CN216381193U - Screw drill sealing transmission shaft assembly - Google Patents
Screw drill sealing transmission shaft assembly Download PDFInfo
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- CN216381193U CN216381193U CN202123066163.4U CN202123066163U CN216381193U CN 216381193 U CN216381193 U CN 216381193U CN 202123066163 U CN202123066163 U CN 202123066163U CN 216381193 U CN216381193 U CN 216381193U
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Abstract
The application relates to a screw rod drilling tool sealing transmission shaft assembly belongs to oil, for the natural gas screw rod drilling tool technical field in the pit, include: the transmission shaft device comprises a shell and a transmission shaft, wherein the shell is of a hollow tubular structure, a bearing assembly for rotatably supporting the transmission shaft is arranged in the shell, and the transmission shaft is positioned in the shell and can rotate in the shell; the sealing device comprises an upper sealing ring which is positioned at the upper end of the shell and is in sealing connection with the transmission shaft, and a lower sealing ring which is positioned at the lower end of the shell and is in sealing connection with the transmission shaft, wherein a closed oil cavity of the lubricating bearing assembly is formed between the upper sealing ring and the lower sealing ring; and the pressure compensation device is positioned on the shell and communicated with the closed oil cavity, and the pressure compensation device balances the pressure difference between the inside of the closed oil cavity and the outside of the closed oil cavity through expansion and contraction. The sealing device has the advantages that the pressure at the two ends of the sealed oil cavity is equal, the pressure inside and outside the sealed oil cavity is equal, the sealing performance of the sealing device is improved, and the service life of the transmission shaft assembly is prolonged.
Description
Technical Field
The application relates to the technical field of underground screw drilling tools for petroleum and natural gas, in particular to a sealing transmission shaft assembly of a screw drilling tool.
Background
The screw drill is one of downhole power tools used in petroleum drilling or workover operations, and the transmission shaft assembly is one of four main components of the screw drill and is also one of the most vulnerable components, and the transmission shaft assembly is used for transmitting the output torque and the rotating speed of a motor to a drill bit and bearing axial and radial loads generated in the drilling process.
The conventional screw drilling tool technology is a mud lubrication transmission shaft assembly technology, has the phenomenon of short service life, cannot perform the operation of a short-radius horizontal well, and cannot meet the current requirements of accelerating the drilling speed to be increased, shortening the drilling period and reducing the drilling cost.
The slurry lubricating transmission shaft assembly mainly comprises a transmission shaft, a lower TC bearing static sleeve, a lower TC bearing movable sleeve, a transmission shaft shell, an anti-drop mechanism, a lower positioning sleeve, a spacer bush, a serial bearing, an upper TC bearing static sleeve, an upper TC bearing movable sleeve and the like.
During drilling, mud pumped by a mud pump enters a transmission shaft assembly through a drilling tool water hole, and one path of mud enters a drill bit nozzle through the transmission shaft water hole, is emitted to the bottom of a well and then returns to the ground with rock debris; the other path flows to the serial bearing through a gap between the upper TC bearing static sleeve and the upper TC bearing movable sleeve, and flows to an annular space outside the drilling tool through a gap between the lower TC bearing static sleeve and the lower TC bearing movable sleeve.
The whole TC bearing and the tandem bearing are exposed in the slurry, and the slurry contains tiny rock particles and chemical corrosion of the slurry, so that the service life of the bearing is greatly shortened. In the underbalanced drilling operation, because the bearings cannot be lubricated and cooled by foam or air, the service life of the mud lubricating bearing is shorter, and the mud lubricating bearing usually fails after being used for 40-50 hours, so that not only is the drilling tool frequently tripped, but also the drilling accidents caused by the dead bearing are easy to cause and cannot meet the requirements of the drilling operation.
At present, the existing sealed transmission shaft assembly generally adopts piston sealing devices at the upper end and the lower end of a bearing respectively to compensate and realize the pressure balance inside and outside a sealed cavity of the sealed transmission shaft assembly, thereby improving the sealing reliability. The piston is under the effect of inside and outside pressure differential, the continuous oil discharge can appear in the sealing washer, the piston also can constantly produce axial displacement, whole piston system is in dynamic balance state, for guaranteeing transmission shaft life, often need set up sufficient piston stroke according to life requirement in the design, piston sealing device self also needs certain length to satisfy the sealing reliability needs, so sealing transmission shaft assembly overall length commonly used is longer, lead to sealing reliability poor, screw rod drilling tool knee-point is long, the build slope rate is lower, the application of sealing transmission shaft assembly in highly deviated well and short radius horizontal well drilling operation has been restricted.
Disclosure of Invention
The embodiment of the application provides a sealed transmission shaft assembly of a screw drill, and aims to solve the problems that in the related art, the sealing reliability of the transmission shaft assembly is poor, and the service life is short.
