DE4143535C2 - Magnet coupling pump - Google Patents

Abstract

The magnet coupling pump (12) is fitted on the front staged end (14a) of an internal shaft (14) with an axial hole (15) and a flywheel (16) is fitted on the shaft by means of an interposed spring (17) and a nut (18). The flywheel rotates in a spiral housing (20) screwed to the main pump bearing housing (10). To the right of the flywheel is a front slide bearing (22) with a bush (23), outer casing (24) and bearer ring (25). Between the bearer ring and the bush (23) is a spring (26), and outside the outer casing (24) is a tension ring (27). The medium handle (z), viz lubricant and coolant fluid, is conducted through the bearings (22, 29, 22h) of the inner shaft (14) from the flywheel outlet (16a) to the other shaft end (14e) and from there through the axial hole (15) of the inner shaft to the suction chamber.

Description

The invention relates to a centrifugal pump according to the Oberbe handle of claim 1.

Such a pump can be found in DE 39 05 307 A1, de inner shaft supporting the impeller in two radial bearings and this associated axial bearings rests. This inner shaft is powered by a set of magnets that do both rotate on the side of a relatively thin hood-shaped jacket.

DE 28 47 099 A1 shows a holder for a spherical cal spherical bearing in engines and transmissions, which - for Replacement of a pair of clip-on glasses - one Has ring made of an elastomer or felt, in the area of the spherical bearing is grooved.

The document to DE 78 36 469 U1 describes a plain bearing for glandless chemical pumps with one on one bearing sleeve-held slide film made of a plastic - like PTEE - with several extending circumferentially Foil sections held in axial slots of the bearing sleeve and are otherwise unsecured on the outer circumference gene.

The Erfin has knowledge of this state of the art the task set, the running behavior of the beginning pump described by a changed storage to ver improve.

The teaching of the independent leads to the solution of this task Claim 1. The sub-claims capture advantage continuing education.

According to the invention, the radial bearings and the axial bearings the pump shaft defines elastic - with for the user  selectable spring rate - suspended, with the Radial bearings arranged in the way are formed that slots from the outer edges go out, preferably on the two outer edges alternately offset - and advantageously axially parallel - are arranged while the thrust bearing be supported by elastic support rings.

Required for the function of the hydrodynamic plain bearings liquid flow serves to remove the heat, which at the same time from the bearing friction and the magnetic Losses of the central rotary coupling described arise. This will result in the hot media being used problems arising from bearing parts and the scope of them the - advantageously made of stainless steel - Parts due to different coefficients of thermal expansion Taken into account and guarantee a safe functioning accomplishes. The elastic bearing suspension is therefore up taking the different strains between the bearing and Carrier material provided and at the same time allows that Adjustability under the acting bearing forces. Through the Defined elasticity of all bearing supports is guaranteed ensures that the pump according to the invention be subcritically is driven. The distance is so large that the rotor ampli tuden lie particularly low - an extremely quiet pumping run is the result.

Thanks to the elasticity of the bearing support, the La adjust under the effect of the bearing forces, an off is equal to minor misalignment and manufacturing errors just as possible as a better compensation of deformations, that result from pipeline forces. The one on the inside radial forces occurring - as such per se knows - taken up by two radial plain bearings, the on stepping axis thrust via a provided on the impeller Thrust bearing introduced into the pump housing.  

According to a further feature of the invention, one is also the spring washers of the radial bearing between the inner shaft and a plain bearing bush arranged, in particular between a carrier ring penetrated by the inner shaft and the Plain bearing bush. The plain bearing bush of the radial bearing is preferred by a circumferential spring ring fe constantly hung up.  

The spring member advantageously has one for better storage outward radial bead as well radial internal formations at the cross-sectional ends. Here the internal spring element of the radial bearing is supported downwards against a bead of the carrier ring and lies on the other hand with the final internal formations of the radially following plain bearing bush.

Thanks to the above provisions, the bearing contour sure that despite the elasticity the magnetic clutch pump operated below the stability limit of storage becomes. Vertical use is also possible.

The elastic bearing suspension according to the invention is like this trained that these in all available tough Materials can be carried out, which is why the Material selection is adaptable to product requirements, but it turned out to be particularly cheap, the material for the wetted parts Use pump parts.

