Patent ID: 6182945
Filing Date: 2001-02-06
Classification: B66D,E21B

Abstract:
A redundant drawworks for use with a drilling rig, comprising:a mounting base;a left gear transmission assembly secured to the mounting base and having a collector gear drive and a first and a second multiple-speed gear transmission, the collector gear drive being coupled to the first and second multiple-speed gear transmissions;a right gear transmission assembly secured to the mounting base and having a collector gear drive and a first and a second multiple-speed gear transmission, the collector gear drive being coupled to the first and second multiple-speed gear transmissions;a drum mounted to a drum shaft, the drum shaft being rotatably coupled to the respective collector gear drives of the left and right gear transmission assemblies;a first and second left motor secured to the mounting base, the first left motor being positioned above and nearer the drum than the second left motor, the first left motor being releasably coupled to the first multiple-speed gear transmission on the left gear transmission assembly by a first left mechanical coupler, and the second left motor being releasably coupled to the second multiple-speed gear transmission on the left gear transmission assembly by a second left mechanical coupler;a first and second right motor secured to the mounting base, the first right motor being positioned above and nearer the drum than the second right motor, the first right motor being releasably coupled to the first multiple-speed gear transmission on the right gear transmission assembly by a first right mechanical coupler, and the second right motor being releasably coupled to the second multiple-speed gear transmission on the right gear transmission assembly by a second right mechanical coupler;the left gear transmission assembly, the first and second left motors, and the first and second left mechanical couplers providing a complete first system which may power and control the drum;the right gear transmission assembly, the first and second right motors, and the first and second right mechanical couplers providing a complete second system which may power and control the drum;the first and second systems being separate from, and independent of, each other; andthe first and second systems simultaneously operable to power and control the drum, or one of the systems being operable to power and control the drum, while the other system is being serviced or maintained.