Abstract:
The thruster pod that is made of a pump plate; a valve plate affixed to the pump plate, and a diaphragm mounted between the pump plate and the valve plate. The pump plate has juxtaposed pressure cavity and outlet cavity, and a partition separating the pressure cavity from the outlet cavity. The pressure cavity communicates with a source of water under pressure and the outlet cavity communicates with an outlet port. The valve plate has a control chamber facing the juxtaposed pressure and outlet cavities. The diaphragm is mounted between the juxtaposed pressure and outlet cavities and the control chamber for movement between a first position and a second position upon a change in pressure in the control chamber. A control valve is mounted in the valve plate for selectively changing a pressure in the control chamber and operating a diaphragm valve.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention pertains to water jet propulsion systems, and more particularly it pertains to water jet propulsion system having selectively operable thrusters and steering nozzles. 
       BACKGROUND OF THE INVENTION 
       [0002]    In order to characterize the present invention over the prior art, reference is made to existing valves on water jet propulsion systems that are used for steering and positioning a water craft: 
         [0000]    U.S. Pat. No. 3,132,477 issued to J. C. Egger on May 12, 1964;
 
U.S. Pat. No. 3,176,648 issued to M. Cavero on Apr. 6, 1965;
 
U.S. Pat. No. 3,492,965 issued to D. J. Wayfield on Feb. 3, 1970;
 
U.S. Pat. No. 3,675,611 issued to J. P. Glass on Jul. 11, 1972;
 
U.S. Pat. No. 4,265,192 issued to G. L, Dunn on May 5, 1981;
 
U.S. Pat. No. 5,014,912 issued to D. A. Brooks on May 14, 1991;
 
U.S. Pat. No. 5,129,846 issued to B. A. Dimijian on Jul. 14, 1992.
 
         [0003]    The valve systems described in the above-mentioned documents have multiple outlet ports that are controlled by mechanical actuators. These systems also comprise a pump and a valve cluster that are located inside the boat. The nozzles extend at a shallow depth under the boat where water pressure at the nozzles is negligible. These systems are designed for above-water operation, basically. 
         [0004]    U.S. Pat. No. 7,124,698 issued to Y. T. Shen et al. on Oct. 24, 2006; describes a maneuvering system for a submarine. A pump draws water from one end of a tube and forces this water to an outlet at the other end of the tube. The outlet is oriented in such a way to steer the water craft. The system is controlled by gate valves operated by mechanical actuators. The pump and the valve actuators need to be sealed from deep water pressure to prevent damage. 
         [0005]    Although the systems of the prior art deserve undeniable merits, it is believed that there is a need in the marine industry for an underwater thruster and guidance system that is easy to manufacture and that is more appropriate for use in remotely operated vehicles in deep sea applications. 
       SUMMARY OF THE INVENTION 
       [0006]    In the present invention, however, there is provided a thruster pod that is insensitive to deep sea pressures. 
         [0007]    In a first aspect of the present invention, there is provided a thruster pod that is made of a pump plate; a valve plate affixed to the pump plate, and a diaphragm mounted between the pump plate and the valve plate. The pump plate has juxtaposed pressure cavity and outlet cavity, and a partition separating the pressure cavity from the outlet cavity. The pressure cavity communicates with a source of water under pressure and the outlet cavity communicates with an outlet port for projecting a jet of water under pressure outside the pump plate. The valve plate has a control chamber facing the juxtaposed pressure and outlet cavities. 
         [0008]    The diaphragm is mounted between the juxtaposed pressure and outlet cavities and the control chamber for movement between a first position and a second position upon a change in pressure in the control chamber. The first position blocking the juxtaposed pressure and outlet cavities, and the second position opening the juxtaposed pressure and outlet cavities for allowing a flow of water under pressure under the partition from the pressure cavity to the outlet cavity and to the outlet port. 
         [0009]    A control valve is mounted in the valve plate for changing a pressure in the control chamber. The control valve has a connection to the pressure cavity; to the control chamber and to ambient water pressure. The control valve is selectively operable between a first condition for connecting the pressure cavity to the control chamber for pushing the diaphragm against the pressure and outlet cavities, and a second condition for connecting the control chamber to ambient water pressure for allowing the diaphragm to relax, for allowing a flow of water under pressure between the pressure cavity and the outlet cavity. 