The embodiment of the application provides a screw rod drilling tool seals transmission shaft assembly includes:
the transmission shaft device comprises a shell and a transmission shaft, the shell is of a hollow tubular structure, a bearing assembly for rotatably supporting the transmission shaft is arranged in the shell, and the transmission shaft is positioned in the shell and can rotate in the shell;
the sealing device comprises an upper sealing ring and a lower sealing ring, wherein the upper sealing ring is positioned at the upper end of the shell and is in sealing connection with the transmission shaft, the lower sealing ring is positioned at the lower end of the shell and is in sealing connection with the transmission shaft, and a closed oil cavity for lubricating the bearing assembly is formed between the upper sealing ring and the lower sealing ring;
the pressure compensation device is positioned on the shell and communicated with the closed oil cavity, and the pressure compensation device balances the pressure difference between the inside of the closed oil cavity and the outside of the closed oil cavity through expansion and contraction.
In some embodiments: the pressure compensation device comprises a rubber oil bag communicated with the oil through hole, and the rubber oil bag balances the pressure difference between the inside of the closed oil cavity and the outside of the closed oil cavity by oil charging and oil discharging.
In some embodiments: the oil storage hole is located at the top of the upper sealing ring or the bottom of the lower sealing ring, at least part of the rubber oil bag is exposed outside the closed oil cavity, and an oil drainage hole for draining grease in the rubber oil bag to the outside of the closed oil cavity is formed in the rubber oil bag.
In some embodiments: the rubber oil bag is of a circular sheet structure, an annular groove with telescopic capacity and an annular bulge are formed in the rubber oil bag, and an annular sealing ring is arranged on the circumference of the rubber oil bag;
the pressure compensation device is characterized by further comprising an oil storage cup pressed on the annular sealing ring, a gland is arranged at one end, away from the rubber oil bag, of the oil storage cup, an oil filling hole is formed in the gland, and a plug for sealing the oil filling hole is further arranged on the gland.
In some embodiments: the oil storage cup is of a cylindrical structure with two ends penetrating, and one end of the oil storage cup, which is close to the gland, is provided with a radial oil groove communicated with the oil storage hole;
the circumference of gland is equipped with the O shape rubber circle with the inner wall sealing connection of oil storage hole, the inner wall of oil storage hole still is equipped with the retaining ring for the hole with gland butt.
In some embodiments: the oil storage hole is close to the oil drain hole has been seted up to the one end of transmission shaft, the draining hole and the oil drain hole intercommunication of rubber oil bag, be equipped with the annular gap with the oil drain hole intercommunication between the casing of upper seal circle top or lower seal circle bottom and the transmission shaft, annular gap just with seal the outside intercommunication of oil pocket.
In some embodiments: the shell comprises an upper shell, a transmission shaft shell, a bearing shell and a lower shell which are sequentially in threaded connection from top to bottom, wherein an upper sealing ring is hermetically connected between the upper shell and the transmission shaft, and a lower sealing ring is hermetically connected between the lower shell and the transmission shaft;
the pressure compensation device is arranged on the upper shell and/or the lower shell, the pressure compensation device is provided with a plurality of pressure compensation devices, and the plurality of pressure compensation devices are circumferentially distributed on the upper shell and/or the lower shell.
In some embodiments: a flow limiting valve is arranged between an inner hole in the top of the upper shell and the transmission shaft, and comprises a static valve connected with the inner hole of the upper shell and a movable valve fixed on the transmission shaft and in clearance fit with the static valve;
the drilling fluid discharge device is characterized in that a radial pressure relief hole is formed in the side wall of the upper shell, and the radial pressure relief hole is communicated with an annular gap between an inner hole in the top of the upper shell and the transmission shaft so as to discharge drilling fluid in the annular gap.
In some embodiments: oil filling channels communicated with the closed oil cavities are formed in the side walls of the transmission shaft shell and the bearing shell, and plugs for plugging the oil filling channels are fixedly arranged on the side walls of the transmission shaft shell and the bearing shell of the oil filling channels;
the bearing assembly comprises an upper thrust bearing and a lower thrust bearing which are positioned in a transmission shaft shell, a bearing ring is arranged between the upper thrust bearing and the lower thrust bearing, and an adjusting washer is arranged between the bottom of the lower thrust bearing and the bearing shell.
In some embodiments: the top threaded connection of transmission shaft has the water cap, the water cap is equipped with the inlet opening with the eye of a river intercommunication of transmission shaft, the bottom of casing is equipped with down scrapes the circle with the transmission shaft laminating down.
The beneficial effect that technical scheme that this application provided brought includes:
the embodiment of the application provides a screw drill sealed transmission shaft assembly, and the screw drill sealed transmission shaft assembly is provided with a transmission shaft device, wherein the transmission shaft device comprises a shell and a transmission shaft, the shell is of a hollow tubular structure, a bearing assembly for rotatably supporting the transmission shaft is arranged in the shell, and the transmission shaft is positioned in the shell and can rotate in the shell; the sealing device comprises an upper sealing ring which is positioned at the upper end of the shell and is in sealing connection with the transmission shaft, and a lower sealing ring which is positioned at the lower end of the shell and is in sealing connection with the transmission shaft, wherein a closed oil cavity of the lubricating bearing assembly is formed between the upper sealing ring and the lower sealing ring; and the pressure compensation device is positioned on the shell and is communicated with the closed oil cavity, and the pressure compensation device balances the pressure difference between the inside of the closed oil cavity and the outside of the closed oil cavity by expanding and contracting.
