Drawworks for drilling rigs

Abstract

A drawworks for drilling rigs having an improved dual brake system that divides the drill line load equally between the dual brakes, a more efficient braking action is realized by the provision of radial guide rollers positioned to urge the brake bands into concentric relation respective the brake drums which maximizes contact therebetween and results in more sensitive control of weight on bit. A chain and sprocket drive line includes flingers immersed in lub oil which effectively distributes lub oil throughout the drive line.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 of the drawing is a part schematical, part diagrammatical plan view representative of part of one embodiment of a drawworks made in accordance with the present invention;

FIG. 2 is a more detailed top plan view that is a part schematical part diagrammatical representation of the apparatus of FIG. 1, with the various parts thereof being numbered and identified later on herein;

FIG. 3 is a part diagrammatical, part schematical representation of a side view of FIG. 2;

FIGS. 4 and 5 are part diagrammatical, part schematical representation showing an alternate embodiment of the drawworks seen disclosed in FIGS. 2 and 3;

FIG. 6 is an enlarged diagrammatical, part cross sectional view taken along line 6-6 of FIG. 4;

FIG. 7 is a perspective front view of the drawworks of this disclosure;

FIG. 8 is a perspective side view of the drawworks of FIG. 7;

FIG. 9 is a perspective rear view of the drawworks disclosed herein;

FIG. 10 is an enlarged detailed view of part of FIG. 9;

FIG. 11 is an enlarged detailed perspective view of a brake equalizer of FIG. 10;

FIG. 12 is a further enlarged detailed perspective view of FIG. 11;

FIG. 13 is a perspective detailed rear view of part of the gear train of FIG. 9;

FIG. 14 is a perspective detailed view of part of the drawworks of FIG. 10;

FIG. 15 is a perspective ¾ rear view of FIG. 13; and,

FIG. 16 is a perspective rear view of the drawworks of this disclosure.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 of the drawings diagrammatically illustrates a drawworks made in accordance with the present invention, wherein there is seen a motor M, radiator R, and transmission T connected by drive line D that forms the prime mover for the drawworks 10 of this disclosure. The drawworks 10 includes cable drum apparatus 12 affixed to drum shaft 14. The drum shaft 14 has the illustrated drum surface 16 for receiving and paying out wire rope or cable 18.

A drum brake assembly 20, 20′ is affixed to the cable drum which in turn is affixed to drum shaft 14 and rotates therewith. The drum brake assembly 20, 20′ circumferentially extends about brake drum 24 for arresting rotation of the drum when the brake band is forced into high friction engagement respective the drum as will be more fully pointed out herein.

A 90 degree gear box 26 is connected to coupling 28 which drives gear 32 which is spaced from gear 34 which is interconnected by an endless chain 36. Gears 34, 38 are affixed to the illustrated common shaft so that gear 38 drives gear 40 by means of an endless chain 42. Gear 40 is indirectly connected to drum shaft 14 by means of a clutch apparatus (not shown) for rotating cable drum apparatus 12 upon engagement of the clutch.

In FIG. 1, those skilled in the art will appreciate that the motor driven 90 degree gear box 26 is detachably mounted at 28 to the shaft of the 32-tooth sprocket 32 which is aligned with and spaced from the illustrated 62-tooth sprocket 34 mounted on a shaft in axially aligned relationship respective to the 21-tooth sprocket 38.

The 21-tooth sprocket drives the illustrated 80-tooth sprocket 40, which is removably attached to the drum shaft 14, whereupon each revolution of the 80-tooth sprocket 40 can directly drive the cable drum upon engaging the twin disk clutch assembly 44. Endless chains 36, 42 engage the drive and driven sprockets as indicted in the drawings as particularly shown in FIGS. 1 and 2. As seen in FIG. 2, the 32-tooth sprocket number 32 drives the 62-tooth sprocket 34 with there being three rows of claim illustrated by the dash line in FIGS. 1 and 2. The 62-tooth sprocket 34 is axially aligned respective its jack shaft which chain drives the double row sprocket 38.

