Alsthom-atlantique

Jean-Pierre Lejeune

Jacques Romand-Monnier

Andre Gilmer

A motor-driven pump assembly which can be used under water and includes at least an electric motor (1, 2, 3)surmounted by at least one pump (4, 5) connected to the motor drive shaft so as to rotate, wherein the motor is electrically energized by means of an electric connection module (8) fixed to the lower end of the motor (1) beyond the space taken up by the shaft, said module having a connector pin (9) connected to a cable (10) which runs along the assembly and is fixed thereto.

Motor-driven pump assembly which can be used under water

The device allows the shafts 5 and 20 to be coupled together on a trial and error basis, said shafts being recessed relative to the ends of the stationary stators. The shaft ends have splines 6 and 21 and are coupled by means of a sleeve 22. Before coupling, the shafts are reference marked relative to the stationary portion by means of cams 27 (and 36 which is not shown in the figure) which enter a groove 6 in the shaft 5 and in a groove of the sleeve 22. During the coupling operation, the cams are retracted by a part 37 at the end of a rod 34 which bears against the cam support yoke 35 for the cam 36 in the case of the cam 27 and by the end 48 of the body in the case of the cam 36. The bodies are connected together by a coupling sleeve 9.

Coupling device, an electric motor fitted with said device and a method

A motor-pump unit for submerging down a well, e.g. an oil well, comprises a motor portion driving a pump portion. The motor portion is filled with fluid to prevent ingress of the surrounding medium which the pump portion pumps. The fluid is maintained at a higher pressure than the surrounding medium by including a flexible tank filled with fluid and in communication with the fluid in the motor portion. The flexible tank is compressed both by the surrounding medium and by resilient compression means so that the pressure inside the motor is higher than the surrounding pressure, thereby ensuring any leakage is outwardly from the motor. Down the well the temperature rises causing the fluid to expand, so the flexible tank is left substantially empty when the unit is prepared at the surface prior to lowering. If a large rise in temperature is to be expected, a resilient compression means which provides adequate excess pressure near the top of the well as the unit is lowered, will provide too much excess pressure at operating depths, and similarly compression means which provide adequate excess pressure at operating depths do not supply enough near the surface. This problem is solved by providing compression means which includes a first spring (79) and a second spring (80) so disposed that the flexible tank (66) is subjected to the sum of their resilient thrusts, with the second spring applying its thrust via release means (83 to 88) which cause said second spring to be released and to relax once its displacement reaches a predetermined value.

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Beaucourt, France

Jean-Pierre Lejeune