CN109578459B

CN109578459B - Clutch for fracturing device and control method

Info

Publication number: CN109578459B
Application number: CN201811594704.0A
Authority: CN
Inventors: 彭平生; 王云海; 肖勇; 李莉莉; 石权; 刘灼; 范杰; 陆英娜
Original assignee: Sinopec Oilfield Equipment Corp; Sinopec Siji Petroleum Machinery Co Ltd
Current assignee: China Petrochemical Corp; Sinopec Oilfield Equipment Corp; Sinopec Siji Petroleum Machinery Co Ltd
Priority date: 2018-12-25
Filing date: 2018-12-25
Publication date: 2020-07-07
Anticipated expiration: 2038-12-25
Also published as: CN109578459A

Abstract

The invention provides a clutch for a fracturing device, which comprises a pump connecting part, a transmission part and a motor connecting part, wherein the pump connecting part is connected with the transmission part in a clutchable manner through a friction plate assembly; the end of the pump connecting part is provided with an oil inlet hole which is used for providing pressure oil for the friction plate assembly; the driving hydraulic oil connecting seat is connected with the transmission part, a flange is arranged on the side wall of the driving hydraulic oil connecting seat, an oil through hole is formed in the flange and is communicated with the oil inlet hole, a hydraulic oil input device is further arranged and is connected with the flange in a sliding and sealing mode, and an oil inlet is formed in the hydraulic oil input device. In the control method, the working state of the clutch is judged by using the rotating speed difference of each part of the clutch and an arranged vibration sensor. By adopting the structure, the pressure oil supply path of the friction plate assembly can be shortened, and the reliability of clutch control is improved.

Description

Clutch for fracturing device and control method

Technical Field

The invention relates to the field of petroleum drilling and production equipment, in particular to a clutch for a fracturing device and a control method.

Background

The fracturing operation is a main measure for increasing and stabilizing yield in the exploration and development of oil and gas fields, and a plurality of high-power fracturing devices are utilized to fracture reservoir rocks and form a flow guide channel. With the development of ultra-deep well and horizontal well technologies, the power of the needed fracturing unit is increased, and the weight and the volume of a single fracturing device are increased. For example, the output pressure of the existing equipment reaches 175Mpa, and higher requirements are also put on the clutch in the equipment due to higher pressure. Chinese patent document CN107237617A describes an electrically driven fracturing device with a single-machine dual-pump structure, in which two pump head assemblies are driven by one motor, and a friction plate assembly of a clutch needs to be switched between a disengaged state and an engaged state by hydraulic driving. Furthermore, the assembly connection length of the whole shaft is long, and the difficulty in ensuring the coaxiality of installation is very high in the whole transmission structure.

In the existing clutch control, whether the clutch is combined or disconnected can be monitored, but the working state of the elastic connecting piece and whether the clutch plate slips are difficult to monitor, and because the high-pressure working condition and the heavy load are involved, if the improper operation is easy to damage equipment and cause safety accidents, the problem that how to find the fault in advance and reduce the later loss is the technical problem to be solved.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a clutch for a fracturing device and a control method, which can shorten a pressure oil conveying path for driving a friction plate assembly and improve the reliability of the clutch. In a preferable scheme, the impact generated in the clutch process of the clutch is buffered, and the coaxiality error of the installation can be compensated to a certain extent.

Another technical problem to be solved by the present invention is to provide a control method for the above clutch, which can monitor the working state of the clutch on line, especially the slipping state of the clutch plate in the clutch, avoid the major loss caused by the clutch failure, and prevent the clutch from slipping in advance when the accident does not occur.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a clutch for a fracturing device comprises a pump connecting part, a transmission part and a motor connecting part, wherein the pump connecting part and the transmission part are connected in a clutchable manner through a friction plate assembly, and the transmission part is connected with the motor connecting part;

the end of the pump connecting part is provided with an oil inlet hole which is used for providing pressure oil for the friction plate assembly;

the driving hydraulic oil connecting seat is connected with the transmission part, a flange is arranged on the side wall of the driving hydraulic oil connecting seat, an oil through hole is formed in the flange and is communicated with the oil inlet hole, a hydraulic oil input device is further arranged and is connected with the flange in a sliding and sealing mode, and an oil inlet is formed in the hydraulic oil input device.

