CN212079919U

CN212079919U - Intermediate rod floating connection structure

Info

Publication number: CN212079919U
Application number: CN202020778276.3U
Authority: CN
Inventors: 张顺平; 李奎; 雷文刚; 符义红; 王磊; 杜倪鹏
Original assignee: Chongqing Pump Industry Co Ltd
Current assignee: Chongqing Pump Industry Co Ltd
Priority date: 2020-05-12
Filing date: 2020-05-12
Publication date: 2020-12-04
Anticipated expiration: 2030-05-12

Abstract

The utility model relates to an intermediate rod floating connection structure, which comprises a crosshead and an intermediate rod, wherein the opposite ends of the crosshead and the intermediate rod are connected; the outer circumferential surface of the intermediate rod is convexly provided with a convex edge, the intermediate rod is connected with the crosshead through a fastener, the fastener is fixedly connected with the crosshead, one end of the fastener, facing the intermediate rod, is provided with a limiting plate, the intermediate rod penetrates through the limiting plate through a mounting hole formed in the limiting plate, the end face of the intermediate rod is abutted to the crosshead, the convex edge is located at one end, facing the crosshead, of the limiting plate, an elastic element is sleeved on an intermediate rod section between the convex edge and the limiting plate, and the elastic element is compressed between the convex edge and the limiting plate so as to keep the intermediate rod abutted to the crosshead through; the elastic elements and the installation holes are provided with circumferential gaps with the corresponding intermediate rod sections so that the intermediate rods have spaces for radial floating. In this scheme, the jie pole can float automatically and adjust its geometric centre and coincide rather than the geometric centre of sealing member mutually, keeps the axiality of both to guarantee sealed effect promotes relevant part life.

Description

Intermediate rod floating connection structure

Technical Field

The utility model belongs to the technical field of pump in the liquid varactor formula machinery, concretely relates to jie pole connection structure that floats.

Background

The reciprocating pump has wide application, the structural principle is mostly a crank link mechanism, and a motor of the reciprocating pump drives a crankshaft in a transmission box body to rotate through a speed reducing mechanism; the crank of the crankshaft is rotatably connected with the front end of a connecting rod, the rear end of the connecting rod is rotatably connected with a crosshead, the crosshead is connected with an intermediate rod, and the intermediate rod is connected with a plunger (part of the intermediate rod is directly connected with the plunger); when the crankshaft rotates, the connecting rod pushes the crosshead to do reciprocating linear motion in the slideway of the transmission box body, and the crosshead drives the intermediate rod and the plunger to do reciprocating linear motion to pump fluid.

In which a seal (gasket or gasket) is installed between the outer circumferential surface of the intermediate rod (which may be understood as a plunger when of unitary construction) and the reciprocating channel (usually provided for the stuffing box). In the pump use, hope that the jie bar has certain automatic aligning ability under some operating modes, because the reason of part machining error, assembly error or operation back sealing member wearing and tearing, probably cause the phenomenon that jie bar geometric centre and sealing member geometric centre do not coincide to lead to the sealing of jie bar not tight, sealed effect receives the influence. But the existing connecting structure of the intermediate rod and the crosshead basically has no self-adjusting function, and can be seen in figure 1, the connecting rod 1 and the crosshead 5 are rotatably assembled together through a small-head bushing 2 and a crosshead pin 3, and the crosshead 5 reciprocates along the axial direction of the crosshead slide way of a stand 4; the connecting end of the intermediate rod 8 (and the crosshead 5) is provided with a ring groove, a snap ring 6 with larger outer diameter is clamped in the ring groove, and the intermediate rod 8 is connected to the corresponding end of the crosshead 5 through a connecting nut 7; one end of the connecting nut 7 close to the crosshead 5 is in threaded connection with the crosshead 5, one end close to the intermediate rod 8 is buckled with the clamping ring 6 through the inward extending convex edge, the intermediate rod 8 can be tightly attached to the corresponding end of the crosshead 5 along with the screwing of the connecting nut 7, so that connection is realized, the sealing element 9 is sleeved on the intermediate rod 8 (between the intermediate rod 8 and a channel (not shown in the figure), is a flexible element and is limited by the channel, and the geometric center of the sealing element can change along with abrasion; the connection mode enables the intermediate rod 8 to move axially along with the crosshead 5, but the intermediate rod 8 has no freedom degrees in radial and circumferential directions, the coaxiality of the intermediate rod 8 and the sealing piece 9 cannot be automatically adjusted, eccentric abrasion of the sealing piece 9 can be caused, and the service life and the sealing effect are influenced.

