Drawworks apparatus and method

1. A drawworks assembly, comprising:

a drum comprising a first end, a second end, and a longitudinal axis,

wherein the first end of the drum comprises a first inner engagement surface, and wherein the second end of the drum comprises a second inner engagement surface;

a coupling assembly configured to transmit torque to the drum; and

a cradle assembly configured to support the drum,

wherein the coupling assembly is releasably coupled to the drum at a first planar engagement interface disposed at the first end of the drum,

wherein the first planar engagement interface is formed between the first inner engagement surface of the drum and an engagement surface of a hub of the coupling assembly,

wherein the cradle assembly is releasably coupled to the drum at a second planar engagement interface disposed at the second end of the drum,

wherein the second planar engagement interface is formed between the second inner engagement surface of the drum and an engagement surface of a hub of the cradle assembly,

wherein both the first and second inner engagement surfaces comprise a plurality of circumferentially spaced first apertures and a plurality of circumferentially spaced second apertures,

wherein the drawworks assembly further comprises:

a plurality of circumferentially spaced fasteners extending through the hub of the coupling assembly, wherein each fastener threadably engages one of the plurality of circumferentially spaced first apertures to releasably couple the coupling assembly with the drum; and

a plurality of circumferentially spaced pin assemblies extending through the hub of the coupling assembly, wherein each pin assembly is disposed in one of the plurality of second apertures to provide for the transmission of torque between the coupling assembly and the drum,

wherein each pin assembly comprises:

an outer sleeve comprising a first end, a second end, and a bore extending between the first and second ends;

a pin disposed in the bore of the outer sleeve, wherein the pin comprises an outer surface having a diameter that varies across the longitudinal length of the pin; and

a threaded fastener extending into an aperture of the pin, wherein rotation of the threaded fastener is configured to longitudinally displace the pin through the bore of the outer sleeve and adjust a diameter of an outer surface of the sleeve, and

wherein a diameter of each pin assembly is greater than a diameter of each fastener.

2. The drawworks assembly of claim 1 , wherein the first planar engagement interface and the second planar engagement interface are both disposed substantially orthogonal to the longitudinal axis of the drum.

3. The drawworks assembly of claim 1 , wherein:

the drum comprises a bore extending between the first and second ends of the drum; and

neither the coupling assembly nor the cradle assembly extend into the bore of the drum.

4. A drawworks assembly, comprising:

a drum comprising a first end, a second end, and a longitudinal axis,

wherein the first end of the drum comprises a first inner engagement surface, and wherein the second end of the drum comprises a second inner engagement surface;

a coupling assembly configured to transmit torque to the drum; and

a cradle assembly configured to support the drum;

wherein the coupling assembly is releasably coupled to the drum at a first planar engagement interface disposed at the first end of the drum,

wherein the first planar engagement interface is formed between the first inner engagement surface of the drum and an engagement surface of a hub of the coupling assembly,

wherein the cradle assembly is releasably coupled to the drum at a second planar engagement interface disposed at the second end of the drum,

wherein the second planar engagement interface is formed between the second inner engagement surface of the drum and an engagement surface of a hub of the cradle assembly,

wherein both the first and second inner engagement surfaces comprise a plurality of circumferentially spaced first apertures and a plurality of circumferentially spaced second apertures, wherein the first apertures and the second apertures are disposed along a common circumference such that each second aperture is disposed circumferentially between a pair of flanking first apertures,

wherein the drawworks assembly further comprises:

a plurality of circumferentially spaced fasteners extending through the hub of the coupling assembly, wherein each fastener threadably engages one of the plurality of circumferentially spaced first apertures to releasably couple the coupling assembly with the drum; and

a plurality of circumferentially spaced pin assemblies extending through the hub of the coupling assembly, wherein each pin assembly is disposed in one of the plurality of second apertures to provide for the transmission of torque between the coupling assembly and the drum,

wherein each pin assembly comprises:

an outer sleeve comprising a first end, a second end, and a bore extending between the first and second ends;

a pin disposed in the bore of the outer sleeve, wherein the pin comprises an outer surface having a diameter that varies across the longitudinal length of the pin; and

a threaded fastener extending into an aperture of the pin, wherein rotation of the threaded fastener is configured to longitudinally displace the pin through the bore of the outer sleeve and adjust a diameter of an outer surface of the sleeve, and

wherein a diameter of each pin assembly is greater than a diameter of each fastener.

5. The drawworks assembly of claim 4 , wherein the first planar engagement interface and the second planar engagement interface are both disposed substantially orthogonal to the longitudinal axis of the drum.

6. The drawworks assembly of claim 4 , wherein:

the drum comprises a bore extending between the first and second ends of the drum; and

neither the coupling assembly nor the cradle assembly extend into the bore of the drum.