CN115853765A - High-temperature bellows pump - Google Patents

Abstract

The application provides a high-temperature bellows pump, which solves the technical problems that a valve core is easy to deform when the existing bellows pump expands at high temperature, so that a gap is generated between a bellows and the valve core, and liquid leakage and even pump body scrapping are caused; the corrugated pipe type gas valve comprises a shell and a valve core arranged in the middle section of the shell, wherein corrugated pipes and push plates are arranged in two gas cavities enclosed by the shell and the valve core, and a connecting shaft is connected between the two push plates; an annular boss is arranged on the inner wall of the shell close to the valve core, the middle part of the connecting shaft penetrates through the annular boss and the valve core, and a shaft sleeve is arranged between the connecting shaft and the annular boss; an expansion space is formed between the part of the connecting shaft, which is at least matched with the valve core, and the valve core; an expansion guide component is arranged between the valve core and the shell. This application wide application is in bellows pump technical field.

Description

High-temperature bellows pump

Technical Field

The present disclosure relates to a bellows pump, and more particularly, to a bellows pump for high temperature.

Background

The bellows pump is a pump that realizes liquid transfer by stretching and contracting a bellows. The existing bellows pump generally comprises a shell, a valve core, two bellows and two push plates, wherein two bellows are connected to two sides of the valve core respectively, the push plate is connected to the other side of the bellows, and the two push plates are connected through a connecting shaft penetrating through the valve core. An air cavity is formed between the shell and the push plate, and the interior of the corrugated pipe is communicated with the pipeline in the valve core to form a liquid cavity. Compressed gas is alternately introduced into the two air cavities of the shell, and the push plate drives the corrugated pipe to extrude the liquid cavity in the pipe in a reciprocating manner under the driving of air pressure, so that liquid entering from the liquid inlet of the valve core is extruded from the liquid outlet of the valve core, and the function of conveying the liquid is realized in a continuous circulation manner.

Wherein, install the axle sleeve between connecting axle and the case, and for resisting chemical corrosion, the case usually adopts high temperature resistant, corrosion-resistant polytetrafluoroethylene material etc. and push pedal and connecting axle usually adopt stainless steel material. Under high temperature (especially 50-180 deg.C), the expansion rate of polytetrafluoroethylene material is much larger than that of stainless steel, and the difference of linear expansion rate is 10-20 times. After the valve core is heated and expanded, the shaft sleeve is driven to deviate, the combined body formed by the push plate and the connecting shaft expands very little, the center of the connecting shaft and the center of the shaft sleeve do not coincide any more, radial extrusion deformation is generated between the center of the connecting shaft and the center of the shaft sleeve, the surface deformation of the valve core is easily caused, so that a gap is generated between the corrugated pipe and the valve core, liquid leakage is caused, chemical liquid corrodes a pump body, and finally the corrugated pipe pump is scrapped.

Disclosure of Invention

In order to solve the above problems, the technical scheme adopted by the application is as follows: the bellows pump for high temperature comprises a shell and a valve core arranged in the middle section of the shell, wherein a bellows and a push plate are arranged in two air cavities enclosed by the shell and the valve core, and a connecting shaft is connected between the two push plates; an annular boss is arranged on the inner wall of the shell close to the valve core, the middle part of the connecting shaft penetrates through the annular boss and the valve core, and a shaft sleeve is arranged between the connecting shaft and the annular boss; an expansion space is formed between the part of the connecting shaft, which is at least matched with the valve core, and the valve core; an expansion guide assembly is arranged between the valve core and the shell.

Preferably, the expansion guide assembly comprises a positioning member and a guide groove respectively arranged on the opposite end surfaces of the valve core and the housing, and the positioning member can extend into the guide groove and move along the radial direction under the guidance of the guide groove.

Preferably, the positioning pieces protrude out of the end face of the valve core, are multiple in number, and are circumferentially and uniformly distributed by taking the central line of the valve core as the center of a circle; the guide grooves are recessed in the end face of the shell, the number of the guide grooves is multiple, and the straight line where the center lines of the guide grooves are located passes through the center line of the valve core.

Preferably, the positioning parts are distributed on one or more circles, and the centers of the one or more circles are all on the central line of the valve core.