The magnetic clutch pump can also be drained thanks to the The bearing suspension is designed cleanly. The Subject of the invention is on the other hand with the Liquid-filled columns of the suspension optimal subdued. Another advantage of the elastic Bearing suspension is the favorable dry running property this pump; the temperature in the warehouse and the different strains between the bearing material and the carrier material are absorbed.

According to the invention, the rotor of the pump should preferably be in two Bearings with different diameters are stored, the impeller side bearing is larger than that clutch side. The installation dimensions for the neighboring one Thrust bearings are much larger. The resulting axial thrust is reduced, and the rotor is more robust overall. Because by the big one  There is a jump in diameter between the two bearings a substantial thrust balance on the impeller acting axial forces. The resulting one also works Axial force always in the direction from the impeller to the rotary coupling.

A special one is within the scope of the invention Material selection for the pairing of the bearings; the material should be of particular hardness in front of the containment shell - and for its protection - occurring in the liquid Solid particles to be ground and thus harmless to be let. Silicon carbide has proven to be favorable for this proven that from a publication of the Hermetic- Pumpen GmbH from 1986 (Krämer and Neumaier, "Centrifugal pumps and rotating positive displacement pumps are more hermetic Type ") is known per se.

The impeller is used for media operated at the boiling point designed as a double flow pump, one pump for the Main flow and the other for the lubrication and cooling flow serves. The cooling and lubricating flow is - by means of Orifice / throttle - adjustable.

The drive torque is at one without shaft sealing of a rotating part compared to the fixed one Pump housing designed magnetic clutch pump - from the External wave coming - via the magnetic Central rotary coupling of the inner shaft - and thus the impeller - supplied, which the drive power in hydraulic Performance. The outer rotor, which according to the invention the outer shaft rests in two roller bearings, comes with the Pumped medium is not in contact because - as mentioned - the The containment shell encloses the inner rotor and the centrifugal pump thus hermetically seals.  

Due to the direct attachment of the slide bearing to the Impeller is made for both indoor and outdoor Outside storage the best possible clearance. As is well known is the total length of the centrifugal pump according to the DIN standard 24256 from center to shaft end. In addition through this mounting of the plain bearing, the on it radial forces acting most efficiently.

Thanks to the large bearing diameter on the impeller side the bearing capacity increased significantly and the overlying hydrodynamic lubricating film at the same Load significantly thicker. Overall, such lead considerations according to the invention for a multiple increase the load capacity compared to conventional constructions.

This high load-bearing capacity of the axial bearing makes the pump almost completely insensitive to axial thrust. This applies to both bumps and Pressure fluctuations over the entire map area including driving against a closed one Slider; previous designs mostly have one permanent thrust compensation and very small Bearing capacity.

Another advantage of the large bearing on the impeller side is the default, the shaft with a larger diameter to carry out what even with 60 Hz machines subcritical and extremely quiet running guaranteed.

The construction according to the invention is advantageous due to the large axial bearing on the impeller against reverse running insensitive, for security reasons only one Speed above the nominal speed must be avoided.  

In the context of the invention, a magnetic clutch pump be particularly well designed, with one Forced control of the coolant and lubricant flow without Bypass flows occur; through this forced guidance ensures that all essential parts are lubricated and are cooled. In contrast, conventional Constructions bypass and therefore undefined partial flows. So can, for example, near the contact surface of the front Bearing unit to the impeller the mouth of a radial Can be provided that an axial bore of the Connects the inner shaft with the pressure chamber of the pump, whereby a Partial flow of the medium between the impeller close Radial bearing and its axial bearing is also positively driven like in the downstream area of the rear radial bearing, after which it flows around the inner rotor, the partial flow after the gap directly to the bore of the inner shaft is led. This further version therefore makes use of at least one radial bore in the impeller around the circuit to complete via the pressure room. This is especially so required if media are close to the boiling line should be promoted; in such a case the Heating of the cooling / lubricating flow in the plain bearing / clutch Lead the area to the formation of vapor bubbles. Would this gaseous medium parts to the suction side of the centrifugal pump returned, there would be a significant Deterioration in pump characteristics. Around The second embodiment thus becomes avoidance of appearance proposed the magnetic clutch pump according to the invention.

Of particular importance is the forced management of the Lubricant or coolant from the impeller outlet through the Bearing of the inner shaft to the shaft end remote from the impeller and from this through the inner shaft to the suction chamber.

