The invention discloses an
oil well pump which comprises an oil outlet valve, a head thread, an internal thread
plunger, an oil
inlet valve, a traveling valve, an oil inlet plug, an upper
coupling, a wear-resistant ring, a pump cylinder, a middle
coupling, a lower
coupling, a connecting
pipe, a pressure reducing valve
assembly, a fixed valve connector and a gas and sand anchor. The upper end of the double-end thread is in threaded connection with the oil outlet valve; the lower end is connected with a
plunger; the lower end of the
plunger is in threaded connection with the oil
inlet valve, the traveling valve is placed in the oil
inlet valve, the oil inlet plug is in threaded connection with the oil inlet valve and abuts against a
valve seat of the traveling valve, the upper portion of the upper coupling is in threaded connection with the oil
pipe through the oil
pipe, the lower portion of the upper coupling is in threaded connection with the pump cylinder, and the top of the pump cylinder abuts against a wear-resisting ring arranged between an inner ring of the upper coupling and an outer ring of the oil outlet valve. The lower end of the connecting pipe is connected with a pressure reducing valve through a lower coupling, the pressure reducing valve is connected with a fixing valve connector through threads, and the fixing valve connector is connected with the upper portion of a gas and sand anchor; a
nickel carbide coating is arranged on the surface of an inner hole of the pump cylinder, a
tungsten carbide coating is arranged on the outer surface of the internal thread plunger, and the
nickel carbide coating and the
tungsten carbide coating form a
corrosion-resistant friction pair with the
potential difference smaller than or equal to 0.3 V.