Preferably, the valve is also provided with an adjusting shaft, and the adjusting shaft is movably arranged in an accommodating cavity formed in the valve core and the wall of the shell; the middle part of the adjusting shaft is positioned in the valve core, and the two ends of the adjusting shaft are positioned in the shell wall; the two ends of the adjusting shaft are both sleeved with elastic pieces in a compressed state, and one ends of the elastic pieces, which are close to the valve core, are abutted against the wall of the shell.

Preferably, an expansion space is formed between at least the part of the adjusting shaft, which is matched with the valve core, and the valve core.

Preferably, the adjusting shafts and the accommodating cavities are arranged in plurality and are circumferentially and uniformly distributed in the valve core and the wall of the housing.

Preferably, a shock absorption bracket with elasticity is arranged in the elastic part gap, and the shock absorption bracket can contract along with the compression of the elastic part and expand along with the extension of the elastic part.

Preferably, the valve core is made of polytetrafluoroethylene materials, and the surface of the shell is covered with a polytetrafluoroethylene film or is sprayed with a polytetrafluoroethylene coating.

The invention has the advantages that the shaft sleeve between the connecting shaft and the valve core is firstly moved to the shell with lower temperature and expansion rate, and an expansion space is arranged between the part of the connecting shaft, which is at least matched with the valve core, and the valve core, so that the mutual influence of the thermal expansion of the valve core, the connecting piece and the shaft sleeve under high temperature environment (especially under the condition of 50-180 ℃) is avoided through reasonable design, the center of the connecting shaft and the center of the shaft sleeve are always kept coincident, the condition of deformation of the surface of the valve core caused by extrusion is avoided, and the liquid leakage caused by the clearance between the corrugated pipe and the valve core is avoided. And then controlling the thermal expansion offset of the valve core in the X, Y and Z directions: (1) An expansion guide assembly is arranged between the valve core and the shell, the expansion guide assembly comprises a positioning piece and a guide groove which are respectively arranged on the opposite end surfaces of the valve core and the shell, the positioning piece can extend into the guide groove and move along the radial direction under the guide of the guide groove to control the radial (X and Y directions) thermal expansion offset of the valve core, so that the center of the expanded valve core is unchanged and always coincides with the action center of the corrugated pipe, and the liquid leakage caused by the gap between the valve core and the corrugated pipe is avoided. (2) The adjusting shaft is additionally arranged between the valve core and the shell to control the thermal expansion offset of the valve core in the axial direction (Z direction), when the valve core expands in the axial direction when being heated and retracts in a cooling mode, the elastic part in a compression state can always apply pressure to the shell to force the shell and the valve core to be always tightly combined, and the condition that a gap is generated to cause leakage and even a pump body is scrapped is avoided.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a schematic front view of a bellows pump of the present invention;

FIG. 2 is a left side view of the structure of FIG. 1;

FIG. 3 isbase:Sub>A cross-sectional view A-A of FIG. 1;

FIG. 4 is a cross-sectional view B-B of FIG. 1;

FIG. 5 is a cross-sectional view C-C of FIG. 1;

FIG. 6 is a cross-sectional view taken along line D-D of FIG. 2;

FIG. 7 is a schematic connection diagram of a connection shaft and a push plate;

fig. 8 is an enlarged view of fig. 6 at a.

The symbols in the drawings illustrate that:

1. a housing; 2. a valve core; 3. a bellows; 4. pushing the plate; 5. a connecting shaft; 6. an annular boss; 7. a shaft sleeve; 8. a positioning member; 9. a guide groove; 10. an adjustment shaft; 11. a first expansion space; 12. an elastic member; 13. an accommodating cavity; 14. blocking the platform; 15. a barrier structure; 16. an annular barrier; 17. a threaded connection; 18. a shock-absorbing support; 19. a second expansion space; 20. a cylindrical sleeve; 21. a damping sheet; 22. a left housing; 23. a right housing; 24. a shell; 25. an end cap; 26. a first seal ring; 27. a second seal ring; 28. an expansion guide assembly.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It is noted that, in the description of the present application, "a plurality" means two or more unless specifically defined otherwise.

The bellows pump for high temperature provided in the embodiment of the present application will now be described.

Referring to fig. 1 and fig. 3, which are schematic structural views of the bellows pump of this embodiment, the bellows pump for high temperature includes a housing 1 and a valve core 2 disposed at a middle section of the housing 1, a bellows 3 and a push plate 4 are disposed in two air cavities enclosed by the housing 1 and the valve core 2, and a connecting shaft 5 is connected between the two push plates 4; an annular boss 6 is arranged on the inner wall of the shell 1 close to the valve core 2, the middle part of the connecting shaft 5 penetrates through the annular boss 6 and the valve core 2, and a shaft sleeve 7 is arranged between the connecting shaft 5 and the annular boss 6; a first expansion space 11 is formed between the valve core 2 and at least the part of the connecting shaft 5 which is matched with the valve core 2.