In the preferred scheme, the driving hydraulic oil connecting seat is hermetically connected with the transmission part through a flange, a cavity is arranged at the end, close to the transmission part, of the driving hydraulic oil connecting seat, and the oil through hole is communicated with the oil inlet hole through the cavity.

In the preferred scheme, a cavity is formed in the end, close to the transmission part, of the driving hydraulic oil connecting seat, and the oil through hole is communicated with the oil inlet hole through an adapter tube arranged in the cavity.

In a preferable scheme, in the hydraulic oil input device, a first sealing disc is fixedly connected with a second sealing disc, the cross sections of the first sealing disc and the second sealing disc are c-shaped, an oil through groove is formed in the inner bottom surface of the c-shaped structure, and the first sealing disc and the second sealing disc form a sealing structure with the side surface of a flange;

the oil inlet is communicated with the oil through hole through the oil through groove.

In a preferable scheme, the first sealing disc and the second sealing disc are fixedly connected at the outer edges through a plurality of screws, and a flexible gasket with adjustable thickness is arranged between the first sealing disc and the second sealing disc;

at least 2 sealing rings are arranged between the first sealing disc and the flange and between the second sealing disc and the flange;

packing is arranged between the first sealing disk and the flange, and between the second sealing disk and the flange.

In the preferred scheme, the transmission part is connected with the motor connecting part through a plurality of elastic connecting pieces, a first connecting hole seat and a second connecting hole seat are arranged at two ends of each elastic connecting piece, and the axial lines of the first connecting hole seat and the second connecting hole seat are mutually crossed in projection on the space;

the first connecting hole seat is fixedly connected with the end face of the transmission part through a screw, and the second connecting hole seat is fixedly connected with the outer wall of the circumference of the motor connecting part through a screw.

In the preferred scheme, the motor connecting part is connected with an output shaft of the motor, the output shaft of the motor is a spline shaft, the motor connecting part is provided with a corresponding spline hole, and the two ends of the spline hole are provided with a sealing ring and a lubricating oil hole.

In the preferred scheme, the motor be two stretching axle motors, the both ends of motor all are connected with the motor connecting portion of clutch, the pump connecting portion and the pump head assembly of clutch are connected.

In a preferred scheme, the directions of the elastic connecting pieces in the clutches at the two ends of the motor are opposite.

In a preferred scheme, a plurality of detection heads are arranged on the outer wall of the transmission part, detection seats are fixedly arranged at corresponding positions, and proximity switches for monitoring the detection heads are arranged on the detection seats;

one of the heads has a length along the circumference greater than the other heads to generate a waveform having a length greater than the other undulations.

A control method adopting the clutch for the fracturing device comprises the following steps:

s1, when the electromagnetic valve of the clutch hydraulic oil way is conducted, judging whether the clutch is combined or not through the rotation speed difference between the motor rotation speed and the rotation speed of the center shaft of the pump head assembly;

s2, starting from the conduction of the electromagnetic valve, and completely combining the clutch, and judging whether the motor connecting part and the transmission part are invalid or not by detecting the rotation speed difference between the motor rotation speed and the proximity switch of the detection seat;

s3, starting from the conduction of the electromagnetic valve, and completely combining the clutch, and judging whether the friction plate assembly of the clutch slips or not by detecting the rotation speed difference between the rotation speed of the central shaft of the pump head assembly and the rotation speed of the proximity switch of the detection seat;

s4, a vibration sensor is further arranged on the shell of the clutch, the vibration frequency in a normal state is collected to serve as a judgment standard, and whether the clutch breaks down or not is judged according to the real-time vibration frequency collected by the vibration sensor;

the working state of the clutch is monitored through the steps.

