US3797060A

US3797060A - Self-propelled machine for cleaning external surfaces of pipelines

Info

Publication number: US3797060A
Application number: US00236813A
Authority: US
Inventors: L Doktorov; V Salukvadze; I Koshman
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-03-22
Filing date: 1972-03-22
Publication date: 1974-03-19
Anticipated expiration: 1991-03-19

Abstract

A self-propelled machine for cleaning external surfaces of pipelines in which the rotor encompassing the pipeline carries cleaning tools rotating together with the rotor and about their own axes parallel to the axis of rotation of the rotor, the tools being kinematically connected with the common drive of the machine through the drive of the rotor and, in addition, having a self-contained kinematic coupling with this drive adapted for changing the speed of rotation of the cleaning tools about their axes at a constant speed of the rotor.

Description

United States Patent [191 Salukvadze et a1.

[ Mar. 19, 1974 SELF-PROPELLED MACHINE FOR CLEANING EXTERNAL SURFACES OF PIPELINES [76] Inventors: Viktor Samsonovich Salukvadze, 5

Parkovaya, 42. kv. 53; Igor Filippovich Koshman, ulitsa Bratskaya, 23, korpus l. kv. 176, both of Moscow; Leonid Borisovich Doktorov, ulitsa Kraskovsky obryv, l1, Moskovskaya oblast, all of U.S.S.R.

[22] Filed: Mar. 22, 1972 [21] Appl. No.: 236,813

[52] US. Cl. 15/88, l5/104.04 [51] B08b 9/02 [58] Field of Search 15/88, 104.04; 118/72 [56] References Cited UNITED STATES PATENTS 2.307.449 1/1943 Carpmail 15/88 2.427.129 9/1947 Fields 1 15/88 2.631.315 3/1953 Hauser.... l5/104.04 2.641.008 6/1953 Smith 15/88 Primary ExaminerEdward L. Roberts Attorney, Agent. or Firm-Holman & Stern [57] ABSTRACT A self-propelled machine for cleaning external surfaces of pipelines in which the rotor encompassing the pipeline carries cleaning tools rotating together with the rotor and about their own axes parallel to the axis of rotation of the rotor, the tools being kinematically connected with the common drive of the machine through the drive of the rotor and, in addition. having .a self-contained kinematic coupling with this drive adapted for changing the speed of rotation of the cleaning tools about their axes at a constant speed of the rotor.

3 Claims, 2 Drawing Figures PATENTED MAR I 9 I974 saw 1 [1P2 4 PATENTEU MR 1 9 I974 3L797L0e0 SHEEI 2 OF 2 SELF-PROPELLED MACHINE FOR CLEANING EXTERNAL SURFACES OF PIPELINES BACKGROUND OF THE INVENTION The present invention relates to devices for cleaning pipeline surfaces and, more particularly the invention relates to self-propelled machines for cleaning the external surface of a pipeline.

The present invention can be used most effectively for cleaning the external surface of a pipeline having a diameter greater than 700 mm, so that further application onto this surface of an insulating coating can be effected, particularly in winter when the pipeline is covered with ice, frozen snow and dirt. The proposed machine can also be used for cleaning pipelines before applying thin-film insulating coatings requiring highquality preparation of the surface.

Known in the art are self-propelled machines for cleaning the external surface of a pipeline which comprise a rotor mounted on a frame and encompassing the pipeline, the rotor carrying cleaning tools rotating therewith and about the axes of their shafts parallel to the axis of rotation of the rotor, each-shaft being kinematically connected with the common drive of the machine through a rotor rotating drive, a cardan joint, and a sprocket engaging a central cogwheel mounted on the frame coaxially to the rotor. (of. USSR Authors Certificates No. 118095 and No. 127118).

In these known self-propelled machines the central cogwheel is stationary. In the process of operation of these machines the rotor rotates with the cleaning tools and the latter simultaneously rotate about the axes of I their shafts, each shaft being connected through a cardan joint with the sprocket performing a planetary motion about the central cogwheel.

As the circumferentialspeed of the rotor and, the rotational speed of the sprockets are constant, the circumferential speed of the cleaning tools is also constant. In this connection, the cleaning tools in these known machines can only be made as cylindrical brushes.

It is known that the quality of cleaning the surface of a pipeline by means of these known machines is characterized by a number of runs or passages of the cleaning toolsthrough each point of the surface being cleaned, i.e., by the overlap factor K determined as follows wherein V, is the circumferential speed of the rotor rotating about the pipeline;

V is the circumferential speed of the working tools rotating about their axes;

6B is thetotal width of all the tools along the line of contact with the pipeline;

D is the diameter of the pipeline;

V is the speed of linear motion of the machine along the pipeline.

