CN219672904U - Center-opening centrifugal pump - Google Patents

Abstract

The utility model provides a middle-open centrifugal pump, wherein shaft sleeves are respectively arranged on pump shafts on the left side and the right side of an impeller, screw sleeves are correspondingly arranged on the outer sides of one or two shaft sleeves, the screw sleeves are in threaded fit with the pump shafts and axially squeeze the corresponding shaft sleeves, the left shaft sleeve and the right shaft sleeve axially squeeze the impeller to axially fix the impeller on the pump shafts, and the screw sleeves are locked to rotate through anti-rotation key pins. The utility model uses the anti-rotation key pin to stop the rotation of the screw sleeve, thereby preventing the screw sleeve from shifting. When the anti-rotation key is used, the screw sleeve is only required to be screwed down lightly, so that the screw sleeve is pressed against the shaft sleeve lightly, and then the screw sleeve is stopped from rotating through the anti-rotation key pin. The anti-rotation swivel nut with the anti-rotation key pin ensures the axial fixation of the impeller and the pump shaft, so that the impeller is not loosened, the extrusion force applied to the pump shaft is also slight compared with the prior art, the pump shaft can not generate bending deformation, overcomes the defects of the prior art, is convenient to assemble and operate, and has good safety and reliability.

Description

Center-opening centrifugal pump

Technical Field

The utility model relates to the technical field of centrifugal pumps, in particular to a middle-open type centrifugal pump.

Background

The middle-open centrifugal pump comprises an upper pump body, a lower pump body, an impeller, a pump shaft, a shell sealing ring, an impeller sealing ring, a shaft sleeve, a fastening nut, a non-driving end shaft box, a driving end bearing box and the like. The impeller is mounted on a pump shaft in a pump cavity formed by an upper pump body and a lower pump body through flat key matching. The left side and the right side of the impeller are respectively provided with a shaft sleeve and a fastening nut, the fastening nut is matched with the threads of the pump shaft to axially squeeze the shaft sleeve, and the shaft sleeves on the left side and the right side squeeze the impeller inwards to fix the impeller on the pump shaft. In order to ensure the fastening capability of the fastening nut and the non-loosening buckling, the fastening nuts on the left side and the right side adopt a double-nut mode.

In the prior art, the perpendicularity error of the end surface and the axial lead exists in the processing process of the impeller, the shaft sleeve and the nut, and the coaxiality error exists in the pump shaft, so that the following two problems are generated:

firstly, in order to ensure the axial fixation of the impeller and ensure that the fastening nut is not loosened, the axial pressure of the fastening nut to the shaft sleeve and the impeller is large, so that the pump shaft is easy to bend and deform, the perpendicularity error between the impeller and the center line of the pump body is increased, and even if the coaxiality of the impeller sealing ring and the shell sealing ring is enlarged and deteriorated. Because impeller sealing ring on the impeller and the casing sealing ring on the pump body are in sliding fit, the coaxiality of impeller sealing ring and casing sealing ring is enlarged and becomes poor, so that the matching relationship between the impeller sealing ring and the casing sealing ring is poor, the assembly is difficult, and the impeller sealing ring or the casing sealing ring is required to be polished so as to ensure the sliding fit relationship of the impeller sealing ring or the casing sealing ring, otherwise, the impeller sealing ring or the casing sealing ring generates interference fit or local contact, the balanced operation of the impeller is influenced, and vibration is generated.

Secondly, in order to ensure that the fastening nuts are not loosened, two nuts are adopted, but the tightening force of the two nuts is greatly influenced by human factors during assembly, and the safety and the reliability are poor.

Disclosure of Invention

The technical problems to be solved are as follows:

in view of the above-mentioned shortcomings and drawbacks of the prior art, the present utility model provides a split centrifugal pump that solves the problems of easy assembly difficulties and poor safety reliability of the prior art.

The technical scheme is as follows:

in order to achieve the above purpose, the main technical scheme adopted by the utility model comprises the following steps:

the embodiment of the utility model provides a middle-open centrifugal pump which comprises an impeller, a pump shaft and shaft sleeves, wherein the impeller and the shaft sleeves are sleeved on the pump shaft, the shaft sleeves are positioned on two sides of the impeller, screw sleeves are correspondingly arranged on the outer sides of one or two shaft sleeves, and the screw sleeves are in threaded fit with the pump shaft and axially squeeze the corresponding shaft sleeves. The anti-rotation key pin is used for limiting the rotation of the screw sleeve. The anti-rotation key pin is connected with the threaded sleeve and the pump shaft.