Further advantages, features and details of the invention result preferred from the following description Exemplary embodiments and with reference to the drawing; this shows in

Fig. 1: the longitudinal section through a magnetic coupling pump with an axially extending shaft for an impeller;

FIG. 2 shows a partial longitudinal section of another embodiment of the magnetic drive pump;

FIG. 3 shows the side view of the shaft;

FIG. 4: an enlarged ring-like detail from FIG. 2, cut along line IV-IV in FIG. 5;

Fig. 5: a partial front view of the detail of Fig. 4;

FIG. 6 shows other elements of Figure 1 in enlarged cross-section, which are cut along the line VI-VI in FIG. 7;.

Fig. 7: the top view of part of Fig. 6;

FIG. 8 is a developed view according to line VIII-VIII of FIG. 7;

Fig. 9 is a longitudinal section through a further embodiment of a magnetic clutch pump;

FIG. 10: an enlarged detail from FIG. 9;

FIG. 11: an enlarged element from FIG. 9, cut along line XI-XI in FIG. 12;

Fig. 12 is a partial end view of Fig. 11.

In a bearing support housing 10 a recess formed as a magnetic clutch pump centrifugal pump 12 1 16 sits of FIG. On the front stepped end 14 _a of an inner shaft 14 having an axial bore 15, an impeller with the interposition of an adjusting spring 17 and is held by a nut 18. This impeller 16 rotates in a spiral housing 20 screwed to the bearing support housing 10 with the interposition of the housing cover 11 and seals 19 .

To the right of the impeller 16 there is a front slide bearing 22 with a slide bearing bush 23 , an outer slide bearing sleeve 24 and a carrier ring 25 in the housing cover 11 . Between the latter and the slide bearing bushing 23 there is a spring 26 and outside the slide bearing bushing 24 there is a clamping ring 27 which, according to FIGS. 4, 5, is designed as an alternately slotted sleeve with an inside diameter e of, for example, 145 mm, radial bores 27 _b of about 5 mm in diameter b are provided at a distance f from the adjacent spring outer edge 28 .

This slide bearing 22 is associated with a front axial slide bearing ring 29 which surrounds the inner shaft 14 and has a carrier ring 30 . The latter is a channel profile placed around the inner shaft 14 with a longer leg 30 _a lying on the shaft 14 , which - as illustrated in FIG. 6 - carries the axial plain bearing ring 29 ; this is supported by the edge of the shorter profile leg 30 _b . The Axialgleitlagerring 29 is provided with radial grooves 33, the angle t to each other measures 25.7 ° and chen the x parallel in pump rotational direction Pultflä connect 33 _a. Their form makes the development of FIG. 8 in conjunction with FIG. 7 clear, to which reference is expressly made and whose drawing shows features according to the invention, such as the surface height difference Ah of 0.034 and the angle of inclination a for an inclination ratio N of 1: 400. The scale of FIG. 7 is 1: 1, that of processing 2: 1.

A central recess 31 of the housing cover 11 penetrated by the shaft 14 tapers from the carrier ring 30 to close to a rear slide bearing 22 _h with a rear slide bearing bush 23 _h , in which at least one spring can be seen at 26 _h ; the plain bearing bushing 23 _h includes a rear plain bearing sleeve 24 _h , to which outward clamping rings connect 27 _h . The rear slide bearing 22 _h follow on the shaft 14, an axial bearing ring 32 as a start-up protection and a carrier ring 34 , in which there is at least one - the rear shaft end 14 _e comprehensive - key 17 _e be.

The carrier ring 34 is connected via a pin 33 to a radial disk 36 of an inner rotor 37 which carries magnetic elements 38 on its axially parallel contour. Between these and magnetic counter-elements 39 of an outer rotor 40 , in a gap 41 parallel to the longitudinal axis A of the centrifugal pump 12, a pot wall 42 of a can 43 surrounded by the outer rotor 40 runs.

The outer rotor 40 is connected by a radial disk 44 to an outer shaft 46 , which is seen in roller bearings 48 , example as deep groove ball bearings, a bearing bracket part 49 . The latter is part of the bearing bracket housing 10 provided here with a bearing cover 50 . The bearing cover 50 adjacent deep groove ball bearing 48 is supported against a snap ring 51 , which a locking ring 51 _a and a sealing element 51 _b against external influences such as dust, moisture or the like are assigned.