Therefore, the screw drilling tool sealing transmission shaft assembly is provided with the pressure compensation device, the pressure compensation device is located on the shell and communicated with the closed oil cavity, and the pressure compensation device balances the pressure difference between the inside of the closed oil cavity and the outside of the closed oil cavity through expansion and contraction. The pressure at the two ends of the closed oil cavity is equal, and the pressure inside the closed oil cavity is equal to the pressure outside the closed oil cavity, so that the sealing performance of the sealing device is improved, and the service life of the transmission shaft assembly is prolonged. Therefore, the sealed transmission shaft assembly of the screw drilling tool has the advantages of simple and compact structure, shortened length of the transmission shaft, small bending deformation of the transmission shaft, improved sealing reliability, long service life and capability of meeting the requirements of slurry drilling construction under underbalanced drilling or severe working conditions. And the bending point distance of the screw drill is short, the build rate is high, and the screw drill is suitable for being applied to drilling operation of a high-inclination well and a short-radius horizontal well.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a schematic structural diagram of an embodiment of the present application;
FIG. 2 is an enlarged view of a portion of FIG. 1 at A;
FIG. 3 is a schematic structural diagram of another embodiment of the present application;
FIG. 4 is a sectional view showing the structure of a rubber oil bladder according to an embodiment of the present invention.
Reference numerals:
1. a housing; 2. a drive shaft; 3. an upper sealing ring; 4. a lower seal ring; 5. a pressure compensation device; 6. a bearing assembly; 7. a flow-limiting valve; 8. a water cap; 9. scraping the ring downwards; 10. sealing the oil cavity; 11. an upper housing; 12. a drive shaft housing; 13. a bearing housing; 14. a lower housing; 15. a rubber seal ring;
7a, a static valve; 7b, a valve; 11a, an oil storage hole; 11b, oil through holes; 11c, an annular gap; 11d, radial pressure relief holes;
12a, an upper wear-resistant bushing; 12b, a first oil filling channel; 12c, a first plug; 13a, a lower wear-resistant bushing; 13b, a second oil filling channel; 13c, a second plug;
51. a rubber oil bladder; 52. an oil storage cup; 53. a gland; 54. plugging with a thread; 55. an O-shaped rubber ring; 56. a retainer ring for a bore;
51a, a circular bulge; 51b, an annular groove; 51c, an annular seal ring; 51d, oil drainage holes;
61. an upper thrust bearing; 62. a lower thrust bearing; 63. a pressure-bearing ring; 64. and adjusting the gasket.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The embodiment of the application provides a sealed transmission shaft assembly of a screw drill, which can solve the problems of poor sealing reliability and short service life of the transmission shaft assembly in the related technology.
Referring to fig. 1 and 3, an embodiment of the present application provides a sealed transmission shaft assembly of a screw drill, including:
the transmission shaft device comprises a shell 1 and a transmission shaft 2, wherein the shell 1 is of a hollow tubular structure, a bearing assembly 6 for rotatably supporting the transmission shaft 2 is arranged in the shell 1, the transmission shaft 2 is positioned in the shell 1 and can freely rotate in the shell 1, and the upper end and the lower end of the transmission shaft 2 extend out of the shell 1. The top of the transmission shaft 2 is used for being connected with a water cap 8 in a threaded mode, and the bottom of the transmission shaft 2 is used for being connected with a drill bit in a threaded mode.
The sealing device comprises an upper sealing ring 3 which is positioned at the upper end of the shell 1 and is in sealing connection with the transmission shaft 2, and a lower sealing ring 4 which is positioned at the lower end of the shell 1 and is in sealing connection with the transmission shaft. An enclosed oil chamber 10 of the lubricating bearing assembly 6 is formed between the upper sealing ring 3 and the lower sealing ring 4, the enclosed oil chamber 10 is used for storing lubricating grease to lubricate moving parts in the shell 1 on one hand, and the enclosed oil chamber 10 is used for ensuring that the moving parts in the shell 1 are not contacted with outside drilling fluid and preventing the drilling fluid from being corroded and the debris from being worn.
And the pressure compensation device 5 is positioned on the shell 1 and is communicated with the closed oil cavity 10, and the pressure compensation device 5 is expanded and contracted to balance the pressure difference between the inside of the closed oil cavity 10 and the outside of the closed oil cavity 10. After the pressure compensation device 5 balances the pressure difference between the inside of the closed oil cavity 10 and the outside of the closed oil cavity 10 through expansion and contraction, the upper sealing ring 3 and the lower sealing ring 4 can keep reliable sealing performance under the non-differential pressure sealing condition.