Optionally, an anti-rotation through hole is formed in the threaded sleeve, a pump shaft hole corresponding to the anti-rotation through hole is formed in the pump shaft, an anti-rotation key pin penetrates through the anti-rotation through hole and then stretches into the pump shaft hole, and the anti-rotation key pin is in threaded fit with the anti-rotation through hole and/or the pump shaft hole.

Optionally, the anti-rotation key pin is in threaded fit with the anti-rotation through hole or the pump shaft hole, and the pump shaft hole or the anti-rotation through hole which is not in threaded fit with the anti-rotation key pin is a strip-shaped hole.

Optionally, a clamping groove is formed in the outer side end of the screw sleeve, a key groove corresponding to the clamping groove is formed in the pump shaft, and the anti-rotation key pin is arranged in the clamping groove and the key groove so as to prevent the screw sleeve from rotating, and a fixed end cover for blocking the clamping groove is arranged on the outer side of the screw sleeve and prevents the anti-rotation key pin from falling off from the clamping groove.

Optionally, the clamping groove is a through hole or a notch, and the fixed end cover is sleeved at the outer side end of the screw sleeve and covers the clamping groove.

Optionally, the key groove or the clamping groove is in a strip-shaped structure.

Optionally, the clamping groove and/or the key groove are multiple.

Optionally, the clamping groove is a groove formed in the inner wall of the screw sleeve, the key groove is a bar-shaped key groove extending along the axial direction of the pump shaft, and the fixed end cover is tightly attached to the outer side end of the screw sleeve to seal the clamping groove.

The beneficial effects are that:

the utility model provides a middle-open centrifugal pump, wherein shaft sleeves are respectively arranged on pump shafts on the left side and the right side of an impeller, screw sleeves are correspondingly arranged on the outer sides of one or two shaft sleeves, the screw sleeves are in threaded fit with the pump shafts and axially squeeze the corresponding shaft sleeves, the left shaft sleeve and the right shaft sleeve axially squeeze the impeller to axially fix the impeller on the pump shafts, and the screw sleeves are locked to rotate through anti-rotation key pins. The utility model uses the anti-rotation key pin to stop the rotation of the screw sleeve, thereby preventing the screw sleeve from shifting. When the anti-rotation key is used, the screw sleeve is only required to be screwed down lightly, so that the screw sleeve is pressed against the shaft sleeve lightly, and then the screw sleeve is stopped from rotating through the anti-rotation key pin. The anti-rotation swivel nut with the anti-rotation key pin ensures the axial fixation of the impeller and the pump shaft, so that the impeller is not loosened, the extrusion force applied to the pump shaft is also slight compared with the prior art, the pump shaft can not generate bending deformation, overcomes the defects of the prior art, is convenient to assemble and operate, and has good safety and reliability.

Furthermore, the anti-rotation key pin can penetrate through the screw sleeve and then extend into the pump shaft hole of the pump shaft to stop rotation of the screw sleeve. The anti-rotation key pin can also be arranged in the clamping groove of the screw sleeve and the key groove of the pump shaft, and the anti-rotation key pin is prevented from falling off by utilizing the fixed end cover, so that the rotation of the screw sleeve is stopped. The utility model provides various modes for selection, and the type of stopping the rotation of the screw sleeve can be selected according to specific conditions so as to further improve the applicability of the utility model.

In summary, the double nuts are not used for positioning the shaft sleeve any more, so that the problems that in the prior art, the double nuts are easy to bend and deform the pump shaft, the perpendicularity error between the impeller and the center line of the pump body is large, and therefore assembly is difficult are well solved, and the two nuts are greatly influenced by human factors during assembly, so that the safety and the reliability are poor are well solved.

Drawings

Fig. 1 is a cross-sectional view of the overall structure of the present utility model.

FIG. 2 is a schematic view of a first form of anti-rotation key pin in use.

Fig. 3 is a right side view of the screw sleeve 7.

Fig. 4 is a cross-sectional view of fig. 3.

Fig. 5 is a schematic view of a second form of use of the anti-rotation key pin.

Fig. 6 is a perspective view of the anti-rotation key pin installation of fig. 2.

Fig. 7 is a perspective view of a third form of installation of the anti-rotation key pin.

