Sealing Requirements For Hydraulic Cutting Machine Cylinders

- Oct 28, 2019-

If the residual air in the cutting machine cylinder is subjected to rapid clamping, the sealing ring may be burnt due to the action of the hydraulic oil.


Speed: General specifications of the cylinder, when the speed of action exceeds 2m / s, its service life will be affected. In the case of 0.3m/s as the end of the stroke, it is recommended to install the buffer mechanism internally for the purpose of protection of the mechanism and safety.


The installation of the machine does not require the anchor bolts to be fixed to the ground, good vibration damping and considerable vertical deflection, so that the machine is stable on the ground. Save installation costs and shorten installation cycle. The machine position can be changed at any time according to the production, eliminating the cost of secondary installation and making the installation of the machine upstairs possible.


The liquid level signal transmitted from the float level transmitter installed on the crude oil buffer tank is still sent to the lower position machine, and the lower position machine outputs the control signal according to the set value of the liquid level, but the control signal is no longer sent to the regulating valve, but It is sent to the inverter, and the inverter controls the speed of the pump to achieve the purpose of controlling the liquid level. The theoretical basis is: In this control system, the controlled variable is the liquid level of the buffer tank, and the manipulated variable is the crude oil outflow of the buffer tank.


The hydraulic pressure valve includes a relief valve, a pressure reducing valve and a sequence valve. This article uses a relief valve as an example to clarify the test items and test methods of the pressure valve. The pressure valve test can be performed on a dedicated test bench or on a comprehensive bench.


(1) Pressure regulation scale and pressure stability test. Adjust the conditioning handwheel of the test valve, from full opening to full closing, then to full opening, from the pressure gauge to see the pressure rise and lower conditions and pressure regulation scale. The pressure gauge pointer should rise and fall steadily. The pressure regulation scale should be satisfactory to the regular pressure regulation scale. At the highest pressure, the pressure pulsation value must not exceed the rule value.


The hydraulic piston seal structure is composed of a wear ring and a combined seal ring. The wear ring supports and guides the piston to prevent it from being scratched or eccentric, and improves the durability of the seal. The wear ring is made of PTFE wear-resistant ring made of PTFE bronze. It has low friction, no creep and bite, can suppress mechanical vibration, has excellent pressure bearing capacity and wear resistance, and is completely suitable for the non-crawling requirement of the tension machine under low speed.


The static seal of the hydraulic cylinder is sealed by O-rings. The material is made of nitrile rubber and the Shore hardness is 75-90. Due to the high system pressure, the O-ring must be added with a retaining ring to prevent the O-ring from being squeezed into the fit clearance and damaged. Therefore, the seal of the piston and the piston rod is sealed by an O-ring, and the front end cover and the cylinder tube are sealed by an O-ring single-side retaining ring.