Abstract:
A bearing support design configured to provide increased resistance to deflection of a crankshaft within a power end. The bearing support design is contoured in the shape of a figure eight and provides an increased surface area for supporting the crankshaft and gearing. The support may be integrally formed in the frame plate of the power end or may alternatively be retrofitted into an existing frame plate and thereby be welded in. The power end having a bearing support at each end of the crankshaft.

Description:
BACKGROUND 
     1. Field of the Invention 
     The application relates generally to power ends and, more particularly, to a bearing support located on each power end frame plate. 
     2. Description of Related Art 
     It is difficult to economically produce hydrocarbons from low permeability reservoir rocks. Oil and gas production rates are often boosted by hydraulic fracturing, a technique that increases rock permeability by opening channels through which hydrocarbons can flow to recovery wells. During hydraulic fracturing, a fluid is pumped into the earth under high pressure (sometimes as high as 50,000 PSI) where it enters a reservoir rock and cracks or fractures it. Large quantities of proppants are carried in suspension by the fluid into the fractures. When the pressure is released, the fractures partially close on the proppants, leaving channels for oil and gas to flow. 
     Specialized pump systems are used to deliver fracture fluids at sufficiently high rates and pressures to complete a hydraulic fracturing procedure or “frac job.” Positive displacement pumps used in Oil Field Well Service Applications are operated, serviced &amp; maintained in harsh environments &amp; operating conditions. These pump systems are usually provided with power ends and fluid ends. Power ends induce movement of a plunger within the fluid end that places fluids under pressure. Within these fluid ends are a number of reciprocating plungers that pressurize fracture fluids. Suction valves and discharge valves control fluid flow to, and from, the plungers. 
     Power ends use large bull gears and pinion shafts to drive the power end crankshafts and typically have large amounts of pinion shaft deflection. In use, the bull gears and pinion shafts usually deflect away from the bull gear causing excessive strain on the pinion bearings, excessive wear on the bull gear and pinion teeth, and excessive strain in the power frames. Such deflection is seen in  FIG. 1 . These issues typically arise because narrow outer power frame plates are used (less than 1″ typically). The lower weight designs commonly used struggle to support the dynamic separation force loads generated by the bull and pinion gear high loads. When failure occurs, cracks can develop in the power frame plates as seen in  FIG. 3 . In an attempt to strengthen the power frame plates, housings may be bolted on to hold the pinion bearings to the thin outer frame plates. However, this fails to adequately increase the strength of the frame plates, as seen in  FIGS. 2 and 3 . 
     Although great strides have been made in power ends, considerable shortcomings remain. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The novel features believed characteristic of the invention are set forth in the description. However, the invention itself, as well as a preferred mode of use, and further objectives and advantages thereof, will best be understood by reference to the following detailed description when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of a pinion gear and a bull gear in a power end frame plate; 
         FIG. 2  is a view of the power end frame plate of  FIG. 1  with a housing attached; 
         FIG. 3  is an enlarged view of the power end frame plate of  FIG. 2 , the power end frame plate showing cracks; 
         FIG. 4  is a chart illustrating the deflection resulting in a crankshaft in a power end according to the preferred embodiment of the present application; 
         FIG. 5  is an enlarged side view of the teeth of a bull gear and pinion gear in operation with the power end of  FIG. 4 ; 
         FIG. 6  is a diagram of the force loads acting on the bull gear and pinion gears of  FIG. 5 ; 
         FIG. 7  is an orthogonal view of the frame plate as used in the power end of the preferred embodiment of the present application, the frame plate having a figure eight bearing support; 
         FIG. 8  is a side and end view of the figure eight bearing support of  FIG. 7 ; 
         FIGS. 9A, 9B, and 9C  are an illustration showing the figure eight bearing support inserts before and after installation into the power end frame plate; 
         FIG. 10  is an oblique view of a support in accordance with an alternative embodiment of the present application; and 
         FIG. 11  is an oblique view of the support of  FIG. 10  secured to a base plate. 
     
    
    