Fig. 8 is an end view of the anti-rotation key pin and fixed end cap of fig. 7 after being installed in place.

Fig. 9 is a cross-sectional view A-A of fig. 8.

[ reference numerals description ]

1a, an upper pump body; 1b, a lower pump body; 2. an impeller; 21. a flat key; 3. a pump shaft; 32. a key slot; 33. a pump shaft hole; 4. a non-drive end axlebox; 5. a drive end bearing box; 6. a shaft sleeve; 7. a screw sleeve; 71. an internal thread; 72. a clamping groove; 73. an anti-rotation through hole; 8. fixing the end cover; 9. an anti-rotation key pin; 10. a housing seal ring; 20. impeller sealing ring

Detailed Description

The utility model will be described in detail below with reference to the accompanying drawings for better explanation of the utility model. Wherein references herein to "upper", "lower", "left", "right", etc. are made to the orientation of fig. 1.

The utility model provides a middle-open centrifugal pump, which comprises an impeller, a pump shaft and a shaft sleeve; the impeller and the shaft sleeve are sleeved on the pump shaft; the shaft sleeves are positioned at two sides of the impeller, screw sleeves are correspondingly arranged at the outer sides of one or two shaft sleeves, and the screw sleeves are matched with the threads of the pump shaft and axially squeeze the corresponding shaft sleeves. The utility model also comprises an anti-rotation key pin for limiting the rotation of the screw sleeve. The utility model solves the problems of difficult assembly and poor safety and reliability caused by large axial pressure of the impeller and bending deformation of the pump shaft due to double nut fastening in the prior art.

In order to better understand the above technical solution, exemplary embodiments of the present utility model will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present utility model are shown in the drawings, it should be understood that the present utility model may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the utility model to those skilled in the art.

Examples:

referring to fig. 1, the present utility model relates to a center-open centrifugal pump, which comprises an upper pump body 1a, a lower pump body 1b, an impeller 2, a pump shaft 3, a housing seal ring 10, an impeller seal ring 20, a non-drive end axlebox 4, a drive end bearing housing 5, and the like.

The non-drive end casing 4 and the drive end casing 5 are respectively installed at both ends of the pump shaft 3. The impeller 2 is located in a pump chamber formed by an upper pump body 1a and a lower pump body 1 b. The impeller 2 is mounted in the middle of the pump shaft 3 by a flat key 21. The impeller seal ring 20 and the casing seal ring 10 effectively reduce liquid leakage and act to withstand wear.

The utility model mainly solves the related problems of installation and fastening of the impeller 2, and aims to ensure the axial fixation of the impeller 2, so that the impeller does not generate axial movement in the high-speed rotation process, and certain axial pressure is needed during fastening, but in the traditional installation mode, the axial pressure is difficult to control by means of double nuts, and the axial pressure is too large to easily cause bending deformation of a pump shaft. The following describes an improvement in the mounting fastening manner of the impeller 2:

regarding the installation of the impeller 2, referring to fig. 1, one sleeve 6 is respectively disposed on the left side and the right side of the impeller 2, and a threaded sleeve 7 is correspondingly disposed on the outer side of one or both of the sleeves 6, that is, the threaded sleeve 7 may be correspondingly disposed on the outer side of one of the sleeves 6, or the threaded sleeves 7 may be correspondingly disposed on the outer sides of both of the sleeves 6, for example: if the screw sleeve 7 is correspondingly arranged on the outer side of one shaft sleeve 6, the screw sleeve 7 can be correspondingly arranged on the left side of the shaft sleeve 6 on the left side of the impeller 2, or the screw sleeve 7 can be correspondingly arranged on the right side of the shaft sleeve 6 on the right side of the impeller 2. If the two shaft sleeves 6 are provided with the threaded sleeves 7 correspondingly on the outer sides, the left side of the shaft sleeve 6 on the left side of the impeller 2 is provided with the threaded sleeves 7 correspondingly, and meanwhile, the right side of the shaft sleeve 6 on the right side of the impeller 2 is also provided with the threaded sleeves 7 correspondingly.

The screw sleeve 7 is in threaded fit with the pump shaft 3 and axially presses the corresponding shaft sleeve 6, namely, if the screw sleeve 7 is arranged on the left side of the shaft sleeve 6 on the left side of the impeller 2, the screw sleeve 7 presses the shaft sleeve 6 on the left side; while the right side of the sleeve 6 on the right side of the impeller 2, if provided with a screw 7, the screw 7 presses the sleeve 6 on the right side. And, the present utility model further includes an anti-rotation key pin 9 for restricting the rotation of the screw sleeve 7.