In an actual pump product, the intermediate rod 8 is basically horizontally arranged, the intermediate rod reciprocates to cause abrasion at the contact part of the sealing element 9 and the intermediate rod 8, under the influence of the self weight of the intermediate rod 8 and processing or assembling factors, the geometric center of the intermediate rod 8 close to one end of the sealing element 9 deviates downwards, but the intermediate rod 8 close to one end of the crosshead 5 has no radial degree of freedom and cannot move, so that the geometric center of the intermediate rod 8 is not on an axis any more in the reciprocating motion process, but on a straight line forming a certain included angle with the axial direction, a certain included angle also exists between the corresponding geometric center and the sealing element 9, and the phenomena of untight sealing and short service life of the sealing element 9 are easy to occur through the use and the operation of the pump.

Disclosure of Invention

The above-mentioned not enough to prior art, the to-be-solved technical problem of the utility model is to provide a neutral rod connection structure that floats avoids the neutral rod can not effective automatically regulated and the problem of the axiality of sealing member, but gains automatic aligning, guarantees sealed effect and promotes life's effect.

In order to solve the technical problem, the utility model adopts the following technical scheme:

the intermediate rod floating connection structure comprises a crosshead and an intermediate rod, the crosshead and the intermediate rod can be respectively axially movably arranged in respective sliding channels, and the crosshead is connected with one opposite end of the intermediate rod; the outer circumferential surface of the intermediate rod is convexly provided with a convex edge, the intermediate rod is connected with the crosshead through a fastener, the fastener is fixedly connected with the crosshead, one end, facing the intermediate rod, of the fastener is provided with a limiting plate, the intermediate rod penetrates through the limiting plate through a mounting hole formed in the limiting plate, the end face of the intermediate rod is abutted to the crosshead, the convex edge is located at one end, facing the crosshead, of the limiting plate, an elastic element is sleeved on an intermediate rod section between the convex edge and the limiting plate, and the elastic element is compressed between the convex edge and the limiting plate to keep the intermediate rod abutted to the crosshead through acting force of the elastic element; and annular gaps are formed among the elastic elements, the mounting holes and the corresponding intermediate rod sections so that the intermediate rods have a space capable of floating in the radial direction.

Further perfecting the technical scheme, the end surface of the intermediate rod, which is abutted against the crosshead, is in a spherical form so as to reduce the contact area of the abutment, and the surface of the crosshead, which is correspondingly abutted against the end surface, is a plane.

Furthermore, the cross head is equipped with the connection counter bore towards the terminal surface recess of jie's pole, connects and has installed the cushion in the counter bore, the jie's pole towards the terminal surface butt of cross head one end in order to pass through cushion and cross head butt on the cushion.

Furthermore, an adjusting block is sleeved at one end, facing the crosshead, of the intermediate rod and abuts against the cushion block through the adjusting block, and the spherical surface is arranged on the end face, facing one end of the cushion block, of the adjusting block.

Further, the adjusting block is equipped with the cavity towards the terminal surface of idle rod one end, idle rod is in towards the one end butt of cross head in the cavity, the internal diameter of cavity with the external diameter on protruding edge corresponds and protruding edge falls into in the cavity, the oral area of cavity is less than protruding edge towards the terminal surface of limiting plate one end so that protruding edge contact compression elastic element.