Sprocket 38 is a double row chain drive for driven sprocket 40, which is an 80 tooth sprocket directly attached to the drum shaft 14, as seen in the schematical representation provided by FIGS. 1-3.

Those skilled in the art will appreciate that the massive chassis or framework 74 supports drum 16 along with the other illustrated attachments by means of the spaced bearing assemblies 50 and 50′.

Spaced from the bearing housing 50′ located on the right side of the drum is an adaptor plate that remains stationary thereby enabling the chain case to be suitably mounted and which extends into removably attached relationship respective a flinger box 64.

The live hub that supports gear 40 is bolted to an adapter plate that serves as a clutch drive ring. A twin disc clutch 45, when actuated, directly connects the 82-tooth sprocket 40 to drive drum shaft 14.

The drawworks drum is rotationally mounted respective the special built up steel chassis that can withstand the torsional loads exerted when complying with the needs of the drilling operation so that all extraneous loads imposed thereon fail to deform the various coacting bearings and housings. As seen in the various sheets of drawings, every moving part of the improved drawworks is readily accessible for inspection, thereby enabling any cause of malfunction to be obviated to avoid unexpected shut-down.

Of equal importance is the arrangement of all the parts that are subject to wear in a manner enabling the entire component or sub-assembly to be removed, and immediately replaced with a new or overhauled component.

It will be noted that the rearwardly depending extension of the drive train and enclosure therefor downwardly slopes to form a lower storage container for holding lubrication oil. Thus, lub oil gravitates towards the illustrated lub chamber where the flingers engage and transfer the lub oil throughout the interior of the power train for proper lubrication of the working parts within the illustrated enclosure, including the lubrication of all the necessary chain driven components which is enhanced and receive ample lubrication by this arrangement.

The improved concentricity of the brake bands respective the brake drums provide exceptional control to be employed by the novel equalizer brake assembly, which is extremely important for controlling the weight on bit and is very important for positive controlled stopping of the traveling block.

other novel aspect of the instant disclosure is found in the alignment of the massive brake bands previously mentioned. It will be noted that radially disposed rollers bear against the brake actuating band to improve the concentricity of the various parts thereof. An additional novel feature found in the brake and drum system is the before mentioned equalizer arrangement which maintains equal force during brake engagement and while slowing a traveling drill string into a wellbore as well as the necessity of exact rate of lowering of the drill bit to achieve the desired rate of penetration which also is required to achieve the desired weight on bit. The illustrated turnbuckle allows manual fine-tuning of this feature of the invention.

CATALOG OF PARTS

10 drawworks

12 cable drum apparatus

14 drum shaft

16 drum surface

18 wire rope or cable

20 ′ drum brake assembly

22 ′ brake band

24 brake drum

26 90 degree gear box

28 coupling [26 to 32]

30 gear train drum shaft 14

32 input sprocket

33 input sprocket shaft

34 intermediate gear shaft

36 endless chain

38 sprocket attached to 34

40 cable drum drive gear connects to shaft 14 by clutch 45

42 endless chain

44 housing

45 clutch

46 water cooled auxiliary brake

48 key way

50-50′ bearing support

52 bearing for gear 40

54 bearing for gear 40

56 fluid swivel for clutch

58 clutch plate mont

60 flinger

62 finger annulua

64 enclosure

66 brake band

68 brake band lining

70 bearings and supports

72 ′ bearings and supports

74 main frame

76 trailing frame

78 cover plate

80 fastener

82 manual brake assembly

84 alignment rollers

86 equalizer

88 turn-buckle

89 crank

90 anchor

Claims

1. A drawworks for a drilling rig comprising, a main frame, a cable drum affixed to a drum shaft, said drum shaft being rotatably supported respective said main frame, first and second drum brake assemblies having brake drums affixed to and spaced apart by said cable drum and axially aligned respective one another,a prime mover, a drive train, a clutch device interconnecting said prime mover respective said cable drum shaft,each said brake assembly includes a brake band having ends, one said brake band circumferentially extending about one said brake drum, one end of said brake band being affixed to the main frame with the remaining end thereof connected to a brake equalizer apparatus that equalizes the braking forces applied to each said brake assembly;said brake equalizer includes apparatus for moving the brake bands relative the brake drums; and further including a plurality of low friction alignment rollers radially extending toward said drum shaft to engage and position the brake bands closely adjacent the brake drums and thereby arrange said brake bands into concentric alignment respective the brake drums; and linkage including bell-cranks for applying equally divided force between each said brake band and brake drum therefor.

