Hydraulic turbine power generator incorporating axial thrust equalization means

A hydraulic turbine-electrical power generator comprising

• a single shaft assembly for mounting a hydraulic turbine and an electrical power generator thereon, said shaft assembly being bidirectionally axially movable,
• a hydraulic turbine mounted adjacent one end of the shaft,
• a ball bearing mounted on said shaft for said turbine,
• said power generator comprising an electrical induction generator mounted on said shaft on the opposite side of the ball bearing from said turbine to be rotatably responsive to the rotary movements imparted to said shaft upon operation of said turbine and in accordance with the speed thereof,
• a radial bearing mounted to said shaft adjacent the opposite end of said shaft from said one end,
• said hydraulic turbine including thrust equalizing means mounted to said shaft adjacent said ball bearing, runner means rotatably mounted to said shaft adjacent said thrust equalizing means to be rotatably responsive to a high velocity fluid flow for providing torque to rotate said shaft at a speed in accordance with applied hydraulic pressure and velocity of the fluid impinging thereon and discharging the fluid flow at a relatively low velocity and pressure, said runner means having a plurality of spaced vanes for receiving said fluid flow and turning it through approximately 90 degrees and discharging the fluid flow axially at a low pressure and velocity,
• a common housing means for said hydraulic turbine and induction generator for enclosing and isolating said shaft between said opposite end of said shaft and said turbine including said thrust equalizing means, said housing terminating adjacent said turbine runner means whereby said runner means and the remaining portion of said shaft is outside said common housing,
• said ball bearing having an inner race mounted to said shaft and an outer race loosely mounted against said common housing means to permit the shaft to move axially, bidirectionally, relative to said housing a preselected amount,
• containment vessel means mounted over and in spaced relationship with said common housing and said remaining portion of said shaft and extending axially outwardly of said common housing and remaining portion of said shaft, said vessel having a fluid flow inlet adjacent the radial bearing end of said vessel and a fluid flow outlet at the opposite end therof, said fluid inlet and outlet being in flow communication with each other so the fluid flow is around said common housing means,
• said vessel including nozzle means having a plurality of spaced vanes spaced for receiving the fluid flow from said vessel fluid inlet and converting said fluid flow into a higher velocity fluid flow for impinging on said runner means for balancing out the hydraulic pressures generated by the centrifugal forces against said fluid flow and rotating said shaft in accordance therewith, thereby causing the hydraulic turbine to have a self-limiting runaway speed,
• said thrust equalizing means comprising a stationary thrust plate ring means secured to the common housing adjacent said ball bearing and extending axially outwardly of said bearing,
• said runner means including throttling ring means constructed and defined integrally with said runner on one side thereof for coaction with the thrust plate ring means for defining a substantially fixed orifice for receiving a portion of said high velocity fluid flow coupled to impinge on said runner means and a variable orifice defined between the throttling ring and the thrust plate and varying in size in accordance with the bidirectional movements of said shaft and receiving said fluid at said variable orifice from said fixed orifice, the fluid conveyed to said variable orifice flows through said ball bearing thereby cooling and lubricating the bearing and into said common housing to thereby cool said induction generator,
• and conduit means coupled to said common housing adjacent said radial bearing and to the low pressure fluid outlet for said vessel for conveying said coolant liquid to said oulet,
• said thrust equalizing means including first wear ring means secured to said common housing for coaction with said throttling ring means and second wear ring means secured to said containment vessel for coaction with the discharge end of said runner means, the diametrical spacing of said first wear ring means is constructed and defined to be larger than the diametrical spacing of said second wear ring means for creating thrust forces upon the application of hydraulic fluid thereto effective to cause the shaft assembly to move in response thereto in a direction therewith until said thrust plate ring means engages said throttling ring means whereby said variable orifice closes and thereby throttling the fluid flow into the variable orifice,
• the closed condition of the variable orifice defines a chamber between said first wear ring means and the closed variable orifice allowing fluid pressure to build up therein so when the pressure is built up in said chamber to a preselected level that counteracts said created thrust forces and for producing movement of said shaft assembly away from said engaged position of said thrust plate ring means and said throttling ring means resulting in a continuous fluid flow into the variable orifice and thereby the continuous reduction of the pressure built up in said chamber whereby the balancing of the generated thrust forces occur gradually and smoothly and without overshoot with the continuous bidirectional axial movements of the shaft assembly during operation of said hydraulic turbine.