The higher the overlap factor, the better (in the general case) the quality of cleaning of the pipeline surface. However, in the known machines the overlap factor can be increased only at the expense of reducing the linear speed V of the machine which is associated with an undesirable drop in the efficiency of the machine. As stated above, the rotor speed V, and the dependent speed V of the cleaning tools remain constant. In this case the circumferential speed of the rotor cannot be increased without inevitable deterioration of the operation of the machine due to drastically increasing inertia loads.

The total circumferential speed of the rotor and the tools V, V, is the peripheral speed of cleaning and, in the final analysis, determines the quality of the cleaned surface of a pipeline provided by the given machine at constant efficiency thereof.

The quality cleaning of pipelines from rust and scale, particularly in the presence of ice, frozen snow and earth, etc. on their surface cannot be provided with the use of the known machines without increasing the peripheral speed of cleaning and the overlap factor, while simultaneously preserving the adequate efficiency of the machine.

Furthermore, it is well known that thin-film insulating coatings, for example epoxy-coal, polyethylene and so on, require complete removal or the corrosion products from the cleaned surface of a pipeline and predetermined roughness of this surface. These factors are of decisive importance for adhesive resistance of the coating and its life. The experience has shown that the known machines are not suitable for cleaning external surfaces of pipelines for the purpose of applying coatings thereto.

SUMMARY OF THE INVENTION An object of the present invention is to provide a selfpropelled machine for cleaning the external surface of a pipeline having the capability of controlling the peripheral speed of leaning at a constant circumferential speed of the rotor.

Another important object of the invention is to provide such a machine that ensures high-quality cleaning of a pipeline for the purpose of applying thereon various insulating coatings regardless of the condition of this surface prior to the cleaning, whereby the efficiency of the machine is not reduced.

These and other objects are attained by providing a self-propelled machine in which a rotor mounted on a frame and encompassing the pipeline carries cleaning tools rotating together with the rotor and about the axes of their shafts parallel to the axis of rotation of the rotor and kinematically connected to the general drive of the machine through the rotor drive, a cardan joint and a sprocket engaged to a central cogwheel mounted on the frame coaxially to said rotor. According to the invention, the central cogwheel in mounted on the frame with a possibility of rotation and has a selfcontained kinematic coupling with the general drive of the machine adapted for changing the rotational speed of this wheel, thereby changing the rotational speed of the cleaning tools about their axes at a constant speed of the rotor.

The self-contained kinematic coupling of the central cogwheel with the common drive of the machine made in the form of an engine with a power take-off reduc tion gear is preferably effected through a chain drive whose driven sprocket is rigidly secured on this cogwheel, while the driving sprocket is mounted on the output shaft of a gear box whose input shaft is connected through a clutch to one of the output shafts of said reduction gear.

Due to such an arrangement, the proposed selfcontained machine provides control of the peripheral speed of cleaning at a constant rotational: speed of the rotor thereby providing for high-quality cleaning of the surface of a pipeline for the purpose of applying thereto various insulating coatings regardless of the condition of this surface before the cleaning, whereby the efficiency of the machine is not reduced.

Furthermore, this machine permits the use of more effective and long-life cleaning tools compared to the known cylindrical brushes.

The proposed machine is preferably provided with cleaning tools made in the form of rotary cutting tools with radially disposed lengths of wire whose one ends are connected to one another, the lateral surfaces of these lengths being pressed to one another in the immediate vicinity to these ends, and whose opposed, free ends adjoin the common cutting face of the tool in the form of a surface of revolution, in which case the ratio of the summary area of the face planes of the free ends to the total area of the cutting surface of the tool is 0.2-0.9.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood from the following detailed description of one particular embodiment of the invention with reference to the accompanying drawings, in which:

FIG. 1 is a functional diagram of the self-propelled machine for cleaning the surfaces of pipelines according to the invention;

FIG. 2 is schematic diagram of mutual disposition of the central cogwheel, sprocket and cleaning tool (a front view, partly in section).

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT The self-propelled machine for cleaning external surfaces of pipelines according to the instant invention comprises a rotor 2 (FIG. I) mounted on a frame 1 and encompassing the pipeline. The rotor 2 carries cleaning tools 3 mounted on their shafts 4 rotating together with the rotor 2 and about their axes parallel to the axis of rotation of the rotor coinciding with the geometrical axis of the pipeline 5. The shafts 4 of the cleaning tools are kinematically connected to the common drive of the machine comprising an engine 6 and a power take-off reduction gear 7. This kinematic coupling is effected through the drive of the rotor 2, a cardan joint 8 (FIG. 2) and a sprocket 9 engaging a central cogwheel 10 mounted on the frame 1 coaxially to the rotor 2.

