By integrating an additional compression volume in its A10 medium pressure pumps, Rexroth obtained improved performance while reducing pulsation and noise level. This pump was among the highlights of Bosch Rexroth’s presence at Agritechnica.
by Andrea Baty
By integrating an additional compression volume, Bosch Rexroth has cut the pressure pulsation of mobile hydraulic systems in the Rexroth A10 medium pressure pumps. This technical solution reduces the noise emissions of agricultural and forestry machinery and improves the controllability of hydraulically operated vehicle functions.
With each new vehicle generation, the demands placed on the hydraulic power increase, often with the same system design. This can increase the pressure pulsation. It is one of the three physical sources of noise emission coming from hydraulic systems in agricultural and forestry machinery, alongside the airborne sound and mechanical vibration. The trend is toward lower total noise emissions, whereby hydraulic systems also need to do their part. That’s why Bosch Rexroth makes an additional contribution in the form of a holistic approach for the pre-compression volume (PCV).
With the standard design of axial piston pumps, there is a substantial drop in flow when the piston transfers from high pressure area to low pressure area. With the solution developed by Bosch Rexroth, not only does the PCV maintain a volume, but the switching process has also been adapted.
The entire structure of the axial piston unit has been optimized
To do this, developers have optimized the entire structure of the axial piston unit, such as the rotary group, swivel angle and other elements. As a result, the flow is not so quickly and clearly interrupted. Bosch Rexroth has thereby cut the pressure pulsation in half over the entire pressure and speed range and reduced the overall sound level of the vehicle. The total noise emissions of machines outside and inside the driver’s cab are reduced without the need for additional soundproofing hardware.
In addition, the solution reduces the total load of the hydraulic system with all its components. This leads to better control of the system and of the vehicle functions. Bosch Rexroth offers the PCV option for the medium pressure axial piston variable pumps A10V(S)O for open circuits. These pumps cover the pressure range up to 280 bar and have proven themselves in a high number of agricultural and forestry machines to be extremely robust and durable.