ROTARY LOBE PUMP WITH INTERNAL BEARING

Abstract

A rotary lobe pump having a pump housing with a pump room, an inlet opening and an outlet opening, a first multi-lobe rotary piston, which is arranged in the pump room and is rotatably mounted about a first axis of rotation, a second multi-lobe rotary piston, which is arranged in the pump room and is rotatably mounted about a second axis of rotation spaced apart from the first axis of rotation and meshingly engages in the first rotary piston, wherein the first and second rotary pistons are drivable in opposite directions and are designed to generate a flow of a conveyed medium from the inlet opening through the pump room to the outlet opening by counter-rotation about the first and second axis of rotation, respectively, and a drive device, which is mechanically coupled to the rotary pistons for driving the rotary pistons.

Claims

1-24. (canceled)

25. A rotary lobe pump for conveying a particle-laden conveyed medium, comprising: a pump housing with a pump room; an inlet opening and an outlet opening; a first, multi-lobe rotary piston, which is arranged in the pump room and is rotatably mounted about a first axis of rotation; a second multi-lobe rotary piston, which is arranged in the pump room, and is rotatably mounted about a second axis of rotation spaced apart from the first axis of rotation and meshingly engages in the first rotary piston; wherein the first and the second rotary pistons are drivable in opposite directions and are designed to generate a flow of the conveyed medium from the inlet opening through the pump room to the outlet opening by counter-rotation about the first and second axis of rotation, respectively; a drive device arranged on one side of the pump housing, which is mechanically coupled to the rotary pistons for driving the rotary pistons; a first fixed axle body, which is arranged inside the first rotary piston and connected to the pump housing on the side of the drive device; and at least one first bearing for rotatably supporting the first rotary piston about the first fixed axle body, wherein the bearing is arranged on an outer surface of the first fixed axle body and inside the first rotary piston.

26. The rotary lobe pump according to claim 25, wherein: the first fixed axle body extends along the first axis of rotation the first rotary piston extends from a first end face of the piston in axial direction to a second end face along the first axis of rotation; and the at least one first bearing is arranged axially with respect to the first axis of rotation between the first and second end face of the piston.

27. The rotary lobe pump according to claim 25, wherein the first bearing is a rolling bearing.

28. The rotary lobe pump according to claim 25, including: a second bearing provided for rotatably supporting the first rotary piston about the first axis of rotation; and wherein the second bearing is arranged on the outer surface of the first fixed axle body and inside the first rotary piston.

29. The rotary lobe pump according to claim 25, including: a second fixed axle body that is connected to the pump housing and arranged inside the second rotary piston; and at least one bearing for rotatably supporting the second rotary piston about the second axis of rotation, wherein the second bearing is arranged on the outer surface of the second fixed axle body and inside the second rotary piston.

30. The rotary lobe pump according to claim 25, wherein: the drive device comprises a first drive unit and a second drive unit; and wherein the first rotary piston is directly coupled to the first drive unit and the second rotary piston is directly coupled to the second drive unit.

31. The rotary lobe pump according to claim 25, wherein: the first and the second rotary piston each have a number of N lobes, wherein N is greater than or equal to two, and the lobes of the first and the second rotary piston extend helically along the circumferential surface of the rotary piston and thereby sweep an angle of at least 180° divided by N, preferably 240° divided by N, further preferably 300° divided by N and preferably 360° divided by N.

32. The rotary lobe pump according to claim 25, wherein: the first and the second rotary piston each have a number of N lobes, wherein N is preferably less than or equal to eight.

33. The rotary lobe pump according to claim 28, including: a first seal for sealing from the first and/or the second bearing to the pump room, arranged between the first fixed axle body and the first rotary piston inside the rotary piston; wherein the first seal is a dynamic seal.

34. The rotary lobe pump according to claim 33, wherein: the first seal for sealing from the first and/or the second bearing to the pump room is arranged at a first end of the bearings and is an axial face seal; and a second seal, which is arranged next to the first seal, the second seal being a rotary shaft seal; wherein the first seal and the second seal enclose between them a barrier chamber, which is subjected to an overpressure relative to the pump room in order to seal the bearing against the entry of the conveyed medium into the region of the bearing.

35. The rotary lobe pump according to claim 33, wherein: the first and/or the second bearing and the first seal are arranged inside a sleeve, wherein the sleeve is connected to the first and/or the second bearing; and the sleeve inside the first rotary piston is detachably connected to the rotary piston in order to rotate with the rotary piston.