The central cogwheel 10, according to the invention, is rotatably mounted on the frame 1 and has an independent kinematic coupling with the common drive of the machine for changing the rotational speed of this wheel.

According to the invention, the independent kinematic coupling of the central cogwheel 10 with the common drive of the machine is effected through a chain drive having a driven sprocket 11 (FIG. '1) rigidly secured to this cogwheel and a driving sprocket 12 mounted on the output shaft 13 of a gear box. A whose input shaft 14 through a clutch 15 is connected to one of the output shafts of the reduction gear 7. I

In the embodiment under consideration the central cogwheel 10 consists of two coaxially disposed drums rigidly interconnected through pins 16, between which drums there are disposed chain links 17 engaging the sprockets 9 and having a pitch equal to that of these sprockets.

Each chain link 17 (FIG. 2) has a wear-resistant bushing 18 on an axle 19 rigidly secured in the drums against axial displacements.

The driven sprocket 11 is a gear rim mounted about the outer diameter of one drumv (left-hand) of the wheel 10. The other drum (right-hand) of the cogwheel 10 in mounted on the frame 1 by means of supporting rollers 20 (FIG. 1).

The rotor 2 is made in the form of two

tyres

21 and 22 interconnected through a ring 23 and secured in supporting rollers 24 and 25 mounted on the frame 1.

The drive for rotation of the rotor 2 consists of a chain drive having a driving sprocket 26 connected with the output shaft of the reduction gear 7 and a driven sprocket 27 disposed between the

tyres

21 and 22 and rigidly secured to the ring 23. The

tyres

22 and 1 21 have apertures for passing the shafts 4 of the tools 3 and the shafts 28 of the sprockets 9. Thc shafts 4 and 28 are connected through the cardan joints 8 passing through the corresponding apertures made in the driven sprocket 27 of the drive for rotation of the'rotor 2.

Each shaft 4 with the tool 3 has an independent operating arrangement 29 to provide for elastic contact of the tool with the worked surface of the pipeline 5 by means of any known method suitable for this purpose. The frame 1 is equipped with two carriages 30 and 31 performing translatory motion along the external surface of the pipeline 5 under the action of the common drive of the machine. The kinematic coupling of the carriages 30 and 31 with the common drive of the machine is effected through a clutch32, a gear box B,

tranmission shafts

33 and 34, a system of

chain drives

35, 36 and 37, and

worm reduction gears

38 and 39. A diesel engine is used as the engine 6.

The proposed self-propelled machine operates as follows.

The engine 6 is started. In this case the shafts of the power take-off reduction gear 7 are rotated, and the torque is transmitted to the rotor 2 of the machine and to the carriages 30 and 31 for longitudinal (relative to the pipeline 5) movement of the machine.

The rotor 2 is rotated by one of the output shafts of the reducer 7 through the driving sprocket 25 and the driven sprocket 27 rigidly secured to the ring 23 which, in turn, is secured to the

tyres

21 and 22 rotating in the supporting rollers 24 and 25 which rotate only about their axes.

The shafts 4 and 28 connected through cardan joints and carrying the cleaning tools 3 and the sprockets 9 rotate together with the rotor 2 about the geometrical axis 00 of the pipeline. In this case the sprockets 9 perform planetary motion about the central cogwheel 10 and rotate the cleaning tools 3 about their own axes. Thus, there is obtained one constant speed of rotation of the cleaning tools about their axes at a constant speed of the rotor: therefore, a constant cleaning speed (or rate) is provided.

The cleaning speed should be understood as the sum of the speed of rotation of the tools about the axis 0-0 of the pipeline 5 created by the rotor 2 and the speed of rotation of the cleaning tools 3 about their axes.

The required cleaning speeds are provided by operating the gear box A whose input shaft 14 through a clutch 15 is connected with the power take-off reduction gear 7, while the output shaft 13 of the chain drive including the sprockets 1 1 and 12 is connected with the cogwheel 10. In this case the kinematic coupling of the motor 6 with the cogwheel l0 and the rotor 2 is effected so as to provide for their mutually opposite rotation. In this case the rotational speed of each of the cleaning tools 3 about its axis will be added to the speed developed by the rotation of the rotor, thus providing for optimum rate of cleaning of the pipeline most expedient under the specific conditions.

It is known and previously stated that the cleaning speed determines the quality of the surface being cleaned at a constant linear speed of the machine; the higher the cleaning speed, the greater number of passages through each point of the pipeline performs the tool; thereforeiit is possible to completely remove all the contaminations from the surface of the pipeline. By changing the rotational speed of the tool, the cleaning speed is changed correspondingly.

