LOCKABLE MOTOR ASSEMBLY FOR USE IN A WELL BORE

摘要

A lockable motor assembly (1) for use in a well bore comprises a PDM motor ( 2) having a rotor (4) and a stator (3). A locking member (12) has a splined projection (13) which is received within a splined recess (14) of the rotor and external splines (15) which mate with splines provided on a sub (5) connected to the stator. The components are held in this configuration by a shear ring (23) until the fluid pressure within a chamber (28) defined betwe en the locking member (12) and the sub (5) is sufficient to cause the shear rin g to shear. The locking member (12) may then move out of the engagement with t he rotor to free the motor for operation. The locking member is held in this position by a ratchet mechanism (35).