According to the clutch for the fracturing device, the structure is adopted, the pressure oil supply path of the friction plate assembly can be shortened, and the reliability of clutch control is improved. In the preferred scheme, the impact generated in the connection process is buffered through the elastic connecting piece, and the crossed structure of the connecting hole seats is adopted, so that the error of the installation coaxiality can be compensated, and the vibration caused by the coaxiality error is reduced. The detection head and the proximity switch are arranged, and the angular speed sensor of the shaft of the motor and the pump head is matched, so that the working state of the clutch can be reliably monitored, and loss expansion is avoided. The vibration sensor can find faults in advance before the faults are enlarged, and equipment loss is reduced.

Drawings

The invention is further illustrated by the following examples in conjunction with the accompanying drawings:

fig. 1 is a schematic view of the overall structure of the fracturing device of the present invention.

Fig. 2 is a front view of the clutch of the present invention.

Fig. 3 is a left side view of the clutch of the present invention.

Fig. 4 is a view from direction B of fig. 2.

FIG. 5 is a partially enlarged view of the hydraulic fluid connecting base according to the present invention.

FIG. 6 is an enlarged view of a portion of another alternative structure of the driving hydraulic link assembly of the present invention.

Fig. 7 is a schematic diagram of a structure of a hydraulically driven oil passage according to the present invention.

In the figure: the hydraulic oil pump comprises a clutch 1, a pump connecting portion 11, an oil inlet 111, a transmission portion 12, a detection head 121, a motor connecting portion 13, a spline hole 131, a lubricating oil hole 132, an elastic connecting piece 14, a first connecting hole seat 141, a second connecting hole seat 142, a connecting portion 143, a detection seat 15, a flange 161, an oil through hole 162, a hydraulic oil input device 17, a first sealing disc 171, a second sealing disc 172, a side sealing element 173, an oil through groove 174, an oil inlet pipe 175, a friction plate assembly 18, an adapter pipe 19, a motor 2, a pump head assembly 3, an electrical cabinet 4, a control cabinet 5, a vibration sensor 6 and an electromagnetic valve 7.

Detailed Description

Example 1:

as shown in fig. 2 to 4, a clutch for a fracturing device comprises a pump connecting part 11, a transmission part 12 and a motor connecting part 13, wherein the pump connecting part 11 is connected with the transmission part 12 in a clutchable manner through a friction plate assembly 18, and the transmission part 12 is connected with the motor connecting part 13; the friction plate assembly 18 is a conventional technique, and includes a piston, a plurality of friction plates, a plurality of pressure plates for friction transmission, and a spring for returning the pressure plates, and clutch transmission is realized by axial movement of the plurality of pressure plates, which are all conventional techniques, for example, a wet friction clutch for a tractor described in patent document CN201820235004.1, and a schematic diagram of the friction plate assembly 18 is shown in fig. 7, and will not be described herein again.

The end of the pump connecting part 11 is provided with an oil inlet hole 111, and the oil inlet hole 111 is used for providing pressure oil for the friction plate assembly 18;

the driving hydraulic oil connecting seat 16 is connected with the transmission part 12, a flange 161 is arranged on the side wall of the driving hydraulic oil connecting seat 16, an oil through hole 162 is arranged on the flange 161, preferably, the oil through hole 162 is arranged along the radial direction, the opening is positioned on the circumferential outer wall of the flange 161, the oil through hole 162 is communicated with the oil inlet hole 111, a hydraulic oil input device 17 is further arranged, the hydraulic oil input device 17 is connected with the flange 161 in a sliding and sealing mode, and an oil inlet is formed in the hydraulic oil input device 17. The oil inlet is connected to the oil inlet pipe 175. With this structure, the pressure oil enters from the side surface, and the pressure oil delivery path is greatly shortened. In the prior art, the end of the pump connecting portion 11 is connected to one end of a shaft in the pump head assembly 3 in a sealing manner, a through hole is formed in the shaft of the pump head assembly 3 in the axial direction, and the other end of the shaft in the pump head assembly 3 is connected to the rotary oil supply port and used for inputting pressure oil. Oil lines of this construction need to pass through shafts in the pump head assembly 3, which greatly increases the chance of failure.