In this centrifugal pump 12 , the drive torque - coming from the outer shaft 46 - is supplied via the magnetic central rotary coupling 52 , which detects the two rotors 37 , 40 in particular, with the magnetic elements 38 , 39 of the inner shaft 14 and thus also the impeller 16 , which converts the drive power into hydraulic Performance. The outer rotor 40 mounted in the two roller bearings 48 does not come into contact with the pumped medium since the containment shell 43 surrounds the inner rotor 37 and thus hermetically seals the centrifugal pump 12 .

Radial forces on the inner shaft 14 are absorbed by the two radial slide bearings 22 , 22 _h , and the axial thrust that occurs is introduced into the housing cover 11 or the spiral housing 20 via the large axial bearing 29 .

In the selected exemplary embodiments, all slide bearing components preferably consist of silicon carbide. The liquid flow necessary for the function of the hydrodynamic slide bearings 22 , 22 _h serves at the same time to remove the heat caused by bearing friction and magnetic losses of the central rotary coupling 52 . The cooling / lubricating flow is taken from a side space 16 _a for the impeller 16 (arrow z), flows through the radial and axial sliding bearing 22 , 29 on the left in FIG. 1, then through the right or rear radial bearing 22 _h , reaches the right axial bearing ring 32 and flows around the inner magnet rotor 38 . The liquid comes back into the suction chamber 54 of the centrifugal pump 12 through the axial shaft bore 15 and is discharged through the impeller 16 .

The drawing shows that the bearings have different diameters - for the thrust bearings 29 , 32 here d and d ₁ -; the radial bearing 22 attached directly to the impeller 16 is larger than the coupling-side bearing 22 _h .

In the embodiment according to FIG. 2, the mentioned cooling flow Z is not supplied to the suction side of the centrifugal pump 12 _a , but is pumped through radial channels 56 in the impeller 16 , which open at the outer edge 58 of the sen, onto the pressure side; the shaft 14 is closed at its end and a nut 18 with a spring ring 61 holds the impeller 16 .

Also in embodiment 12 _b in Fig. 9, the impeller end of the inner shaft 14 is closed, and from the shaft bore 15 in the stepped shaft end 14 _a radial blade channels 56 _b , which end here, however, at the impeller rear 59 where the contour of the impeller 16 detaches in cross section from the subsequent slide bearing bush 23 ; the position of this mouth 57 is determined by about half the impeller radius r.

Also in this embodiment, the containment shell 43 or its pot wall 42 ends at an intermediate ring 45 , but this is opposed in FIG. 9 by an end ring 64 of the outer rotor 40 , the impeller-side surface of which is approximately flush with the corresponding surface of the inner rotor 37 . The end ring 64 ends radially near the inner surface of the housing 10 .

In particular, FIG. 10 shows that the clamping ring 27 of the radial bead 22 in front of its plain bearing 22 offers an outward radial bead 66 and radial internal formations 67 at the cross-sectional ends. The inner spring 26 is of U-shaped cross-section with an impeller-side longer radial leg 69 and lies with end outer feet 70 of the radially following slide bearing bush 23 - on the shaft side, it is supported against a shaped bead 72 of the carrier ring 25 .

The Fig. 11, 12 illustrate the rear clamping ring 27 _h prior to this embodiment. Its inner diameter q, which is determined by the inner formations 67 , is here 60 mm with an axial length of 50 mm and a length t _{1 of} the radial bead 66 of 8 mm. Axial-parallel edge slots 74 of width i of 3 mm emanate from the outer spring edge 28 and are offset from one another according to FIG. 11 and end approximately at the radial bead 66 .