When the impeller needs to be fastened, taking the screw sleeve 7 arranged on the left side and the right side as an example, the screw sleeve 7 is screwed, so that the corresponding shaft sleeve 6 is axially extruded, and the shaft sleeve 6 is axially extruded to the impeller 2. The impeller 2 bears the axial pressure transmitted by the shaft sleeves 6 at two sides, so that the impeller is fixed on the pump shaft 3, the axial movement is avoided, then the rotation of the screw sleeve 7 is limited by the anti-rotation key pin 9, the axial movement of the screw sleeve 7 is further limited, and the axial movement of the impeller 2 is better prevented. The use of the swivel nut 7 and the anti-rotation key pin 9 solves the problem that a large fastening force is needed when double bolts are used for fastening in the past, the swivel nut 7 only needs to lightly press the shaft sleeve 6 with a force, the limit of the shaft sleeve 6 can be met, and the force is far smaller than the fastening force of double nuts in the prior art.

The rotation preventing key pin 9 limits the rotation of the screw sleeve 7 in the following manner:

mode one: referring to fig. 5, the insert 7 is provided with an anti-rotation through hole 73, and the anti-rotation through hole 73 is opened along the radial direction of the insert 7. The pump shaft 3 is provided with a pump shaft hole 33 corresponding to the rotation preventing hole 73. The rotation preventing key pin 9 passes through the rotation preventing through hole 73 and then extends into the pump shaft hole 33, and the rotation preventing key pin 9 is in threaded fit with the rotation preventing through hole 73 and/or the pump shaft hole 33. By "and/or" is meant herein:

meaning one: the anti-rotation key pin 9 can be only in threaded fit with the anti-rotation through hole 73, namely, the anti-rotation key pin 9 is provided with external threads, the anti-rotation through hole 73 is provided with internal threads, and after the anti-rotation key pin 9 passes through the anti-rotation through hole 73 in a screwing mode, the lower end of the anti-rotation key pin 9 stretches into the pump shaft hole 33 so as to fulfill the aim of stopping rotation of the screw sleeve 7. The anti-rotation key pin 9 then merely protrudes into the pump shaft bore 33 but does not engage the pump shaft bore 33 in a threaded manner. In addition, the diameter of the pump shaft hole 33 is preferably just enough for the anti-rotation key pin 9 to be inserted.

Further, the pump shaft hole 33 that is not threadedly engaged with the rotation preventing key pin 9 may be provided as a bar-shaped hole extending in the axial direction of the pump shaft 3. The strip-shaped holes are arranged to expand the opening of the pump shaft hole 33 along the axial direction of the pump shaft 3 so as to facilitate the insertion of the anti-rotation key pin 9, and the inconvenience in mounting the anti-rotation key pin 9 when a little error dislocation exists between the pump shaft hole 33 and the anti-rotation through hole 73 along the axial direction of the pump shaft 3 can be avoided. The width of the pump shaft hole 33 is preferably such that the insertion of the rotation preventing key pin 9 is just accommodated, and the rotation preventing key pin 9 is prevented from shaking in the pump shaft hole 33, and the width of the pump shaft hole 33 is the distance between the two side walls of the pump shaft hole 33 extending in the axial direction of the pump shaft 3.

Meaning two: the anti-rotation key pin 9 can be only in threaded fit with the pump shaft hole 33, namely, the anti-rotation key pin 9 is provided with external threads, the pump shaft hole 33 is provided with internal threads, and after the anti-rotation key pin 9 directly passes through the anti-rotation through hole 73, the lower end of the anti-rotation key pin 9 extends into the pump shaft hole 33 and is in threaded fit with the pump shaft hole 33, so that the purpose of stopping rotation of the threaded sleeve 7 is achieved. The rotation preventing key pin 9 passes through the rotation preventing through hole 73 only, but is not screw-engaged with the rotation preventing through hole 73. In addition, the diameter of the rotation preventing through hole 73 is preferably just enough for the rotation preventing key 9 to pass through.

