Differential-area piston type mixed-phase motors

A motor for powering a use device, said motor using pressurized, saturated or near-saturated liquid fluid from a source as input and exhausting said fluid when expended to a drain, said motor comprising:

• a casing defining a main chamber;
• a piston dividing said main chamber into first and second portions;
• means for moving said piston through a hydraulic power stroke and an expansion power stroke, said moving means including first means for selectively placing said source and said first portion of said main chamber in fluid communication with one another to move said piston through the hydraulic power stroke and placing said second portion of said main chamber in fluid communication with said drain port, said moving means further including second means for selectively placing said first and second portions of said main chamber in fluid communication with one another and closing said main chamber to said source and said drain to allow said saturated liquid to at least partially expand and change phase forcing said piston to move through the expansion power stroke;
• means for controlling said first and second selectively placing means;
• and
• means for transferring to said use device energy from said moving piston.

A motor for converting energy associated with change of phase of a fluid, said energy for powering a use device, said motor comprising:

• first and second casings defining first and second main chambers, respectively;
• first and second pistons dividing said first and second main chambers into first and second portions and third and fourth portions, respectively,
• a main shaft having opposite ends, said main shaft extending through said first and second casings and attaching at said first and second opposite ends to said first and second pistons, respectively;
• a drive shaft attached to one of said first and second pistons, said drive shaft extending through a corresponding one of said first and second casings which contains said one piston to which said drive shaft is attached;
• a fluid drain line;
• a source of pressurized, saturated or near saturated liquid;
• and
• an eight way, two position valve, said valve having a first position placing said source and said first portion of said first main chamber in fluid communication with one another and placing said second portion of said first main chamber and said fluid drain line in fluid communication with one another and placing said third and fourth portions of said second main chamber in fluid communication with one another to close said second main chamber to said source and said drain line, said valve having a second position placing said first and second portions of said first main chamber in fluid communication with one another to close said first main chamber to said source and said drain line and placing said source and said third portion of said second main chamber in fluid communication with one another and placing said fourth portion of said second main chamber and said fluid drain line in fluid communication with one another;
• wherein said first piston in a first hydraulic power stroke and said second piston in a first expansion power stroke in a first half cycle combine to drive said use device and said first piston in a second hydraulic power stoke and said second piston in a second expansion stroke in a second half cycle combine to drive said use device, said controlling means moving said valve between said first and second positions.

A method for using a motor to convert energy from a pressurized, saturated or near saturated liquid to mechanical energy, said motor including a main chamber with first and second portions and means for reciprocating to simultaneously increase the size of the other, said motor also including means for moving said reciprocating means through a hydraulic power stroke and an expansion power stroke, said moving means including first means for selectively placing a source of said liquid and said first portion of said main chamber in fluid communication with one another and placing said second portion of said main chamber in fluid communication with a drain, said moving means further including second means for selectively placing said first and second portions of said main chamber in fluid communication with one another to form a single motor chamber, said motor further including means for controlling said first and second selectively placing means and means for transferring energy from said reciprocating means to a use device, said method comprising the steps of:

• switching with said controlling means said first placing means so that said source of pressurized, saturated or near saturated liquid and said first portion of said main chamber are in fluid communication with one another and said second portion of said main chamber is in fluid communication with said drain wherein said reciprocating means moves through a hydraulic power stroke;
• switching with said controlling means said second placing means so that said first and second portions of said main chamber are in fluid communication with one another wherein said liquid partially changes phase and expands to force said reciprocating means through an expansion power stroke.