Adjustable side liner for a pump

1. An adjustment assembly for a pump casing of a pump, the pump casing including a main part and a side part having a main axis and a side wall section extending laterally with respect to the main axis, the adjustment assembly being operable to cause relative displacement between the side part and the main part of the pump casing, the adjustment assembly including: a drive device and an actuator which can be activated externally of the pump, said drive device comprising a ring shaped member operatively connected to the side part, said ring shaped member having a threaded portion thereon, and a housing having a threaded portion operatively mounted to or on the housing, the threaded portions being of complementary configuration so as to cooperate with one another, said drive device being operable to cause said relative displacement of the side part in response to activation of said actuator, said relative displacement capable of being a simultaneous combination of axial and rotational movement such that the rotational movement spreads the wear in use on the side wall of the side part.

2. An adjustment assembly according to claim 1 , wherein the pump includes an outer housing which encapsulates the pump casing.

3. An adjustment assembly according to claim 1 , further including a transmission mechanism operable to transmit power from the actuator to said drive device.

4. An adjustment assembly according to claim 3 , wherein said transmission mechanism includes a ring gear on said ring shaped member and a pinion gear in meshing engagement therewith, said pinion gear being operatively connected to said actuator.

5. An adjustment assembly according to claim 3 , wherein the transmission mechanism includes a worm gear and associated worm wheel.

6. An adjustment assembly according to claim 1 , wherein the drive device includes an inner annular ring operatively connected to the side part, the inner annular ring having a threaded section on its outer surface which cooperates with a threaded section on the housing arranged such that rotation of the inner annular ring causes axial displacement thereof.

7. An adjustment assembly according to claim 1 , wherein said ring-shaped member comprises a coupling ring which is operatively connected to the side part, said coupling ring having a threaded portion on an inner surface thereof, a support ring operatively mounted to the outer housing of the pump, said support ring having a threaded portion on an outer surface thereof which is complementary to and receives the threaded portion of the coupling ring so that relative rotation therebetween causes axial movement of both the coupling ring and the side part in relation to the outer housing.

8. An adjustment assembly according to claim 7 , wherein said transmission mechanism comprises a ring gear mounted to the coupling ring for rotation therewith and a pinion gear rotated by the actuator and in meshing engagement with the ring gear.

9. An adjustment assembly according to claim 8 , wherein the ring gear overlies the coupling ring and is secured thereto so that they rotate together in use.

10. An adjustment assembly according to claim 8 , wherein the ring gear is secured to the coupling ring by means of a key and keyway.

11. An adjustment assembly according to claim 1 , wherein said ring shaped member includes a rim, said threaded portion being on a surface of said rim.

12. An adjustment assembly for a pump casing of a pump, the pump casing including a stationary main part and a side part having a main axis and a side wall section extending laterally with respect to the main axis, the adjustment assembly being operable to cause displacement of the side part relative to the main part of the pump casing, the adjustment assembly including: a drive device having a ring shaped member, an actuator and a transmission mechanism which operatively connects the drive device to the actuator, the transmission mechanism providing meshing engagement between the actuator and the drive device, the actuator being arranged so that rotation thereof causes rotation of the transmission mechanism so that said drive device is operable to cause said relative displacement of the side part, said relative displacement capable of being a combination of axial and rotational movement, wherein rotation of the actuator in one direction causes the relative displacement.

13. An adjustment assembly according to claim 12 , wherein said relative displacement can be effected while the pump is operating.

14. An adjustment assembly according to claim 12 wherein the pump includes an outer housing which encapsulates the pump casing.

15. An adjustment assembly according to claim 12 wherein the actuator can be activated externally of the pump.

16. An adjustment assembly according to claim 12 , further comprising a locking device positioned to engage and lock elements of the drive device and operable to enable the drive device to effect relative displacement that is rotational only.