Abstract: The static seal (30) includes a rotary seal body (32) comprising an annular base portion (34) which is drivingly mountable on a rotary component such as a shaft and an annular cantilever portion (40) connected at one end to the base portion (34). The seal (30) 5 further includes a rotary seal face (48) and circumferential weights (44) connected to the cantilever portion (40). The seal is configured to dilate under centrifugal force to provide a running clearance between the rotary seal face and a complementary static seal face with which the rotary seal face is in contact when the rotary seal body (28) is stationary. The rotary seal body is further configured so as to facilitate the breaking up of slurry which may set around the seal when the pump (10) of which the seal forms part is inoperative.

Abstract: A centrifugal pump (10) includes a pump casing (12) within which an impeller (14) is mounted for rotation, cantilever fashion, on a shaft (16). The casing (12) has an axial inlet (20), and a peripheral volute (22) around the impeller (14) leading to an outlet (24). The impeller (14) has axially spaced annular sides (26, 28) with radially outwardly arranged, rearwardly curved, vanes (30) between the sides. Outwardly of the sides, clearing corresponding sides of the casing (12), auxiliary vanes (32, 34) are provided to generate a pressure gradient to prevent or counteract leakage of working fluid. Leading faces of the auxiliary vanes slope relative to a perpendicular to the sides, i.e. the leading edges are at an obtuse angle to the sides (26, 28).

Abstract: The static seal (30) includes a rotary seal body (32) comprising an annular base portion (34) which is drivingly mountable on a rotary component such as a shaft and an annular cantilever portion (40) connected at one end to the base portion (34). The seal (30) 5 further includes a rotary seal face (48) and circumferential weights (44) connected to the cantilever portion (40). The seal is configured to dilate under centrifugal force to provide a running clearance between the rotary seal face and a complementary static seal face with which the rotary seal face is in contact when the rotary seal body (28) is stationary. The rotary seal body is further configured so as to facilitate the breaking up of slurry which may set around the seal when the pump (10) of which the seal forms part is inoperative.

Abstract: In a casing of a rotary machine, cast components are sealingly mounted together by means of seals accommodated in (semi-) enclosed cavities. A ring seal includes an annular base and an annular skirt extending axially from the base. To ameliorate manufacturing tolerances, the seal defines circumferentially spaced, intermittent cavities to allow seal material to be deformed into the cavities as required. Land areas between cavities have cross-sectional surfaces increasing progressively from a free surface of small area to cause compressive force required for deformation to increase exponentially with an exponent larger than 1. The cavities may be peripherally spaced, being open at a radially outer surface of the seal. The seal may be of elastic material which may be incompressible. The skirt may taper away from the base. The base may have a projecting sealing lip. The skirt may have, at a free end, a slanted, peripheral lip.

Abstract: A centrifugal pump (10) includes a pump casing (12) within which an impeller (14) is mounted for rotation, cantilever fashion, on a shaft (16). The casing (12) has an axial inlet (20), and a peripheral volute (22) around the impeller (14) leading to an outlet (24). The impeller (14) has axially spaced annular sides (26, 28) with radially outwardly arranged, rearwardly curved, vanes (30) between the sides. Outwardly of the sides, clearing corresponding sides of the casing (12), auxiliary vanes (32, 34) are provided to generate a pressure gradient to prevent or counteract leakage of working fluid. Leading faces of the auxiliary vanes slope relative to a perpendicular to the sides, i.e. the leading edges are at an obtuse angle to the sides (26, 28).

Abstract: A rotary pump 10, e.g. a centrifugal slurry pump, has a main casing 12 housing an impeller 18 rotatable in an impeller cavity 16 defined between end liners 25, 28 and a peripheral main casing portion 24. The end liner 28, at a suction end of the impeller, is slidingly sealed via an annular seal 32 against the main casing portion 24. A radially inner, axially outwardly extending tubular portion 36 integral with the end liner 28 is aligned with a stationary tubular inlet portion 40. Seats 38, 44 respectively on the tubular portions 36, 40 oppose each other over a bridge cavity accommodating an annular bridge 50 which is expansible to allow the end liner 28 to be adjusted axially to close any gap with the impeller 18 caused by wear. Two variations of the annular bridge 50 are disclosed.

Abstract: A rotary pump includes an impeller mounted on a shaft (12) supported for rotation in bearings. A bearing and bearing casing assembly (26) proximate the impeller is prone to ingress of undesirable matter. A shield assembly (40) includes the shaft (12) and a shield (40) rotatable with the shaft and positioned intermediate the impeller and the bearing assembly (26). The shield comprises an integral, moulded, disc (42) and composite rim (44), which includes a lip (50) having an inwardly proud beading (52) normally touching an outer periphery (34.1) of the bearing assembly. A cowl (48) surrounds the lip with clearance when the shaft (12) rotates. The beading (52) dilates under centrifugal force to provide running clearance.

Abstract: A rotary pump includes an impeller mounted on a shaft (12) supported for rotation in bearings. A bearing and bearing casing assembly (26) proximate the impeller is prone to ingress of undesirable matter. A shield assembly (40) includes the shaft (12) and a shield (40) rotatable with the shaft and positioned intermediate the impeller and the bearing assembly (26). The shield comprises an integral, moulded, disc (42) and composite rim (44), which includes a lip (50) having an inwardly proud heading (52) normally touching an outer periphery (34.1) of the bearing assembly. A cowl (48) surrounds the lip with clearance when the shaft (12) rotates. The beading (52) dilates under centrifugal force to provide running clearance.

Abstract: In a casing of a rotary machine, cast components are sealingly mounted together by means of seals accommodated in (semi-) enclosed cavities. A ring seal includes an annular base and an annular skirt extending axially from the base. To ameliorate manufacturing tolerances, the seal defines circumferentially spaced, intermittent cavities to allow seal material to be deformed into the cavities as required. Land areas between cavities have cross-sectional surfaces increasing progressively from a free surface of small area to cause compressive force required for deformation to increase exponentially with an exponent larger than 1. The cavities may be peripherally spaced, being open at a radially outer surface of the seal. The seal may be of elastic material which may be incompressible. The skirt may taper away from the base. The base may have a projecting sealing lip. The skirt may have, at a free end, a slanted, peripheral lip.

Abstract: A rotary pump 10, e.g. a centrifugal slurry pump, has a main casing 12 housing an impeller 18 rotatable in an impeller cavity 16 defined between end liners 25, 28 and a peripheral main casing portion 24. The end liner 28, at a suction end of the impeller, is slidingly sealed via an annular seal 32 against the main casing portion 24. A radially inner, axially outwardly extending tubular portion 36 integral with the end liner 28 is aligned with a stationary tubular inlet portion 40. Seats 38, 44 respectively on the tubular portions 36, 40 oppose each other over a bridge cavity accommodating an annular bridge 50 which is expansible to allow the end liner 28 to be adjusted axially to close any gap with the impeller 18 caused by wear. Two variations of the annular bridge 50 are disclosed.