In order to form the first expansion space 11 for the valve core 2 to be subjected to thermal expansion yielding, the valve core 2 and/or the connecting shaft 5 can be optionally treated, and preferably, the connecting shaft 5 is subjected to necking treatment, so that the expansion of the valve core 2 and the connecting shaft 5 is not influenced mutually. In addition, the shaft sleeve 7 moves to the shell 1 with the expansion rate similar to or the same as that of the connecting shaft 5, so that the probability of deformation of the connecting shaft 5 due to self expansion or expansion influence of other components can be reduced to the maximum extent. In addition, the shaft sleeve 7 is made of oil-free modified polytetrafluoroethylene resin with a low friction coefficient, the material has excellent wear resistance, and the defects are that the material is low in hardness and can expand when being heated, and the temperature of the shell 1 is far lower than that of the valve core 2, so that the expansion amount of the shaft sleeve 7 transferred to the shell 1 can be greatly reduced, and the performance of the bellows pump cannot be adversely affected.

Further, the gas injected into the gas cavity is cold dry compressed air, when the bellows 3 changes from rest to motion, the pressure of the injected gas is constant, the amount of the injected gas increases with the contraction of the bellows 3, the temperature of the cold dry compressed air is far lower than the temperature of the bellows 3 and other components inside the bellows pump, and the gas continuously absorbs the heat of the surrounding high-temperature environment along with the continuous injection and discharge of the gas, so that the purpose of cooling the housing 1 can be achieved. In a high-temperature environment, the temperature of the working corrugated pipe pump shell 1 is only 50-55 ℃, and the maximum temperature of the standby corrugated pipe pump shell 1 is not more than 60 ℃ (the room temperature is 23 +/-2 ℃). When the shaft sleeve 7 is arranged on the shell 1, the influence of thermal expansion can be effectively avoided, and under the environment of 60 ℃, the expansion amount of the shaft sleeve 7 is about 0.1-0.15mm, and the change amount can not generate adverse influence on the performance of the corrugated pipe pump.

In order to avoid the corrosion of the connecting shaft 5 by the external environment, the connecting shaft 5 needs to be isolated from the outside to avoid the corrosion. A first sealing ring 26 is arranged between the valve core 2 and the shell 1 outside the connecting shaft 5.

When high-temperature (especially 50-180 ℃) liquid continuously flows in the bellows pump, the temperature of the valve core 2 is gradually increased from the pipeline wall in the valve core 2, and the valve core 2 is gradually expanded when being heated. The valve core 2 is made of polytetrafluoroethylene materials, the whole valve core is of a flat cylindrical structure, and the thermal expansion coefficient and the thermal conductivity of the polytetrafluoroethylene are combined with the actual product structure to lead out the thermal expansion amount in each direction. In order to prevent the valve core 2 from being deformed by heat and causing the center of the valve core 2 to shift, please refer to fig. 4, which is a schematic B-B cross-sectional view of the bellows pump in fig. 1. An expansion guide assembly 28 is arranged between the valve core 2 and the shell 1, the expansion guide assembly 28 comprises a positioning piece 8 and a guide groove 9 which are respectively arranged on the opposite end surfaces of the valve core 2 and the shell 1, and the positioning piece 8 can extend into the guide groove 9 and move along the radial direction under the guide of the guide groove 9.

Furthermore, the positioning parts 8 protrude from two end faces of the valve core 2, are multiple in number, and are circumferentially and uniformly distributed by taking the central line of the valve core 2 as the center of a circle. Correspondingly, the guide grooves 9 are recessed in two end faces of the housing 1 opposite to the valve core 2, the number of the guide grooves is also multiple, and a straight line where the center line of the guide groove 9 is located passes through the center line of the valve core 2. In the process that the valve core 2 is heated and expanded, the positioning piece 8 can directionally move under the limitation of the guide groove 9, and the center of the valve core 2 is ensured to be always kept unchanged.

Furthermore, in consideration of the interference of other factors such as gravity, the positioning members 8 are distributed on one or more circles, and the centers of the one or more circles are all on the central line of the valve core 2.