         [0010]    In another aspect of the present invention, the control valve has a cylindrical cavity; a first magnet mounted in a fixed manner in this cylindrical cavity and a second magnet movably mounted in the cylindrical cavity. The second magnet is movable between a first location in a proximity of the first magnet and a second location away from the first magnet. The first and second magnets are mounted to attract each other. 
         [0011]    The control valve has a passage there through to the aforesaid control chamber between the first and second magnets. The passage is selectively openable to the source of water under pressure when the second magnet is in the first location, and closed to the source of water under pressure and open to ambient water pressure when the second magnet is in the second location, connecting the control chamber to ambient water pressure. 
         [0012]    The control valve also has a solenoid that is operable for selectively moving the second magnet between the first and second locations. 
         [0013]    In another aspect of the present invention, a combination of a pressure cavity, an outlet cavity, a control chamber, a control valve and a segment of the diaphragm constitutes one diaphragm valve. The thruster pod has a plurality of diaphragm valves therein that are selectively operable to operate corresponding outlet ports. 
         [0014]    In yet another aspect of the present invention, the pump plate is circular and has four diaphragm valves and outlet ports oriented radially there about. 
         [0015]    In yet a further aspect of the present invention, there is provided a diaphragm support plate between the diaphragm and the pump plate to protect the diaphragm from excessive pump pressure. 
         [0016]    In yet another aspect of the present invention, the source of water under pressure is obtained by a pump impeller mounted in the pump plate. 
         [0017]    This brief summary has been provided so that the nature of the invention may be understood quickly. A more complete understanding of the invention can be obtained by reference to the following detailed description of the preferred embodiment thereof in connection with the attached drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The drawings illustrate two preferred embodiments of underwater thruster pods. More specifically; 
           [0019]      FIG. 1  illustrates a torpedo having the thruster pod according to the first preferred embodiment mounted on the front end thereof; 
           [0020]      FIG. 2  illustrates another torpedo wherein the flow from one outlet nozzle in used as a source of fluid under pressure to operate a linear actuator; 
           [0021]      FIG. 3  is a plan view of the pump and pump plate in the first preferred thruster pod; 
           [0022]      FIG. 4  is a plan view of the diaphragm support plate that is preferably mounted in the first preferred thruster pod; 
           [0023]      FIG. 5  is a plan view of the diaphragm mounted in the first preferred thruster pod; 
           [0024]      FIG. 6  is a plan view of the valve plate mounted in the first preferred thruster pod; 
           [0025]      FIG. 7  is a partial enlarged plan view of the pump and pump plate illustrated in  FIG. 3 ; 
           [0026]      FIG. 8  is a partial enlarged plan view of the valve plate illustrated in  FIG. 6 ; 
           [0027]      FIG. 9  is a cross-section view of the pump and pump plate as viewed substantially along lines  9 - 9  in  FIGS. 7 and 8 , showing one of the diaphragm valves in a closed mode; 
           [0028]      FIG. 10  is another cross-section view of the pump and pump plate as viewed substantially along lines  9 - 9  in  FIGS. 7 and 8 , showing one of the diaphragm valves in an open mode; 
           [0029]      FIG. 11  is a plan view of the pump and pump plate in the second preferred thruster pod; 
           [0030]      FIG. 12  is a plan view of the diaphragm support plate that is preferably mounted in the second preferred thruster pod; 
           [0031]      FIG. 13  is a plan view of the diaphragm mounted in the second preferred thruster pod; 
           [0032]      FIG. 14  is a plan view of the valve plate mounted in the second preferred thruster pod; 
           [0033]      FIG. 15  is a partial enlarged plan view of the pump and pump plate illustrated in  FIG. 11 ; 
           [0034]      FIG. 16  is a partial enlarged plan view of the valve plate illustrated in  FIG. 14 ; 
           [0035]      FIG. 17  is a cross-section view of the pump and pump plate as viewed substantially along lines  17 - 17  in  FIGS. 15 and 16 , showing one of the diaphragm valves in a closed mode; 
           [0036]      FIG. 18  is another cross-section view of the pump and pump plate as viewed substantially along lines  17 - 17  in  FIGS. 15 and 16 , showing one of the diaphragm valves in an open mode. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0037]    While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will be described in details herein two specific embodiments of the present invention, with the understanding that the present disclosure is to be considered as an example of the principles of the invention and is not intended to limit the invention to the embodiments illustrated and described. 