When the screw drill sealed transmission shaft assembly works in a well bottom, in the initial stage, the external pressure of the sealed oil cavity 10 is equal to the annular pressure at the well depth, the internal pressure of the sealed oil cavity 10 is equal to the atmospheric pressure, and at the moment, the external pressure of the sealed oil cavity 10 is greater than the internal pressure of the sealed oil cavity 10. Under the action of the internal and external pressure difference of the pressure compensation device 5, the pressure compensation device 5 generates shrinkage deformation towards the inside of the closed oil cavity 10, the internal volume of the pressure compensation device 5 is reduced, and the pressure is increased until the internal pressure and the external pressure are balanced.
Because the length of the transmission shaft assembly is generally within 1.5 m, the annular pressure at the upper part and the annular pressure at the lower part of the sealed transmission shaft assembly of the screw drill are basically equal, and the external pressure of the sealed oil cavity 10 is also equal to the internal pressure of the sealed oil cavity 10 for the lower part of the sealed transmission shaft assembly of the screw drill. The lower part of the screw drill sealed transmission shaft assembly can be not provided with a pressure compensation device 5 any more, and the length of the transmission shaft 2 is further reduced. The upper sealing ring 3 and the lower sealing ring 4 can keep reliable sealing performance under the non-differential pressure sealing condition.
When the screw drill sealing transmission shaft assembly works in a drilling process, the transmission shaft 2 rotates in the shell 1 at a high speed for a long time, lubricating grease in the closed oil cavity 10 generates heat to generate volume expansion, and the internal pressure of the closed oil cavity 10 is greater than the external pressure of the closed oil cavity 10. Redundant lubricating grease in the closed oil cavity 10 enters the pressure compensation device 5, the pressure compensation device 5 expands and deforms, the size of the pressure compensation device is increased, the balance of the internal pressure and the external pressure of the closed oil cavity 10 is kept again, and the reliable sealing of the upper sealing ring 3 and the lower sealing ring 4 on the transmission shaft 2 and the shell 1 is kept.
The screw drill sealed transmission shaft assembly provided by the embodiment of the application is provided with the pressure compensation device 5, the pressure compensation device 5 is positioned on the shell 1 and is communicated with the closed oil cavity 10, and the pressure compensation device 5 balances the pressure difference between the inside of the closed oil cavity 10 and the outside of the closed oil cavity 10 through self expansion and contraction. The pressure at the two ends of the closed oil cavity 10 is equal, the pressure inside the closed oil cavity 10 is equal to the pressure outside the closed oil cavity 10, the sealing performance of the sealing device is improved, and the service life of the transmission shaft assembly is prolonged.
The sealed transmission shaft assembly of the screw drilling tool has the advantages of simple and compact structure, shortened length of the transmission shaft 2, small bending deformation of the transmission shaft 2, improved sealing reliability, long service life and capability of meeting the requirements of slurry drilling construction under underbalanced drilling or severe working conditions. And the bending point distance of the screw drill is short, the build rate is high, and the screw drill is suitable for being applied to drilling operation of a high-inclination well and a short-radius horizontal well.
In some alternative embodiments: referring to fig. 1 to 4, the embodiment of the present application provides a sealed transmission shaft assembly of a screw drill, an oil storage hole 11a for accommodating a pressure compensation device 5 is formed in a side wall of a housing 1 of the sealed transmission shaft assembly of the screw drill, and an oil through hole 11b communicating with a closed oil cavity 10 is formed in the oil storage hole 11 a. The pressure compensating device 5 includes a rubber oil bag 51 communicating with the oil through hole 11b, and the rubber oil bag 51 balances the pressure difference between the inside of the closed oil chamber 10 and the outside of the closed oil chamber 10 by oil charging and discharging.
The oil storage hole 11a is located at the top of the upper sealing ring 3 or the bottom of the lower sealing ring 4, so that the rubber oil bag 51 can be at least partially exposed outside the closed oil cavity 10, and when the pressure outside the closed oil cavity 10 is greater than the pressure inside the closed oil cavity 10, the pressure outside the closed oil cavity 10 presses the rubber oil bag 51 to fill oil into the closed oil cavity 10, so as to accurately sense and balance the pressure difference between the inside and the outside of the closed oil cavity 10. The rubber oil bag 51 is provided with an oil drain hole 51d for draining the grease in the rubber oil bag 51 to the outside of the closed oil chamber 10.
The oil drain hole 51d on the rubber oil bag 51 is a pinhole with a small diameter, and the oil drain hole 51d is in a closed state when the internal and external pressures of the closed oil chamber 10 are the same; when the internal pressure of the closed oil chamber 10 is greater than the external pressure of the closed oil chamber 10 and the pressure difference reaches a threshold value, the oil drain hole 51d is automatically opened to drain the grease in the rubber oil bag 51 to the outside of the closed oil chamber 10, so that the balance of the internal and external pressures of the closed oil chamber 10 is ensured, and the service life of the rubber oil bag 51 is ensured.