A method of operating a hydraulic turbine-generator including the steps of providing a single rotatable shaft having a hydraulic turbine mounted adjacent one end of the shaft and an electrical induction generator having a rotor and an alternating current exciting field stator for receiving electrical signals of varying preselected frequencies for changing the synchronous speed of said generator mounted adjacent the opposite end of the shaft from said one end,

• mounting a radial bearing adjacent said opposite end of the shaft and fixed thereto adjacent said generator,
• mounting a ball bearing on said shaft with said turbine to be axially, and bidirectionally movable thereon over a preselected axial distance,
• said hydraulic turbine having radial runner means mounted to the shaft for receiving hydraulic fluids having a predetermined high fluid pressure and velocity for rotating said shaft and
• enclosing said single shaft including the induction generator and the turbine except for said runner means within a single housing with fluid flow communication between a portion of the fluid coupled to said runner means and said single housing
• conveying a hydraulic fluid of a predetermined high pressure and velocity for impinging against said radial runner means for balancing out the hydraulic pressures of the runner generated centrifugal forces against the injected fluid pressure and creating torque to rotate the shaft at a preselected speed and thereby said generator in accordance with the hydraulic pressure and velocity of said hydraulic fluid and discharging the hydraulic fluid from said runner means at a lower hydraulic pressure and velocity,
• automatically and continuously balancing out the generator turbine axial thrust forces by causing the thrust forces generated with the application of the high pressure hydraulic fluid to the runner means to cause the shaft assembly to axially move said preselected axial distance in response to the thrust force in the direction of the thrust force, conveying a portion of the hydraulic fluid conveyed to said runner means between said runner means and said housing through said ball bearing to thereby lubricate the bearing and conveyed past the induction generator for cooling the generator, and then conveying said fluid portion to the low pressure side of the discharged runner fluid,
• after the shaft moves said preselected axial distance, automatically throttling the hydraulic fluid being conveyed to the ball bearing to cause a build up in a fluid pressure between said housing and the runner means until the pressure is built up for counteracting the generated thrust thereby producing a movement of the shaft away from the throttling position so as to reduce the build up of pressure until the shaft movement is reversed and the shaft movements are automatically and continuously reversed whereby the generated thrust forces are balanced out and the turbine operates at essentially zero thrust over the entire usable hydraulic fluid range, and
• exciting the stator winding of said induction generator with a A.C. current having a frequency selected in accord with the speed of said shaft for producing a preselected output frequency for optimizing the overall efficiency of the turbine generator.

A thrust equalizing mechanism for use with a hydraulic turbine-electrical power generator mounted on a single shaft as a shaft assembly and a ball bearing mounted intermediate the turbine and power generator in a common housing except the turbine runner is mounted on the shaft outside the common housing adjacent the ball bearing, and a containment vessel enclosing the common housing and the shaft in a spaced relationship therewith,

• said ball bearing having an inner race secured to said shaft and an outer race loosely mounted against the common housing with a bearing clearance for permitting the shaft to move axially, bidirectionally, a predetermined axial distance, said thrust equalizing mechanism comprising a stationary thrust plate ring means mounted to said housing between the housing and said turbine runner,
• said runner means including throttling ring means constructed and defined integrally with said runner means on one side thereof for coaction with the thrust plate ring means for defining a substantially fixed orifice for receiving a portion of a high velocity hydraulic turbine flow coupled to impinge on said runner means and a variable orifice defined between the throttling ring means and the thrust plate means and varying in size in accord with said movements of said shaft and receiving the hydraulic fluids at said variable orifice from said fixed orifice, said variable orifice opening being initially greater than said fixed orifice opening, the arrangement and construction of the variable orifice and said thrust plate ring means permits the hydraulic fluid to be conveyed through said ball bearing and through said common housing,
• said thrust equalizing mechanism further including first ring wear means secured to said common housing and spaced from said throttling ring means and second wear ring means secured to said containment vessel adjacent said fluid discharge end of said runner means, the arrangement and construction of the diametrical spacing of said first wear ring means is defined to be larger than the diametrical spacing of said second wear ring means for creating thrust forces effective to cause the shaft assembly to move axially in the direction of the thrust forces until said thrust plate ring means engages said throttling ring means whereby the variable orifice is closed thereby throttling the hydraulic fluid flow into the variable orifice,
• said closed condition of said variable orifice defines a chamber between said first ring means and the closed variable orifice allowing fluid pressure to build up therein so when the pressure is build up in said chamber to a preselected level for offsetting the thrust forces created and leading to a movement of said shaft assembly away from said fluid throttling condition and thereby resulting in a continuous fluid flow into the variable orifice and the reduction of the pressure built up in said chamber whereby the balancing of the generated thrust forces occur gradually and smoothly and without overshoot with the continuous bidirectional, alternate axial movements of the shaft assembly, and
• conduit means coupled to said housing for conveying said portion of the fluid in the housing to adjacent the fluid discharge side of said runner means.