         [0038]    In the drawings, the same numerals are used to illustrate and described the same elements in both embodiments where the description permits. 
         [0039]    Referring firstly to  FIG. 1 , there is illustrated a torpedo  20  having the thruster pod  22  according to the first preferred embodiment mounted in its front end, and a nose cone  24  directing water to an impeller mounted inside the thruster pod  22 . The thruster pod  22  may be operated in a wireless manner such that it can be used in remotely operated vehicles (ROV) of many types. This wireless system may comprise an antenna  26 , which is illustrated for convenience. It will be appreciated that an antenna  26  may be used for surface application, and can be replaced by a tether line (not shown) when the thruster pod  22  is used in underwater vehicles. 
         [0040]    The impeller (not shown) is operated by an electric motor  30  mounted in the front end of the torpedo. The electric motor  30  is illustrated in dashed lines for convenience in  FIG. 1 . 
         [0041]    The thruster pod  22  has several jet ports  32  around its circumference. Some of these jet ports  32  have nozzles  34  that are curved and oriented backward for propelling the torpedo in the forward direction. The other jet ports  32  are oriented radially and can be used intermittently for steering the water craft. 
         [0042]    Referring now to  FIG. 2 , it will be appreciated that one or more jet ports  32  can be used as a source of hydraulic pressure connected by piping  36  to hydraulic equipment or tooling. Such feature is explained in the illustration of a stabilizer fin  38  that is operated by an hydraulic cylinder  40 . 
         [0043]    The first preferred thruster pod  22  and its operation are illustrated in  FIGS. 3-10 . Broadly, the thruster pod  22  is made of a pump impeller  50  mounted at the centre of a pump plate  52 ; a diaphragm  54  and a valve plate  56 . Preferably, a diaphragm support plate  58  is also included between the pump plate  52  and the diaphragm  54  for preventing wear, fatigue and damage to the diaphragm  54  from pump pressure. 
         [0044]    The first preferred thruster pod  22  has eight (8) outlet ports  60 , jet nozzles or jet ports. Each nozzle is connected to an outlet cavity  62  in the pump plate  52 . Each outlet cavity  62  is bordering a pressure cavity  64 , and it is separated from that pressure cavity  64  by a partition  66 . The pressure cavity  64  communicates with the impeller housing  68  or a volute in which the impeller  50  rotates. 
         [0045]    It will be appreciated that when the impeller  50  rotates, a pressure is created inside the pump housing  68  and in all the pressure cavities  64 . 
         [0046]    Referring now to  FIG. 4 , the diaphragm support plate  58 , has side-by-side pressure opening  70  and outlet opening  72  pairs for each pressure and outlet cavity pair in the pump plate  52 . The pressure opening  70  is fully open, while the outlet opening  72  has grate-like openings for preventing damage to the diaphragm  54  from pump pressure. 
         [0047]    The pump plate  52 , the diaphragm support plate  58  and the valve plate  56  can be made of metal or plastic material in a casting or a CNC machining process. 
         [0048]    The diaphragm  54  is made of thin, strong, flexible and impermeable diaphragm material. A hole  74  at the centre of the diaphragm  54  lets pressure from the pump housing  68  be transmitted to the valve plate  56 , for the purpose of transmitting control pressure to the valve plate  56 . 
         [0049]    The valve plate as a central cavity  80  communicating with the hole  74  at the centre of the diaphragm  54  and with the pump housing  68 . Eight radial slots  82  join the central cavity  80  to eight control valves  84  respectively. Each control valve  84  is connected by conduits  86  to a respective control chamber  88 . It will be appreciated that the valve plate  56  has a radial slot  82 ; a control valve  84 ; conduits  86  and a control chamber  88  for each pressure and outlet cavity pair  62 ,  64  in the pump plate  52 , and for each diaphragm valve in the thruster pod  22 . 
         [0050]    In use, the pump plate  52 ; the diaphragm support plate  58 , the diaphragm  54  and the valve plate  56  are stacked over each other in the order in which they are illustrated, and fastened to each other in any suitable way. The views illustrated in  FIGS. 3 and 6  are the faces of each plate  52 ,  56 . In use these faces are mounted against each other. 