In some alternative embodiments: referring to fig. 2 and 4, the embodiment of the present application provides a sealed transmission shaft assembly of a screw drill, a rubber oil bag 51 of the sealed transmission shaft assembly of the screw drill is a circular sheet-shaped structure, an annular groove 51b and an annular protrusion 51a with telescopic capability are provided on the rubber oil bag 51, and an annular sealing ring 51c is provided on the circumference of the rubber oil bag 51. The annular groove 51b, the annular protrusion 51a and the annular seal ring 51c of the rubber oil bag 51 are integrally formed of an elastic rubber material.
The pressure compensation device 5 further comprises an oil storage cup 52 pressed on the annular sealing ring 51c, a gland 53 is arranged at one end of the oil storage cup 52 far away from the rubber oil bag 51, an oil filling hole (not shown in the figure) for adding lubricating grease into the oil storage cup 52 is formed in the gland 53, and a plug 54 for closing the oil filling hole is further arranged on the gland 53. The oil reservoir 52 has a cylindrical structure with both ends penetrating therethrough, and a radial oil groove communicating with the oil storage hole 11a is opened at one end of the oil reservoir 52 close to the cover 53. An O-ring 55 is provided around the gland 53 to be sealingly connected to the inner wall of the oil reservoir 11a, and a hole stopper 56 is provided on the inner wall of the oil reservoir 11a to abut against the gland 53.
An oil discharge hole is formed in one end, close to the transmission shaft 2, of the oil storage hole 11a, an oil discharge hole 51d of the rubber oil bag 51 is communicated with the oil discharge hole, an annular gap 11c communicated with the oil discharge hole is formed between the shell 1 at the top of the upper sealing ring 3 or the bottom of the lower sealing ring 4 and the transmission shaft 2, and the annular gap 11c is communicated with the outside of the closed oil cavity 10.
The rubber oil bag 51, the oil storage cup 52, the gland 53, the plug 54 and the O-shaped rubber ring 55 of the embodiment of the application jointly form the pressure compensation device 5 for storing lubricating grease, the pressure compensation device 5 is located in the oil storage hole 11a and is communicated with the oil storage hole 11a, and the oil storage hole 11a is communicated with the closed oil cavity 10 through the oil through hole 11 b. The pressure compensation device 5 can sense the pressure difference between the inside and the outside of the closed oil cavity 10, and adaptively adjust the expansion and the contraction of the rubber oil bag 51 according to the pressure difference between the inside and the outside of the closed oil cavity 10, thereby achieving the effect of balancing the pressure inside and the pressure outside the closed oil cavity 10.
An annular gap 11c communicated with an oil discharge hole is formed between the shell 1 at the top of the upper sealing ring 3 or the bottom of the lower sealing ring 4 and the transmission shaft 2, the annular gap 11c is communicated with the outside of the closed oil cavity 10, the pressure of the annular gap 11c is the same as the pressure of the outside of the closed oil cavity 10, the rubber oil bag 51 is exposed outside the closed oil cavity 10 through the oil discharge hole, the oil discharge hole can discharge lubricating grease in the rubber oil bag 51 to the outside of the closed oil cavity 10, the rubber oil bag 51 can also accurately sense the pressure of the outside of the closed oil cavity 10 through the oil discharge hole, and when the pressure of the outside of the closed oil cavity 10 is larger than the pressure of the inside of the closed oil cavity 10, the pressure of the outside of the closed oil cavity 10 presses the rubber oil bag 51 to charge the inside of the closed oil cavity 10.
In some alternative embodiments: referring to fig. 1 and 3, the embodiment of the present application provides a sealed transmission shaft assembly of a screw drill, a housing 1 of the sealed transmission shaft assembly of the screw drill includes an upper housing 11, a transmission shaft housing 12, a bearing housing 13 and a lower housing 14, which are sequentially connected by a thread from top to bottom, an upper seal ring 3 is hermetically connected between the upper housing 11 and a transmission shaft 2, and a lower seal ring 4 is hermetically connected between the lower housing 14 and the transmission shaft 2. The pressure compensation device 5 is located on the upper housing 11, and the pressure compensation device 5 may be provided on both the upper housing 11 and the lower housing 14. The pressure compensation device 5 may be provided in plurality according to actual needs, and a plurality of pressure compensation devices 5 are circumferentially arranged on the upper casing 11 and the lower casing 14.
The joints of the upper shell 11, the transmission shaft shell 12, the bearing shell 13 and the lower shell 14 are all provided with rubber sealing rings 15, so that the sealing performance of the threaded joints of the upper shell 11, the transmission shaft shell 12, the bearing shell 13 and the lower shell 14 is ensured. Drilling fluid outside the enclosed oil chamber 10 is prevented from entering the inside of the enclosed oil chamber 10 to contaminate and corrode moving parts within the upper housing 11, the drive shaft housing 12, the bearing housing 13, and the lower housing 14.
