Abstract: A drag pump for pumping fluid from an inlet to an outlet includes a stator and a rotor. One of the stator or rotor includes a disc having a plurality of channels each of the channels extending from an inlet portion of the disc at or close to an inlet edge towards an outlet portion at or close to an outlet edge. The plurality of channels each has walls for guiding fluid flow from the inlet edge to the outlet edge in response to relative motion between the stator and the rotor. The disc further includes a plurality of protrusions extending from the channels, each of the protrusions being arranged to divide a channel at the inlet or the outlet end of the channel, into sub-channels that extend for a portion of a length of the channel and do not extend for a whole length of the channel.

Abstract: A drag pump for pumping fluid from an inlet to an outlet includes a stator and a rotor. One of the stator or rotor includes a disc having a plurality of channels each of the channels extending from an inlet portion of the disc at or close to an inlet edge towards an outlet portion at or close to an outlet edge. The plurality of channels each has walls for guiding fluid flow from the inlet edge to the outlet edge in response to relative motion between the stator and the rotor. The disc further includes a plurality of protrusions extending from the channels, each of the protrusions being arranged to divide a channel at the inlet or the outlet end of the channel, into sub-channels that extend for a portion of a length of the channel and do not extend for a whole length of the channel.

Abstract: A scroll compressor may include a scroll pumping mechanism which includes an orbiting scroll having an orbiting scroll wall extending axially from an orbiting scroll plate towards a fixed scroll and a fixed scroll having a fixed scroll wall extending axially from a fixed scroll plate towards the orbiting scroll. An axial end portion of one of the scroll walls includes a first sealing arrangement and a second sealing arrangement arranged in series along the scroll wall from the inlet to the outlet for sealing between the axial end portion of the scroll wall and the scroll plate of the opposing scroll. The first sealing arrangement may have first sealing characteristics which are selected according to the sealing requirements local to the first sealing arrangement and the second sealing arrangement may have second, different sealing characteristics which are selected according to sealing requirements local to the second sealing arrangement.

Abstract: The present invention relates to a scroll pump (10) comprising two scrolls (20, 22) which are co-operable for pumping fluid from an inlet (24) to an outlet (26) on relative orbiting motion of the scrolls. Each scroll comprises a scroll base (30, 36) from which a spiral scroll wall (28, 34) extends generally axially towards the base of the opposing scroll. The pump comprises a tip seal arrangement comprising an axial end portion of one or both of the scroll walls which locates a tip seal (508) for resisting the passage of pumped fluid across the or both scroll walls between the or both scroll walls and the scroll base of the opposing scroll. The tip seal arrangement limits axial movement of the tip seal towards the scroll base of the opposing scroll along a first spiral region (507) of the or both scrolls between the inlet and the outlet.

Abstract: The present invention relates to a scroll pump with two scrolls that are co-operable for pumping fluid from an inlet to an outlet on relative orbiting motion of the scrolls. Each scroll comprises a scroll base from which a scroll wall extends generally axially towards the base of the opposing scroll. A gas conduit having an inlet at a first location of the pumping channel and an outlet at a second location of the pumping channel allows over-compression at the first location of the pumping channel to be exhausted to the second location of the pumping channel. A one-way valve located in the gas conduit allows the passage of gas through the conduit from the conduit inlet to the conduit outlet when a predetermined pressure differential between the first and second locations of the pumping channel is generated during roughing when the scroll inlet is at or close to atmosphere.

Abstract: The present invention is a scroll pump comprising two intermeshing scrolls arranged so that on relative orbital movement of the scrolls gas is pumped from an inlet to an outlet. The scrolls have a plurality of successive scroll wraps I, II, II, IV, V, VI between the inlet and the outlet. There is a single-start condition in which fluid is pumped from the inlet to the outlet along a single flow path extending through each of the scroll wraps in succession and a multi-start condition in which fluid is pumped from the inlet along a plurality of flow paths which extend in parallel through radially adjacent scroll wraps and converge to a single flow path prior to the outlet. A valve arrangement is operable for switching the scroll pump between the single-start and the multi-start conditions.

Abstract: The present invention is a scroll pump comprising two intermeshing scrolls arranged so that on relative orbital movement of the scrolls gas is pumped from an inlet to an outlet. The scrolls have a plurality of successive scroll wraps I, II, II, IV, V, VI between the inlet and the outlet. There is a single-start condition in which fluid is pumped from the inlet to the outlet along a single flow path extending through each of the scroll wraps in succession and a multi-start condition in which fluid is pumped from the inlet along a plurality of flow paths which extend in parallel through radially adjacent scroll wraps and converge to a single flow path prior to the outlet. A valve arrangement is operable for switching the scroll pump between the single-start and the multi-start conditions.

Abstract: The present invention relates to a scroll pump with two scrolls that are co-operable for pumping fluid from an inlet to an outlet on relative orbiting motion of the scrolls. Each scroll comprises a scroll base from which a scroll wall extends generally axially towards the base of the opposing scroll. A gas conduit having an inlet at a first location of the pumping channel and an outlet at a second location of the pumping channel allows over-compression at the first location of the pumping channel to be exhausted to the second location of the pumping channel. A one-way valve located in the gas conduit allows the passage of gas through the conduit from the conduit inlet to the conduit outlet when a predetermined pressure differential between the first and second locations of the pumping channel is generated during roughing when the scroll inlet is at or close to atmosphere.

Abstract: The present application relates to a scroll compressor comprising a scroll pumping mechanism which comprises an orbiting scroll (20) having an orbiting scroll wall (34) extending axially from an orbiting scroll plate (36) towards a fixed scroll (22) and a fixed scroll having an fixed scroll wall (28) extending axially from a fixed scroll plate (30) towards the orbiting scroll. The compressor further comprises an axially extending drive shaft (14) having an eccentric shaft portion (16) so that rotation of the eccentric shaft portion imparts an orbiting motion to the orbiting scroll relative to the fixed scroll for pumping fluid from an inlet (24) to an outlet (26) of the pumping mechanism.

Abstract: The present invention relates to a scroll pump (10) comprising two scrolls (20, 22) which are co-operable for pumping fluid from an inlet (24) to an outlet (26) on relative orbiting motion of the scrolls. Each scroll comprises a scroll base (30, 36) from which a spiral scroll wall (28, 34) extends generally axially towards the base of the opposing scroll. The pump comprises a tip seal arrangement comprising an axial end portion of one or both of the scroll walls which locates a tip seal (508) for resisting the passage of pumped fluid across the or both scroll walls between the or both scroll walls and the scroll base of the opposing scroll. The tip seal arrangement limits axial movement of the tip seal towards the scroll base of the opposing scroll along a first spiral region (507) of the or both scrolls between the inlet and the outlet.