Claims (17)

1. Centrifugal pump with an impeller rotatable in a housing on an inner shaft that is slide-mounted in radial bearings with at least one passage from a suction chamber to a pressure chamber and with a pair of magnetic couplings assigned to the inner shaft, the inner rotor of which, with the interposition of a can, is connected to an outer rotor connected to an outer shaft A plate-like axial bearing ring is assigned to an impeller-side radial bearing and a second axial bearing is assigned to a second radial bearing arranged on the shaft end remote from the impeller, characterized in that the radial bearings ( 22 , 22 _h ) and axial bearings ( 29 , 32 ) are elastically suspended, on the circumference and in the interior of the radial bearings ( 22 , 22 _h ) spring washers ( 26 , 26 _h , 27 , 27 _h ) are arranged, which have slots extending from the outer edges ( 28 ) and wherein on the axial bearings ( 29 , 32 ) elastic carrier rings ( 30 , 34 ) are arranged. 2. Centrifugal pump according to claim 1, characterized in that the slots ( 74 ) of the spring washers ( 26 , 26 _h , 27 , 27 _h ) on both outer edges ( 28 ) of the spring washers ( 26 , 26 _h , 27 , 27 _h ) mutually alternately are staggered. 3. Centrifugal pump according to claim 1 or 2, characterized in that the slots ( 74 ) of the spring washers ( 26 , 26 _h , 27 , 27 _h ) are axially parallel. 4. Centrifugal pump according to one of claims 1 to 3, characterized in that at the respective radial bearings (22, 22 _h) arranged internal spring ring (26, 26 _h) between the inner shaft (14) and a Gleitla gerbuchse (23, 23 _h) is provided. 5. Centrifugal pump according to claim 4, characterized in that the internal spring ring ( 26 , 26 _h ) between a on the inner shaft ( 14 ) arranged carrier ring ( 25 ) and the plain bearing bush ( 23 , 23 _h ) is arranged. 6. Centrifugal pump according to claim 4 or 5, characterized in that the slide bearing bush ( 23 , 23 _h ) of the Ra diallager ( 22 , 22 _h ) is surrounded by a further external spring ring ( 27 , 27 _h ). 7. Centrifugal pump according to one of claims 1 to 6, characterized in that the impeller-side radial bearing ( 22 ) is larger than the remote impeller radial bearing ( 23 _h ). 8. Centrifugal pump according to claim 7, characterized in that the impeller-side larger radial bearing ( 22 ) is attached directly to the impeller ( 16 ). 9. Centrifugal pump according to one of claims 6 to 8, characterized in that the external spring ring ( 27 , 27 ') has an outwardly directed radial bead ( 66 ) and at the ends radial internal formations ( 67 ). 10. Centrifugal pump according to claim 9, characterized in that the slots ( 74 ) of the spring washers ( 27 , 27 _h ) end approximately at the radial bulge ( 66 ). 11. Centrifugal pump according to claim 9 or 10, characterized in that the axial length (t ₁ ) of the radial bead ( 66 ) to the length (n) of the spring ring ( 27 ) holds ver as 1: 6.25. 12. Centrifugal pump according to one of claims 4 to 11, characterized in that the inner Fe derring ( 26 ) of the impeller-side radial bearing ( 22 ) wave-like against a bead ( 72 ) of the ring carrier ring ( 25 ) and on the other hand with end-side outside constructions ( 70 ) on the plain bearing bush ( 23 ). 13. Centrifugal pump according to one of claims 1 to 12, characterized in that the impeller side Axialla gerring ( 29 ) for deriving the axle thrust in a Ge housing cover ( 11 ) is larger that the shaft end ( 14 _e ) and the second radial bearing ( 22 _h ) assigned second thrust bearing ( 32 ). 14. Centrifugal pump according to claim 13, characterized in that the elastic support ring ( 30 ) of the axial bearing ring ( 29 ) is designed as a U-shaped ring with a radial bearing ring ( 29 ) bearing radially on the inside, renal leg ( 30 _a ) and one on the axial bearing ring ( 29 ) axially adjacent shorter profile leg ( 30 _b ). 15. Centrifugal pump according to at least one of claims 1 to 14, characterized in that the spring rings ( 26 , 26 _h ; 27 , 27 _h ) and the elastic support rings ( 30 ; 34 ) are made of the material of the liquid-contact pumps. 16. Centrifugal pump according to one of claims 13 to 15, characterized in that the axial plain bearing ring ( 29 ) has radial grooves or grooves ( 33 ), each of which is provided between sliding projections ( 33 _a ) rising in the direction of pump rotation (x). 17. Centrifugal pump according to one of claims 1 to 16, characterized in that at least one of the bearings ( 22 , 22 _h , 29 , 32 ) consists of a hard material pairing between them forming a grinding gap for particles of the conveying medium.