阅读说明：本技术 可调节式试井天滑轮 (Adjustable well testing sky pulley ) 是由 王玉根 汪琛又 汪敏 杨永春 王灏 程地碧 郑永 郑辉 王勇 汪春浦 粟超 钟 于 2019-11-11 设计创作，主要内容包括：本发明公开了一种可调节式试井天滑轮,涉及油气田设备技术领域。本发明包括弧形压丝组件、滑轮组件和滑轮支架组件,所述滑轮支架组件包括安装座、调节丝杆螺母、调节丝杆、滑轮支架、回转锁止套和支架锁止套,滑轮支架一端用于安装滑轮组件,另一端插入调节丝杆内且通过滑轮径向轴承相对于调节丝杆转动；回转锁止套套设在调节丝杆和调节丝杆螺母上用于调节丝杆和调节丝杆螺母的锁止。本发明结构简单,设计合理,能调节滑轮高度,顺利地将捕捉在井口的仪器分离开。(The invention discloses an adjustable well testing sky pulley, and relates to the technical field of oil and gas field equipment. The pulley support assembly comprises an arc-shaped wire pressing assembly, a pulley assembly and a pulley support assembly, wherein the pulley support assembly comprises a mounting seat, an adjusting screw nut, an adjusting screw, a pulley support, a rotary locking sleeve and a support locking sleeve; and the rotary locking sleeve is sleeved on the adjusting screw rod and the adjusting screw rod nut and is used for locking the adjusting screw rod and the adjusting screw rod nut. The invention has simple structure and reasonable design, can adjust the height of the pulley and smoothly separate the instrument captured at the wellhead.)

1. Adjustable well testing day pulley, including arc pressure silk subassembly, loose pulley assembly and pulley bracket subassembly, its characterized in that: the pulley bracket assembly comprises an adjusting screw nut mounting seat (17), an adjusting screw nut (16), an adjusting screw (22), a pulley bracket (21), a rotary locking sleeve (23) and a bracket locking sleeve (26), the mounting seat (17) is fixedly mounted on the adjusting screw rod nut (16), the adjusting screw rod (16) is hollow, one end of a pulley bracket (21) is used for mounting a pulley assembly, the other end of the pulley bracket (21) is inserted into the adjusting screw rod (17) and rotates relative to the adjusting screw rod through a pulley radial bearing (20), a bracket locking sleeve (26) is mounted in the adjusting screw rod (17) and is connected with the lower end of the pulley bracket (21), the adjusting screw rod (17) is matched with the adjusting screw rod nut (16), and the rotary locking sleeve (23) is sleeved on the adjusting screw rod (17) and the adjusting screw rod nut (16) and used for locking the adjusting screw rod (17) and the adjusting screw rod nut (16); the thread hole of the adjusting screw rod nut (16) corresponding to the adjusting screw rod (17) is a waist-shaped hole, and the thread of the threaded hole of the adjusting screw rod nut (16) is arranged on the straight side of the waist-shaped hole; the cross section of the thread matching section of the adjusting screw rod (17) and the adjusting screw rod nut (16) is in a kidney-shaped hole shape, and the thread on the adjusting screw rod (17) is arranged on the arc side of the kidney-shaped hole-shaped screw rod section; the screw thread on the arc side of the adjusting screw rod (17) is matched with the screw thread on the straight side in the threaded hole of the adjusting screw rod nut (16); the pulley assembly comprises a pulley (10), a pulley shaft (12) and pulley bearings (11), the pulley (10) is arranged on the pulley shaft (12), the pulley bearings (11) are arranged at two ends of the pulley shaft (12), and the pulley shaft (12) rotates relative to the pulley support (21) through the pulley bearings (11) at the two ends; the arc-shaped wire pressing assembly comprises a guide support (1), an arc-shaped floating seat (4) and a wire pressing wheel (7), the wire pressing wheel (7) is installed at two ends of the arc-shaped floating seat (4), the arc-shaped floating seat (4) is installed at the upper end of the guide support (1), and the lower end of the guide support (1) is installed at one end, on a pulley support (21), of the pulley assembly; the radian of the wire pressing formed by the wire pressing wheels (7) at the two ends of the arc-shaped floating seat (4) is the same as the radian of the pulley (10) on the corresponding pulley component.

