阅读说明：本技术 一种钻井泵中间法兰和机架连接结构 (Connecting structure for intermediate flange and frame of drilling pump ) 是由 黄秀芳 于 2021-08-26 设计创作，主要内容包括：本发明公开了一种钻井泵中间法兰和机架连接结构,涉及石油工程设备领域,具体涉及一种钻井泵中间法兰和机架连接结构,包括中间法兰、压板、M12螺栓、机架、O形密封圈,机架和中间法兰的相互位置要求高的定位面均一次性安装加工,精度高,机架和中间法兰用圆周上的O形密封圈密封,这样的一种钻井泵中间法兰和机架连接结构能够非常好地保证中间法兰的内孔的轴心线与机架的十字头滑道孔轴线高的同轴度精度,非常好地保证中间法兰的端面与机架的十字头滑道孔轴线高的垂直度精度,延长了中间杆密封圈寿命,避免了缸套腔的泥浆水渗透到十字头腔和十字头腔的润滑油渗透到缸套腔的老大难问题。(The invention discloses a connecting structure of a middle flange and a frame of a drilling pump, which relates to the field of petroleum engineering equipment, in particular to a connecting structure of a middle flange and a frame of a drilling pump, comprising a middle flange, a pressure plate, an M12 bolt, a frame and an O-shaped sealing ring, wherein the positioning surfaces with high requirements on the mutual positions of the frame and the middle flange are all installed and processed at one time, the precision is high, the frame and the middle flange are sealed by the O-shaped sealing ring on the circumference, the connecting structure of the intermediate flange and the rack of the drilling pump can well ensure the high coaxiality precision of the axis of the inner hole of the intermediate flange and the axis of the cross head slideway hole of the rack, well ensure the high verticality precision of the end surface of the intermediate flange and the axis of the cross head slideway hole of the rack, prolong the service life of the intermediate rod sealing ring, and avoid the long-standing problem that slurry water in a cylinder sleeve cavity permeates into the cross head cavity and lubricating oil in the cross head cavity permeates into the cylinder sleeve cavity.)

1. The utility model provides a drilling pump flange and frame connection structure, its characterized in that, flange (1), clamp plate (2), M12 bolt (3), frame (4), O shape sealing washer (5), lathe (6), boring cutter dish (7), boring cutter arbor (8), hole (1.1), terminal surface (1.2), edge (1.3), O-shaped groove (1.4), excircle (1.5), axial lead (1.6), cross head chamber (4.1), hole (4.3), cross head slide way hole (4.4), slide way hole axis (4.5), baffle (4.7), chamfer inclined plane (4.8), chamfer sword (7.1), boring cutter (7.2).

2. A drilling pump intermediate flange and frame connection according to claim 1, the mutual position requirements of the intermediate flange (1) being very high, the outer circle (1.5), the inner hole (1.1), the end face (1.2), the edge (1.3) and the O-shaped groove (1.4) of the intermediate flange (1) being mounted and processed in one step.

3. The connecting structure of the middle flange and the frame of the drill pump as claimed in claim 1, wherein the difference between the diameter of the crosshead slipway hole (4) of the frame (4) and the diameter of the positioning inner hole (4.3) for installing the middle flange is 14 to 16mm, a hole with high position precision of the frame of the drill pump can be processed by a machine tool (6), the boring cutter bar (8) belongs to a simply supported beam support under the bearing support of two ends of the machine tool (6) and has very good rigidity, the boring cutter head (7) is installed on the boring cutter bar (8), the hole cutter (7.2) and the chamfering cutter (7.1), the crosshead slipway hole (4.4), the inner hole (4.3) and the chamfering inclined plane (4.8) of the frame (4) are processed in one process, and the coaxiality precision of the crosshead slipway hole (4.4), the inner hole (4.3) and the chamfering inclined plane (4.8) of the frame (4) is ensured to be high.

