128916M 80*148*363mm Mud lubricating bearings for drill motor

Our main bearings products including bearings of petroleum screw drilling tools, equal-wall-thickness rubber stator of petroleum screw drilling tools, roller bearings(bearing roll),55SiMoVa or 8620 steel ball of three-roller rock bit, roller, thrust block and pad as well as hobbing cutter shaft of coal mine development, and main and supporting components and parts of construction machinery. The bearings for petroleum screw drilling tools(multi-row thrust ball bearings)are our leading products developed and filled the gap of China in 1980s.Up to now, there are more than 20 series including over 200 models.

Whether you’re drilling for oil or gas, the bearings in a mud motor at the end of a drill string have a direct impact on productivity and reliability. These mud motor bearings have to endure extreme operating conditions. In addition to severe axial and shock loads, these bearings are “lubricated” with highly abrasive mud, which for a bearing is the definition of an extreme operating condition.

Down hole motor or drilling motor for the oil drilling industry

Bearing Assembly of Downhole Motor is used to transmit motor rotary dynamic force to the bit, meanwhile to withstand axial and radial load from drilling weight. Inside of the Bearing Assembly,Monton uses TC Radial Bearing and a stacked thrust bearings. The thrust bearings support the downward force resulting from the “weight on bit” (WOB) and the loads from the combination of hydraulic thrust and weight loads from internal components.Monton provides different bearing assemblies, designed to meet the diverse requirements of the drilling industry.

Mud Motor Radial Bearing

 A mud motor bearing assembly, comprising: a stationary housing having an inner wall surface defining an interior bore; a rotatable drive shaft extending through the interior bore of the stationary housing, the rotatable drive shaft having a tubular drive shaft with a uniform outer diameter terminating at an outlet section with an enlarged outer diameter, the rotatable drive shaft including an inner bore for passage of a drilling fluid; a bearing section bearing a radial load and an axial load, the bearing section including at least a pair of stationary bearing rings and at least a pair of rotating bearing rings in stacked arrangement, each of the stationary bearing rings having an inner periphery and an outer periphery, the outer periphery of each of the stationary bearing rings operatively engaged to the inner wall of the stationary housing, the inner periphery of each of the stationary bearing rings including a projection, each of the rotating bearing rings having an inner periphery and an outer periphery, the inner periphery of each of the rotating bearing rings operatively engaged to the tubular drive shaft, the outer periphery of each of the rotating bearing rings including a projection, the projections of the pair of stationary bearing rings forming a recess that accommodates the projection of one of the pair of rotating bearing rings in sliding engagement; wherein the stacked arrangement alternates between at least partially overlapping stationary bearing rings and rotating bearing rings. 

Mud motor bearings

Mud motor bearings, or ball bearings have conventionally been used to react thrust, or axial, loads in down hole mud motors. When low rpm power sections are used in the application such bearings provide sufficient life and reliability. However, bearing component fatigue causes life to decrease linearly as speed increases. This fatigue makes ball bearings unsuitable for high rpm motors. Standard engineering practice dictates that ball bearings are specified according to L10 life, or the number of revolutions a group of identical bearings is expected to sustain before 10% fail. As revolutions are related to speed, bearings operating in a higher speed motor will fail before those operating in a low speed motor, e.g. one could roughly expect a 90% reduction in bearing life if speed was increased from 100 to 1000 rpm. In addition to life, friction and horsepower losses are often of interest in drilling. Ball bearings are referred to as frictionless bearings due to the rolling nature of the elements, however in practice frictional losses exist due to rolling resistance and sliding. An order of magnitude approximation of the coefficient of friction (cof) for an angular contact bearing operating in ideal non-abrasive lubricant conditions is 0.0032.1 In drilling mud, the cof can be assumed to be significantly higher.

Bearing Assembly

The function of the bearing assembly in a positive displacement drilling motor is to support axial load (typically weight on bit) and centralize and support side loading on the motor’s driveshaft. The bearing assemblies used in drill motors have been developed for use in different applications with certain motor configurations offering a choice of axial bearing type options. All MONTON bearings are fluid-lubricated and optimized for specific drilling applications.

Ball Bearing The Ultra Ball Bearing assembly has been improved over the years and suits for the majority of drilling applications. These bearings are used on various power sections where moderate weight on bit and drilling torque are required. With the introduction of high power Ultra drilling motors with an increased torque output, the ball bearings have been continuously improved to handle it.

The ball bearing assembly is the bearing of choice for many applications as modern PDC bit designs demand higher torque, available from today’s drill power sections. This bearing assembly is suited to more demanding applications using low or medium speed motors, where the objective is to increase drilling performance by driving more torque to the bit.

The 6 ¾ in. extreme™ ball bearing assemblies have been developed to maximize performance and reliability in challenging drilling environments and are reserved for exclusive use with the extreme motors. Also featuring an increased internal diameter, this bearing type allows for a step-change in torque capacity of the motor driveshaft-necessary assuring reliable delivery of the massive torque generated by the extreme power section.

Bearing Sub-assembly

The bearing sub assembly transmits the torque and speed of the rotor, as well as the compressive load from the bottom hole assembly (BHA). The primary components of the bearing assembly are the driveshaft, bearing housing, radial bearings, and axial bearings.

The axial bearings are a stacked ball-and-race design that provides durable performance down hole while maintaining ease of repair. The bearing assembly is also a mud-lubricated design in which the drilling fluid provides lubrication to both the radial and axial bearings while drilling. An advantage of mud lubrication is that there are minimal limitations on bit pressure drop compared to sealed bearing assembly. The bit pressure drop can be maximized for optimum penetration rate without adversely affecting the life of the bearing subassembly. Also, because mud-lubricated bearing subs assemblies do not contain any elastomeric seals, they can be run in the highest down-hole temperatures and in highly aromatic drilling fluids without fear of degradation. The bearing housings are available with a threaded outside diameter for screw-on stabilizers for tool sizes with an outside diameter greater than 5”. This option allows the stabilizers to be changed in the field.