Further, at this time, the rotation preventing through hole 73 which is not in threaded fit with the rotation preventing key pin 9 may be provided as a bar hole extending along the axial direction of the screw sleeve 7, and the bar hole is provided to expand the opening of the rotation preventing through hole 73 along the axial direction of the screw sleeve 7, so as to facilitate insertion of the rotation preventing key pin 9, and to avoid the problem of inconvenient installation of the rotation preventing key pin 9 caused when a small error is misplaced between the pump shaft hole 33 and the rotation preventing through hole 73 along the axial direction of the screw sleeve 7. The width of the rotation preventing through hole 73 is preferably such that the rotation preventing key pin 9 can be just accommodated for insertion, and the rotation preventing key pin 9 is prevented from shaking in the rotation preventing through hole 73, and the width of the rotation preventing through hole 73 is the distance between two side walls of the rotation preventing through hole 73 extending along the axial direction of the screw sleeve 7.

Meaning three: the anti-rotation key pin 9 is screw-fitted with both the anti-rotation through hole 73 and the pump shaft hole 33. That is, the rotation preventing key pin 9 is externally threaded, and the rotation preventing through hole 73 and the pump shaft hole 33 are internally threaded, and in use, the rotation preventing key pin 9 is screwed to pass through the rotation preventing through hole 73 and then extend into the pump shaft hole 33 in a threaded fit manner, and then be in threaded fit with the pump shaft hole 33.

In addition, for the above-described anti-rotation key pin 9, for convenience of screwing, a "straight" groove, a "cross" groove, or the like, similar to the groove at the top of the tapping screw, may be provided at the top of the anti-rotation key pin 9.

When the screw sleeve 7 is mounted, the screw sleeve 7 is sleeved on the pump shaft 3, and the screw sleeve 7 is screwed to a proper position in the direction of the shaft sleeve 6, so that the anti-rotation through hole 73 on the screw sleeve 7 corresponds to the pump shaft hole 33 on the pump shaft 3. And taking the anti-rotation key pin 9, and extending the anti-rotation key pin 9 into the pump shaft hole 33 on the pump shaft 3 after passing through the anti-rotation through hole 33 on the swivel nut 7, so that the anti-rotation key pin 9 is in threaded fit with the anti-rotation through hole 73 and/or the pump shaft hole 33 to prevent the swivel nut 7 from rotating. The rotation preventing through hole 73 and the pump shaft hole 33 may be perforated in advance according to an appropriate position where the screw sleeve 7 is located so that the rotation preventing through hole 73 and the pump shaft hole 33 may correspond.

The rotation preventing hole 73 in the screw sleeve 7 and the pump shaft hole 33 in the pump shaft 3 may be provided in at least one group or may be provided in plural groups. When a plurality of sets are provided, the rotation preventing through holes 73 and the pump shaft holes 33 are circumferentially distributed along the outer surfaces of the screw sleeve 7 and the pump shaft 3, respectively. The arrangement of the plurality of rotation preventing through holes 73 and the pump shaft 3 can select the number of the rotation preventing key pins 9 to be inserted as required to enhance the strength of preventing the rotation of the screw sleeve 7.

Mode two: referring to fig. 2-4 and 6, the outside end of the sleeve 7 is provided with a clamping groove 72, wherein the outside end is the left end of the sleeve 7 if the sleeve 7 is the left side of the impeller 2, and the outside end of the sleeve 7 is the right end of the sleeve 7 if the sleeve 7 is the right side of the impeller 2. The pump shaft 3 is provided with a key groove 32 which can correspond to the clamping groove 72. The anti-rotation key pin 9 is installed in the catching groove 72 and the key groove 32 to prevent the rotation of the screw sleeve 7. The outside of the swivel nut 7 is provided with a fixed end cover 8 for blocking the clamping groove 72, and the anti-rotation key pin 9 is prevented from falling off from the clamping groove 72. The outside of the screw sleeve 7: the outside of the sleeve 7 is the left side of the sleeve 7 if it is the sleeve 7 on the left side of the impeller 2, and the outside of the sleeve 7 is the right side of the sleeve 7 if it is the sleeve 7 on the right side of the impeller 2. Further, the slot 72 may be a notch. Referring to fig. 2 and 6, since the opening is formed in the form of an opening formed at the outer circumferential surface of the outer end of the screw sleeve 7 and an opening formed at the end surface of the outer end of the screw sleeve 7, the fixing cap 8 at this time can cover the outer circumferential surface of the outer end of the screw sleeve 7 to block the opening located on the outer circumferential surface and can also abut against the outer end of the screw sleeve 7 to block the opening of the opening located on the outer end, and the fixing cap 8 at this time is similar to a bottle cap structure. The fixing end cap 8 may be fixedly connected to the threaded sleeve 7, and the fixing manner may be a screw manner, or any other known fixing manner, such as spot welding, may be adopted. When the fixed end cover 8 and the screw sleeve 7 are fixed in a screw mode, the screw penetrates through the outer side end of the fixed end cover 8 and is fixedly connected with the outer side end of the screw sleeve 7, namely, the axial direction of the screw is parallel to the axial direction of the pump shaft 3, and even if the screw is loosened, the screw moves along the axial direction of the pump shaft 3, so that the rotation of the pump shaft 3 cannot be affected immediately.