An upper wear-resistant bush 12a is fixedly arranged in an inner hole of the transmission shaft shell 12, and the inner hole of the upper wear-resistant bush 12a is matched and rotationally connected with the transmission shaft 2. The inner hole of the bearing shell 13 is fixedly provided with a lower wear-resistant bush 13a, and the inner hole of the lower wear-resistant bush 13a is matched and rotatably connected with the transmission shaft 2. The upper wear-resistant bush 12a and the lower wear-resistant bush 13a are both located in the closed oil chamber 10, so that the lubricating grease in the closed oil chamber 10 sufficiently lubricates the mating surfaces of the upper wear-resistant bush 12a and the lower wear-resistant bush 13a and the transmission shaft 2.
The upper wear-resistant bush 12a and the lower wear-resistant bush 13a are used for improving the wear resistance between the transmission shaft housing 12 and the bearing housing 13 and the transmission shaft 2 and prolonging the service life of the transmission shaft housing 12 and the bearing housing 13, and the upper wear-resistant bush 12a and the lower wear-resistant bush 13a are also used for providing radial positioning for the transmission shaft 2 in the housing 1 and improving the coaxiality between the transmission shaft 2 and the housing 1. The surfaces of the matching surfaces of the transmission shaft 2 and the upper wear-resistant bush 12a and the lower wear-resistant bush 13a are plated with chrome or sprayed with carbide, the thickness is 0.05mm-0.50mm, and the sealing performance of the sealing element is prevented from being influenced after the transmission shaft 2 is worn.
In some alternative embodiments: referring to fig. 1 and 3, the embodiment of the present application provides a sealed transmission shaft assembly of a screw drill, a flow limiting valve 7 is arranged between an inner hole at the top of an upper shell 11 of the sealed transmission shaft assembly of the screw drill and a transmission shaft 2, the flow limiting valve 7 comprises a static valve 7a connected with the inner hole of the upper shell 11, and a movable valve 7b fixed on the transmission shaft 2 and in clearance fit with the static valve 7 a. The side wall of the upper shell 11 is provided with a radial pressure relief hole 11d, and the radial pressure relief hole 11d is communicated with an annular gap 11c between an inner hole in the top of the upper shell 11 and the transmission shaft 2 so as to discharge drilling fluid in the annular gap 11 c.
The top of the transmission shaft 2 is in threaded connection with a water cap 8, the water cap 8 is provided with a water inlet communicated with a water hole of the transmission shaft 2, and the water cap 8 is in threaded connection with the transmission shaft 2 to fix the movable valve 7b on the transmission shaft 2. The movable valve 7b and the static valve 7a are metal cylinders which are coaxially arranged, the movable valve 7b and the static valve 7a are in clearance fit, the movable valve 7b and the static valve 7a rotate relatively during work, the fit clearance between the movable valve 7b and the static valve 7a is 0.15-0.35mm, and the movable valve 7b and the static valve 7a have the functions of radial positioning and flow limitation. In order to improve the wear resistance of the movable valve 7b and the static valve 7a of the flow limiting valve 7 and prevent the flow of drilling fluid which flows from the pressure relief hole 11d to the shaft annulus from being increased after the fit clearance is increased, the movable valve 7b and the static valve 7a can be made of hard alloy pieces or surface welding wear-resistant alloy.
This application has seted up radial pressure release hole 11d on last casing 11's lateral wall, and radial pressure release hole 11d communicates with the annular gap 11c between 11 top holes of last casing and the transmission shaft 2 to the drilling fluid in the discharge annular gap 11 c. This radial pressure release hole 11d can be with the drilling fluid discharge to the annular space in the well in the annular space 11c, and the first aspect can utilize the drilling fluid to cool the heat that the valve 7b and the quiet valve 7a produced, and the second aspect can reduce the pressure of drilling fluid in the annular space 11c, is favorable to balancing the interior outer differential pressure of closed oil pocket 10. The bottom of the lower shell 14 is provided with a lower scraping ring 9 which is attached to the transmission shaft 2, and the lower scraping ring 9 is used for preventing rock debris at the well bottom from entering the lower shell 14 and damaging moving parts in the lower shell 14.
In some alternative embodiments: referring to fig. 1 and 3, in the sealed transmission shaft assembly of the screw drill according to the embodiment of the present invention, oil injection channels communicated with the closed oil cavity 10 are respectively formed on the side walls of the transmission shaft housing 12 and the bearing housing 13 of the sealed transmission shaft assembly of the screw drill, and plugs for plugging the oil injection channels are further fixedly arranged on the side walls of the transmission shaft housing 12 and the bearing housing 13. The oil injection passage specifically includes a first oil injection passage 12b provided on a side wall of the transmission shaft housing 12, and a second oil injection passage 13b provided on a side wall of the bearing housing 13. The plug specifically comprises a first plug 12c for plugging the first oil injection channel 12b, and a second plug 13c for plugging the second oil injection channel 13 b.
