Abstract: A turbomachine comprising a housing defining a bearing cavity and a turbine chamber separated by a first wall, a heat shield disposed between the first wall and the turbine wheel, a heat shield cavity defined between the first wall and the heat shield. The shaft extends through a passage defined in part by a first aperture in the wall and a second aperture in the heat shield. A first seal is provided between the shaft and the first aperture. The housing defines a first gas channel communicating with the heat shield cavity for connection to a pressure source for raising pressure within the heat shield cavity. A second channel is provided between the heat shield cavity and the passage, the second channel opening to the passage on the opposite side of the first seal to the bearing assembly. A second seal is provided between the shaft and the second aperture.

Abstract: According to an aspect of the present invention, there is provided a variable geometry turbine comprising: a turbine wheel mounted on a turbine shaft within a housing assembly for rotation about a turbine axis, the housing assembly defining a gas flow inlet passage upstream of the turbine wheel; an annular wall member defining a wall of the inlet passage and which is displaceable in a direction substantially parallel to the turbine axis to control gas flow through the inlet passage; at least one moveable rod operably connected via a first end of the rod to the annular wall member, the rod being moveable to control displacement of the annular wall member, the rod extending in a direction substantially parallel to the turbine axis, the rod being connected to the annular wall member via a first arm and a second arm, a first end of the first arm and a first end of the second arm being attached to the rod, and a second end of the first arm being attached to the annular wall member at a first circumferential positi

Abstract: A turbomachine comprises a housing (71) defining a bearing cavity (71) and a turbine chamber (77a) separated by a first wall. A heat shield (72) is disposed between the first wall and the turbine wheel (77), a heat shield cavity (78) being defined between the first wall and the heat shield (72). The shaft (81) extends through a passage (85) defined at least in part by a first aperture (86) in said wall and a second aperture (87) in the heat shield (72). A first seal (88) is provided between the shaft (81) and said first aperture (86). The housing defines a first gas channel (79) communicating with the heat shield cavity (78) for connection to a pressure source for raising pressure within the heat shield cavity (78). A second channel (92) is provided between the heat shield cavity (78) and said passage (85), the second channel opening to said passage (85) on the opposite side of said first seal (88) to said bearing assembly (82).

Abstract: According to an aspect of the present invention, there is provided a variable geometry turbine comprising: a turbine wheel mounted on a turbine shaft within a housing assembly for rotation about a turbine axis, the housing assembly defining a gas flow inlet passage upstream of the turbine wheel; an annular wall member defining a wall of the inlet passage and which is displaceable in a direction substantially parallel to the turbine axis to control gas flow through the inlet passage; at least one moveable rod operably connected via a first end of the rod to the annular wall member, the rod being moveable to control displacement of the annular wall member, the rod extending in a direction substantially parallel to the turbine axis, the rod being connected to the annular wall member via a first arm and a second arm, a first end of the first arm and a first end of the second arm being attached to the rod, and a second end of the first arm being attached to the annular wall member at a first circumferential positi

Abstract: A turbomachine comprises a housing (71) defining a bearing cavity (71) a and a turbine chamber (77a) separated by a first wall. A heat shield (72) is disposed between the first wall and the turbine wheel (77), a heat shield cavity (78) being defined between the first wall and the heat shield (72). The shaft (81) extends through a passage (85) defined at least in part by a first aperture (86) in said wall and a second aperture (87) in the heat shield (72). A first seal (88) is provide between the shaft (81) and said first aperture (86). The housing defines a first gas channel (79) communicating with the heat shield cavity (78) for connection to a pressure source for raising pressure within the heat shield cavity (78). A second channel (92) is provided between the heat shield cavity (78) and said passage (85), the second channel opening to said passage (85) on the opposite side of said first seal (88) to said bearing assembly (82).