2. The adjustable well testing sky pulley of claim 1, wherein: the adjusting screw rod nut (16) is columnar, a threaded hole matched with the adjusting screw rod (17) in the adjusting screw rod nut (16) is a through hole, the lower end of the through hole is a straight hole section, and the length of the straight hole section is greater than that of a threaded section matched with the adjusting screw rod (17) in the through hole in a threaded mode.

3. The adjustable well testing sky pulley of claim 1, wherein: the upper end of the adjusting screw rod (17) is provided with a sinking platform, a groove is formed in the sinking platform, the pulley radial bearing (20) is installed in the sinking platform in an interference fit mode, and the pulley support (21) is installed in the pulley radial bearing (20) in an interference fit mode.

4. The adjustable well testing sky pulley of claim 1, wherein: the rotary locking sleeve (23) is a cylinder, an inner hole is a through hole and consists of two sections, namely a straight hole section and a waist-shaped hole section, the straight hole section is sleeved on the adjusting screw rod nut (16), and the waist-shaped hole section is matched with the adjusting screw rod (17); the rotary locking sleeve (23) is arranged on the adjusting screw nut (16), and the upper end surface of the adjusting screw nut (16) is attached to the contact surface of the straight hole section and the waist-shaped hole section of the rotary locking sleeve (23).

5. The adjustable well testing sky pulley of claim 1 or 4, wherein: long waist-shaped holes are formed in the outer circumference of the straight hole section of the rotary locking sleeve (23), the waist-shaped holes are spirally distributed, the lift angle is consistent with the threads in the adjusting screw rod nut (16), a rotary locking sleeve limiting screw (24) is arranged in each waist-shaped hole, and the rotary locking sleeve limiting screw (24) is installed on the adjusting screw rod nut (16); the two ends of the waist-shaped hole are limit limits and are arc-shaped, and the arc is concentric with the limit screw; the two limit surfaces are provided with sinking platforms which are concentric with the arcs of the limits, and the diameter of the sinking platform is slightly larger than that of a boss of a locking hand wheel (25) of the rotary locking sleeve.

6. The adjustable well testing sky pulley of any one of claims 1-4, wherein: the locking hole has been seted up to pulley support (21) lower extreme, has seted up the locking through-hole on support locking cover (26), sets up the mounting hole of locking support locking cover on accommodate the lead screw (17), and locking hole and locking through-hole are packed into through the mounting hole in support locking cover set screw (27), are in the same place pulley support and support locking cover locking.

7. The adjustable well testing sky pulley of claim 1, wherein: guide bracket (1) includes that installation department and upper end that lower extreme and pulley support (21) are connected support the supporting part of the floating seat of arc (4), and the supporting part upper end is provided with the screw thread, and screw thread department threaded connection has height control hand wheel (5), and the floating seat cover of arc is established on the supporting part, overlaps on the supporting part between the floating seat of arc (4) lower surface and installation department upper surface to be equipped with guide bracket return spring (3).

8. The adjustable well testing sky pulley of claim 1, wherein: the arc floating seat (4) is sleeved on a part of the supporting part and is provided with a waist-shaped hole, the supporting part is provided with an arc floating seat limiting screw (6), and the limiting screw (6) penetrates through the waist-shaped hole to limit the adjusting amplitude of the arc floating seat (4).

Technical Field

The invention relates to the technical field of oil and gas field equipment, in particular to the technical field of a well testing blowout preventer for testing oil and gas wells, and more particularly relates to an adjustable well testing crown block.

Background

The well testing is based on the seepage theory, various well testing devices and testing instruments are used as means to monitor the dynamic and static states of oil, gas and water wells, and the technology for explaining and analyzing physical parameters of oil and gas reservoirs and the production capacity of the oil, gas and water wells through the obtained well testing data provides reliable basis for the exploration and development of oil and gas fields.

In the well testing process, the instrument is jacked due to the fact that a depth finder fails, the working of operators is not correct, the yield of fluid in a well is too high and the like, the rope cap of the instrument is successfully caught by a catcher arranged at the lower end of a blowout prevention box, the lighter instrument string is separated from the instrument in an artificial mode, when the instrument string is taken out, the distance from a second flat part at the upper part of the caught instrument string to the top of the blowout prevention box is larger than the distance from the lower edge of a pulley to a blowout prevention pipe opening due to the fact that a pulley support on the existing well testing day is short, after the blowout prevention box is buckled, the blowout prevention box, the catcher and the instrument string which are integrated cannot be pulled up to the second flat part where a blocking fork can be clamped to the instrument string, the catcher and the instrument string cannot be normally separated, the instrument string cannot be taken out of a well mouth, and the well. At present, a mechanical hoisting method is mostly adopted on site to solve the problems that the cost of crane tracking for going into the well is high, mechanical injury and equipment damage risks exist, and the requirements of well testing production are not met.