Specifically, the positioning member 8 and the guide groove 9 of the present embodiment are all provided with six, and the length of the guide groove 9 is greater than or equal to the expansion amount. The positioning piece 8 is arranged on the valve core 2 according to the expansion amount under specific conditions, the radius of the positioning piece 8 positioned on the upper semicircle is R1, the radius of the positioning piece 8 positioned on the lower semicircle is R2, and the radii R1 and R2 are unequal, which is because the lower part of the valve core 2 is influenced by gravity or other conditions, and the stretching amounts of the upper part and the lower part are different.

When the valve core 2 is expanded, the positioning member 8 is limited by the two straight edges of the guide groove 9 and moves away from the center of the valve core 2 along the center line of the guide groove 9. Therefore, under the cooperation of the positioning piece 8 and the guide groove 9, the radial (X and Y directions) thermal expansion offset of the valve core 2 is controlled, so that even if the valve core 2 is not perfectly circular after expansion, the center of the valve core 2 can still be kept unchanged, namely, the valve core can be kept coincident with the action center of the corrugated pipe 3, and liquid leakage caused by a gap between the valve core 2 and the corrugated pipe 3 is avoided.

In order to reduce the friction influence when the valve core 2 moves, the valve core 2 is made of polytetrafluoroethylene materials, and the surface of the shell 1 is covered with a polytetrafluoroethylene film or sprayed with a polytetrafluoroethylene coating, so that the friction coefficient between the valve core and the shell is only about 0.03. Thus, the spool 2 can be slowly moved on the surface of the housing 1 with little influence of frictional force when thermal expansion occurs.

The following operating conditions generally exist due to the use of bellows pumps: (1) The device is arranged in other equipment to perform long-time high-temperature action and continuously convey liquid; (2) The installed equipment is stopped for a short time for various reasons, but the bellows pump is stopped but is continuously heated; (3) The installed equipment does not act for a long time, the bellows pump stops working for a long time, and the internal temperature is gradually reduced to the room temperature. The three working conditions are not independent, and various working conditions are continuous and cyclic, so that the bellows pump needs to be continuously converted under the working conditions of continuous high-temperature action, continuous high-temperature stop, continuous normal-temperature placement and the like, and when various working conditions are converted, the valve core 2 is continuously expanded and retracted, the fixed-distance type connection mode between the valve core 2 and the shell 1 cannot meet the requirements of variable working conditions, the connection part between the valve core 2 and the shell 1 is easily subjected to permanent deformation to generate leakage, and therefore, the control on the thermal expansion offset of the valve core 2 in the radial direction (X and Y directions) is insufficient.

Referring to fig. 1, 2, 4 to 6, in one embodiment, the thermal expansion offset in the axial direction (Z direction) is controlled, specifically, an adjusting shaft 10 is additionally arranged between the valve core 2 and the housing 1, and the adjusting shaft 10 is movably disposed in a receiving cavity 13 formed in the walls of the valve core 2 and the housing 1; the middle part of the adjusting shaft 10 is positioned in the valve core 2, and the two ends are positioned in the wall of the shell 1; a second expansion space 19 is formed between at least the part of the adjusting shaft 10, which is matched with the valve core 2, and the second expansion space 19 can be formed by referring to the first expansion space 11, which will not be described repeatedly. The two ends of the adjusting shaft 10 are all sleeved with elastic parts 12 in a compressed state, one end, far away from the valve core 2, of each elastic part 12 is connected with the adjusting shaft 10, one end, close to the valve core 2, of each elastic part 12 abuts against a blocking table 14 in the containing cavity 13, and the blocking table 14 is located in the wall of the shell 1. The connection between the elastic element 12 and the adjusting shaft 10 may be a fixed connection or a movable sleeve connection. And a blocking structure 15 is provided at the end of the adjustment shaft 10. Referring to fig. 8, the blocking structure 15 may be a combination of an annular blocking portion 16 and a threaded connection portion 17, the annular blocking portion 16 abuts against the distal end of the elastic member 12, and the threaded connection portion 17 is fixed to the adjusting shaft 10 through a threaded connection. The elastic element 12 can be any element capable of providing an axial elastic restoring force, when the valve core 2 expands axially when heated, the two side shells 1 are pushed to move towards the far end (away from the valve core 2), the shells 1 press the elastic elements 12 at the two ends of the adjusting shaft 10 through the stopping table 14, and the elastic elements 12 are compressed under force. At this time, the elastic member 12 can also give a reaction force to the housing 1, so that the housing 1 and the valve body 2 are tightly combined. When the valve core 2 is cooled and axially retracted, the restoring force of the elastic part 12 forces the shell 1 to move towards the near end (close to the valve core 2) along with the retraction of the valve core 2, so that the valve core 2 and the shell 1 are kept tightly combined, and the leakage caused by the generation of a gap is avoided.