The maximum cleaning speeds are required when the pipeline surface is covered with ice, frozen ground and snow. An increased cleaning speed is also required when preparing the pipeline surface for thin-film insulating coatings to create microgeometry (roughness) of the treated surface and to completely remove the rust and scale from this surface.

Sometimes, when the pipeline surface is in good condition for example in the case of only thin mill scale on this surface or when no stringent requirements are imposed thereon, it is expedient to reduce the cleaning speed, in which case the gear box A is set to a required speed, and the cogwheel 10 is rotated in the direction of the rotor, thus reducing the speed of rotation of the tools 3 about their axes.

Low cleaning speeds make it possible to reduce the power consumption of the engine and to increase its life.

After selecting the rated cleaning speed and adjusting the arrangement 29 for creating a required elastic contact of the tools 3 with the pipeline surface, the gear box B connected through the clutch 32 with the reduction gear 7 is operated at a specified speed. In this case the torque is transmitted to the carriages 30 and 31 mounted on the frame and effecting the longitudinal displacement of the machine along the pipeline. To prevent the proposed machine from overturning, it is provided with a supporting wheel (not shown) the construction of which is similar to that of the wheels employed in the known machines of this type. This wheel is connected to the frame 1 of the machine through suitable links and is capable of running on the ground.

Since the speed of rotation of the cleaning tools about their axes can be controlled at a constant speed of the rotor, the cleaning tools of the proposed machine can be made in the form of rotary cutting tools with radially disposed wire lengths with interconnected ends on one side, the lateral faces of these lengths being pressed to one another in the immediate vicinity -to these ends, while the opposite, free ends adjoin the common cutting face of the tool in the form of a surface of revolution. in which case the ratio of the summary area of the face planes of the free ends to the total area of the cutting surface of the tool is O.2-0.9.

The use of such tools in the proposed machine widens the technological facilities of the machine and considerably improves its operational characteristics.

We claim:

1. A self-propelled machine for cleaning external surfaces of pipelines having a common drive and comprising: a frame means; carriages mounted on said frame means and kinematically coupled with said common drive so as to move said carriages along the external surfaces of a pipeline to be cleaned; a rotor rotatably surrounding said pipeline and carrying rotatable cleaning tools operatively associated therewith,said rotor being mounted on said frame means and provided with an independent drive means for transmitting a driving torque from said common drive of the machine, said cleaning tools having their axes of rotation parallel to the axis of rotation of said rotor; means for providing an elastic contact between said cleaning tools and said external surface of said pipeline, said means being mounted on said rotor adjacent said tools; a central cogwheel rotatably mounted on said frame means coaxially with said rotor to rotate relative thereto; sprockets of said machine having their axes parallel to the rotational axis of said rotor, said sprockets being mounted on said rotor so as to operatively engage said cogwheel; a cardan joint for providing kinematic connection of each of said sprockets with a corresponding one of said cleaning tools through said independent rotor drive means so that during rotation of said rotor and said cogwheel said sprockets and said cleaning tools rotate around their own axes at identical rotational speeds, said central cogwheel having means for independent kinematic coupling thereof with said common drive of the machine for changing the speed of said cogwheel relative to the rotational speed of said rotor so that the rotational speed of said cleaning tools and said sprockets about their axes changes while the rotational speed of said rotor remains constant.

2. A machine as claimed in claim 1, wherein said means for independent kinematic coupling of said central cogwheel with the common drive of the machine is effected through a chain drive having a driven and a driving sprocket and wherein said common drive comprises an engine with a power-take-off reduction gear having at least one output shaft, said driven sprocket of said chain drive being rigidly secured on said central cogwheel, and said driving sprocket being secured to the output shaft of a gear box'whose input shaft is connected through a clutch to one of said output shafts of said reduction gear. I

3. A machine as claimed in claim 1, in which the cleaning tools are made in the form of rotary cutting tools having radially arranged lengths of wire some ends of which are connected to one another while the other opposite ends remain free, the lateral surfaces of said lengths being pressed against one another in the immediate vicinity of said ends, while the opposite free ends of said wire lengths adjoin the common cutting face of the tool to form a surface of revolution, so that the ratio of the sum of the area of the face planes of the free ends to the total area of the cutting face of the tool is equal to 0.2-0.9.

Claims

2. A machine as claimed in claim 1, wherein said means for independent kinematic coupling of said central cogwheel with the common drive of the machine is effected through a chain drive having a driven and a driving sprocket and wherein said common drive comprises an engine with a power-take-off reduction gear having at least one output shaft, said driven sprocket of said chain drive being rigidly secured on said central cogwheel, and said driving sprocket being secured to the output shaft of a gear box whose input shaft is connected through a clutch to one oF said output shafts of said reduction gear.