Preferably, as shown in fig. 6, the driving hydraulic oil connecting seat 16 is hermetically connected to the transmission part 12 through a flange, a cavity is formed at an end of the driving hydraulic oil connecting seat 16 close to the transmission part 12, and the oil through hole 162 is communicated with the oil inlet hole 111 through the cavity. According to the structure, the connecting structure is simplified, but the sealing requirement is high, and particularly under the condition of large vibration, the sealing failure is easily caused.

In a preferred embodiment, as shown in fig. 5, a cavity is formed at the end of the driving hydraulic oil connecting seat 16 close to the transmission part 12, and the oil through hole 162 is communicated with the oil inlet hole 111 through an adapter tube 19 disposed in the cavity. With this structure, the sealing requirement is reduced, and the sealing reliability is improved.

In a preferred scheme, as shown in fig. 5, in the hydraulic oil input device 17, a first sealing disc 171 is fixedly connected with a second sealing disc 172, the cross section of the assembly of the first sealing disc 171 and the second sealing disc 172 is in a c shape, an oil through groove 174 is arranged on the inner bottom surface of the c-shaped structure, and the assembly of the first sealing disc 171 and the second sealing disc 172 and the side surface of the flange 161 form a sealing structure;

the oil inlet communicates with the oil passing hole 162 through the oil passing groove 174. With the structure, the reliability of sealing between the hydraulic oil input device 17 and the flange 161 of the driving hydraulic oil connecting seat 16 is improved, and due to the adoption of a side sealing scheme, the influence of equipment vibration, particularly radial micro-amplitude vibration on the sealing effect can be ignored.

In a preferred scheme, as shown in fig. 5 and 6, the first sealing disc 171 is fixedly connected with the second sealing disc 172 at the position of the outer edge through a plurality of screws, and a flexible gasket with adjustable thickness is arranged between the first sealing disc 171 and the second sealing disc 172; the provision of a flexible gasket enables wear of the seal to be compensated for, for example by tightening the screws to seal securely against the flange 161 after a leak failure has occurred during use. Furthermore, wear of the seal may also be compensated for by replacing the gasket with a different thickness.

At least 2 sealing rings are arranged between the first sealing disc 171 and the second sealing disc 172 and the flange 161;

packing is also provided between the first and

second sealing discs

171, 172 and the flange 161. With this structure, the sealing effect is further improved.

Preferably, as shown in fig. 3 and 4, the transmission part 12 and the motor connecting part 13 are connected by a plurality of elastic connecting pieces 14, a first connecting hole seat 141 and a second connecting hole seat 142 are arranged at two ends of each elastic connecting piece 14, and the axial lines of the first connecting hole seat 141 and the second connecting hole seat 142 cross each other in a projection on the space;

the first connecting hole seat 141 is fixedly connected with the end face of the transmission part 12 through a screw, and the second connecting hole seat 142 is fixedly connected with the circumferential outer wall of the motor connecting part 13 through a screw. With this structure, the structure of the elastic coupling member 14 can absorb the shock generated during the clutch process. And the stressed structure of the elastic connecting piece 14 is less affected by direction, so that the coaxiality error of installation or the coaxiality error generated after the equipment runs for a period of time can be compensated. And because the elastic connecting piece 14 adopts a twisted structure, even if coaxiality errors exist, the vibration of the equipment caused by the coaxiality errors can be reduced to the minimum. In a preferred embodiment, the elastic connecting element 14 is made of one or more of steel wire, plastic fabric and rubber. Preferably, a combination structure of steel wires, plastic fabrics and rubber is adopted, at the end of the elastic connecting member 14, the steel wires are wound and woven to form the frameworks of the first connecting hole seat 141 and the second connecting hole seat 142, the plastic fabrics form the second layer of framework and also are used for ensuring the reliable combination between the steel wires and the rubber so as to reduce the abrasion between the steel wires due to micro friction, and the rubber covers the framework so as to maintain the shape of the whole structure without deformation. The plastic fabric is a woven fabric of aramid fiber. With the structure, the effects of reliable stress and deformation resistance are realized.

