How to Reduce the Noise of Hydraulic Press

Causes of hydraulic press noise:

1. Poor quality of hydraulic pumps or motors is usually the main part of noise in hydraulic transmission. Poor manufacturing quality of hydraulic pumps, accuracy that does not meet technical requirements, large fluctuations in pressure and flow, failure to eliminate oil entrapment, poor sealing, and poor bearing quality are the main causes of noise. During use, wear of hydraulic pump parts, excessive clearance, insufficient flow, and easy pressure fluctuations can also cause noise.
2. Air intrusion into the hydraulic system is the main cause of noise. Because when air invades the hydraulic system, its volume is larger in the low-pressure area. When it flows to the high-pressure area, it is compressed, and the volume suddenly decreases. When it flows into the low-pressure area, the volume suddenly increases. This sudden change in the volume of bubbles produces an “explosion” phenomenon, thereby generating noise. This phenomenon is usually called “cavitation”. For this reason, an exhaust device is often set on the hydraulic cylinder to discharge gas.
3. Vibration of the hydraulic system, such as slender oil pipes, many elbows, and no fixation, during the oil circulation process, especially when the flow rate is high, can easily cause pipe shaking. Unbalanced rotating parts of the motor and hydraulic pump, improper installation, loose connection screws, etc., will cause vibration and noise.

Treatment measures:

1. Reduce noise at the source

1) Use low-noise hydraulic components and hydraulic presses

The hydraulic press uses low-noise hydraulic pumps and control valves to reduce the speed of the hydraulic pump. Reduce the noise of a single hydraulic component.

2) Reduce mechanical noise

•Improve the processing and installation accuracy of the hydraulic pump group of the press.
•Use flexible couplings and pipeless integrated connections.
•Use vibration isolators, anti-vibration pads, and hose sections for the pump inlet and outlet.
•Separate the hydraulic pump group from the oil tank.
•Determine the pipe length and configure pipe clamps reasonably.

3) Reduce fluid noise

•Make the press components and pipes well sealed to prevent air from entering the hydraulic system.
•Exclude air that has been mixed into the system.
•Use an anti-noise oil tank structure.
•Reasonable piping, installing the oil tank higher than the hydraulic pump, and improving the pump suction system.
•Add an oil drain throttle valve or set up a pressure relief circuit
•Reduce the reversing speed of the reversing valve and use a DC electromagnet.
•Change the length of the pipeline and the position of the pipe clamp.
•Use accumulators and mufflers to isolate and absorb sound.
•Cover the hydraulic pump or the entire hydraulic station and use reasonable materials to prevent noise from propagating in the air. Absorb and reduce noise.

2. Control during transmission

1) Reasonable design in the overall layout. When arranging the plane design of the factory area, the main noise source workshop or device should be away from the workshop, laboratory, office, etc., which requires quietness. Or concentrate the high-noise equipment as much as possible to facilitate control.
2) Use additional barriers to prevent noise transmission. Or use natural terrain such as hills, slopes, woods, grass, tall buildings, or additional structures that are not afraid of noise.
3) Use the directional characteristics of the sound source to control noise. For example, the exhaust outlets of high-pressure boilers, blast furnaces, oxygen generators, etc., face the wilderness or the sky to reduce the environmental impact.

3. Protection of recipients

1) Provide personal protection for workers, such as wearing earplugs, earmuffs, helmets, and other noise-proof products.
2) Take workers in rotation to shorten workers’ working time in high-noise environments.