GB173010A - Improvements relating to submersible dynamo-electric machines - Google Patents

Abstract

173,010. Byrne, E. L. W. Aug. 11, 1920. Pumping-machines. - Submersible dynamoelectric machines such as motors for driving pumps of the type in which the machine is protected by allowing the liquid to rise within a bell or casing so as to compress the internal atmosphere are provided with means to prevent loss or deterioration of the internal atmosphere while permitting sufficient communication between the inside and the outside of the casing to transmit the working pressures. The machine or the parts of it to be protected mav be nearly completely isolated from the remainder of the internal atmosphere. Fig. 2 shows a method in which the shaft is carried through a narrow opening connecting the two parts of the casing. Fig. 1 (Provisional) shows a separate passage forming the connection; in this case a fan or screw may be fitted to the shaft where it passes through the casing to circulate the air or other gas. The liquid inside the casing may be nearly isolated from the external fluid, communication being by means of a substantially central restricted port or through a seal. Fig. 2 shows a seal 31, and Figs. 5 and 5a a restricted port. An isolating layer or hydraulic seal of oil through which water of condensation can escape may be provided to prevent contact between the surface of the water and the gas within the casing. The seal may be so arranged that it will retain the oil layer when the machine is raised and may be so proportioned as to allow an initial filling of water, and if necessary the initial volume of gas may be reduced to allow for expansion. An inert gas may be substituted for the air in the casing to reduce the possibility of less by chemical action. An initial hydraulic head may be imposed on the protective atmosphere to prevent loss when working at shallow depths through expansion due to heating. Fig. 1 (Complete) shows the water inlet 18 provided with a pipe 19 to permit such a head to be imposed; a filter 20 may be used. A cock 21 may be provided to allow sufficient liquid to be placed in the apparatus to prevent loss of gas by expansion, and two- or multiple-point suspension 23 may be provided to prevent tilting. A switch 24 may also be provided to give warning when the maximum permissable internal water level is reached. An horizontal drive may be afforded to external apparatus as shown for example in Fig. 7. In an electrically-driven pump the liquid may be admitted to both the bell or casing and the pump through a common intake as shown, for example, in Fig. 1 (Complete), or separate inlets may be employed as shown, for example, in Fig. 2. The admission of the liquid to the casing may be by a port communicating with the suction port of the pump as shown, for example, in Fig. 3. According to one Provisional Specification, means for adding gas to the upper part of the casing may be provided. According to another Provisional Specification, the inlet passage may be provided with inlet ,and outlet valves arranged to open at predetermined differences in internal and external pressures.