Disclosure of Invention

The invention aims to provide an adjustable well testing sky pulley which is simple in structure, reasonable in design, and capable of adjusting the height of the pulley and smoothly separating instruments caught at a well head.

In order to solve the problems in the prior art, the invention is realized by the following technical scheme:

adjustable well testing day pulley, including arc pressure silk subassembly, loose pulley assembly and pulley bracket subassembly, its characterized in that: the pulley bracket assembly comprises a mounting seat, an adjusting screw nut, an adjusting screw, a pulley bracket, a rotary locking sleeve and a bracket locking sleeve, wherein the mounting seat is fixedly mounted on the adjusting screw nut; the adjusting screw rod is matched with the adjusting screw rod nut, and the rotary locking sleeve is sleeved on the adjusting screw rod and the adjusting screw rod nut and used for locking the adjusting screw rod and the adjusting screw rod nut; the thread hole of the adjusting screw rod nut corresponding to the adjusting screw rod is a waist-shaped hole, and the thread of the threaded hole of the adjusting screw rod nut is arranged on the straight side of the waist-shaped hole; the cross section of the thread matching section of the adjusting screw rod and the adjusting screw rod nut is in a kidney-shaped hole shape, and the thread on the adjusting screw rod is arranged on the arc side of the kidney-shaped hole-shaped screw rod section; the screw thread on the arc side of the adjusting screw rod is matched with the screw thread on the straight side in the screw hole of the adjusting screw rod nut; the pulley assembly comprises a pulley, a pulley shaft and pulley bearings, the pulley is arranged on the pulley shaft, the pulley bearings are arranged at two ends of the pulley shaft, and the pulley shaft rotates relative to the pulley support through the pulley bearings at the two ends; the arc-shaped wire pressing assembly comprises a guide support, an arc-shaped floating seat and wire pressing wheels, the wire pressing wheels are arranged at two ends of the arc-shaped floating seat, the arc-shaped floating seat is arranged at the upper end of the guide support, and the lower end of the guide support is arranged at one end of the pulley support, on which the pulley assembly is arranged; and the radian of the wire pressing formed by the wire pressing wheels at the two ends of the arc-shaped floating seat is the same as that of the pulley on the corresponding pulley component.

The adjusting screw rod nut is columnar, a threaded hole matched with the adjusting screw rod on the adjusting screw rod nut is a through hole, the lower end of the through hole is a straight hole section, and the length of the straight hole section is greater than that of a threaded section matched with the adjusting screw rod in the through hole in a threaded mode.

The upper end of the adjusting screw rod is provided with a sinking platform, a groove is formed in the sinking platform, the pulley radial bearing is installed in the sinking platform in an interference fit mode, and the pulley support is installed in the pulley radial bearing in an interference fit mode with an inner ring of the pulley radial bearing.

The rotary locking sleeve is a cylinder, the inner hole is a through hole and consists of two sections, namely a straight hole section and a waist-shaped hole section, the straight hole section is sleeved on the adjusting screw rod nut, and the waist-shaped hole section is matched with the adjusting screw rod; the rotary locking sleeve is arranged on the adjusting screw rod nut, and the upper end surface of the adjusting screw rod nut is attached to the contact surface of the straight hole section and the waist-shaped hole section of the rotary locking sleeve.

The outer circumference of the straight hole section of the rotary locking sleeve is provided with a long waist-shaped hole which is spirally distributed, the lift angle is consistent with the thread in the adjusting screw rod nut, a limit screw is arranged in the waist-shaped hole, and the limit screw is arranged on the adjusting screw rod nut; the two ends of the waist-shaped hole are limit limits and are arc-shaped, and the arc is concentric with the limit screw; the two limit surfaces are provided with sinking platforms which are concentric with the arcs of the limits, and the diameter of the sinking platform is slightly larger than that of the rotary locking sleeve locking hand wheel boss.