2. The drawworks of claim 1 wherein said drive train comprising a plurality of spaced shafts arranged in said housing in parallel relationship respective one another; chain drive sprockets mounted on said shafts; an endless chain between said drive sprockets connected to rotate said drive shaft in response to being rotated by a prime mover.

3. The drawworks of claim 2, wherein there is further included an auxiliary brake apparatus for increasing friction between said cable drum shaft and said cable drum upon demand.

4. A drawworks for a drilling rig comprising a main frame, a cable drum affixed to a drum shaft, bearing means by which said drum shaft is rotatably supported respective said main frame; first and second brake drums axially aligned respective one another and affixed to said cable drum to thereby rotate concurrently with said brake drum shaft;a prime mover, a clutch device, a drive train interconnecting said prime mover respective said cable drum shaft by means of said clutch device;a brake assembly for concurrently engaging each said brake drum; each said brake assembly includes a discontinuous brake band extending circumferentially about the brake drum and having ends, with one end fixed respective said main frame and with the other end thereof being affixed to a brake equalizer apparatus by which the brake bands of the brake assemblies are equally tensioned and thereby equally applied to the brake drums to controllably arrest rotation of the cable drum;said brake equalizer including a turnbuckle having ends connected to increase brake band tension when the turntable is adjusted in one rotational direction and to decrease brake band tension when adjusted in an opposite direction; and, a plurality of low friction alignment rollers radially arranged about the brake band and adjustably forcing the brake band into concentric relationship respective the brake drum, whereby, a maximum braking contact surface is realized upon engagement between the brake drum and brake band apparatus as a result of the coacting surfaces thereof being positioned for maximum engagement therebetween.

5. The apparatus of claim 4, wherein there is a power train within a trailing housing having a forward end attached to said main frame and connected for rotating the drum shaft; said trailing housing being positioned respective to said main frame to downwardly slope towards the prime mover to thereby provide an oil accumulator system within the interior of the trailing housing; and wherein, said power train has a sprocket connected to an input shaft and provided with radial flingers disposed within the housing lubrication accumulator.

6. The apparatus of claim 5 and further including a clutch between the drum shaft and the brake drum, a fluid actuated brake arranged between said drum shaft and said drum for engagement thereof when heavy loads are imposed on said cable drum.

7. A drawworks for a drilling rig; said drawworks having a unitized main frame, a cable drum having opposed ends affixed to a drum shaft having opposed ends rotatably mounted respective said main frame; a brake drum assembly at each of said opposed ends mounted respective the cable drum, a brake band terminating in fixed and free ends and circumferentially extending about each of the brake drums; said fixed end being attached to said main frame with the brake band extending circumferentially about said brake drum with the free end being attached respective a tensioner device for adjusting tension of the brake band within a range of values;and a brake system including apparatus for controlling the tension in the brake bands to thereby provide a braking force on the cable drum that is proportional to the applied braking force.

8. The apparatus of claim 7, wherein there is provided a plurality of low friction apparatus extending from the main frame into contact respective the outer surface of the brake bands for urging the brake bands radially toward the drum shaft to thereby bring the braking surface of the brake drum and the brake band into concentricity respective one another.

9. The apparatus of claim 8 including a drawworks drive train comprising a series of spaced shafts arranged in the housing in parallel relationship respective one another; chain drive sprockets mounted on said shafts; an endless chain between said drive sprockets connected to rotate said main shaft in response to a prime mover; and wherein said housing has an oil reservoir formed therein which slopes upward towards the drawworks drum with there being sprockets from which flingers radially extend to engage and fling oil throughout the housing.