         [0051]    Although a pump impeller  50  has been illustrated in  FIG. 3 , it will be appreciated that all that is required in the pump plate  52  is a source of water under pressure. Therefore, a pump may be located somewhere else than illustrated and connected to the pump housing  68  by piping for example. 
         [0052]    Referring now more specifically to  FIGS. 7 to 10 , the operation of the first preferred thruster pod  22  will be explained. 
         [0053]    Firstly, each control valve  84  contains a fixed magnet  90  that is mounted stationary to the top portion of a cylindrical cavity  92  as seen in  FIGS. 9 and 10 . A second magnet  94 , referred to as a movable magnet is movably mounted in the cylindrical cavity  92  under the fixed magnet  90 . The slot  82  communicates with the cylindrical cavity  92  in a region immediately under the fixed magnet  90 , when both magnets  90 ,  94  are separated from each other, as may be appreciated from the illustration in  FIG. 9 . When both magnets  90 ,  94  are separated, the pressure from the pump housing  68  is transmitted through the slot  82 ; into the cylindrical cavity  92  and into the control chamber  88  via the conduit  86 . 
         [0054]    A drain hole  96  in the bottom of the cylindrical cavity  92  allows ambient pressure to enter the valve cavity  92 , and into the control chamber  88  via the conduit  86  as it may be understood when looking at  FIG. 10 . 
         [0055]    The magnets  90 ,  94  are mounted to attract each other. Therefore, when there is no outside influence, both magnets  90 ,  94  are held against each other as shown in  FIG. 10 , such that the movable magnet  94  closes the passage from the slot  82  to the control chamber  88 . The pressure in the control chamber  88  is thereby reduced to the ambient water pressure Wp through the drain hole  96 . The pump pressure Pp in the pressure cavity  64  forces the diaphragm  54  downward to create a passage under the partition  66  and to open the pressure cavity  64  to the outlet cavity  62  and to a corresponding outlet port  60 . A flow of water under pressure is thereby obtained at the outlet port  60 . 
         [0056]    When the movable magnet  94  is separated from the fixed magnet  90 , by force of a solenoid  98  for example, the control chamber  88  is pressurized to pump pressure Pp from the pressure cavity  64  through the slot  82 . As a result, the diaphragm  54  is pushed upward to block the openings  70  and  72  and to shut off the flow to the corresponding outlet port  60 . 
         [0057]    It will be appreciated that the pump pressure Pp always included ambient water pressure Wp when the thruster pod  22  is used underwater. Therefore, the diaphragm valves are operated on a differential pressure which remains the same whether the thruster pod  22  is operated in surface water or in deep water. External pressure does not affect the operation of the thruster pod  22 . 
         [0058]    It will also be appreciated that the movable magnet  94  can be displaced without touching it such that sealing of an actuator from deep sea pressure is not required. The positioning of the movable magnet  94  may be effected by a solenoid  98  as shown, or by a stronger magnet (not shown) that is moved in and out of a proximity of the control valve  84  by a servo motor for example. 
         [0059]    Referring now to  FIGS. 11-18 , the thruster pod  122  according to the second preferred embodiment will be described. The elements in this second embodiment that have same functions as their equivalents in the first embodiment are labelled with numbers differing from their equivalent elements by  100 , to facilitate the understanding of the principle of the invention. 
         [0060]    The second preferred thruster pod  122  and its operation are illustrated in  FIGS. 11-18 . The thruster pod  122  in the second preferred embodiment is made of a pump impeller  150  mounted at the centre of a pump plate  152 ; a diaphragm  154  and a valve plate  156 . A diaphragm support plate  158  is also preferably included between the pump plate  152  and the diaphragm  154 , for preventing wear, fatigue and damage to the diaphragm  154  from pump pressure. 
         [0061]    The second preferred thruster pod  122  has four (4) outlet ports  160  or jet nozzles. Each nozzle  160  is connected to an outlet cavity  162 . Each outlet cavity  162  is bordering a pressure cavity  164 , and it is separated from that pressure cavity  164  by a partition  166 . The pressure cavity  164  communicates with the impeller housing  168  or a volute in which the impeller  150  rotates. 