In one embodiment, no gap exists to ensure that the end surfaces of the valve core 2 opposite to the shell 1 are tightly attached everywhere. The adjusting shafts 10 and the accommodating cavities 13 can be arranged in a plurality of numbers and are circumferentially and uniformly distributed in the walls of the valve core 2 and the shell 1. Referring to fig. 4 and 5, there are 4 adjusting shafts 10, and two adjusting shafts are provided at the upper and lower parts thereof; two connecting shafts 5 are arranged and oppositely arranged in the middle; the adjusting shaft 10, the connecting shaft 5 and the expansion guide assembly 28 are distributed in a staggered manner. Regarding the formation of the accommodating cavity 13, a transverse through hole is arranged in the valve core 2, the walls of the shell 1 at two sides of the valve core 2 are respectively provided with a groove hole corresponding to the transverse through hole, and the through hole and the two groove holes are combined to form the accommodating cavity 13. The stopping table 14 is a structure provided on the inner wall of the accommodating cavity 13 of the housing 1 portion, and may be a ring structure or a separate block structure.

In addition, when the bellows pump operates, the inside of the bellows pump is always impacted, and when the frequency of the impact force applied to the elastic member 12 is close to the natural frequency, a loud noise is generated. In one embodiment, a shock absorbing bracket 18 with elasticity is additionally arranged between the elastic members 12, and the shock absorbing bracket 18 can contract along with the compression of the elastic members 12 and expand along with the extension of the elastic members 12. The shock-absorbing support 18 generally comprises a cylindrical sleeve 20 and a shock-absorbing sheet 21 which is arranged outside the cylindrical sleeve 20 and has a shape matched with that of the elastic element 12, wherein the cylindrical sleeve 20 is sleeved with the adjusting shaft 10, and the shock-absorbing sheet 21 is inserted between each part of the elastic element 12, so that the elastic element 12 does not collide with each other to generate sound when vibrating.

Referring to fig. 8, the elastic member 12 is preferably a spring, and the damping pieces 21 of the damping bracket 18 are spiral damping pieces with shapes matched with those of the spring, and the spring is distributed among the spiral damping pieces. When the spring is in a compressed state, the spiral damping sheet is also pressed to be tightly attached to the spring, so that the spring is prevented from vibrating and generating noise. During assembly, the cylindrical sleeve 20 is sleeved on the adjusting shaft 10 according to the rotation direction of the spring, and then the spring is wound and distributed among the spiral shock absorbing pieces.

In order to facilitate assembly, the casing 1 comprises a left casing 22 and a right casing 23 which are oppositely arranged, the left casing 22 and the right casing 23 respectively comprise a shell barrel 24 and an end cover 25 which are provided with an annular boss 6, one end of the shell barrel 24 provided with a guide groove 9 is connected with the valve core 2, and the other end of the shell barrel 24 is connected with the end cover 25. In particular, the connection may be a fixed connection or a detachable connection. The detachable connection can adopt a bolt and other connection modes. Further, the inner diameter of the annular boss 6 matches the outer diameter of the corrugated tube 3. A second sealing ring 27 is arranged between the shell 24 and the end cover 25, the shape of the second sealing ring 27 is matched with that of the push plate 4, and the second sealing ring is positioned on the outer side of the push plate 4 to play a role in sealing the air cavity.

Regarding the position of the shaft sleeve 7, the end face of the shell 24 opposite to the end cover 25 is provided with a mounting hole, the shaft sleeve 7 is arranged in the mounting hole near one end of the end cover 25, the position is closest to the mass center of the corrugated pipe 3, the connecting shaft 5 and the push plate 4 when a rigid body (please refer to fig. 7) works, the position is closest to a stress point, and the bending stress of the connecting shaft 5 is reduced.

