Hydraulic Transformer

A hydraulic transformer comprising:

• a housing comprising a high-pressure connection, a low-pressure connection and an operating pressure connection, a barrel member which is rotatably mounted in the housing and provided with a plurality of compression chambers of which the volume changes upon rotating the barrel member, wherein a back side of the barrel member comprises barrel ports which communicate with the respective compression chambers and a face plate which is supported by the housing and provided with a front side that supports the back side of the barrel member, a back side that faces the housing, a circumferential outer wall and a central hole that is surrounded by a circumferential inner wall, which face plate is rotatable with respect to the housing within a predetermined angle, wherein the front side is provided with three arcuate face plate ports along which the barrel ports travel upon rotating the barrel member, wherein the face plate ports communicate with the high-pressure connection through a first passage in the face plate, the low-pressure connection through a second passage in the face plate and the operating pressure connection through a third passage in the face plate, respectively, wherein one of the first to third passages has an opening at the back side of the face plate, one of the first to third passages has an opening at the circumferential outer wall of the face plate and one of the first to third passages has an opening at the circumferential inner wall of the face plate.