4. The connecting structure of the middle flange and the rack of the drill pump as claimed in claim 1, wherein the middle flange (1) is mounted on the rack (4) in such a manner that the O-shaped sealing ring (5) is mounted in the O-shaped groove (1.4) of the middle flange (1), the outer circle (1.5) of the middle flange (1) is mounted in the inner hole (4.3) of the rack (4), the edge (1.3) of the middle flange (1) is in line contact with the chamfer inclined plane (4.8) of the rack (4), the outer circle (1.5) of the middle flange (1) is in clearance fit with the inner hole (4.3) of the rack (4), the clearance is 0-0.051 mm, the middle flange (1) is pressed by the pressing plate (2), and then 6M 12 bolts (3) are screwed into the screw holes of the partition plate (4.7) of the rack (4).

5. A drill pump mid-flange and frame attachment structure as claimed in claim 1, said M12 bolts (3) but not limited to such gauge bolts.

Technical Field

The invention relates to the field of petroleum engineering equipment, in particular to a connecting structure of a middle flange and a rack of a high-power drilling pump.

Background

Although the well drilling pump and the automobile motion mechanism belong to a crankshaft connecting rod mechanism, a connecting rod journal of a crankshaft is matched with a connecting rod big head hole, and the connecting rod performs plane motion to convert the rotary motion of the crankshaft into the linear motion of a piston, the connection method of a connecting rod small head and the piston is very different: the piston speed of the automobile is very high, the piston force is small, the small end of the connecting rod is directly connected with the piston, the piston has axial force, and the piston also has lateral pressure to the cylinder sleeve; the piston speed of the drilling pump is very low, the piston force is very large, the small end of the connecting rod of the drilling pump can not be directly connected with the piston, the distance between the center of the small end hole of the connecting rod of the high-power drilling pump above 2200hp and the connecting surface of the piston reaches more than 1150mm, the small end hole of the connecting rod is connected with a crosshead pin, the end surface of the crosshead is connected with an intermediate rod, the intermediate rod is connected with a piston rod, and the piston rod is connected with the piston, so that the design aims are as follows: the cross head transfers the lateral pressure of the piston to the cylinder sleeve to the lateral pressure of the cross head to the cross head slideway, and the piston only bears axial force, thereby prolonging the service life of the piston cylinder sleeve; the cylinder sleeve piston is convenient to replace. The drill pump housing is thus divided into a crosshead chamber and a cylinder jacket chamber. The crosshead cavity needs to lubricate friction pairs among a crankshaft, a connecting rod and a crosshead by using lubricating oil, the cylinder sleeve cavity adopts a water cooling method for a cylinder sleeve piston friction pair, wherein an intermediate rod connected with the crosshead and a piston rod moves between the crosshead cavity and the cylinder sleeve cavity, and in the structure, water (slurry exists in the crosshead cavity and the cylinder sleeve cavity, so that muddy water for short) and oil in the crosshead cavity and the cylinder sleeve cavity cannot leak mutually, so that an intermediate rod sealing structure must be designed between the two cavities.

But the life of the sealing ring of the intermediate rod is short, so that water (with slurry) in the cylinder sleeve cavity often permeates into the crosshead cavity to seriously pollute the lubricating oil, and the lubricating oil in the cross cavity also permeates into the cylinder sleeve cavity.

For the size of an inner hole of a middle rod sealing ring of a high-power drilling pump with the height of more than 2200hp between 100mm and 120mm, the size of an outer circle of a middle rod sealing ring seat is between 140mm and 160mm, a connecting hole between a cross head cavity and a cylinder sleeve cavity of a rack is not a whole circle and is a waist-shaped hole, so that a part is required to be arranged, the outer part of the part is matched with the waist-shaped hole of the rack, the inner hole is matched with the outer circle of the middle rod sealing ring seat, the end face of the part is matched with the end face of the middle rod sealing ring seat, the part is a middle flange, and the main function is to ensure that muddy water in the cylinder sleeve cavity cannot leak into the cross head cavity.