In a preferred scheme, as shown in fig. 1, the motor connecting portion 13 is connected to an output shaft of the motor 2, the output shaft of the motor 2 is a spline shaft, the motor connecting portion 13 is provided with corresponding spline holes 131, and sealing rings and a lubricating oil hole 132 are provided at two ends of the spline holes 131. With the structure, the axial displacement of the clutch 1 in the transmission process can be compensated, and the axial error in the installation process can be compensated.

In a preferred embodiment, as shown in fig. 1, the motor 2 is a double-shaft motor, both ends of the motor 2 are connected to the motor connecting portion 13 of the clutch 1, and the pump connecting portion 11 of the clutch is connected to the pump head assembly 3.

In the preferred embodiment, the directions of the elastic connecting pieces 14 in the clutches 1 at both ends of the motor 2 are opposite. The opposite direction here means the opposite direction in the circumferential direction.

As shown in fig. 2 and 3, a plurality of detection heads 121 are disposed on the outer wall of the transmission part 12, a detection seat 15 is fixedly disposed at a corresponding position, and a proximity switch for monitoring the detection heads 121 is disposed on the detection seat 15; with this structure, the rotational speed of the transmission portion 12 is detected, and thus, the operating condition of the clutch is evaluated. Such as angular velocity sensors or encoders associated with the motor and shaft of the pump head, can reliably monitor the operating state of the clutch, such as the presence of a friction plate slip. The proximity switch in this example is a non-contact switch such as a giant reluctance type proximity switch, an inductive type proximity switch, or an eddy current type proximity switch.

One of the detection heads 121 has a length along the circumference greater than the other detection heads 121 to generate a waveform having a length greater than the other undulations. According to the scheme, the phenomenon of error judgment due to missed shooting can be avoided by better recording the number of rotation turns of the waveform. The greater the number of detection heads 121 along the circumference, the higher the detection accuracy.

When the hydraulic pump is used, the motor 2 is started, the shaft of the motor 2 drives the motor connecting part 13 of the clutch 1 to rotate, the friction plate assembly 18 is not combined at the moment, the shaft of the pump head assembly 3 does not rotate, and when the hydraulic pump needs to work, pressure oil passes through the hydraulic oil input device 17 from the oil inlet pipe 175 and is input into the oil inlet hole 111 to drive the friction plate assembly 18 to be combined, and the shaft of the pump head assembly 3 rotates. When the separation is needed, the pressure oil is released, the friction plate assembly 18 is driven to reset under the action of the spring, and the shaft of the pump head assembly 3 stops rotating. As shown in fig. 1, the operation states of the pump head assemblies 3 at both ends can be independently controlled by the clutch 1.

Example 2:

on the basis of embodiment 1, a control method adopting the clutch for the fracturing device comprises the following steps:

s1, when the controller sends out an instruction, for example, a PLC sends out an instruction, the electromagnetic valve 7 of the hydraulic oil circuit of the clutch 1 is conducted, the hydraulic oil enters the oil inlet hole 111 of the clutch 1, and whether the clutch 1 is combined or not is judged through the rotation speed difference between the rotation speed of the motor 2 and the rotation speed of the shaft in the pump head assembly 3; at this time, after a period of time, the rotating speed of the motor 2 should be the same as the rotating speed of the shaft in the pump head assembly 3, if the rotating speeds are different, a fault is prompted, and if the period of time is overtime, the fault is prompted. Thereby avoiding a situation in which the clutch 1 fails. An angle sensor is provided in the electric machine 2, and the sum of the angle sensors over a period of time divided by the time is the rotational speed. An encoder is provided on the shaft of the pump head assembly 3 to derive the shaft rotational speed of the pump head assembly 3.

S2, starting from the conduction of the electromagnetic valve 7, and completely combining the clutch 1, and judging whether the motor connecting part 13 and the transmission part 12 are failed or not by detecting the rotation speed difference between the rotation speed of the motor 2 and the rotation speed of the proximity switch of the detection seat 15; because the elastic connecting piece 14 is adopted between the motor connecting part 13 and the transmission part 12, the situation that the elastic connecting piece 14 fails is not eliminated, and by adopting the scheme, whether the elastic connecting piece 14 fails or not can be judged.