The bearing assembly 6 comprises an upper thrust bearing 61 and a lower thrust bearing 62 which are arranged in the transmission shaft shell 12 at intervals up and down, a bearing ring 63 is arranged between the upper thrust bearing 61 and the lower thrust bearing 62, and an adjusting washer 64 is arranged between the bottom of the lower thrust bearing 62 and the bearing shell 13. The upper thrust bearing 61, the lower thrust bearing 62, the pressure ring 63 and the adjusting washer 64 are the same as the axial positioning of the transmission shaft 2, and ensure that the transmission shaft 2 reliably rotates when the transmission shaft 2 is pressed.
Principle of operation
The embodiment of the application provides a sealed transmission shaft assembly of a screw drill, and the sealed transmission shaft assembly of the screw drill is provided with a transmission shaft device, wherein the transmission shaft device comprises a shell 1 and a transmission shaft 2, the shell 1 is of a hollow tubular structure, a bearing assembly 6 for rotatably supporting the transmission shaft 2 is arranged in the shell 1, and the transmission shaft 2 is positioned in the shell 1 and can rotate in the shell 1; the sealing device comprises an upper sealing ring 3 which is positioned at the upper end of the shell 1 and is in sealing connection with the transmission shaft 2, and a lower sealing ring 4 which is positioned at the lower end of the shell 1 and is in sealing connection with the transmission shaft 2, wherein a closed oil cavity 10 of the lubricating bearing assembly 6 is formed between the upper sealing ring 3 and the lower sealing ring 4; and the pressure compensation device 5 is positioned on the shell 1 and is communicated with the closed oil cavity 10, and the pressure compensation device 5 expands and contracts to balance the pressure difference between the inside of the closed oil cavity 10 and the outside of the closed oil cavity 10.
Therefore, the sealed transmission shaft assembly of the screw drill is provided with the pressure compensation device 5, the pressure compensation device 5 is located on the shell 1 and is communicated with the closed oil cavity 10, and the pressure compensation device 5 is expanded and contracted to balance the pressure difference between the inside of the closed oil cavity 10 and the outside of the closed oil cavity 10. The pressure at the two ends of the closed oil cavity 10 is equal, the pressure inside the closed oil cavity 10 is equal to the pressure outside the closed oil cavity 10, the sealing performance of the sealing device is improved, and the service life of the transmission shaft assembly is prolonged. Therefore, the sealed transmission shaft assembly of the screw drilling tool has the advantages of simple and compact structure, shortened length of the transmission shaft 2, small bending deformation of the transmission shaft 2, improved sealing reliability, long service life and capability of meeting the requirements of slurry drilling construction under underbalanced drilling or severe working conditions. And the bending point distance of the screw drill is short, the build rate is high, and the screw drill is suitable for being applied to drilling operation of a high-inclination well and a short-radius horizontal well.
In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.
It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A sealed transmission shaft assembly of a screw drill, comprising:
the transmission shaft device comprises a shell (1) and a transmission shaft (2), wherein the shell (1) is of a hollow tubular structure, a bearing assembly (6) for rotatably supporting the transmission shaft (2) is arranged in the shell (1), and the transmission shaft (2) is positioned in the shell (1) and can rotate in the shell (1);
the sealing device comprises an upper sealing ring (3) which is positioned at the upper end of the shell (1) and is in sealing connection with the transmission shaft (2), and a lower sealing ring (4) which is positioned at the lower end of the shell (1) and is in sealing connection with the transmission shaft (2), wherein a closed oil cavity (10) for lubricating the bearing assembly (6) is formed between the upper sealing ring (3) and the lower sealing ring (4);
the pressure compensation device (5) is located on the shell (1) and communicated with the closed oil cavity (10), and the pressure compensation device (5) is expanded and contracted to balance pressure difference between the inside of the closed oil cavity (10) and the outside of the closed oil cavity (10).
2. The sealed drive shaft assembly of a progressive cavity drill of claim 1 wherein:
seted up on the lateral wall of casing (1) and held pressure compensation device (5) oil storage hole (11a), set up oil hole (11b) with closed oil pocket (10) intercommunication in oil storage hole (11a), pressure compensation device (5) include with communicating rubber oil bag (51) of oil hole (11b), rubber oil bag (51) are through the oil charge with the oil drain come the inside and the outside pressure differential of closed oil pocket (10) of balanced closed oil pocket (10).
3. The sealed drive shaft assembly of a progressive cavity drill of claim 2 wherein:
the oil storage hole (11a) is located at the top of the upper sealing ring (3) or the bottom of the lower sealing ring (4), at least part of the rubber oil bag (51) is exposed outside the closed oil cavity (10), and an oil drainage hole (51d) for draining grease in the rubber oil bag (51) to the outside of the closed oil cavity (10) is formed in the rubber oil bag (51).