36. The rotary lobe pump according to claim 35, including: a clamping device, which is connected to the sleeve and is adjustable between an operating state and a release state by means a fastener connection; wherein in the operating state there is a force closure connection between the sleeve and the first rotary piston and in the release state the sleeve and the first rotary piston are movable relative to one another.

37. The rotary lobe pump according to claim 36, wherein: the clamping device has a tool engagement for relative moving the clamping device and the sleeve in respect to the rotary piston.

38. The rotary lobe pump according to claim 37, wherein: the clamping device and the sleeve rest against a shoulder of the rotary piston inside the rotary piston and are releasably clamped against the shoulder; and wherein the distance between the sleeve and the shoulder is adjustable by a fastener connection of the clamping device.

39. The rotary lobe pump according claim 35, including: a washer arranged between the sleeve and the shoulder of the rotary piston for adjusting the axial position of the first rotary piston relative to the sleeve.

40. The rotary lobe pump according to claim 29, including: a third fixed axle body connected to the pump housing and arranged inside the first rotary piston; and at least one bearing for rotatably supporting the first rotary piston about the first axis of rotation, wherein the bearing is arranged on the outer surface of the third fixed axle body and inside the first rotary piston.

41. The rotary lobe pump according to claim 40, including: a fourth fixed axle body connected to the pump housing and arranged inside the second rotary piston; and at least one bearing for rotatably supporting the second rotary piston about the second axis of rotation, wherein the bearing is arranged on the outer surface of the fourth fixed axle body and inside the second rotary piston.

42. The rotary lobe pump according to claim 25, including: a hydraulic motor arranged inside the first rotary piston to drive the rotary piston.

43. The rotary lobe pump according claim 42, wherein: the hydraulic motor comprises a rotor rotatable about the first axis of rotation and mechanically coupled to the rotary piston inside the first rotary piston for driving the rotary piston; the hydraulic motor has a stator, which is arranged inside the rotor and is connected to or integral designed with the first fixed axle body; and an inlet and an outlet are connected to the hydraulic motor and extend inside the first fixed axle body and preferably to the outside of the pump housing.

44. The rotary lobe pump according to claim 25, wherein: the drive device for driving the rotary pistons drives two drive shafts coupled via a synchronisation gear, wherein a first drive shaft is mechanically coupled to the first rotary piston and a second drive shaft is mechanically coupled to the second rotary piston; and the synchronisation gear has a toothed belt for synchronously driving the drive shafts.

45. The rotary lobe pump according to claim 25, including: a shaft-hub connection, for transmitting a torque, which connects the first drive shaft and the first rotary piston in a torque-proof manner and is arranged inside the first rotary piston; and wherein the shaft-hub connection is connected to an internal thread inside the rotary piston.

46. The rotary lobe pump according to claim 25, including: a second drive device mechanically coupled to the second rotary piston for driving the second rotary piston.

47. The rotary lobe pump according to claim 46, wherein: the first drive device and the second drive device are arranged on opposite sides of the pump housing.

48. A method for servicing a rotary lobe pump for conveying a particle-laden conveyed medium, preferably a rotary lobe pump according to claim 36, wherein the servicing method comprises: releasing a detachable connection between a sleeve and a rotary piston, which are rotatably arranged in a pump room, wherein the sleeve is arranged inside the rotary piston; and axial pulling the sleeve out of the rotary piston, wherein at least one bearing and one seal are connected to the sleeve in such a way that they are moved axially out of the rotary piston with the sleeve when the sleeve is pulled out.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Preferred embodiments of the invention are explained by way of example with reference to the accompanying figures. They show:

[0049] FIG. 1 is a side view of a first embodiment, shown with a partial section through the first axis of rotation in the area of the first rotary piston;

[0050] FIG. 2 is a side view of a second embodiment with a sleeve, shown with a partial section through the first axis of rotation in the area of the first rotary piston;

[0051] FIG. 3 is a side view of a third embodiment with a drive device, shown with a partial section through the first axis of rotation in the area of the first rotary piston;

[0052] FIG. 4 is a side view of a fourth embodiment with a hydraulic motor arranged inside the first rotary piston, shown with a partial section through the first axis of rotation in the area of the first rotary piston;

[0053] FIG. 5 is a side view of a fifth embodiment with a synchronisation gear, shown with a partial section through the first axis of rotation in the area of the first rotary piston;

[0054] FIG. 6 is a side view of a sixth embodiment with two drive devices on opposite sides, shown with a partial section through the first axis of rotation in the area of the first rotary piston;

[0055] FIG. 7 is a side view of a seventh embodiment with two fixed axle bodies per axis of rotation, shown with a partial section through the first axis of rotation in the area of the first rotary piston; and

[0056] FIG. 8 is a side view of an eighth embodiment with an alternative arrangement of the fixed axle body, shown with a partial section through the first axis of rotation in the area of the first rotary piston.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0057] In the figures, identical or essentially functionally identical or similar elements are designated with the same reference signs.