S3, starting from the conduction of the electromagnetic valve 7 to the complete combination of the clutch 1, judging whether the friction plate assembly 18 of the clutch 1 slips or not by detecting the rotation speed difference between the rotation speed of the central shaft of the pump head assembly 3 and the rotation speed of the proximity switch of the detection seat 15; slipping of friction disc assembly 18 can generally generate heat in a short period of time, causing an accident, and therefore should prevent the friction disc from generating more heat, although some models are provided with temperature sensors, temperature sensors are generally dull to the operating mode of quick temperature rise, and temperature sensors' durability has been less than ideal, and there is a greater possibility of failure. After a period of time, the rotating speed of the shaft in the pump head assembly 3 is the same as the rotating speed detected by the proximity switch of the detection seat 15, and if the rotating speeds are different, a fault is prompted; and if the time period is overtime, prompting a slip fault.

In a preferred scheme, as shown in fig. 1, S4, a vibration sensor 6 is further arranged on a housing of the clutch 1, the vibration frequency in a normal state is collected as a judgment standard, and whether the clutch 1 has a fault is judged according to the real-time vibration frequency collected by the vibration sensor 6; some atypical faults may be difficult to detect due to complex conditions, but these faults often present a vibration variation. Usually, the vibration frequency of the clutch 1 is between 10 Hz and 45Hz, the vibration data are integrated and then subjected to FFT to obtain fundamental wave data and second harmonic data, and the fundamental wave data and the second harmonic data of the vibration frequency in a normal state are used as reference data. By comparing the fundamental wave data and the second harmonic wave data of the real-time vibration frequency judgment with the reference data, a fault can be found in an earlier time period.

The working state of the clutch 1 is monitored through the steps, the fault of the equipment can be found in advance, the fault is prevented in the sprouting stage through maintenance, the safety of the equipment is greatly improved, and the service life of the equipment is prolonged.

The above-described embodiments are merely preferred embodiments of the present invention, and should not be construed as limiting the present invention, and the scope of the present invention is defined by the claims, and equivalents including technical features described in the claims. I.e., equivalent alterations and modifications within the scope hereof, are also intended to be within the scope of the invention. For the sake of brevity, all the combinations of the embodiments are not exemplified, and therefore, the technical features of the embodiments can be combined with each other to generate more technical solutions without conflict.

Claims

1. The utility model provides a clutch for fracturing unit, it includes pump connecting portion (11), transmission portion (12) and motor connecting portion (13), but is connected with clutching mode through friction disc assembly (18) between pump connecting portion (11) and the transmission portion (12), characterized by: the transmission part (12) is connected with the motor connecting part (13);

the transmission part (12) is connected with the motor connecting part (13) through a plurality of elastic connecting pieces (14), a first connecting hole seat (141) and a second connecting hole seat (142) are arranged at two ends of each elastic connecting piece (14), and the axial lines of the first connecting hole seat (141) and the second connecting hole seat (142) are mutually crossed in projection on space;

the first connecting hole seat (141) is fixedly connected with the end face of the transmission part (12) through a screw, and the second connecting hole seat (142) is fixedly connected with the circumferential outer wall of the motor connecting part (13) through a screw;

the end of the pump connecting part (11) is provided with an oil inlet hole (111), and the oil inlet hole (111) is used for providing pressure oil for the friction plate assembly (18);

the driving hydraulic oil connecting seat (16) is connected with the transmission part (12), a flange (161) is arranged on the side wall of the driving hydraulic oil connecting seat (16), an oil through hole (162) is formed in the flange (161), the oil through hole (162) is communicated with the oil inlet hole (111), a hydraulic oil input device (17) is further arranged, the hydraulic oil input device (17) is connected with the flange (161) in a sliding and sealing mode, and an oil inlet is formed in the hydraulic oil input device (17);

the driving hydraulic oil connecting seat (16) is hermetically connected with the transmission part (12) through a flange, a cavity is formed in the end, close to the transmission part (12), of the driving hydraulic oil connecting seat (16), and the oil through hole (162) is communicated with the oil inlet hole (111) through the cavity;

or the end of the driving hydraulic oil connecting seat (16) close to the transmission part (12) is provided with a cavity, and the oil through hole (162) is communicated with the oil inlet hole (111) through an adapter tube (19) arranged in the cavity.