4. A sealed drive shaft assembly for a progressive cavity drill according to claim 2 or claim 3, wherein:
the rubber oil bag (51) is of a circular sheet structure, an annular groove (51b) with telescopic capacity and an annular bulge (51a) are arranged on the rubber oil bag (51), and an annular sealing ring (51c) is arranged on the circumference of the rubber oil bag (51);
pressure compensation arrangement (5) are still including pressing oil storage cup (52) on ring packing (51c), the one end that rubber oil bag (51) were kept away from in oil storage cup (52) is equipped with gland (53), the oil filler point has been seted up on gland (53), still be equipped with plug (54) of sealed oil filler point on gland (53).
5. The sealed drive shaft assembly of a progressive cavity drill of claim 4 wherein:
the oil storage cup (52) is of a cylindrical structure with two ends penetrating through, and one end, close to the gland (53), of the oil storage cup (52) is provided with a radial oil groove communicated with the oil storage hole (11 a);
the circumference of gland (53) is equipped with O shape rubber circle (55) with the inner wall sealing connection of oil storage hole (11a), the inner wall of oil storage hole (11a) still is equipped with retaining ring (56) for the hole that butts with gland (53).
6. The sealed drive shaft assembly of a progressive cavity drill of claim 3 wherein:
oil storage hole (11a) are close to the oil drain hole has been seted up to the one end of transmission shaft (2), oil drain hole (51d) and the oil drain hole intercommunication of rubber oil pocket (51), be equipped with between casing (1) and transmission shaft (2) of going up sealing washer (3) top or lower sealing washer (4) bottom annular gap (11c) with the oil drain hole intercommunication, annular gap (11c) and with seal oil pocket (10) outside intercommunication.
7. The sealed drive shaft assembly of a progressive cavity drill of claim 1 wherein:
the shell (1) comprises an upper shell (11), a transmission shaft shell (12), a bearing shell (13) and a lower shell (14) which are sequentially in threaded connection from top to bottom, the upper sealing ring (3) is hermetically connected between the upper shell (11) and the transmission shaft (2), and the lower sealing ring (4) is hermetically connected between the lower shell (14) and the transmission shaft (2);
the pressure compensation device (5) is positioned on the upper shell (11) and/or the lower shell (14), the pressure compensation device (5) is provided with a plurality of pressure compensation devices, and the plurality of pressure compensation devices (5) are circumferentially distributed on the upper shell (11) and/or the lower shell (14).
8. The sealed drive shaft assembly of a progressive cavity drill of claim 7 wherein:
a flow limiting valve (7) is arranged between an inner hole in the top of the upper shell (11) and the transmission shaft (2), and the flow limiting valve (7) comprises a static valve (7a) connected with the inner hole of the upper shell (11) and a movable valve (7b) which is fixed on the transmission shaft (2) and is in clearance fit with the static valve (7 a);
the drilling fluid discharge device is characterized in that a radial pressure relief hole (11d) is formed in the side wall of the upper shell (11), and the radial pressure relief hole (11d) is communicated with an annular gap (11c) formed between an inner hole in the top of the upper shell (11) and the transmission shaft (2) so as to discharge drilling fluid in the annular gap (11 c).
9. The sealed drive shaft assembly of a progressive cavity drill of claim 7 wherein:
oil injection channels communicated with the closed oil cavity (10) are formed in the side walls of the transmission shaft shell (12) and the bearing shell (13), and plugs for plugging the oil injection channels are fixedly arranged on the side walls of the transmission shaft shell (12) and the bearing shell (13);
the bearing assembly (6) comprises an upper thrust bearing (61) and a lower thrust bearing (62) which are positioned in a transmission shaft shell (12), a pressure bearing ring (63) is arranged between the upper thrust bearing (61) and the lower thrust bearing (62), and an adjusting washer (64) is arranged between the bottom of the lower thrust bearing (62) and the bearing shell (13).
10. The sealed drive shaft assembly of a progressive cavity drill of claim 7 wherein:
the top threaded connection of transmission shaft (2) has water cap (8), water cap (8) are equipped with the inlet opening with the eye of a river intercommunication of transmission shaft (2), the bottom of casing (14) is equipped with scrapes circle (9) with the lower of transmission shaft (2) laminating down.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123066163.4U CN216381193U (en) | 2021-12-08 | 2021-12-08 | Screw drill sealing transmission shaft assembly |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123066163.4U CN216381193U (en) | 2021-12-08 | 2021-12-08 | Screw drill sealing transmission shaft assembly |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216381193U true CN216381193U (en) | 2022-04-26 |
Family
ID=81221359
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202123066163.4U Active CN216381193U (en) | 2021-12-08 | 2021-12-08 | Screw drill sealing transmission shaft assembly |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216381193U (en) |
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2021
- 2021-12-08 CN CN202123066163.4U patent/CN216381193U/en active Active
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