Through analysis, the service life of the sealing ring of the intermediate rod is short, and the important reason that the muddy water in the cylinder sleeve cavity permeates into the crosshead cavity and the lubricating oil in the crosshead cavity permeates into the cylinder sleeve cavity is that the lubricating oil is inappropriately related to the connection structure of the intermediate flange and the rack, so that the axial misalignment error between the inner hole of the intermediate flange and the inner hole of the crosshead slide way of the crosshead cavity is caused greatly, and the problem to be solved urgently is solved by designing the connection structure of the intermediate flange and the rack of the high-power drilling pump.

Disclosure of Invention

The invention aims to provide a connecting structure of a middle flange and a frame of a high-power drilling pump.

The technical scheme of the invention is as follows:

and analyzing the reason of large coaxiality error of the inner hole of the middle flange and the axis of the crosshead slide way hole of the crosshead cavity, and then taking corresponding countermeasures.

Firstly, the invention compares the coaxiality error of the inner hole of the middle flange and the axis of the crosshead slide way hole of the crosshead cavity with each other and analyzes the reason:

1. when processing contrast flange and intermediate lever seal ring seat complex hole and terminal surface, will contrast the big terminal surface of flange (do not have the machined surface) and contrast baffle (the baffle between frame cross chamber and the cylinder liner chamber) terminal surface (do not have the machined surface) with bolted connection together earlier, join in marriage on flange and the baffle terminal surface and make two location pinhole in contrast, pack into two pinhole with two locating pins, with the electric welding with two round pins with contrast flange welding together. The positioning of contrast intermediate flange and contrast frame belongs to six degrees of freedom of one-sided two round pin restriction, it is the X axle to establish contrast frame cross head slide axis, be the Z axle with contrast frame bottom surface vertical axis, contrast frame bent axle hole direction is the Y axle, two not terminal surfaces of processing and two locating pins restriction contrast intermediate flange's X axle, Y axle, Z axle move the degree of freedom, around the X axle, the rotation degree of freedom of Y axle, Z axle, wherein two not terminal surface restriction of processing are contrast intermediate flange's X axle move the degree of freedom, around the rotation degree of freedom of Y axle, Z axle. After processing contrast flange, need tear contrast flange open, contrast flange need add the sealing rubber circle of a 2mm thickness between contrast flange and baffle terminal surface when final assembly again, then with the bolt with contrast flange and contrast frame connection together.

The problem that the location exists like this, the contrast baffle terminal surface is the face that does not process, be thick reference surface, thick reference surface does not have the repeated locate function, in addition processing contrast flange does not add the rubber packing between contrast baffle and contrast flange, add the rubber packing during use, thick reference positioning error has more been increased, three degrees of freedom (restriction flange X axle removes the degree of freedom in the middle of the restriction during that the flange assembly is also compared (restriction flange X axle, around Y axle rotational freedom, around Z axle rotational freedom) and compare processing flange and add the change, cause contrast flange and the hole of middle pole seal receptacle complex and terminal surface position to have taken place the error.

2. The diameter of a cross head sliding channel hole for mounting the machine frame is large, the rigidity of the cutter bar is good, the cutter bar can be supported at two ends to form a simply supported beam structure, and the rigidity is good. The precision of processing the crosshead slide way hole is high.

3. The distance between the end face of the high-power drilling pump with the power of more than 2200hp and the end face of the middle flange matched with the middle rod sealing seat and the distance between the hole and the end face of the frame are at least more than 1000mm, the diameter of the middle flange matched with the diameter of the middle rod sealing seat matched hole is between 140mm and 160mm, the diameter of a cutter bar processed on the machine tool is limited and cannot be too large, the cutter bar needs to be extended outwards for a special length, the cutter bar belongs to an extending beam structure, the rigidity of the cutter bar is poor, the winding degree can occur, the vertical error between the processed and compared middle flange matched with the end face of the middle rod sealing seat and the axis of a crosshead slide way hole is large due to the winding degree of the cutter bar, and the coaxiality error between the processed and compared middle flange matched with the middle rod sealing seat and the axis of the crosshead slide way hole is large.