The locking hole has been seted up to pulley support lower extreme, has seted up the locking through-hole on the support locking cover, sets up the mounting hole of locking support locking cover on the accommodate the lead screw, and support locking cover set screw packs into locking hole and locking through-hole through the mounting hole, and is in the same place pulley support and support locking cover locking.

The guide support comprises an installation part and a supporting part, wherein the lower end of the installation part is connected with the pulley support, the upper end of the supporting part supports the arc floating seat, threads are arranged at the upper end of the supporting part, a height adjusting hand wheel is connected with the threads at the thread position, the arc floating seat is sleeved on the supporting part, and a return spring is sleeved on the supporting part between the lower surface of the arc floating seat and the upper surface of the installation part.

The arc floating seat is sleeved on a part of the supporting part and is provided with a waist-shaped hole, the supporting part is provided with a limit screw, and the limit screw penetrates through the waist-shaped hole to limit the adjusting amplitude of the arc floating seat.

The working principle of the invention is as follows:

based on the principle of two identical inner and outer thread engagement bearing forces, after the pulley bracket is sleeved with the adjusting screw rod, the adjusting screw rod and the rotary locking sleeve are rotated together by 90 degrees anticlockwise (namely the rotary locking sleeve is limited to the right limit), and the thread on the arc side of the adjusting screw rod is engaged with the thread on the straight side of the adjusting screw rod nut, so that the adjusting screw rod nut supports the adjusting screw rod, and the pulley bracket is supported; the rotation locking sleeve and the external thread adjusting screw rod are rotated clockwise by 90 degrees (namely, the rotation locking sleeve is limited at the left limit), so that the adjusting screw rod and the adjusting screw rod nut thread are changed into a disengaged state from an engaged state, namely, the arc side of the adjusting screw rod corresponds to the arc side of the inner hole of the adjusting screw rod nut, and the threads are not engaged with each other, thereby realizing the lifting and descending of the external thread adjusting screw rod and realizing the principle of randomly adjusting the height of the pulley.

Before well testing, firstly, an adjusting screw rod nut welded with a cross mounting seat is connected with an adjusting screw rod nut mounting seat by a cross mounting seat fixing screw, a rotary locking sleeve is sleeved on the adjusting screw rod nut, the adjusting screw rod nut is connected with the rotary locking sleeve by a rotary locking sleeve limiting screw, the adjusting screw rod nut mounting seat is sleeved on a circular table at the upper end of a blowout-preventing pipe, then the lower end of a pulley bracket is inserted into an external thread adjusting screw rod, the pulley bracket locking sleeve is arranged from the lower end of the external thread adjusting screw rod, the internal thread of the pulley bracket locking sleeve is screwed with the external thread at the lower end of the pulley bracket by a straight screwdriver, the through hole of the external thread adjusting screw rod, the internal thread hole at the inner side of the straight edge of the pulley bracket and the internal thread hole at the outer side of the pulley bracket locking sleeve are aligned, the fixing screw of the pulley bracket locking sleeve penetrates through the, Pulley support lower extreme internal thread hole and locking, one hand clockwise gyration locking cover and external screw thread accommodate the lead screw 90 degrees (the spacing left limit of gyration locking cover promptly), another hand will connect integrative loose pulley assembly's pulley support lower extreme and pass gyration locking cover and insert a support section of thick bamboo in, the upper portion round step bottom surface to external screw thread accommodate the lead screw meets with gyration locking cover top surface, accommodate the lead screw nut promptly and support the design height that highly returns former pulley, anticlockwise rotation locking cover and external screw thread accommodate the lead screw 90 degrees (the spacing right limit of gyration locking cover promptly), with gyration locking cover locking hand wheel locking, can carry out the well testing operation.

The instrument is started to a well mouth, the test gate 2/3 is closed firstly, the instrument string is confirmed to the detection gate plate after being arranged above the gate, the test gate is closed completely, the pressure is zero after emptying, the external thread adjusting screw rod and the rotary locking sleeve are rotated clockwise by 90 degrees (namely, the rotary locking sleeve is limited at the left side), the external thread adjusting screw rod is lifted to the maximum height, then the external thread adjusting screw rod and the rotary locking sleeve are rotated anticlockwise by 90 degrees (namely, the rotary locking sleeve is limited at the right side), the rotary locking sleeve is locked by the hand wheel, the external thread adjusting screw rod is locked without descending, and the adjusting screw rod of the adjustable well testing sky pulley is adjusted to the maximum lifting height.

