Pin Joint For An Eccentric Screw Pump |
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申请号 | US14498382 | 申请日 | 2014-09-26 | 公开(公告)号 | US20150010342A1 | 公开(公告)日 | 2015-01-08 |
申请人 | Michael Groth; Reinhard Denk; | 发明人 | Michael Groth; Reinhard Denk; | ||||
摘要 | A pin joint for eccentric screw pumps. The special design of the inner joint head of the pin joint, with its bores for the flushing liquid and the length of the joint pin, makes it possible also to carry out cleaning using the CIP method. | ||||||
权利要求 | |||||||
说明书全文 | The invention relates to an open pin joint and a method for operating this pin joint for eccentric screw pumps in the hygiene sector. The joint has an inner and an outer joint head, wherein each joint head comprises at least one diametrical bore, which is penetrated by a pin which is provided at both ends with a cap in each case. The inner spherical joint head has a convex bore course in the region of the pin. A pin joint for an eccentric screw pump emerges from DE 10 2006 058 166 A1. The pin joint is surrounded by a collar in order to keep the lubricant in the region of the joint. When the lubricant is replaced, the interior of the joints can also comprise a central lubricant channel per joint in order to remove the lubricant. Since the joint does not have to be completely cleaned for the replacement of lubricant, this design of the joint may be sufficient. DE 101 16 641 A1 discloses a pin joint with a part of a drive shaft and a part of a coupling rod. An end region of the drive shaft is provided with a coaxial plug-in socket. The coupling pin of the coupling rod projects into this plug-in socket. For the cleaning of the interior of the plug-in socket, the wall of the latter comprises two diametrical flushing bores. The problem of the present invention is to design a pin joint which can also be used for the hygiene sector, wherein attention is focused in particular on the difficult, but necessary cleaning of the bore of the inner joint head which accommodates a joint pin. The inventive technical solution to the problem is achieved by the features of the invention. According to a first embodiment of the pin joint according to the invention, a spherical joint head comprises at its end face at least two channels which are disposed eccentrically with respect to the longitudinal axis. In a preferred embodiment of the pin joint, the channels are inclined at an angle of 10° to 30° outwards from the longitudinal axis of the drive shaft in the direction of the outer side of the pin joint. The cleaning liquid thus flows in the paraxial region of the drive shaft into the inner joint head and flows radially offset to the inlet at the inner side of the inner joint head. The cleaning of the joint or joints accordingly takes place radially from the longitudinal axis of the jointed shaft from the inner joint head to the outer joint head. In order that the flushing liquid passes into every region of the gap between the pin and the inner and outer joint head, the pin extends in its length by at least 5% of the cap diameter beyond the external diameter of the outer joint heads. The effect of lengthening the pin is that the pin can move radially in the joint and a relative motion component thus results in the joint gaps, which leads to circulation of the cleaning liquid. The cross-section of the pin/pins is reduced compared to the cross-section of the bores. For the further improvement of the flow of the cleaning liquid, the channels for the cleaning liquid are disposed in such a way that they each emerge in the case of the inner joint head in the region of the pin, in which region its bore diverges from the longitudinal axis of the jointed shaft radially in the direction of the respective outer joint head. The cleaning of the open pin joint according to the invention takes place during the rotation of the joint or joints, wherein the flushing liquid exerts a radially acting pressure on the flushing liquid on account of the eccentric wobbling motion of the joint. The wobbling motion causes a constant reduction and increase in the cylindrical annular space between the pin and the bore of the inner joint head. Each joint head connection thus represents its own pump for the flushing liquid. Since the flushing liquid is introduced eccentrically into the joint, where the gap between the joint head and the pin is at its smallest, the quantity of flushing liquid corresponding to the pin joint according to the invention is much greater per unit of time. The flushing liquid is displaced from the inner region into the outer region of the pin joint. The invention is explained below with the aid of diagrammatic drawings. In the figures: Suction port 54 is located in the immediate vicinity of sealing housing 56 and seal 58, which can be embodied as a slip-ring seal. Suction port 54 is disposed tangential to or on pump housing 52. Seal 58 sits on intermediate shaft 44, which is rigidly connected to drive shaft 46. Jointed shaft 42 is connected non-rotatably by joints, here pin joints 34, both to intermediate shaft 42 and also to rotor 40. A variant of a pin joint 34 is represented in Two channels 26, 28 begin at end face 24 of inner joint head 10, said channels extending into diametrical bore 15. Flushing liquid passes through these bores from the pump housing in a targeted manner into bore 15 and here removes residues of the conveyed medium. Since the bores do not run centrally along longitudinal axis 30 of intermediate shaft 44, but at an angle A of 10° to 30°, this radially directed flow assists removal from or cleaning of bore 15. On account of the wobbling motion of joint head 10, the radially widening inner faces of bore 15 push the flushing liquid out of the internal region of joint head 10. The channels in head end 60 of the joint head emerge, at a distance from longitudinal axis 30, in the region of bore 15 in the already diverging surface region. A further possibility for cleaning a pin joint with flushing liquid is represented in A plan view of pressure flange 48 of the eccentric screw pump 36 is reproduced in 10 joint head 12 joint head 14 bore 15 bore 16 bore 18 pin 20 cap 22 cap 24 end face 26 channel 28 channel 30 longitudinal axis 34 pin joint 36 eccentric screw pump 38 stator 40 rotor 42 jointed shaft 44 intermediate shaft 46 drive shaft 48 pressure flange 50 screws 52 pump housing 54 suction port 56 sealing housing 58 seal 62 outlet 64 axis |