Furthermore, an annular groove is formed in the outer circumferential surface of one end, facing the crosshead, of the intermediate rod, and a clamping ring is embedded in the annular groove and formed into the convex edge through the outer edge of the clamping ring.

Further, both ends of the outer edge of the retainer ring are respectively extended in the axial direction to form a widened portion so as to increase the contact area with the inner wall of the cavity.

Furthermore, the fastening piece comprises the limiting plate and a plurality of screws, the outer diameter of the limiting plate is larger than that of the connecting counter bore and covers the opening of the connecting counter bore, the plurality of screws are circumferentially arranged at intervals and axially penetrate through the limiting plate and fixedly connect the limiting plate to the crosshead, the connecting counter bore has a certain depth, the cushion block is arranged at the bottom of the connecting counter bore, and the elastic element, the clamping ring and the adjusting block are uniformly arranged in the connecting counter bore; an annular clearance is formed between the adjusting block and the inner side wall of the connecting counter bore so as to avoid the interference of the radial floating of the intermediate rod.

Further, the terminal surface of cross head be equipped with connect the coaxial counter bore of counter bore, connect the counter bore and set up in the diapire of counter bore, limiting plate and screw all are located in the counter bore.

Further, the elastic element is a combination of a plurality of butterfly springs.

Compared with the prior art, the utility model discloses following beneficial effect has:

1. the utility model discloses an intermediate lever connection structure that floats connects intermediate lever and cross head through the fastener, fastener towards the one end and the cross head fixed connection of cross head, the fastener is towards the resilience effort of limiting plate, elastic element and the protruding edge of intermediate lever through to the one end of intermediate lever, makes intermediate lever and cross head keep looks butt, simultaneously, still has the hoop clearance between elastic element and mounting hole and the corresponding intermediate lever section, reserves the space of radial float for the intermediate lever, realizes the unsteady connection of intermediate lever and cross head; like this, the one end that the jie pole leaned on the cross head can radial movement, no matter be part machining error, assembly error or the reason of operation back sealing member wearing and tearing, during operation, the jie pole can float automatically and adjust its geometric centre and sealing member geometric centre coincidence mutually, keeps the axiality of both to the sealed effect of guarantee promotes relevant part life.

2. The utility model discloses a jie's pole connection structure that floats, the floating movement of connection is nimble, and connection structure is compact succinct, and it is good to maintain maintainability, and the operation is used reliably and stably.

Drawings

FIG. 1 is a schematic view of a prior art connection structure of an intermediate rod and a crosshead in the background art;

FIG. 2 is a schematic structural diagram of an embodiment of a floating rod connection structure;

FIG. 3 is an enlarged view of a portion of the intermediate position of FIG. 2;

wherein, the connecting rod 1, the small-head bushing 2, the crosshead pin 3, the machine base 4, the crosshead 5, the clamping ring 6, the connecting nut 7, the intermediate rod 8 and the sealing element 9,

the connecting counter bore 51, the counter bore 52, the fastener 70, the limiting plate 71, the screw 72, the convex edge 81, the annular groove 82, the elastic element 10, the adjusting block 11 and the cushion block 12.

Detailed Description

The following describes the present invention in further detail with reference to the accompanying drawings.