The invention firstly moves the shaft sleeve 7 between the connecting shaft 5 and the valve core 2 to the shell 1 with lower temperature and expansion rate, and an expansion space is arranged between the part of the connecting shaft 5, which is at least matched with the valve core 2, and the reasonable design avoids the mutual influence of the thermal expansion of the valve core 2, the connecting piece and the shaft sleeve 7 under high temperature environment (especially under the condition of 50-180 ℃), so that the center of the connecting shaft 5 and the center of the shaft sleeve 7 are always kept coincident, thereby avoiding the condition that the surface of the valve core 2 is deformed due to extrusion, and avoiding the liquid leakage caused by the clearance between the corrugated pipe 3 and the valve core 2. And then controlling the thermal expansion offset of the valve core 2 in the X, Y and Z directions: (1) An expansion guide assembly 28 is arranged between the valve core 2 and the shell 1, the expansion guide assembly 28 comprises a positioning piece 8 and a guide groove 9 which are respectively arranged on the opposite end surfaces of the valve core 2 and the shell 1, the positioning piece 8 can extend into the guide groove 9 and move along the radial direction under the guide of the guide groove 9, and the radial (X and Y directions) thermal expansion offset of the valve core 2 is controlled, so that the center of the expanded valve core 2 is unchanged and always coincides with the action center of the corrugated pipe 3, and the liquid leakage caused by the gap generated between the valve core 2 and the corrugated pipe 3 is avoided. (2) The adjusting shaft 10 is additionally arranged between the valve core 2 and the shell 1 to control the axial (Z-direction) thermal expansion offset of the valve core 2, when the valve core 2 expands axially when heated and contracts when cooled, the elastic part 12 in a compressed state can always apply pressure to the shell 1 to force the shell 1 and the valve core 2 to be always tightly combined, and the condition that the leakage and even the pump body is scrapped due to the generation of a gap is avoided.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the embodiments of the present application, and they should be construed as being included in the present application.

Claims (9)

1. A kind of high-temperature uses the bellows pump, including the body, valve core locating in the middle section of body, said body and two air cavities that the valve core encloses are equipped with bellows, push pedal, connect with the connecting axle between two said push pedals; the method is characterized in that: an annular boss is arranged on the inner wall of the shell body close to the valve core, the middle part of the connecting shaft penetrates through the annular boss and the valve core, and a shaft sleeve is arranged between the connecting shaft and the annular boss; an expansion space is formed between the part of the connecting shaft, which is at least matched with the valve core, and the valve core; an expansion guide assembly is arranged between the valve core and the shell.

2. A bellows pump for high temperature use according to claim 1, wherein: the expansion guide assembly comprises a positioning piece and a guide groove which are respectively arranged on the opposite end surfaces of the valve core and the shell, and the positioning piece can extend into the guide groove and move along the radial direction under the guidance of the guide groove.

3. A high temperature bellows pump as claimed in claim 2, wherein: the positioning pieces protrude out of the end face of the valve core, are multiple in number and are uniformly distributed in the circumferential direction by taking the central line of the valve core as the circle center; the guide grooves are recessed in the end face of the shell, the number of the guide grooves is multiple, and the straight line of the center line of each guide groove passes through the center line of the valve core.

4. A high temperature bellows pump as claimed in claim 3, wherein: the positioning pieces are distributed on one or more circles, and the centers of the circles are all on the central line of the valve core.

5. A bellows pump for high temperature use according to any one of claims 1 to 4, wherein: the valve core is movably arranged in the valve body, and the valve core is movably arranged in the valve body; the middle part of the adjusting shaft is positioned in the valve core, and two ends of the adjusting shaft are positioned in the shell wall; the two end parts of the adjusting shaft are sleeved with elastic pieces in a compressed state, and one end, close to the valve core, of each elastic piece abuts against the wall of the corresponding housing.

6. A high temperature bellows pump as claimed in claim 5, wherein: an expansion space is formed between the part of the adjusting shaft, which is at least matched with the valve core, and the valve core.

7. A high temperature bellows pump as claimed in claim 6, wherein: the adjusting shafts and the accommodating cavities are arranged in plurality and are circumferentially and uniformly distributed in the valve core and the shell wall.

8. A high temperature bellows pump as claimed in claim 5, wherein: and an elastic shock absorption support is arranged in the gap of the elastic piece, and can contract along with the compression of the elastic piece and expand along with the stretching of the elastic piece.

9. A high temperature bellows pump as claimed in claim 1, wherein: the valve core adopts polytetrafluoroethylene, and the surface of the shell is covered with a polytetrafluoroethylene film or sprayed with a polytetrafluoroethylene coating.

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