a signal indicative of a wear characteristic of the clutch stack.

Disclosed are a method and a device for detecting a position of a piston rod, a hydraulic cylinder and a working machine. The method includes: acquiring a target image at a target position; obtaining a pixel information corresponding to the target image; comparing the pixel information with a pixel database of the piston rod, a full-stroke pixel information of the piston rod and a relationship between the full-stroke pixel information of the piston rod and a displacement of the piston rod are stored in the pixel database of the piston rod, and the full-stroke pixel information at least comprises the pixel information within a range in which the piston rod is configured to move relative to the target position; and determining a position information of the piston rod based on a comparison result.

In order to secure a reached extension position of a piston rod (22, 22) of an in particular multi stage operating cylinder device (100) with at least one operating cylinder unit (50) not only through the operating pressure in the cylinder (1, 1) of the operating cylinder unit (50) but additionally mechanically, a mechanical safety through interlocking safety elements (4a, b) in the interior of the operating cylinder device (100) is provided which is activated exclusively by the operating pressure in the first pressure cavity and disengaged by a pressure in a second operating cavity.

A method for producing round stock (10) which is provided with at least one inscription and/or marking (16), at least the surface (12) of the round stock (10) consisting of a metallic material, in particular of chromium or steel, for example of hardened steel, chromium-plated steel or stainless steel. In order to improve this method such that disadvantages and shortcomings are avoided, the method includes the following steps: placing on the surface (12) at least one cover (20) which is adapted to the shape of the surface (12) and in particular has the inscription and/or marking (16), such that the region to be provided with the inscription and/or marking (16) is not covered by the cover (20),exposing the round stock (10) to a first electrolyte (30) together with the cover (20), material being removed from the surface (12) by said electrolyte in the region to be provided with the inscription and/or the marking (16) while producing depressions (14), andexposing the round stock (10) together with the cover (20) and the depressions (14) not covered by the cover (20) to a second electrolyte (32) by which the depressions (14) are filled to produce the inscription and/or marking (16) which differs from the surface (12) optically, in particular with respect to color. The present invention also relates to round stock (10) which is manufactured from a metallic material, with the round stock being provided with a correspondingly produced inscription and/or marking (16).

A power transmission device with a clutch plate wear sensor system includes a power transmission shaft configured to transmit torque and a clutch configured to selectively deliver power into or out of the power transmission shaft. The clutch includes a clutch stack and clutch piston that moves to selectively actuate the clutch stack between an engaged state to deliver power through the clutch and a disengaged state to not deliver power through the clutch. The clutch stack wear sensor system includes at least one detectable element arranged for movement in unison with the clutch piston and a sensor arranged to detect the detectable element and provide a signal indicative of a wear characteristic of the clutch stack.

A method is provided for detecting a reciprocal position between a cylinder and a piston of a piston-cylinder unit of a vehicle. The method includes measuring, by means of an optical sensor, a value of an indicative parameter of a color of a reference mark positioned on a portion of the piston. The method also includes comparing the measured value with at least a predetermined threshold value thereof different to a minimum detected threshold of the indicative parameter by the optical sensor; and emitting an alarm signal perceptible by a driver of a vehicle if the measured value is comprised between the threshold value and the minimum value.

The present invention relates to using a self calibrating and recalibrating 230, 925 optical sensors piston rod displacement. Self calibration enables field calibration of uncalibrated 230, 925 optical sensors. During operation, recalibration enables detecting and correcting for wear and damage of the 200 piston rod and/or 230, 925 optical sensors. 210 Calibration positions on the surface of the 200 piston rod are imaged by 230 optical sensors using laser or darkfield lenses designed for optical computer mice. Natural surface patterns can be used in locations where 210 calibration positions are required, which reduces or eliminates the need for marked 210 calibration positions. Marked 210 calibration positions are spatially unique encoded sequences used to determine the piston rod absolute position. Storing only the significant features of 210 calibration positions saves significant memory. The reduced memory requirements of each 210 calibration position enables the use of closely spaced or continuous 210 calibration positions. Multiple 210 calibration position features and multiple 230, 925 optical sensors together collectively provide immunity to localized 208 surface damage. Proximity sensors, 925 time of flight sensors and 031 cumulative relative displacement are used to estimate the 200 piston rod absolute displacement and reduce the number of spatially unique 210 calibration positions needed to compare in order to determine the piston rod absolute displacement.

A pressure resistant apparatus includes a cylindrical body portion, and a lid portion having an annular wall portion, end portions of the body portion and the wall portion being joined to each other to close an opening of the body portion by the lid portion, wherein an annular first groove portion is formed to extend in a peripheral direction on at least one of inner peripheral surfaces of the body portion and the wall portion, and an inner diameter of the first groove portion is larger than inner diameters of the body portion and the end portion of the wall portion.

Provided are a functional cylinder body, including a plurality of layers having magnetic patterns and non-magnetic patterns formed adjacently, and a manufacturing method therefor. The functional cylinder body comprises at least: a cylinder main body; a first functional pattern part, which includes first patterns and first functional patterns, the first patterns having first recess patterns and first non-recess patterns formed by forming recesses on a first material layer made of any one of a magnetic material and a non-magnetic material, the first functional patterns being made of any one of the magnetic material and the non-magnetic material embedded in the first recess patterns; and a second functional pattern part, which is formed in a position of the cylinder main body shallower than a position of the first recess patterns and has magnetic patterns of the magnetic material and non-magnetic patterns of the non-magnetic material formed adjacently.

A fluid power control system for load handling mobile equipment includes a pair of hydraulic actuators for moving respective cooperating load-engaging members selectively toward or away from each other, or in a common direction, at respective asynchronous speeds to selectively attain either synchronous or asynchronous respective positions of the actuators. The actuators have sensors enabling a controller to monitor their respective movements and correct unintended differences in the actuators' respective movements, such as unintended differences in relative intended positions, speeds, or rates of change of speeds. Respective hydraulic valves responsive to the controller separately and nonsimultaneously decrease respective flows through the respective actuators to more accurately and rapidly correct differences from the intended relative movements of the actuators.