Referring to fig. 2 and 3, the floating connection structure of the intermediate rod of the embodiment includes a crosshead 5 and an intermediate rod 8, where the crosshead 5 and the intermediate rod 8 are respectively axially movably disposed in their respective sliding channels, an outer diameter of the intermediate rod 8 is smaller than an inner diameter of its sliding channel (typically, a stuffing box), and a ring of flexible sealing member 9 is disposed between an outer circumferential surface of the intermediate rod 8 and an inner wall of its sliding channel, an outer side surface of the flexible sealing member 9 abuts against the inner wall of the sliding channel, an inner side surface of the flexible sealing member 9 abuts against the outer circumferential surface of the intermediate rod 8, the crosshead 5 is connected with one end of the intermediate rod 8, the other end of the crosshead 5 is also connected with a connecting rod 1, the connecting rod 1 is rotatably assembled with the crosshead 5 through a small-head bushing 2 and a pin 3, and the sliding channel of the crosshead 5 is provided by a; the outer circumferential surface of one end, facing the crosshead 5, of the intermediate rod 8 is convexly provided with a convex edge 81, the intermediate rod 8 is connected with the crosshead 5 through a fastener 70, the fastener 70 is fixedly connected with the crosshead 5, one end, facing the intermediate rod 8, of the fastener 70 is provided with a limit plate 71, one end, facing the crosshead 5, of the intermediate rod 8 passes through a limit plate 71 through a mounting hole formed in the limit plate 71 and abuts against the crosshead 5 through the end surface of the limit plate, the convex edge 81 is located at one end, facing the crosshead 5, of the limit plate 71, namely between the crosshead 5 and the limit plate 71, an elastic element 10 is sleeved on a rod section between the convex edge 81 and the limit plate 71, and the elastic element 10 is compressed between the convex edge 81 and the limit plate 71 to keep the intermediate rod 8 and the crosshead 5 abutted; the elastic element 10 and the installation hole have a circumferential clearance with the corresponding intermediate rod section so that the intermediate rod 8 has a space with radial floating, namely, during machining, the inner hole of the elastic element 10 and the inner diameter of the installation hole are both larger than the diameter of the corresponding intermediate rod section, and the larger quantity value meets the specific design requirement so as to ensure the circumferential clearance and the radial floating quantity of the intermediate rod 8.

The idle rod floating connection structure of the embodiment connects the idle rod 8 and the crosshead 5 through the fastener 70, but only one end of the fastener 70 facing the crosshead 5 is fixedly connected with the crosshead 5, and the fastener 70 facing one end of the idle rod 8 passes through the limit plate 71, the elastic element 10 and the resilience acting force of the convex edge 81 of the idle rod 8, so that the idle rod 8 is kept in contact with the crosshead 5, and when the idle rod floating connection structure operates, no matter the crosshead 5 moves towards the idle rod 8 (pushes the idle rod 8) or the crosshead 5 moves towards the connecting rod 1 (pulls the idle rod 8), no clearance type impact affecting the service life of the idle rod 8 is caused, meanwhile, an annular clearance is formed between the elastic element 10 and the mounting hole and the corresponding idle rod section, a radial floating space is reserved for the idle rod 8, and the floating connection of the idle rod 8 and the crosshead 5 is realized; like this, it can radial movement to decide pole 8 to lean on the one end of cross head 5, no matter be part machining error, assembly error or the reason of operation back sealing member 9 wearing and tearing, during operation, it can automatic float and adjust its geometric centre and the coincidence of sealing member 9 geometric centre to decide pole 8, keeps the axiality of both to the sealed effect of guarantee promotes relevant part life.

In practice, the outer diameter of the protruding edge 81 is preferably larger than the inner diameter of the mounting hole, so that the intermediate rod 8 can still be driven to reciprocate when the crosshead 5 reciprocates even without mounting the elastic element 10, the floating function is not affected, but the elastic element 10 can keep the intermediate rod 8 in contact with the crosshead 5, and the situation that the crosshead 5 drives the intermediate rod 8 to reciprocate every time to cause impact and reduce the service life of the intermediate rod and the crosshead 5 is avoided, so that the elastic element 10 is also necessary to be mounted selectively. Regarding the specific form of the fastening member 70, the space of the pump can be designed according to the needs, for example, the coupling nut 7 in fig. 1 can also be used as the fastening member 70 of the present technical solution, only a shoulder step needs to be provided on the crosshead 5 for the end surface to abut when the coupling nut 7 is screwed, rather than fastening the intermediate rod 8 to achieve screwing; for the compact and indirect structure of the present technical solution, different forms of the fastening member 70 are adopted, please refer to the following analysis and description.