[0058] FIG. 1 shows a rotary lobe pump 1 comprising a pump housing 70, wherein the pump housing 70 encloses the pump room 60. Two drive devices 80a, 80b are arranged on one side of the pump housing. The first drive device 80a is connected to the first fixed axle body 20. The fixed axle body 20 is connected to the pump housing 70. The drive device 80a has a shaft 11, which is connected by means of a shaft-hub connection 12 to the drive shaft 13, which extends through the fixed axle body 20 along the first axis of rotation 100a. The drive shaft 13 is thereby connected to the first rotary piston 50a by means of a shaft-hub connection 25 and thus transmits a torque from the first drive device 80a to the first rotary piston 50a. The second rotary piston 50b is similarly driven by the second drive device 80b, which drives a second drive shaft (not shown) that is mechanically coupled to the second rotary piston 50b and rotates about the second axis of rotation 100b. The first rotary piston 50a and the second rotary piston 50b each have a plurality of twisted lobes. The two rotary pistons 50a, 50b engage with each other in a meshed manner. The first rotary piston 50a is rotatably mounted about the axis of rotation 100a by means of a first bearing 34 and a second bearing 35, which are arranged on the first fixed axle body 20 by means of a spacer sleeve 33. In addition to the first bearing 34, a dynamic seal 32 is arranged on the first fixed axle body 20 to seal the bearings against the pump room 60. The seal 32 is thereby axially fixed by a retaining ring 31, which is arranged inside the first rotary piston 50a. The second bearing 35, which is arranged at the end of the first fixed axle body, is fixed by means of a fastening device 36. The fastening device 36 is thereby detachably connected to both the second bearing 35 and the first fixed axle body 20.

[0059] FIG. 2 shows a rotary lobe pump 1 in which two drive devices 80a, 80b drive two rotary pistons 50a, 50b which are located in a pump room 60, wherein the pump room 60 is arranged in a pump housing 70. The rotary pistons 50a, 50b are rotatably mounted about the axes of rotation 100a and 100b respectively. A dynamic seal 32, a first bearing 34, a spacer sleeve 33, a second bearing 35, and a second spacer sleeve 40 are arranged on the first fixed axle body 20. The position of the bearings 34, 35 on the fixed axle body 20 is fixed by means of a fixing device 36, which fixes the second spacer sleeve 40 on the fixed axle body 20. A sleeve 37 is arranged on the outer rings of the bearings 34, 35 so that the bearings are inside the sleeve. A retaining ring 31, which is mounted in the sleeve 33, secures the position of the dynamic seal 32 in the axial direction. The sleeve 33 is also arranged on a shoulder 51 of the bore of the first rotary piston 50a and is clamped against this shoulder 51 by a clamping device 38, which is arranged on the other side of the shoulder 51 than the sleeve 37. The clamping device 38 can establish a detachable connection between the sleeve 37, the shoulder 51, and the clamping device 38 by means of a screw connection 39.

[0060] FIG. 3 shows a rotary lobe pump 1 with only one drive device 80a. The drive shaft 13, which rotates about the axis of rotation 100a, is driven via the drive device 80a. The drive shaft 13 drives the first rotary piston 50a via a shaft-hub connection 25. The second rotary piston 50b is driven by the first rotary piston 50a, which meshes with the second rotary piston 50b. The synchronisation of the rotary pistons 50a, 50b takes place via the engagement of the two rotary pistons. The bearing of the first rotary piston 50a corresponds here essentially to the bearing of the embodiment shown in FIG. 2.

[0061] FIG. 4 shows a rotary lobe pump 1 that is driven by a hydraulic motor. The hydraulic motor is thereby arranged inside the first rotary piston 50a. The hydraulic motor has a stator 81 which is arranged on the fixed axle body 20 and inside the first rotary piston 50a. The fixed axle body 20 is configured as a solid material component, wherein a hydraulic inflow conduit 88 and a hydraulic outflow conduit 89 extend through the fixed axle body 20. The inflow conduit 88 and the outflow conduit 89 extend through the fixed axle body 20 out of the pump housing 70 and can be connected outside the rotary lobe pump 1. When the direction of rotation is reversed, the inflow conduit 88 and the outflow conduit 89 are reversed. The rotor 82 rotates about the first axis of rotation 100a and is connected to the first rotary piston 50a to transmit torque to the rotary piston. The rotor 82 is connected by means of a screw connection 83 to the sleeve 37, which, in turn, is connected to the first rotary piston 50a. The screw connection 83 also connects a connecting part 84 to the rotor 82, wherein the rotor 82 and the connecting part 84 are clamped from different sides against a shoulder 52 of the bore within the first rotary piston 50a. Thereby, the positions of the connecting part 84 and the rotor 82 as well as the sleeve 37 connected thereto with the bearing arranged therein are determined, so that they positions are axially fixed.