         [0062]    It will be appreciated that when the impeller  150  rotates, a pressure is created inside the pump volute  168  and in all the pressure cavities  164 . 
         [0063]    Referring now to  FIG. 12 , the diaphragm support plate  158 , has side-by-side pressure opening  170  and outlet opening  172  pairs corresponding to the location of each pressure and outlet cavity pair  162 ,  164  in the pump plate  152 . The pressure opening  170  is fully open while the outlet opening  172  has a grate-like openings for preventing damage to the diaphragm  154  from pump pressure. 
         [0064]    The pump plate  152 , the diaphragm support plate  158  and the valve plate  156  are made in a same way as explained in the thruster of the first preferred embodiment. 
         [0065]    The diaphragm  154  is made of thin, strong, flexible and impermeable diaphragm material. A hole  174  at the centre of the diaphragm  154  lets pressure from the pump housing  168  be transmitted to the valve plate  156 , for the purpose of transmitting control pressure to the valve plate  156 . 
         [0066]    The valve plate as a central cavity  180  communicating with the hole  174  at the centre of the diaphragm  154  and with the pump housing  168 . Four radial slots  182  join the central cavity  180  to four control valves  200  respectively. Each control valve  200  is connected by a conduit  186  to a respective pressure control chamber  188 . It will be appreciated that the valve plate  156  has a radial slot  182 ; a valve  200 ; conduits  186  and a pressure control chamber  188  for each pressure and outlet pair  162 ,  164  in the pump plate  152  and for each diaphragm valve in the thruster pod  122 . 
         [0067]    In use, the pump plate  152 ; the diaphragm support plate  158 , the diaphragm  154  and the valve plate  156  are stacked over each other in the order in which they are illustrated, and fastened to each other in any suitable way. The views illustrated in  FIGS. 11 and 14  are the faces of each plate  152 ,  156 . In use these faces are mounted against each other. 
         [0068]    Referring now more specifically to  FIGS. 15 to 18 , the operation of the second preferred thruster pod  122  will be explained. 
         [0069]    Firstly, each control valve  200  contains a fixed magnet  210  that is mounted in a stationary manner to the top portion of a cylindrical cavity  212 , as seen in  FIGS. 17 and 18 . A second magnet  214 , referred to as a movable magnet, is movably mounted in the cylindrical cavity  212  under the fixed magnet  210 . The slot  182  communicates with the cylindrical cavity  212  in a region immediately under the fixed magnet  210 , and with the pressure control chamber  188 , through the slot  186  as may be appreciated from the illustrations in  FIGS. 17 , and  18 . 
         [0070]    When both magnets  210 ,  214  are separated, the pressure from the pump housing  168  is transmitted from the cylindrical cavity  212  to the control chamber  188  via the conduit  186 . 
         [0071]    A calibrated orifice  220  between the fixed and the movable magnets  210 ,  214  communicates with a drain channel  222  when the movable magnet  214  is moved away from the fixed magnet  210 . When the movable magnet is pulled away from the fixed magnet  210 , by the force of a solenoid  198  for example, the pump pressure in the conduit  182  is released to this drain channel  222 , thereby reducing the pressure inside the control chamber  188 . 
         [0072]    As a result of this pressure reduction in the control chamber  188 , the diaphragm  154  is forced to open to allow a flow F under the partition  166  from the pressure cavity  164  to the outlet cavity  162  and the outlet port  160  as indicated in  FIG. 18 . 
         [0073]    It will be appreciated that the orifice  220  is calibrated to release only sufficient pressure to allow the operation of the control valve  200 , without adversely affecting the operation or the performance of other diaphragm valves in the thruster pod  122 . 
         [0074]    When the solenoid  198  is de-energized, the movable magnet  214  is attracted to the fixed magnet  210  thereby closing the drain hole  220  and re-establishing a pump pressure Pp in the control chamber  188 . 
         [0075]    The control valve  200  also works on a differential pressure between the pump pressure Pp and the ambient or water pressure Wp. It will be appreciated that this pressure differential remains the same whether the thruster pod  122  is operated in surface water or in deep water. External pressure does not affect the operation of the thruster pod  122 . 
         [0076]    As to other manner of usage and operation of the present invention, the same should be apparent from the above description and accompanying drawings.