HYDRAULIC BOTTOMHOLE MOTOR Russian patent published in 2007 - IPC E21B4/02 

FIELD: drilling, particularly fluid rotary type drives used in the borehole.

SUBSTANCE: bottomhole motor comprises hollow body, gerotor mechanism installed in the body and spindle assembly. The gerotor mechanism includes stator coaxially arranged in the body and rotor inserted in the stator. The spindle assembly comprises shaft with axial bearing. The shaft is carried by upper and lower radial supports. The radial supports consist of outer and inner bushes and are arranged in spindle assembly body. The shaft is connected with rotor through drive shaft at inlet end and with drilling bit through lower sub at outlet shaft end. Installed between gerotor mechanism and spindle section body is adjustable sub. Bottomhole motor has upper and lower anticrash devices. Upper anticrash device includes shaft, thrust and nut. Lower one is made as figured bush. Upper anticrash device is connected to rotor. Lower one is installed on spindle section shaft and is arranged between inner bush of lower radial support and axial bearing. Adjustable sub may vary angle of spindle section and stator axes inclination so that support part of adjustable sub clutch extends at acute angle of not more than 3° to drive axis. Spindle section shaft has circumferential collar. Figured bush comprises inner and outer circumferential collars. Circumferential collar of spindle section shaft and inner circumferential collar of shaped bush are made as threads directed towards spindle section shaft rotation direction so that circumferential collar of spindle section may rest upon inner circumferential collar of shaped bush. Outer circumferential collar of spindle section shaft may bear on thrust end of lower sub. Outer bush or lower radial support is fastened directly to lower sub body so that extreme end surface of radial support mates that of lower sub body.

EFFECT: increased accuracy of hole drilling and service life, decreased accident risk and improved operational characteristics.

3 cl, 4 dwg