2. A clutch for a fracturing unit as set forth in claim 1, wherein: in the hydraulic oil input device (17), a first sealing disc (171) is fixedly connected with a second sealing disc (172), the cross section of the assembly of the first sealing disc (171) and the second sealing disc (172) is c-shaped, an oil through groove (174) is formed in the inner bottom surface of the c-shaped structure, and the assembly of the first sealing disc (171) and the second sealing disc (172) and the side surface of a flange (161) form a sealing structure;

the oil inlet is communicated with the oil through hole (162) through an oil through groove (174).

3. A clutch for a fracturing unit as set forth in claim 2, wherein: the first sealing disc (171) and the second sealing disc (172) are fixedly connected at the outer edge position through a plurality of screws, and a flexible gasket with adjustable thickness is arranged between the first sealing disc (171) and the second sealing disc (172);

at least 2 sealing rings are arranged between the first sealing disc (171) and the flange (161) and between the second sealing disc (172);

packing is arranged between the first sealing disk (171) and the flange (161) and between the second sealing disk (172) and the flange.

4. A clutch for a fracturing unit as set forth in claim 1, wherein: the motor connecting portion (13) is connected with an output shaft of the motor (2), the output shaft of the motor (2) is a spline shaft, the motor connecting portion (13) is provided with corresponding spline holes (131), sealing rings are arranged at two ends of each spline hole (131), and a lubricating oil hole (132) is further arranged.

5. A clutch for a fracturing unit, according to claim 4, wherein: the motor (2) is a double-extension-shaft motor, two ends of the motor (2) are connected with a motor connecting part (13) of the clutch (1), and a pump connecting part (11) of the clutch is connected with the pump head assembly (3).

6. A clutch for a fracturing unit, according to claim 5, wherein: in the clutches (1) at the two ends of the motor (2), the directions of the elastic connecting pieces (14) are opposite.

7. A clutch for a fracturing unit as set forth in claim 1, wherein: a plurality of detection heads (121) are arranged on the outer wall of the transmission part (12), detection seats (15) are fixedly arranged at corresponding positions, and proximity switches for monitoring the detection heads (121) are arranged on the detection seats (15);

one of the detection heads (121) has a length along the circumference greater than the length of the other detection heads (121) to generate a waveform having a length greater than the other undulations.

8. A control method using the clutch for a fracturing device according to any one of claims 1 to 7, comprising the steps of:

s1, when the electromagnetic valve (7) of the hydraulic oil circuit of the clutch (1) is conducted, whether the clutch (1) is combined or not is judged through the rotating speed difference between the rotating speed of the motor (2) and the rotating speed of the central shaft of the pump head assembly (3);

s2, starting from the conduction of the electromagnetic valve (7), completely combining the clutch (1), detecting the rotation speed difference between the rotation speed through the rotation speed of the motor (2) and the proximity switch of the detection seat (15), and judging whether the motor connecting part (13) and the transmission part (12) are failed or not;

s3, starting from the conduction of the electromagnetic valve (7), completely combining the clutch (1), and judging whether the friction plate assembly (18) of the clutch (1) slips or not by detecting the rotation speed difference between the rotation speed of the central shaft of the pump head assembly (3) and the rotation speed of the proximity switch of the detection seat (15);

s4, a vibration sensor (6) is further arranged on the shell of the clutch (1), the vibration frequency in a normal state is collected to serve as a judgment standard, and whether the clutch (1) breaks down or not is judged according to the real-time vibration frequency collected by the vibration sensor (6);

the working state of the clutch (1) is monitored through the steps.