Further, the key groove 32 or the clamping groove 72 may have a bar-shaped structure, and the function of the bar-shaped structure is mainly to adjust fault tolerance in the axial direction, and the specific function thereof is referred to the function of the pump shaft hole 33 and the anti-rotation through hole 73 in the foregoing "meaning one" and "meaning two", which are not described herein.

Furthermore, when the key groove 32 is a bar-shaped structure, the width of the bar-shaped structure, that is, the distance between the two side walls of the bar-shaped structure extending in the axial direction of the pump shaft 3 is preferably just enough for the insertion of the anti-rotation key pin 9. At this time, the shape of the inner wall of the clamping groove 72 is adapted to the shape of the outer wall of the anti-rotation key pin 9, and the size of the inner wall of the clamping groove 72 preferably just meets the requirement that the anti-rotation key pin 9 is inserted, so that the shaking caused by overlarge gap is prevented.

When the catching groove 72 is a bar-shaped structure, the width of the bar-shaped structure, i.e., the distance between the two side walls of the bar-shaped structure extending in the axial direction of the nut 7, is preferably just enough for the insertion of the anti-rotation key pin 9. At this time, the shape of the inner wall of the key slot 32 is adapted to the shape of the outer wall of the anti-rotation key pin 9, and the size of the inner wall of the key slot 32 preferably just satisfies the insertion of the anti-rotation key pin 9, so that the shaking caused by the overlarge gap is prevented.

When the screw sleeve 7 is screwed to a proper position during installation, the anti-rotation key pin 9 is inserted into the clamping groove 72 and the key groove 32, and then the fixed end cover 8 and the screw sleeve 7 are fixed.

Further, referring to fig. 4 and 6, a shoulder structure may be provided at the outer end of the screw sleeve 7, so that when the fixing end cap 8 is sleeved at the outer end of the screw sleeve 7, the outer circumferential surface of the fixing end cap 8 may be aligned with the outer circumferential surface of the screw sleeve 7, i.e., the outer circumferential surface of the fixing end cap 8 may not protrude from the outer circumferential surface of the screw sleeve 7.

Mode three: referring to fig. 7 and 9, the outer end of the screw sleeve 7 is provided with a clamping groove 72; the pump shaft 3 is provided with a key groove 32 which can correspond to the clamping groove 72. The anti-rotation key pin 9 is installed in the catching groove 72 and the key groove 32 to prevent the rotation of the screw sleeve 7. The outside of the swivel nut 7 is provided with a fixed end cover 8 for blocking the clamping groove 72, and the anti-rotation key pin 9 is prevented from falling off from the clamping groove 72. The clamping groove 72 is a groove formed on the inner wall of the screw sleeve 7, namely, the clamping groove 72 only forms an opening on the end face of the outer side end of the screw sleeve 7, and does not form an opening on the outer circular surface of the outer side end of the screw sleeve 7, and the whole outer circular surface of the screw sleeve 7 is not provided with the opening of the clamping groove 72, see the structure shown in fig. 7. At this time, the key groove 32 is a bar-shaped key groove extending in the axial direction of the pump shaft 3. When the sleeve 7 is screwed into place, referring to fig. 9, the outer end of the bar-shaped key groove 32 (i.e., the left end of the key groove 32 in fig. 9) forms a distance H with the outer end of the sleeve 7 (i.e., the left end of the sleeve 7 in fig. 9) that is sufficient to ensure insertion of the anti-rotation key pin 9. During installation, the anti-rotation key pin 9 is inserted into the key slot 32 from the distance H, and the anti-rotation key pin 9 is pushed transversely, namely, the anti-rotation key pin 9 is pushed rightwards in fig. 9 until the upper end of the anti-rotation key pin 9 is accommodated in the clamping groove 72, and then the clamping groove 72 is blocked by using the fixed end cover 8 to be tightly attached to the outer side end of the screw sleeve 7 (namely, the left side end of the screw sleeve 7 shown in fig. 9) and fixed, so that the anti-rotation key pin 9 is prevented from falling off. At this time, the catching groove 72 may just receive the upper end of the rotation preventing key pin 9, i.e., the upper end of the rotation preventing key pin 9 does not shake in the catching groove 72. The fixing end cap 8 may be fixed to the threaded sleeve 7 by a screw or the like, and any other known fixing method may be used, for example: the joint of the fixed end cover 8 and the screw sleeve 7 adopts the modes of spot welding and the like. When the fixed end cover 8 and the screw sleeve 7 are fixed by adopting a screw mode, the screw penetrates through the fixed end cover 8 and then is connected with the end face of the outer side end of the screw sleeve 7, namely, the axial direction of the screw is parallel to the axial direction of the pump shaft 3.