[0062] FIG. 5 shows a rotary lobe pump 1, which has a drive device 80a. The drive device 80a is connected to a synchronisation gear 90. Two drive shafts 13a, 13b are driven by the synchronisation gear 90, which rotate in opposite directions about the axes of rotation 100a and 100b. Furthermore, in this embodiment, the components are essentially arranged as in the embodiment shown in FIG. 2.

[0063] FIG. 6 shows a rotary lobe pump 1, wherein two drive devices 80a, 80b are arranged on opposite sides of the pump housing 70. Thereby, the first drive device 80a drives the first rotary piston 50a, which is mounted rotatably about the axis of rotation 100a. Furthermore, the second drive device 80b drives the second rotary piston 50b, which is rotatably mounted about the axis of rotation 100b. This embodiment allows the use of drive devices with larger diameters than the maximum possible diameters when arranged one above the other on the same side of the pump housing 70.

[0064] FIG. 7 shows a rotary lobe pump 1, which has two drive devices 80a, 80b. Thereby, the drive device 80a is connected to the fixed axle body 20 and the fixed axle body 20 is connected to the pump housing 70. The drive device 80a has a shaft 11, which is connected by means of a shaft-hub connection 12 to the drive shaft 13, which extends through the fixed axle body 20 along the first axis of rotation 100a. The drive shaft 13 is thereby connected to the rotary pistons 50a and 50c by means of a shaft-hub connection 25, and thereby transmits a torque from the drive device to this rotary piston. The rotary pistons 50a and 50c are thereby connected to each other in such a way that their end faces rest against each other and the connection is designed tight. This applies analogously to the rotary pistons 50b and 50d, which are driven by the drive device 80b and are mounted rotatably about the axis of rotation 100b. The rotary pistons 50a and 50c are arranged along the axis of rotation 100a in such a way that the directions of rotation of the twists of the lobes have opposite directions of rotation. The rotary pistons 50b and 50d are also arranged along the axis of rotation 100b in such a way that the directions of rotation of the twists of the lobes have opposite directions of rotation. In addition to the fixed axle body 20, another fixed axle body 220 is connected to the pump housing 70 along the axis of rotation 100a on the opposite side of the pump room 60. This fixed axle body 220 is designed as a solid material component. The rotary piston 50c is rotatably mounted around the fixed axle body 220. This bearing is thereby arranged with a first rolling bearing 234 and a second rolling bearing 235 and a spacer sleeve 233 arranged in between on the second fixed axle body 220. The outer ring of the bearings 234, 235 is connected to a sleeve 237, which is arranged inside the rotary piston 50c and connected to it. Next to the bearing 234, a dynamic seal 232 is arranged on the second fixed axle body 220 to seal the bearing against the pump room 60. The dynamic seal 232 is secured by a retaining ring 231, which is placed in the sleeve 237.

[0065] FIG. 8 shows a rotary lobe pump 1, in which the fixed axle body 220 is made of solid material and is arranged in the pump room 60. Thereby, the fixed axle body 220 is connected to the pump housing 70 on the side opposite to the drive device 80a. The drive device 80a has a shaft 11, which is connected to the first rotary piston 50a by means of a shaft-hub connection 12, 25. The first rotary piston 50a is thereby rotatably mounted about the first axis of rotation 100a. A dynamic seal 332 is arranged on the shaft 11 at the pump housing 70. Two bearings 235, 234 and a dynamic seal 232 are arranged on the fixed axle body 220, wherein the bearings are kept apart by a spacer sleeve 233. The seal 232 is axially fixed with a retaining ring 231 that is placed in the sleeve 237 surrounding the bearings and the seal. The sleeve 233 is connected to the outer rings of the bearings 235, 234 and to the first rotary piston 50a. The sleeve 233 is clamped against a shoulder 51 within the first rotary piston 50a by means of a clamping device 238, wherein the clamping device 238 comprising a plurality of screws 239. The bearing 235 is positioned on the fixed axle body 220 by means of a second spacer sleeve 240. The second spacer sleeve 240 is thereby secured on the fixed axle body 220 by a fastening device 241.