Due to the reasons, the error of the coaxiality of the axis of the crosshead slide way hole for comparing the inner hole of the middle flange with the crosshead cavity is large, and the error of the verticality of the axis of the crosshead slide way hole for comparing the matching end surface of the middle flange and the sealing ring seat of the middle rod is large.

Compared with the sealing between the end face of the middle flange and the partition plate, the end face sealing gasket is adopted in the invention, and the partition plate is a non-processing surface, so that the phenomenon that lubricating oil in the crosshead cavity leaks into the cylinder sleeve cavity is often caused when the sealing is not good.

The invention ensures the high coaxiality precision of the inner hole of the intermediate flange and the axis of the crosshead slide way hole of the crosshead cavity:

1. the connection of the intermediate flange and the frame is realized by matching the excircle of the intermediate flange with a hole processed on the partition plate, the hole limits four degrees of freedom of the intermediate flange, namely the Y-axis movement degree of freedom, the Z-axis movement degree of freedom, the rotation degree of freedom around the Y axis and the rotation degree of freedom around the Z axis of the intermediate flange, the hole processed on the partition plate is inverted by a small angle, the maximum diameter after chamfering is increased by 1mm than that of a positioning hole, the line contact is kept on the chamfer surface of the intermediate flange, only the X-axis degree of freedom of the intermediate flange is limited, and the rotation degree of freedom around the X axis is not limited.

2. The diameter difference of the cross head slide way mounting hole and the middle flange mounting hole of the rack is very small, so that the cutter bars supported by two ends can be used for processing at one time, and the cutter bars can be processed together with a very small angle. Thus, the coaxiality of the two holes and the chamfer angle on the frame is very high.

3. The holes and end faces of the middle flange and the frame positioning excircle and the middle flange and the middle rod sealing seat are processed under the condition of one-time installation, and the mutual position precision is very high.

By adopting the method, the coaxiality of the inner hole of the middle flange and the axis of the cross head slideway hole of the cross head cavity is high, and the method is very easy to ensure.

Because the coaxiality precision of the inner hole of the middle flange and the axis of the crosshead slide way hole of the crosshead cavity is high, and the additional force to the middle flange is very small when the middle rod moves, the middle flange and the partition plate can be fixed together by adding 6M 12 bolts to the middle flange pressing plate.

4. The plane seal between the intermediate flange and the frame is changed into an O-shaped sealing ring on the excircle of the intermediate flange matched with the hole on the partition plate, the O-shaped groove on the excircle of the intermediate flange and the hole on the partition plate are both precisely processed, and the sealing performance is very reliable. And the lubricating oil in the crosshead cavity is prevented from leaking into the cylinder sleeve cavity.

Drawings

FIG. 1 is a cross-sectional view of an intermediate flange;

FIG. 2 is a perspective view of the intermediate flange;

FIG. 3 is a sectional view of a connection structure of a middle flange and a frame of a high-power drilling pump;

FIG. 4-enlarged view of detail B of FIG. 3;

FIG. 5-schematic view of the machining of crosshead shoe bores and mid-flange mounting holes and chamfers;

FIG. 6-enlarged detail C of FIG. 5;

FIG. 7-compare mid-flange perspective;

FIG. 8-comparative mid-flange tooling holes and end cross-sectional views;

FIG. 9-enlarged detail D of FIG. 8;

FIG. 10-comparison of a cross-sectional view of a high power drill pump center flange and frame connection;

fig. 11-fig. 10 are enlarged views of detail E.