Wherein, the end surface of the intermediate rod 8 which is abutted with the crosshead 5 is in a spherical form so as to reduce the contact area of the abutment.

Like this, through reducing the area of contact of jie's pole 8 and cross head 5 looks butt, pressure is unchangeable and area of contact reduces, can reduce frictional force, does benefit to the removal of jie's pole 8 automatic floating adjustment its geometric centre, avoids causing the flexibility ratio of floating to be restricted because of frictional force is too big.

Wherein, cross head 5 is equipped with the connection counter bore 51 towards the terminal surface recess of jie pole 8, installs cushion 12 in the connection counter bore 51, and the preferred alloy structure steel of cushion 12, hardness is high, and cushion 12 is the plane towards outside terminal surface, and jie pole 8 is in order to pass through cushion 12 and cross head 5 looks butt on the cushion 12.

Thus, although the end surface of the intermediate lever 8 abutting against the crosshead 5 is a spherical surface, theoretically, it becomes a point contact, and the pressure at the point contact position becomes large, and the contact stress is large, but the problem that the crosshead 5 is damaged due to excessive stress can be prevented by using a special spacer 12 for bearing, rather than directly contacting the crosshead 5; the service life is prolonged; the cushion block 12 belongs to a quick-wear part and can be maintained and replaced when necessary, as shown in the figure, the outward end surface of the cushion block 12 is a plane and is provided with a countersunk head threaded hole, namely, when the cushion block 12 is convenient to replace, the cushion block is connected with the countersunk head threaded hole through a tool so as to be taken out, and the maintenance and the replacement are convenient.

Wherein, the end of the intermediate rod 8 facing the crosshead 5 is sleeved with a cylindrical adjusting block 11 and abuts against the cushion block 12 through the adjusting block 11, the adjusting block 11 is preferably alloy structural steel, and the spherical form is arranged on the end face of the adjusting block 11 facing one end of the cushion block 12. When the intermediate rod 8 floats in the radial direction, the adjusting block 11 and the intermediate rod 8 move synchronously, so that the advantages of small friction force and convenience in floating are kept.

Thus, the service life is further prolonged; the adjusting block 11 belongs to a wearing part and can be maintained and replaced when necessary. Certainly, the contact between the adjusting block 11 and the cushion block 12 is not absolutely rigid, but is elastically deformed, the point contact is actually a circular area, and the point contact is not easy to damage, and the contact part between the cushion block 12 and the adjusting block 11 is certainly yielding, so that the functional effect of the technical scheme is not influenced.

Wherein, the terminal surface of adjusting block 11 orientation idle rod 8 one end is equipped with the cavity, idle rod 8 is in towards the one end butt of cross head 5 in the cavity (be plane butt each other, the sphere form has been arranged on adjusting block 11), the internal diameter of cavity with protruding external diameter along 81 corresponds and protruding along 81 falls into in the cavity, the oral area of cavity is less than protruding along 81 towards the terminal surface of limiting plate 71 one end (axial epirelief is along the terminal surface protrusion in the oral area of cavity of 81 orientation limiting plate 71 one end) so that protruding along 81 contact compression elastic element.

Therefore, when the intermediate rod 8 is effectively kept to float in the radial direction, the adjusting block 11 and the intermediate rod 8 move synchronously, and the connection reliability is good.

Referring to fig. 3, an annular groove 82 is formed on an outer circumferential surface of an end of the intermediate rod 8 facing the crosshead 5, and a snap ring 6 is embedded in the annular groove 82 and is formed as the convex edge 81 by an outer edge of the snap ring 6.

Therefore, the processing and the installation are convenient, and the snap ring 6 is also a quick-wear part, which is beneficial to the replacement during the maintenance.