     While the system of the present application is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present application as described herein. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An illustrative embodiment of the invention is described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer&#39;s specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. 
     In the specification, reference may be made to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the present application, the devices, members, apparatuses, etc. described herein may be positioned in any desired orientation. Thus, the use of terms to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components, respectively, as the device described herein may be oriented in any desired direction. 
     Referring to  FIGS. 4-6  in the drawings, deflection forces exerted upon bull gears and pinion shafts configured to drive the power end crankshafts is illustrated. As seen in  FIG. 4 , crankshaft  101  is shown in an unloaded position and in a loaded position under stress. The deflection of crankshaft  101  can be seen. Deflection is caused by the naturally occurring separation forces that develop between the pinion gear and bull gear as the teeth push against each other during high loads (See  FIG. 5 ). As seen in  FIGS. 5 and 6 , gear teeth are designed using rounded shapes that permit them to minimize friction as engagement occurs. The rounded shape allows them to “roll” against each other instead of “drag” as contact is made. The round surfaces result in indirect force transfers causing the gears to push apart as the “roll” effect moves the contact points above and below the direct line forces, thereby causing the deflection seen in  FIG. 4 . 
     Referring now also to  FIGS. 7-9C  in the drawings, a figure eight pinion bearing support  103  is integrally formed in the power end frame plate  105 . In the contemplated embodiment, support  103  is welded directly to the frame plate  105 . Thus, the support slides within the openings  701 ,  703  formed by the plate  105 , which in turn are configured to receive the bull gear and pinion therethrough. A transition opening  707  is formed between openings  701  and  703  as shown in  FIG. 9B  Thereafter, the support  103  is welded directly to the plate  105 . The extra material and thickness of support  103  provides significant advantages. As noted previously, deflection in crankshaft  101  results in excessive strain on the pinion bearings, excessive wear on the bull gear and pinion teeth, and excessive strain in the power frames. The support overcomes these disadvantages by providing additional support and rigidity. One way this feature is achieved is by increasing the surface contact with the plate via the supports, as depicted in  FIG. 7 . 
     To effectively handle the natural deflection forces generated by the high horsepower gear loads, the present application discloses the use of support  103  integrally formed into frame plate  105 . The use of support  103  minimizes weight added to the overall power end compared to externally detachable housings currently in use. The power end  104  includes a frame plate  105  at opposing ends of its body. Crankshaft  101  extends between each frame plate end. Use of support  103  on a single end of the power end is insufficient to handle the forces generated. In the preferred embodiment, support  103  is used at both ends of the power end in communication with the frame support  105  and crankshaft  101 . 
       FIGS. 8-9C  further illustrate the contoured shape and manner of assembly of support  103  in communication with that of frame plate  105 . In particular,  FIG. 8  illustrates a drawings for support  103 , while  FIGS. 9A-9C  illustrates support  103  before and after installation and welding into frame plates  105 . 
     As depicted in  FIG. 8 , frame support  103  is a robust and wide insert shaped to resemble a figure eight. In the preferred embodiment, support  103  includes a body  801  having a first circular end  803  integrally joined to a second circular end  805  via a transition member  807 . First end  803  forms an opening  809  that receives the bull gear, while second end  807  forms an opening  811  that receives a pinion gear. As shown, both opening  809 ,  811  are coaxially aligned with each other. 
     In  FIGS. 9A-9C , the assembly of plate  105  and support  103  are shown. In the contemplated embodiment, support  103  is welded inside the thinner outer power frame plates  105 . By welding, support  103  is retrofittable with existing frame plates  105 . Also, frame plates  105  may be integrally formed with support  103  to save the welding time during construction. Inner surface  107  of support  103  provides a full and rigid surface contact support for the pinion bearings. By displacing the forces acting upon frame plate  105  through crankshaft  101 , the pinion bearings are properly supported and can handle the large naturally occurring separation forces generated by the bull and pinion gears. 
     Referring now to  FIGS. 10 and 11  in the drawings, a support  1001  is shown in accordance with an alternative embodiment of the present application. It will be appreciated that support  1001  is substantially similar in form and function to support  103  and hereby incorporates one of more of the features discussed above. 
     In the contemplated embodiment, frame support  1001  is a robust and wide insert shaped to resemble a figure eight. In the preferred embodiment, support  1001  includes a body  1003  having a first circular end  1005  integrally joined to a second circular end  1007  via a transition member  1009 . First end  1005  forms an opening  1011  that receives the bull gear, while second end  1007  forms an opening  1013  that receives a pinion gear. As shown, both opening  1011 ,  1013  are coaxially aligned with each other. 
     One of the unique features of support  1001  is the use of a flange  1015  that extends from body  1003  and is configured to engage with a front surface  1101  of plate  105 , as shown in  FIG. 11 . In the preferred embodiment, the flange  1015  is welded to the front surface  1101 ; however, alternative embodiments could use different types of fastening means, e.g., bolts to secure the support to the front surface. Thus, in the contemplated embodiment, the support  1001  could be used to retrofit existing plate  105  embodiments by merely placing the support on the front surface and thereafter welding the flange thereto. 
     Use of the supports  103 ,  1001  on both ends of the power end have many advantages, including at least the following: (1) increasing bull gear and pinion service life; (2) increasing pinion bearing service life; (3) reducing catastrophic pinion bearing and failures; (4) eliminating power frame crack failures caused by gear separation forces; and (5) reducing power end horse power loses due to reduced gear deflection, which results in less friction. 
     The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. It is therefore evident that the particular embodiments disclosed above may be altered or modified, and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the description. It is apparent that an invention with significant advantages has been described and illustrated. Although the present invention is shown in a limited number of forms, it is not limited to just these forms, but is amenable to various changes and modifications without departing from the spirit thereof.