US 2015/0176342 A1Published application

Mud motor drive-shaft with improved bearings

AssigneeNewsco Directional Support Services Inc.

InventorJOE FICKEN

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Abstract

An improved arrangement for bearings for a drive-shaft for off-set or bent drive subassemblies between a mud-motor and a drill-bit in a bottom-hole assembly for directional drilling is provided by using elliptically shaped rollers housed in mating slots in the end or ends of the drive shaft to roll on their axes which are approximately perpendicular to the radius of the shaft and approximately aligned with the shaft's longitudinal axis, to engage with other mating slots in driven or driving housings attached to respectively the mud motor and to the drill's driven bit. The rollers are designed so that as the shaft pivots around a centroid of its tip end(s) the shape of the bearings' outer surface rotates within the slots with improved loading characteristics, with more bearing-to-slot surface area and less point loading than arrangements in the prior art, such as tapered roller bearings or ball bearings.

a bearing assembly for use in the transmission of torque in a bottom-hole assembly of a drilling system to provide a bendable drill-string while continuing to transfer torque past the bend, comprising:

a. a drive attachment to either a driven or drive component of a drive system of a bottom-hole assembly,
b. a bonnet attached at an outer end to the drive attachment and with an opening at the other end for a drive-shaft to protrude,
c. the drive shaft having a ball-end,
d. the bonnet when attached to the drive attachment will rotate simultaneously with the drive attachment's rotation, the bonnet being either driving or driven,
e. the bonnet having an internal receptacle to receive the ball-end of the drive shaft and to hold the drive shaft from excessive movement toward or away from the drive attachment,
f. the drive shaft having shaft receptacles on its outer surface for receiving a first part of mating rollers,
g. the bonnet's interior surface having bonnet receptacles for receiving a second part of the mating rollers,
h. the shaft receptacles and the bonnet receptacles being aligned when assembled to together form voids within which the mating rollers closely fit,
i. the mating rollers being barrel shaped each having a curved outer surface and being approximately cylindrical with a longitudinal roller axis,
j. the receptacles being aligned so that the longitudinal axes of each roller is approximately parallel to and radially spaced from the longitudinal axis of the drive shaft and the drive component when those components are aligned, and with each other,
k. the fit between the bonnet and the ball-end permitting the drive shaft's axis to deviate from or bend away from alignment with the axis of the drive component to which the bonnet is attached,
l. the mating surfaces of the receptacles of the bonnet and the shaft together with the rollers prevent the shaft from rotation without simultaneous rotation of the bonnet and the attached drive component.

9 more elements

Facts

Application

14/504,624Filed 2 Oct 2014

Priority

2 Oct 2013

Published

25 Jun 2015

Term ends

Not estimatedThe source records don’t support an estimate.

Classification5 codes

E21B 7/067
Deflecting the direction of boreholes: with means for locking sections of a pipe or of a guide for a shaft in angular relation, e.g. adjustable…
E21B 17/03
Couplings; joints: between drilling rod or pipe and drill motor or surface drive, e.g. between drilling rod and hammer
F16D 3/221
The rolling members being balls, rollers, or the like, guided in grooves or sockets in both coupling parts: the rolling members being located in…
E21B
Earth or rock drilling

Abstract

Claims6