Currently, there is a tendency replacement joints flexible torsion bars located inside the shaft mud motor. But with them came new problems, which are defined and limited scope of the torsion: in the lower part of the drill string (BHA) with a small angle of inflection (low-intensity set of angle) to 10/10m and PDM with a small torque. The main difference between this arrangement is to reduce the linear dimensions of BHA. Alternating Load - Chief whip torsions (for 100 hours at a frequency of rotation 180ob/min typed 1 million cycles of bending!). 

 Cardan joints and razzazorennye spline (for the possibility of skewed axes) is also found in the patent literature, but their advantage over other designs - easy to manufacture - leveled by a low carrying capacity and resource. 

 The most widely used today have hinges with ball and roller bearings (biscuits). There are even double-row layout of the balls in the same support, but under the current scheme of "ball-bearing inside the cylinder," this action may cause more harm than good: shifting the point of contact and increases the tension. 

 The main drawback of these structures: if the angle of inflection (for which, in general, and need a hinge) at any time interval, torque is transmitted only two opposite element-dried (ball or roller). However, unlike similar with Cardan joints, stiffness of bearing walls above and is present alternating work biscuit, which increases the service life. On the other hand, in the same degree of increased demands on the accuracy of making these joints, and increases their cost. 

 Before the invention of the author has been tasked to create a joint downhole motor with a high load capacity, long lifetime, maintainability is technologically expensive to manufacture. How he managed to unite these often contradictory qualities, we will see. 

 Goal is achieved due to the fact that the hinge downhole motor containing housing with the longitudinal groove, a shaft with a spherical-fifth pillar and bearings, and located between the body and the shaft bearing elements (biscuits), according to the invention, groove in the body in the form of partial linear or radial key slots, load-bearing elements in the form of leaf discs in general, or at least one convex spherical surface, and an additional hole, cutting, or hollow (hollow), by elastomeric springs a hole for filling oil to the valve is made in the center (axis) of the shaft, the spherical head of the shaft holds undercut (to prevent contact with a larger bearings in the swing of the shaft) and its lateral opening for the supply of oil. 

 

 The inventive hinge downhole motor schematically illustrated in the drawings: 

 Figure 2 shows a longitudinal section of the hinge; 

 Figure 3 shows the cross section of the hinge on the center axis of rotation of ball bearing shaft; 

 Figure 1 shows the axonometric view of the hinge. 

 

Hinge downhole motor consists of a housing hinge 1, which with the help of thread (in this case the nipple) is attached to the shaft of the spindle bearing drilling mud motor (BZD) or its drive element (not shown). The cylindrical hole of the body 1 is inserted ball bearing shaft 2 with a spherical head of a similar diameter. The other end of the shaft 2 to cone planting and / or splines attached to the shaft of the spindle bearing drilling mud motor (BZD) or its drive element. From the fallout from the housing 1 the shaft sleeve holds two-limiter 3, which is attached to the body of a screw 4 with the end slots, where, after tightening screw 5 zachekanivaetsya edge of the body 1 to prevent loosening during operation. Elastomer seal 5 and 6 cover protects the joint from entering the mud and oil leakage from the joint to improve its efficiency. 

 One end of the elastomeric cover 6 is clamped between the hub-limiter 3 and a screw 4, while the other is attracted to the worm shaft 2 (or similar) collar 7. Axial thrust on the shaft 2 on body 1 is transmitted through the spherical heel 8 and heel 9, under which a shaft 2 in the spherical head is undercut G. 

  9 heel keeps on bias-rivet pin 10. Charging of oil carried through the hole in the center of the shaft 2, which is then sealed with valve 11. The torque from the shaft 2 to body 1 (and vice versa) is transmitted through the bearing elements (dried) 12, which are placed in cylindrical holes (bores) in the shaft 2 and in the general case can be made leaf discs, but the drawings are shown with a convex spherical surface, which is in contact with the keyway slots partial body 1. 

 When using dried hinge 12 will be worn, as well as contact with the surface of the housing 1 and shaft 2, so to maintain contact between the biscuit 12 and the body 1 provides elastomeric springs 13, which will move the biscuits 12 in the contact zone. 

 Jobs hinge downhole motor based on the transfer of torque from the drilling mud motor through the spindle support on rock cutting tool. The axis of rotation is constantly changing its position because of the mechanism of deviation angle of the borehole (not shown) and the precession of the rotation of the shaft gerotor motor. Simultaneously, through the joint effort is resulting from the pressure of working fluid and the weight of the drill string falling on rock cutting tool. 

