Devices for Measuring Friction Force of Hydraulic Piston Mechanisms

Abstract

The invention discloses a device for measuring friction force of a hydraulic piston mechanism. The device comprises a driving system, a loading system, a piston assembly and a measuring system; the piston assembly comprises an oil cylinder and a piston, wherein the oil cylinder is internally provided with an annular groove and two protruding parts, the piston is arranged in an inner hole of the oil cylinder, the two protruding parts and the piston form a sealing band, and the two protruding parts support the piston; the loading system is used for injecting pressure oil into the annular groove;the driving system drives the piston to move in the inner hole of the oil cylinder in the axial direction; and the measuring system is used for measuring and analyzing pressure of the driving system.Compared with the prior art, according to the device, the oil cylinder is internally provided with the protruding parts to support the piston and to form the sealing band with the piston, other factors which can generate the friction force with the piston are eliminated, so that actual working conditions can be simulated more truly and accurately; the driving speed of the piston can be conveniently adjusted by adopting the hydraulic driving system; and the whole device is simple in structure and high in measuring precision.

Description

technical field [0001] The invention relates to a piston friction measuring device, in particular to a device for measuring the friction of a hydraulic piston mechanism. Background technique [0002] Hydraulic transmission has been widely used due to its advantages of high power density, fast response, flexible control and layout, but its outstanding disadvantages are low efficiency and high energy consumption. In today's increasingly scarce energy, the disadvantages of high energy consumption are becoming more and more protrude. Friction is the main cause of energy consumption. The piston mechanism is the mechanism with the largest number of hydraulic components. For example, a five-star motor has five pairs of piston mechanisms, and a plunger pump generally has nine pairs of piston mechanisms. Each pair of piston mechanisms has friction, causing energy losses, reducing mechanical efficiency. Manufacturers of hydraulic components design and manufacture generally only test...

AI Technical Summary

Problems solved by technology

The document "Friction of hydraulic rod seals at high velocities" (Journal: Tribology international, 2015) discloses a method for measuring the friction force between the sealing ring and the piston. A 120°distributed force sensor measures the friction force. The advantage of this method is that the crank connecting rod mechanism can realize the high-speed movement of the piston. The disadvantage is that it does not eliminate multiple friction forces that are not related to the measured friction force, such as bearings at both ends, bearings, etc. Friction will be generated at both end seals and gap seals, etc. These friction forces are additional friction forces, not the friction forces that need to be measured in project research. Secondly, the maximum loading pressure of this method is only 100bar, which is higher than most hydraulic transmission pressures. At 100bar, the solution adopts gap seal. The higher the pressure, the more difficult the gap seal is. When the pressure exceeds 200bar (this is a common pressure level), the gap seal leaks too much, which may make the test impossible. Finally, the structure of the crank connecting rod mechanism is complicated. , difficult to manufacture, high cost

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