Successful Downsizing With the New QXEHX

written by Gabi Olpp, updated on Wednesday, June 3, 2020

Reducing the drive torques by increasing the speed in the drive train for greater economy and higher energy efficiency.

The optimized design of the internal gear units has enabled noise levels and size to be reduced, thus increasing operational safety and productivity. Applications that particularly benefit are those using highly dynamic open circuits, such as injection molding and die casting machines as well as metal forming presses.

Facts and figures

  • Downsizing possible thanks to ~20% higher maximum speeds
  • Noise level reduced by 3 dB(A)
  • Extended range of displacements in all frame sizes

Commissioning / First start-up

As well as being correctly and professionally installed, the pump must be run-in with special and defined operating cycles. This is essential for ensuring that the machine will function properly. By using the procedure described in the following film, you will create the optimum conditions for long machine service life.

Reducing the noise levels

The specialists from Bucher Hydraulics have completely reworked the concept of the internal gear pump and developed the new QXEHX series with a focus on customer benefits. The innovative solution meets users' needs to downsize the power train in order to reduce the total cost of ownership. The new pump offers around 20 percent higher maximum speeds compared with the QXEH, thanks to a redesign of the suction and pressure galleries inside the pump body, among other changes. This results in optimized flow patterns and a significant reduction in pressure losses. This optimization, coupled with the proven special gear profile, reduces the noise level of the QXEHX by 3 dB(A). The quiet operation saves the work and costs of implementing sound-insulation measures in the application.

More displacement in a smaller size

Bucher Hydraulics offers the new internal gear pump in frame sizes with overlapping displacements, so that the ideal pump size can be selected for individual requirements. For example, a displacement of 40 cm³/rev was previously only available in frame size 5, but users can now also choose the size 4 version, with approx. 30 percent less weight. This reduces the installation space needed for the pump and lowers costs.

The QXEHX is currently available in sizes 4 and 5 with displacements of 20 to 80 cm³/rev. Combined with a servo- or reluctance-motor, it meets all the requirements for a future-proof solution, thanks in no small part to the reliable reverse mode for pressure relief. The internal gear pump is designed for applications with a highly dynamic open circuit, such as injection molding and die casting machines as well as metal forming presses and hydraulic power units in general.

Typical design with symmetrically arranged crescent

With the QXEHX, Bucher Hydraulics is expanding its proven series of QX internal gear units, which have been impressing users for years thanks to their non-compensated design. A typical feature is the very long pressure build-up region over the entire symmetrically arranged crescent, which also makes the new QXEHX a very reliable pump.

Read the technical article here
More information



Follow us