Wherein, the two ends of the outer edge of the snap ring 6 respectively extend along the axial direction to form a widened part so as to increase the contact area with the inner wall of the cavity. Wherein, a clearance is arranged between the end surface facing the widened part in the cavity and the bottom wall of the cavity so as to prevent the clamping ring 6 from being impacted when the crosshead 5 drives the intermediate rod 8 to and fro each time.

Therefore, the contact area between the inner wall of the cavity and the inner wall of the cavity is widened, so that the connection stability and reliability can be further improved, and the movement synchronism is guaranteed.

The fastening piece 70 comprises a limiting plate 71 and a plurality of screws 72, the outer diameter of the limiting plate 71 is larger than that of the connecting counterbore 51 and covers the opening of the connecting counterbore 51, the plurality of screws 72 are circumferentially arranged at intervals and axially penetrate through the limiting plate 71 to fixedly connect the limiting plate 71 to the crosshead 5, the connecting counterbore 51 has a certain depth, the cushion block 12 is arranged at the bottom of the connecting counterbore 51, and the elastic element, the clamping ring 6 and the adjusting block 11 are uniformly arranged in the connecting counterbore 51; the adjusting block 11 and the inner side wall of the connecting counterbore 51 have annular clearance therebetween to avoid interference with radial floating of the intermediate rod 8.

Therefore, the compactness of the structure is improved, the connection structure is prevented from being exposed, the integrity is better, and the connection stability and reliability can be correspondingly improved.

The end face of the crosshead 5 is provided with a counter bore 52 coaxial with the connecting counter bore 51, the connecting counter bore 51 is arranged on the bottom wall of the counter bore 52, and the limiting plate 71 and the screw 72 are both located in the counter bore 52 (connected to the bottom wall of the counter bore 52). Therefore, the end surfaces of the cross heads 5 are not exposed in related connection, the structure is compact and indirect, and the design of the space in the pump is facilitated. In practice, the inner side wall section of the connecting counter bore 51 between the limiting plate 71 and the cushion block 12 is provided with a wear-resistant bushing, the elastic element, the clamping ring 6 and the adjusting block 11 are also positioned in the wear-resistant bushing, and the wear-resistant bushing belongs to a wearing part and can be repaired and replaced.

Wherein, the elastic element 10 is a combination of several butterfly springs.

Therefore, the elastic element 10 is reliable in work and action, and can flexibly process the contact positions (radial directions) of the two ends with the limiting plate 71 and the convex edge 81 respectively by combining a back-to-back continuous connection mode of the butterfly springs, and the design values of the inner diameter of the mounting hole and the diameter of the convex edge 81 can be more flexible in design.

In operation, in the floating connection structure of the intermediate rod in this embodiment, the connection section between the intermediate rod 8 and the crosshead 5 belongs to a flexible active link, and is free in five degrees of freedom (except the axial direction). The whole intermediate rod 8 is completed by a guide sleeve with a sealing member 9 downwards overcoming the self gravity, and the intermediate rod 8 is deviated along with the guide sleeve when the geometric center is deviated after the sealing member 9 is worn because the guide sleeve is assembled with the sealing member 9. In the reciprocating motion process, the geometric center of the intermediate rod 8 coincides with the geometric center of the sealing element 9 at any time, and the sealing failure phenomenon caused by the inconsistency of the centers can not occur.

The intermediate rod floating connection structure of the embodiment has the following advantages:

1. in the reciprocating motion process of the intermediate rod 8, the motion center of the intermediate rod is always consistent with the center of the sealing position of the sealing element 9, and the sealing reliability of the intermediate rod is ensured.

2. The center of the intermediate rod 8 is automatically adjusted according to the change of the center of the sealing position of the sealing element 9.

3. The coaxiality of the intermediate rod 8 and the sealing element 9 in the movement process is greatly ensured.

4. The service life of the sealing element 9 and the intermediate rod 8 is prolonged, the sealing effectiveness is ensured, and the operation cost and the maintenance cost are reduced.