The reference numbers are as follows:

1-middle flange, 2-pressing plate, 3-M12 bolt, 4-frame, 5-O-shaped sealing ring, 6-machine tool, 7-boring cutter head, 8-boring cutter rod, 9-comparison middle flange, 10-boring cutter head, 11-machine tool main shaft, 12-machine tool main shaft box, 13-M16 bolt, 14-plane sealing gasket, 15-comparison frame, 1.1-inner hole, 1.2-end surface, 1.3-edge, 1.4-O-shaped groove, 1.5-excircle, 1.6-axial lead, 4.1-crosshead cavity, 4.2-cylinder sleeve cavity, 4.3-inner hole, 4.4-slideway hole, 4.5-crosshead slideway hole axial lead, 4.6-crankshaft cavity, 4.7-crankshaft baffle, 4.8-chamfer bevel, 7.1-chamfer cutter, 7.2-boring hole cutter, boring cutter, 6-comparison machine tool, 9-comparison middle flange, 10-boring cutter head, 11-machine tool main shaft, 12-machine tool main shaft box, 13-M16 bolt, 4.2-chamfer cutter head, 4-chamfer bevel, 4-chamfer cutter head, 4.3-chamfer, 4-chamfer, and-chamfer, 9.1-inner hole, 9.2-right end face, 9.3-M16 threaded through hole, 9.4-positioning pin, 9.5-left end face, 9.6-excircle, 9.7-side face, 9.8-axial lead, 15.1-inner hole, 15.2-clapboard, 15.3-end face and 15.4-crankshaft hole.

Detailed Description

The invention is further described with reference to the following figures and detailed description.

The embodiments of the present invention are not limited to the following examples, and various changes made without departing from the spirit of the present invention are within the scope of the present invention.

Referring to fig. 1 to 11, the connection structure of the intermediate flange and the frame of the drilling pump of the present embodiment includes an intermediate flange 1, a pressure plate 2, M12 bolts 3, a frame 4, an O-ring 5, a machine tool 6, a boring head 7, a boring bar 8, compared with the middle flange 9, the boring cutter head 10, the machine tool main shaft 11, the machine tool main shaft box 12, the M16 bolt 13, the plane sealing gasket 14, compared with the rack 15, the inner hole 1.1, the end face 1.2, the edge 1.3, the O-shaped groove 1.4, the outer circle 1.5, the axial lead 1.6, the crosshead cavity 4.1, the cylinder sleeve cavity 4.2, the inner hole 4.3, the crosshead slide way hole 4.4, the crosshead slide way hole axis 4.5, the crankshaft cavity 4.6, the partition plate 4.7, the chamfer inclined plane 4.8, the chamfer cutter 7.1, the boring cutter 7.2, the inner hole 9.1, the right end face 9.2, the M16 threaded through hole 9.3, the positioning pin 9.4, the left end face 9.5, the outer circle 9.6, the side face 9.7, the axial lead 9.8, the inner hole 15.1, the partition plate 15.2, the end face 15.3 and the crankshaft hole 15.4.

Referring to fig. 1 and 2, all surfaces of the intermediate flange 1 are processed, wherein an inner hole 1.1 of the intermediate flange 1 is matched with an outer circle of an intermediate rod sealing ring seat (not shown), an end surface 1.2 of the intermediate flange 1 is matched with an end surface of the intermediate rod sealing ring seat, an outer circle 1.5 of the intermediate flange 1 is matched with an inner hole 4.3 of the frame 4, an edge 1.3 of the intermediate flange 1 is matched with a chamfer inclined surface 4.8 of the frame 4, an O-shaped sealing ring 5 is arranged in an O-shaped groove 1.4 of the intermediate flange 1, therefore, the coaxiality precision of the excircle 1.5 and the inner hole 1.1, the edge 1.3 and the O-shaped groove 1.4 of the intermediate flange 1 is required to be high, the verticality precision of the excircle 1.5 of the intermediate flange 1 and the end surface 1.2 of the intermediate flange 1 is required to be high, the excircle 1.5, the inner hole 1.1, the end surface 1.2, the edge 1.3 and the O-shaped groove 1.4 of the intermediate flange 1, which have very high requirements on the mutual positions, can be mounted and processed at one time, and thus the installation and the processing can be easily ensured.