Further, the number of the key grooves 32 and the locking grooves 72 in the second mode and the third mode may be plural, and the number of the key grooves 32 and the locking grooves 72 may be selected according to the need, so as to enhance the strength of preventing the rotation of the screw sleeve 7.

To sum up, the fastening force generated by the threaded fit of the threaded sleeve 7 and the pump shaft 3 is a source of axial pressure of the impeller 2, an inner spigot groove can be formed in the threaded sleeve 7 provided by the embodiment, an inner thread 71 is formed on the inner spigot groove, and a section of outer thread is formed on the pump shaft 3. During installation, the screw sleeve 7 is sleeved on the pump shaft 3, the screw sleeve 7 is moved to the position where the external threads are arranged on the pump shaft 3, the screw sleeve 7 is screwed, so that the internal threads of the internal spigot grooves of the screw sleeve 7 are in threaded fit with the external threads arranged on the pump shaft 3, and therefore axial pressure is generated to squeeze the shaft sleeve 6. In addition, the anti-rotation key pin 9 is adopted to stop rotation of the screw sleeve 7, so that the problems existing in the prior art in a double-bolt mode are well solved.

The assembly of the impeller 2 of the present utility model will now be further combed, the description of which is given by way of example only, and which has been chosen or combined to facilitate a complete description, but which is not limiting of the embodiments of the present utility model, and which describes the mounting and fastening of the impeller 2 by way of example only.

Referring to fig. 1, the impeller 2 is fitted around the pump shaft 3 by passing the pump shaft 3 through the center hole of the impeller 2, and the impeller 2 is fixedly connected by the flat key 21. And 2 shaft sleeves 6 are respectively sleeved on the pump shaft 6 from the left side and the right side of the impeller 2. After the sleeve 6 is sleeved, two threaded sleeves 7 are sleeved on the pump shaft 3 from the left side and the right side, the threaded sleeves 7 are moved, and when the threaded sleeves 7 move to external threads arranged on the pump shaft 3, the threaded sleeves 7 are screwed, so that internal threads of the threaded sleeves 7 are matched with the external threads arranged on the pump shaft 3. After the screw sleeve 7 contacts with the shaft sleeve 6, the clamping groove 72 formed on the screw sleeve 7 corresponds to the key groove 32 formed on the pump shaft 3. The anti-rotation key pin 9 is taken, and the anti-rotation key pin 9 passes through the clamping groove 72 on the screw sleeve 7 and is arranged in the key groove 32 formed on the pump shaft 3. And then taking the fixed end cover 8, sleeving the fixed end cover 8 on the pump shaft 3, and axially moving the fixed end cover 8 towards the screw sleeve 7, so that the fixed end cover 8 is sleeved at the outer side end of the screw sleeve 7, and at the moment, the fixed end cover 8 covers the clamping groove 72 and the anti-rotation key pin 9 which are formed in the screw sleeve 7. And then the screw is taken out, the fixed end cover 8 is fixed on the outer end surface of the screw sleeve 7, namely, the screw penetrates through the outer end surface of the fixed end cover 8 and then is connected with the outer end surface of the screw sleeve 7, and the axial direction of the screw is parallel to the axial direction of the pump shaft 3.