  Due to severe constraints of overall increase in the external diameter of the hinge is not possible and the main way to increase cross-section of the housing 1 and shaft 2 is to reduce the structural openings in the dangerous section. A related transition from balls and rollers in contrasting to the invention, analogues of leaf discs with a possible spherical surface. This decreases the depth of holes in the shaft 2 and is practically eliminated the main disadvantage of prototyping, leading to premature failure hinge - wedging effect of contact on the side surfaces of the housing 1 and shaft 2 with the bearing elements in the form of balls and rollers. 

 Rusk 12 in the form of leaf discs in the proposed joint design work only for the cut, and the shaft 2 to perform their cylindrical hole with a depth of close to half the thickness of the plate washer 12. In the housing 1 under the remaining ½ ..., 2 / 3 of the biscuits 12 executes Slot slots (the number of biscuits, 12), linear or radial, which then reveal a cylindrical hole equal in diameter spherical head of the shaft 2 passing generally through the symmetrically arranged concentric okontsovok key slots. As a result, the body 1 are longitudinal grooves in the form of partial key grooves, linear or radial. 

 Differences between linear and radial keyway slots are determined mainly by technology implementation: concentric to the axis of the housing 1 or it tangentially (with symmetry about the center of the groove). For strength and other characteristics are virtually identical, since the main effort falls on the edge of the grooves. Minor groove width of the wedge in the housing 1 in conjunction with shallow cylindrical hole in the shaft 2 under 12 can maximize the crackers diameter of the shaft 2 and the ball head on the shaft 2 in order to increase the maximum torque is transferred joint. 

 The hole for filling oil in the center (axis) of the shaft 2 allows us to abandon a similar hole in the prototype, made from the side of the hinge housing 1. This reduces the linear dimensions of the body 1 and eliminate the stress concentrator on the surface. At the same time reduces the probability of depressurization valve 11 due to centrifugal loads during the rotation of the hinge. The hole in the center of the shaft 2 in the neutral zone of the axis of loading fibers, as is known from the theory of strength, practically does not weaken the cross-section. 

  When using a spherical heel 8 of smaller diameter than the spherical head of the shaft 2 (to reduce the size of the body 1) and an equivalent diameter sphere thrust bearing 9 (for a larger bearing surface and reduce wear and tear) in the spherical head of the shaft 2 performs undercut G. With him ruled out Contact the shaft 2 with bearings 9, with the rotation (swing) of the shaft 2 in the hinge. 

 Undercut T is outside the zone of dangerous loads, thus reducing the cross section will not happen. An additional hole in the side undercuts T for passage of oil can be performed instead of the axial (not shown) to reduce the probability that an abrasive (mud) in the contact zone of a spherical thrust bearing heel 8 and 9, with fuel oil and the internal cavity of the hinge to facilitate the filling of the viscous greases . 

 Bush-limiter 3 is to ensure joint tightness in the hinge in conjunction with a screw 4 and cover 6 with one hand and the body 1, 5 and sealing screw 4 - on the other, as well as to prevent the inadvertent release of the engagement of the shaft 2 of housing 1. Moreover, the sleeve-limiter 3 shall not impede the free rotation (swing) of the shaft 2 in a spherical support heel thrust bearing 8 and 9. 

 Rusk 12 (as heel 9) can be produced as turning and cutting-shaping in high-performance rubber stamps from a sheet with at least one (external) polished surface. Moreover, in the latter case, you can much easier to get outside a spherical shape the desired size with high purity of the surface. Even the technological edge utyazhki biscuits to 12, with cutting will not be a defect (in these places is just H = provides a transition between the outer spherical surface and the lateral cylindrical). 

 With a sufficient thickness of biscuit 12 to perform its recess (blind hole) to set the elastomeric springs 13, which overcomes a biscuit 12 from the hole in the shaft 2 to the body 1. This option is preferable, since the wear of the outer spherical surface of the biscuit 12, he will gradually moving out of the hole on the shaft 2. Thus, during operation in the contact between the partial keyway (linear or radial) of the body 1 and the spherical head shaft 2 is provided with a fresh biscuit neiznoshennoy lateral edge 12, thereby reducing the gap, run-out and vibration. 

 When planned repairs hinge (if housing parts maloiznosheny) replaces only 12 and dried them elastomer springs 13, resulting in high maintainability. And if the double hinge (to ensure equal angle), then the case 1 change places for inclusion in the work of the opposite edges of the partial maloiznoshennyh key grooves (linear or radial) in the shell 1 and the holes in the shaft 2. 

 Thanks to all the proposed innovations could create a hinge screw downhole motor with a high load capacity, long lifetime, maintainability is technologically expensive to manufacture.