Referring to fig. 5 and 6, the difference between the diameter of the crosshead slide way hole 4 of the frame 4 and the diameter of the crosshead slide way hole 4.3 for installing the intermediate flange positioning inner hole is 14 to 16mm, a hole with high position precision of the drill pump frame can be processed by using a machine tool 6, the boring cutter bar 8 belongs to a simple beam support under the support of bearings at two ends of the machine tool 6, the rigidity is very good, the boring cutter bar 8 is provided with the boring cutter 7, the boring cutter 7 is arranged on the boring cutter 7, the crosshead slide way hole 4.4 of the frame 4 and the crosshead slide way hole 4.3 for installing the intermediate flange positioning inner hole 4.3 of the frame 4 can be processed, the chamfering cutter 7.1 is arranged on the boring cutter 7, and the chamfer angle 4.8 of the frame 4 can be processed, so that the coaxiality precision of the crosshead slide way hole 4.4 of the frame 4, the intermediate flange positioning inner hole 4.3 for installing the frame 4 and the chamfer angle 4.8 of the frame 4 is very high.

Referring to fig. 3 and 4, the mounting position of the intermediate flange 1 on the frame 4 is that the intermediate flange 1 is mounted between the crosshead cavity 4.1 and the cylinder sleeve cavity 4.2 of the frame 4, specifically, the O-ring seal 5 is mounted in the O-ring 1.4 of the intermediate flange 1, the outer circle 1.5 of the intermediate flange 1 is mounted in the inner hole 4.3 of the frame 4, the edge 1.3 of the intermediate flange 1 is in line contact with the chamfer angle 4.8 of the frame 4, wherein the matching of the excircle 1.5 of the middle flange 1 and the inner hole 4.3 of the frame 4 is in a clearance matching form, the clearance is 0-0.051 mm, then the pressing plate 2 is used for pressing the middle flange 1, 6M 12 bolts 3 are screwed into the screw holes of the partition plate 4.7 of the human frame 4, the assembly is finished, the connection can meet the requirements of easy assembly of the intermediate flange 1 and guarantee that the coaxiality precision of the axis 1.6 of the inner hole 1.1 of the intermediate flange 1 and the axis 4.5 of the crosshead slide way hole of the frame 4 is very high, and the vertical precision of the end surface 1.2 of the intermediate flange 1 and the axis 4.5 of the crosshead slide way hole of the frame 4 is very high.

Referring to fig. 7, 8 and 9, the outer shape of the comparison intermediate flange 9 is a kidney shape, the inner hole 15.1 of the comparison frame 15 is also a kidney shape, the inner hole 9.1 of the comparison intermediate flange 9 is matched with the outer circle of the intermediate rod seal ring seat (not shown), the right end face 9.2 of the comparison intermediate flange 9 is matched with the end face of the intermediate rod seal ring seat, when the inner hole 9.1 of the comparison intermediate flange 9 and the right end face 9.2 of the comparison intermediate flange 9 are processed, the left end face 9.5 of the comparison intermediate flange 9 and the end face 15.3 of the partition 15.2 of the comparison frame 15 are connected together by 10M 16 bolts 13 (particularly, the left end face 9.5 of the comparison intermediate flange 9 and the end face 15.3 of the partition 15.2 of the comparison frame 15 are blank surfaces which are not processed), two positioning pin holes are arranged on the end faces 15.3 of the comparison intermediate flange 9 and the partition 15.2 of the comparison frame 15, two positioning pins 9.4 are arranged in the two pin holes, and the two positioning pins 9.4 are welded together with the comparison intermediate flange 9.2 by electric welding, the positioning of the comparison intermediate flange 9 and the comparison rack 15 belongs to one-side two-pin limitation six degrees of freedom, the axis 4.5 of a cross head slide way hole of the comparison rack 15 is an X axis, the vertical axis of the bottom surface of the comparison rack is a Z axis, the direction of a crankshaft hole 15.4 of the comparison rack 15 is a Y axis, the two unmachined end surfaces 9.5, 15.3 and two positioning pins 9.4 limit the X axis, the Y axis and the Z axis moving degrees of freedom and the rotation degrees around the X axis, the Y axis and the Z axis of the comparison intermediate flange 9, wherein the two unmachined end surfaces 9.5 and 15.3 limit the X axis moving degrees of freedom, the rotation degrees of freedom around the Y axis and the Z axis of the comparison intermediate flange 9.