The blowout prevention box and the blowout prevention pipe are connected through a screw thread, a steel wire is pulled upwards by a hand winch or manpower, the blowout prevention box and the instrument string ascend together, a blocking fork is clamped into a second flat square on the instrument string, then the steel wire is slowly lowered, the blocking fork is located at the opening of the blowout prevention pipe, a wellhead operator holds the upper end of a main body of the catcher by one hand, the catcher rotates a sleeve by the other hand, a clamping block is completely retracted into the main body under the action of a clamping block return spring, the restraint on a rope cap is relieved, the rope cap is separated from the catcher, the blowout prevention box slides downwards along the steel wire to the ground to be placed, and then the instrument string is taken out of the blowout prevention pipe. The well testing steel wire is standardized to be lifted and lowered, so that the possibility of not using a crane is realized when the high-pressure and high-yield well testing operation needs larger weight.

Compared with the prior art, the invention has the technical effects that:

1. the invention has the advantages of novel design, ingenious and reasonable design, simple and compact integral structure, simple and convenient processing and manufacturing, low cost, excellent performance, safety, reliability, simple installation process, convenient field assembly, high applicability, convenient height adjustment and reutilization.

2. According to the invention, the inner hole of the adjusting screw rod nut is provided with a waist-shaped hole-shaped trapezoidal thread section, the straight side is provided with threads, the threads are consistent with the external threads of the external thread adjusting screw rod, the rotary locking sleeve and the external thread adjusting screw rod rotate for 90 degrees during lifting and positioning operation, the contact surface between the internal threads on the upper part of the bracket and the external thread adjusting screw rod is large, the bearing capacity is large, automatic guiding is not inclined, and the height adjusting effect in an effective range is good. When the height needs to be adjusted, the arc side of the adjusting screw rod corresponds to the arc side of the inner hole of the adjusting screw rod nut, and the threads are not mutually occluded, so that the rapid adjustment between the adjusting screw rod nut and the adjusting screw rod is realized, and the operation requirement is met. Compared with an adjusting screw rod and an adjusting screw rod nut in the prior art, the height adjustment of the adjusting screw rod nut is realized through the thread matching between the adjusting screw rod and the screw rod nut, the height adjustment speed of the adjusting mode is relatively low, and the operation requirement cannot be met.

3. The adjusting screw rod nut extends longer from the cross mounting seat, so that the guide of the external thread adjusting screw rod and the protection of the external thread of the adjusting screw rod are facilitated, the carrying link is prevented from being damaged, the reliability of use in the range of effective height and optional adjustment is enhanced, and the body of an operator is protected from being injured when the external thread adjusting screw rod returns. During the well testing tripping operation, the external thread adjusting screw rod is seated on the adjusting screw rod nut, the stress problem of the pulley in the tripping process is not influenced, and the device is safer than a device which only increases the rigid length of the pulley support.

4. The lower end of the pulley bracket is provided with a pulley radial bearing, so that the pulley can freely rotate in the radial direction without clamping stagnation. The lower end of the pulley bracket is provided with a bracket locking sleeve, so that the pulley bracket is prevented from being separated from the adjusting screw rod, and the pulleys are prevented from moving up and down relative to the adjusting screw rod in the adjusting process.

5. The long waist-shaped hole is established to gyration locking cover straight hole section excircle, and the heavy platform is established respectively to the spacing limit normal direction surface at waist-shaped hole both ends, is equipped with the central screw hole of the gyration locking cover locking hand wheel of boss with gyration locking cover stop screw in, passes gyration locking cover waist-shaped hole again, installs on the internal thread hole of adjusting screw nut outside upper end, makes gyration locking cover locking and delocalization position more reliable. The rotary locking sleeve is sleeved on the adjusting screw rod nut, the upper end surface of the trapezoidal nut section of the adjusting screw rod nut is attached to the contact surface of the straight hole section and the waist-shaped hole section of the rotary locking sleeve, the hole diameter of the straight hole section is slightly larger than the outer diameter of the adjusting screw rod nut, the straight hole section and the adjusting screw rod nut are in transition fit, the adjusting screw rod nut can also play a certain guiding role for the raised external thread adjusting screw rod, and the verticality during operation is guaranteed. The annular knurl is established to gyration locking cover excircle, increases frictional force, improves well head operation degree of safety.