Finally, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the present invention can be modified or replaced by other means without departing from the spirit and scope of the present invention, which should be construed as limited only by the appended claims.

Claims

1. The intermediate rod floating connection structure comprises a crosshead and an intermediate rod, the crosshead and the intermediate rod can be respectively axially movably arranged in respective sliding channels, and the crosshead is connected with one opposite end of the intermediate rod; the method is characterized in that: the outer circumferential surface of the intermediate rod is convexly provided with a convex edge, the intermediate rod is connected with the crosshead through a fastener, the fastener is fixedly connected with the crosshead, one end, facing the intermediate rod, of the fastener is provided with a limiting plate, the intermediate rod penetrates through the limiting plate through a mounting hole formed in the limiting plate, the end face of the intermediate rod is abutted to the crosshead, the convex edge is located at one end, facing the crosshead, of the limiting plate, an elastic element is sleeved on an intermediate rod section between the convex edge and the limiting plate, and the elastic element is compressed between the convex edge and the limiting plate to keep the intermediate rod abutted to the crosshead through acting force of the elastic element; and annular gaps are formed among the elastic elements, the mounting holes and the corresponding intermediate rod sections so that the intermediate rods have a space capable of floating in the radial direction.

2. The intermediate rod floating connection structure of claim 1, wherein: the end face of the intermediate rod, which is abutted to the crosshead, is in a spherical form so as to reduce the contact area of the abutment.

3. The intermediate rod floating connection structure of claim 2, wherein: the cross head is equipped with the connection counter bore towards the terminal surface recess of jie's pole, connects and has installed the cushion in the counter bore, the jie's pole towards the terminal surface butt of cross head one end in order to pass through cushion and cross head butt on the cushion.

4. The intermediate rod floating connection structure of claim 3, wherein: one end of the intermediate rod facing the crosshead is sleeved with an adjusting block and is abutted to the cushion block through the adjusting block, and the spherical surface is arranged on the end face of the adjusting block facing one end of the cushion block.

5. The intermediate rod floating connection structure of claim 4, wherein: the adjusting block is equipped with the cavity towards the terminal surface of idle rod one end, idle rod is in towards the one end butt of cross head in the cavity, the internal diameter of cavity with the external diameter on protruding edge corresponds and protruding edge falls into in the cavity, the oral area of cavity is less than protruding edge towards the terminal surface of limiting plate one end so that protruding edge contact compression elastic element.

6. The intermediate rod floating connection structure of claim 5, wherein: an annular groove is formed in the outer circumferential surface of one end, facing the crosshead, of the intermediate rod, a clamping ring is embedded in the annular groove, and the convex edge is formed by the outer edge of the clamping ring.

7. The intermediate rod floating connection structure of claim 6, wherein: the two ends of the outer edge of the clamping ring extend along the axial direction to form widened parts so as to increase the contact area with the inner wall of the cavity.

8. The intermediate rod floating connection structure of claim 7, wherein: the fastening piece comprises a limiting plate and a plurality of screws, the outer diameter of the limiting plate is larger than that of the connecting counter bore and covers the opening of the connecting counter bore, the plurality of screws are circumferentially arranged at intervals and axially penetrate through the limiting plate and fixedly connect the limiting plate to the crosshead, the connecting counter bore has a certain depth, the cushion block is arranged at the bottom of the connecting counter bore, and the elastic element, the clamping ring and the adjusting block are uniformly arranged in the connecting counter bore;

an annular clearance is formed between the adjusting block and the inner side wall of the connecting counter bore so as to avoid the interference of the radial floating of the intermediate rod.

9. The intermediate rod floating connection structure of claim 8, wherein: the terminal surface of cross head be equipped with connect the coaxial counter bore of counter bore, connect the counter bore and set up in the diapire of counter bore, limiting plate and screw all are located in the counter bore.

10. The intermediate rod floating connection structure of claim 1, wherein: the elastic element is a combination of a plurality of butterfly springs.