Referring to fig. 8, the crosshead shoe hole 4.4 of the comparison frame 15 and the inner hole 9.1 of the comparison intermediate flange 9 are not completed simultaneously in one process, the crosshead shoe hole 4.4 has good rigidity of the boring bar due to the large diameter of the hole, the axis 4.5 of the crosshead shoe hole has high precision, fig. 8 is a process for separately processing the inner hole 9.1 of the comparison intermediate flange 9, because the diameter of the inner hole 9.1 of the middle flange 9 is smaller, the boring cutter head 10 and the machine tool main shaft 11 belong to the support of the extending beam relative to the machine tool main shaft box 12, the diameters of the boring cutter head 10 and the machine tool main shaft 11 are small, the distance extending out of the machine tool main shaft box 12 is more than 1000mm, the axis of the machine tool main shaft 11 is necessarily bent, the coaxiality error between the shaft axis 9.8 of the inner hole 9.1 of the comparative intermediate flange 9 processed in the way and the shaft axis 4.5 of the crosshead slide way hole is inevitably large, the right end face 9.2 of the comparison intermediate flange 9 is inevitably large in perpendicularity error with the axis 4.5 of the crosshead slide way hole.

Referring to fig. 10 and 11, in the case where the comparative intermediate flange 9 is mounted to the comparative frame 15, in contrast to the mounting when the inner bore 9.1 of the comparison intermediate flange 9 and the right end face 9.2 of the comparison intermediate flange 9 are machined, a planar sealing gasket 14 is added between the end face 9.5 of the comparative intermediate flange 9 and the end face 15.3 of the comparative frame 15, so that the connection has the problem that, the end face 9.5 of the comparison intermediate flange 9 and the end face 15.3 of the comparison frame 15 are both surfaces which are not machined and are rough reference surfaces which do not have the function of repeated positioning, and an elastic plane sealing gasket 14 is additionally arranged between the two rough references, so that the positioning error of the rough references is further increased, namely, compared with the coaxiality error of the shaft axis 9.8 of the inner hole 9.1 of the middle flange 9 and the axis 4.5 of the crosshead slide way hole is larger, the perpendicularity error is larger compared with the right end face 9.2 of the middle flange 9 and the axis 4.5 of the crosshead slide way hole.

Referring to fig. 3 and 10, because the position accuracy of the intermediate flange 1 is high, and the additional force applied to the intermediate flange 1 when the intermediate rod moves is very small, the intermediate flange 1 and the partition plate 4.7 of the frame 4 can be safely fastened by adding 6M 12 bolts 3 to the pressing plate 2, the position accuracy is low compared with that of the intermediate flange 9, the additional force applied to the intermediate flange when the intermediate rod moves is very large, and the intermediate flange 9 and the partition plate 15.2 need 10M 16 bolts 13 to ensure safety.

Through comparative analysis, the connecting structure of the intermediate flange and the rack of the drilling pump can well ensure the high coaxiality precision of the axial lead 1.6 of the inner hole 1.1 of the intermediate flange 1 and the 4.5 high axial line of the cross head slideway hole of the rack 4, and the high verticality precision of the end surface 1.2 of the intermediate flange 1 and the 4.5 high axial line of the cross head slideway hole of the rack 4, thereby prolonging the service life of the intermediate rod sealing ring and avoiding the long-standing problem that slurry in a cylinder sleeve cavity permeates into a cross head cavity and lubricating oil in the cross head cavity permeates into the cylinder sleeve cavity.

The above detailed description of the embodiments of the present invention is provided in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art, and these changes are within the protection of the present invention and also within the protection scope of the present invention.