When the middle-open centrifugal pump works, the screw sleeve 7 is stopped by the anti-rotation key pin 9, namely, the screw sleeve 7 cannot rotate relative to the pump shaft 3, so that the screw sleeve 7 cannot move along the axial direction of the pump shaft 3, the pressing limiting effect of the screw sleeve 7 on the shaft sleeve 6 is ensured, and the limiting effect of the shaft sleeve 6 on the impeller 2 is further ensured.

In summary, the utility model provides a middle-open centrifugal pump, which does not need to press a shaft sleeve 6 with great force, well solves the problems that in the prior art, double nuts are easy to bend and deform a pump shaft, so that the perpendicularity error between an impeller and the center line of a pump body is large, and further, the assembly is difficult, and the two nuts are twisted and tightly influenced by human factors during the assembly, so that the safety and the reliability are poor, and is beneficial to popularization and application.

In the present utility model, the terms "connected," "fixed," and the like should be construed broadly unless otherwise specifically indicated and defined. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the description of the present specification, the terms "embodiment" or "manner a" and the like refer to a particular feature, structure, or characteristic described in connection with the embodiment or example being included in at least one embodiment or example of the present utility model. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

While embodiments of the present utility model have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the utility model, and that alterations, modifications, substitutions and variations may be made in the above embodiments by those skilled in the art within the scope of the utility model.

Claims (10)

1. A middle-open centrifugal pump comprises an impeller (2), a pump shaft (3) and a shaft sleeve (6); the impeller (2) and the shaft sleeve (6) are sleeved on the pump shaft (3); the shaft sleeves (6) are positioned on two sides of the impeller (2), and are characterized in that: a threaded sleeve (7) is correspondingly arranged on the outer side of one or two shaft sleeves (6), and the threaded sleeve (7) is in threaded fit with the pump shaft (3) and axially extrudes the corresponding shaft sleeve (6);

and the anti-rotation key pin (9) is used for limiting the rotation of the screw sleeve (7).

2. A split centrifugal pump as defined in claim 1, wherein: the anti-rotation key pin (9) is connected with the threaded sleeve (7) and the pump shaft (3).

3. A split centrifugal pump as defined in claim 2, wherein: an anti-rotation through hole (73) is formed in the screw sleeve (7), and a pump shaft hole (33) which can correspond to the anti-rotation through hole (73) is formed in the pump shaft (3); the anti-rotation key pin (9) penetrates through the anti-rotation through hole (73) and then stretches into the pump shaft hole (33), and the anti-rotation key pin (9) is in threaded fit with the anti-rotation through hole (73) and/or the pump shaft hole (33).

4. A split centrifugal pump as claimed in claim 3, wherein: the anti-rotation key pin (9) is in threaded fit with the anti-rotation through hole (73) or the pump shaft hole (33); the pump shaft hole (33) or the anti-rotation through hole (73) which is not in threaded fit with the anti-rotation key pin (9) is a bar-shaped hole.

5. A split centrifugal pump as claimed in claim 3 or 4, wherein: the number of the anti-rotation through holes (73) and the pump shaft holes (33) is plural.

6. A split centrifugal pump as defined in claim 2, wherein: the outer side end of the screw sleeve (7) is provided with a clamping groove (72); a key groove (32) which can correspond to the clamping groove (72) is formed in the pump shaft (3); an anti-rotation key pin (9) is arranged in the clamping groove (72) and the key groove (32) so as to prevent the screw sleeve (7) from rotating; the outside of swivel nut (7) is provided with and is used for shutoff fixed end cover (8) of draw-in groove (72), prevents anti-rotation key round pin (9) follow in draw-in groove (72) drops.

7. A split centrifugal pump as defined in claim 6, wherein: the clamping groove (72) is a notch; the fixed end cover (8) is sleeved at the outer side end of the screw sleeve (7) and covers the clamping groove (72).

8. A split centrifugal pump as defined in claim 7, wherein: the key groove (32) or the clamping groove (72) is of a strip-shaped structure.

9. A split centrifugal pump as defined in claim 6, wherein: the clamping groove (72) is a groove formed in the inner wall of the screw sleeve (7); the key groove (32) is a bar-shaped key groove extending along the axial direction of the pump shaft (3); the fixed end cover (8) is tightly attached to the outer side end of the screw sleeve (7) to seal the clamping groove (72).

10. A split centrifugal pump as claimed in any one of claims 6 to 9, wherein: the number of the clamping grooves (72) and the number of the key grooves (32) are plural.