Abstract: A steerable drilling device has an outer tube extending along a longitudinal axis; a drill bit joint inserted into said outer tube, a lower end of said drill bit joint extending out of a lower end of said outer tube for connection to a drill bit; a joint drive mechanism, provided in said outer tube and configured to drive said drill bit joint to swing relative to the longitudinal axis; and a lower connection mechanism. The lower connection mechanism has a connection body connected to said joint drive mechanism in such a manner that said joint drive mechanism is non-rotatable with respect to said connection body, a first centralizer arranged between said connection body and said outer tube, a circuit system arranged in said connection body and configured to provide an electrical signal to said joint driving mechanism, and an attitude sensor arranged in said connection body.

Abstract: An ammonia-resistant motor used for a closed-type refrigerating compressor comprising a stator and a rotor; during work, the stator and the rotor of the motor are immersed in the ammonia refrigerant; the winding, the slot wedge and the slot insulation are locked through self-lock fasteners, thereby preventing them from moving in the slot; the self-lock fasteners are fluorine plastic fasteners; the end portion of the motor winding is wound with a layer or multi-layers of fluorine plastic tape, and the outer layer of the fluorine plastic tape is provided with a binding tube; the binding tube is made from fluorine plastic, and the tensile strength of the binding tube is greater than that of the fluorine plastic tape.

Abstract: An ammonia-resistant motor used for a closed-type refrigerating compressor comprising a stator and a rotor; during work, the stator and the rotor of the motor are immersed in the ammonia refrigerant; the winding, the slot wedge and the slot insulation are locked through self-lock fasteners, thereby preventing them from moving in the slot; the self-lock fasteners are fluorine plastic fasteners; the end portion of the motor winding is wound with a layer or multi-layers of fluorine plastic tape, and the outer layer of the fluorine plastic tape is provided with a binding tube; the binding tube is made from fluorine plastic, and the tensile strength of the binding tube is greater than that of the fluorine plastic tape.