6. The round side of the adjusting screw rod nut mounting seat is provided with a rectangular hole, so that the stress is not influenced, and the weight is reduced. The upper aperture of the external thread adjusting screw rod is slightly smaller than the diameter of a pulley radial bearing at the lower end of the pulley bracket, the depth of the aperture is slightly larger than the thickness of the pulley radial bearing, and the port of the pulley bracket locking sleeve after tight fitting is connected with a lower inner step of a central through hole of the external thread adjusting screw rod; when the crown block rotates radially, the pulley bracket and the external thread adjusting screw rod cannot interfere with each other, and the rotation is flexible. The external thread adjusting screw rod is hollow, so that the supporting strength is not influenced, the whole weight is reduced, and the lifting and resetting operation of the external thread adjusting screw rod by well mouth operators is labor-saving, convenient, flexible and free. A through hole is arranged on one side of the external thread adjusting screw rod, so that the pulley bracket locking sleeve fixing screw can be conveniently mounted and dismounted, and the pulley bracket locking sleeve fixing screw is not loosened after being screwed down.

7. The external thread adjusting screw rod is matched with the rotary locking sleeve through the waist-shaped hole, and the external thread adjusting screw rod and the rotary locking sleeve can synchronously rotate to a locking limit or an unlocking limit, so that the height of the top pulley is adjusted. After the external thread adjusting screw rod is lifted upwards, the two sides of the arc provided with the trapezoidal threads are opposite to the directions of the winch and the blowout prevention pipe, the thread matching is tight, the arc is firmly occluded with each other when stressed and does not incline, and large and uniform supporting force is provided for the pulley support. Compared with the other independent increase of a telescopic multi-section telescopic pipe well testing top pulley connected through a bolt, the longitudinal lifting of the external thread adjusting screw rod has the advantages of more convenient height adjustment and simplification of the construction process flow. Pulley support locking cover and pulley support fifth section stepped shaft outside all establish with the identical internal thread of pulley support locking cover set screw external screw thread, fixed pulley support locking cover lower extreme pulley support, more reliable, when one of them part internal thread became invalid, another part internal thread still played the fixed action to smooth support lower extreme lock sleeve in sky, was unlikely to become flexible. The raised crown block facilitates separation of the blowout prevention box from the catcher, so that the instrument string is loaded into and unloaded from the blowout prevention pipe. The on-site maintenance and replacement are convenient, the repair and use can be carried out for many times, the service life is long, the time and the labor are saved, the working efficiency is improved, and the labor intensity is reduced. The blowout preventer is replaced by the external thread adjusting screw rod with different lengths, so that the requirements of assembling and disassembling the blowout preventer string under different well conditions on site can be met.

Drawings

FIG. 1 is a schematic view of the overall structure of an adjustable well testing sky pulley of the present invention;

FIG. 2 is a schematic structural view of an arc wire pressing assembly according to the present invention;

fig. 3 is a schematic view of a sheave assembly of the present invention;

FIG. 4 is an exploded view of the pulley bracket assembly of the present invention;

FIG. 5 is a schematic view of the overall structure of the pulley bracket assembly of the present invention;

FIG. 6 is a schematic longitudinal cross-sectional view of an adjusting lead screw nut of the present invention;

FIG. 7 is a schematic longitudinal sectional view of the lead screw of the present invention;

reference numerals: 1. the guide support, 2, a guide support fixing screw, 3, a guide support return spring, 4, an arc floating seat, 5, a height adjusting hand wheel, 6, an arc floating seat limit screw, 7, a wire pressing wheel, 8, a wire pressing wheel fixing shaft, 9, a wire pressing wheel fixing shaft cotter pin, 10, a pulley, 11, a pulley bearing, 12, a pulley shaft, 13, a key, 14, a pulley bearing cover, 15, a pulley bearing cover fixing screw, 16, an adjusting screw nut, 17, an adjusting screw nut mounting seat, 18, a cross mounting seat, 19, a cross mounting seat fixing screw, 20, a pulley radial bearing, 21, a pulley support, 22, an adjusting screw, 23, a rotary locking sleeve, 24, a rotary locking sleeve limit screw, 25, a rotary locking sleeve locking hand wheel, 26, a support locking sleeve, 27, and a support locking sleeve fixing screw.

Detailed Description

The technical scheme of the invention is further elaborated in the following by combining the drawings in the specification.