Hydristor
Encyclopedia
device invented by Tom Kasmer is based on the dual pressure balanced hydraulic vane pump invented by Harry F. Vickers in 1925.
Vane pump details
The Vickers design included an elliptic chamber which confined the radial motion of the vanes nested in the rotor slots. As the rotor and vanes turn, each vane is first pushed radially inward followed by a maximum radial extension and that happens twice per revolution. The displacement of the fixeddevice is calculated by determining the difference in vane extension between minimum and maximum, times the axial length of the vanes and rotor. This multiplies to an area subject to the hydraulic pressure in the device whether used as a motor or a pump. Then an average of the minimum and maximum extensions establishes a 'radius of motion' for the pressurized equivalent pressure/force area. of each vane which passes one of the 4 axial sealing areas. What happens is that this equivalent area patch travels through the circumference or the equivalent linear distance resulting from rotating the 'radius of motion' through one complete revolution of 360 degrees.
The elliptic chamber is called a 'cam ring' by the industry. As a vane moves into, say, a maximum extension, and then rotates into a minimum extension region of the cam ring, it passes through a gradual transition from maximum to minimum followed by a gradual transition
back to maximum and this happens twice per revolution. In order to prevent oil under pressure from bypassing the vanes, 4 sealing areas
are created by means of 4 kidney shaped ports located in the transition areas between minimum and maximum. The spaces between the kidney ports are called the sealing areas and this port system is located at either, or both axial ends of the rotor and vanes. The configuration of the ports and sealing areas are such that the space between any two adjacent vanes is slightly less than the coverage of
the sealing area. In other words, as the vanes rotate through the sealing area, for a small amount of rotation, both adjacent vanes are
within the sealing area. As the rotation continues, the first vane in line leaves the sealing area, but not before the next vane in succession is firmly in the sealing region.
The effect is to prevent the exchange of oil from any two adjacent chambers located on either side of a given sealing area and the oil can only be interchanged by the actual rotation of the rotor and vanes. This is the pumping mechanism for the historical vane pump or motor. The term 'pressure balanced' comes from the fact that pressure in any chamber is matched by the same pressure in the diametrically opposite chamber and the hydraulic radial side thrust calculated by a 'side view area' and the two forces are opposite and cancel; hence the name
'pressure balanced'.
Hydristor details
Revolutions per minute
Revolutions per minute is a measure of the frequency of a rotation. It annotates the number of full rotations completed in one minute around a fixed axis...
-squared centripetal forces. The speed is limited to about 6-7,000 RPM and the pressure is limited to about 2,500 PSI. Another pressure-related problem is that the pressure forces into the axial rotor to stationary kidney endplate clearance and buckles the device ends thus increasing fluid blowby referred to as 'volumetric efficiency
Volumetric efficiency
Volumetric efficiency in internal combustion engine design refers to the efficiency with which the engine can move the charge into and out of the cylinders. More specifically, volumetric efficiency is a ratio of what quantity of fuel and air actually enters the cylinder during induction to the...
'. Typically, vane pumps and motors
Pneumatic motor
A pneumatic motor or compressed air engine is a type of motor which does mechanical work by expanding compressed air. Pneumatic motors generally convert the compressed air to mechanical work through either linear or rotary motion...
have two external ports but there are actually two separate sets of chambers which form two separate pumps and motors. The internal plumbing is y-connected to create only two external ports.
For the Hydristor. a 'concentric nesting of endless metal belts' replaces the fixed elliptic cam ring. And, all the vane tips
contact the inner surface of the belt. The historical friction of the vane tips now causes the belt set to rotate at approximately the
same speed as the rotor and vanes, but there is a very slight 'walking behind' of the vane contact area and there is a very slight speed slippage which results in the inner belt wear being spread out and this results in much longer belt life. Also, the belt set now confines the pressure and speed-squared forces like a pressure vessel and the potential speed of operation is very much higher. The result of all this is to raise both the operating pressure and the operating speed and this amounts to a 10 times increase in hydraulic packaging density and similar decrease in weight per unit power.
Related patents
There are 3 US and international patentPatent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
s on this device: 6022201 - Hydraulic vane pump with flexible band control,
6527525 - Hydristor control means, 6612117 - Hydristor heat pump.
A fourth patent was pending US and international approval, and was granted in 2005: 20050036897 - Rotary vane pump seal.
Hydristor efficiency
The fixed relationships of the elliptic cam ring are replaced by 4 curved surface (cupped) movable pistonPiston
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from...
s located at the 4 sealing areas, at 12,3,6, and 9 o'clock like the face of a clock. The curvature of each piston rides on a 'hydrodynamic oil bearing' similar to hydroplaning tires in the wet and this virtually eliminates metal-to-metal contact and friction. The first Hydristor achieved almost 95% efficiency
Efficient energy use
Efficient energy use, sometimes simply called energy efficiency, is the goal of efforts to reduce the amount of energy required to provide products and services. For example, insulating a home allows a building to use less heating and cooling energy to achieve and maintain a comfortable temperature...
overall and the present designs are in the 97+% range. If the 4 pistons are positioned equidistant from the center of rotation, no oil is expressed or accepted by any of the kidney ports. This is called 'neutral'. For a clockwise rotation, if 3 and 9 pistons are moved inward with 6 and 12 moving outward, all moving an equal amount, then a device displacement in proportion to the piston movement is created. If the 6 and 12 pistons were moved in with 3 and 9 moving equally out, then all the oil flows reverse. Since the piston positions are infinitely variable, any possible displacement between zero and + or - maximum displacement can be created. If two such Hydristor units are packaged face-to-face with the 4 port kidney plate between them, an infinitely variable transmission
Continuously variable transmission
A continuously variable transmission is a transmission that can change steplessly through an infinite number of effective gear ratios between maximum and minimum values. This contrasts with other mechanical transmissions that offer a fixed number of gear ratios...
is formed. This transmission can select any ratio in the forward direction and in the reverse direction without the need for any gears.
Hydristor value
A 2006 article for COE NewsNet discusses a few details related to the design and test of the Hydristor. In this article, the Appendix provides some over-arching concepts that are important for evaluation of the Hydristor and related technologies. As an infinitely variable transmissionContinuously variable transmission
A continuously variable transmission is a transmission that can change steplessly through an infinite number of effective gear ratios between maximum and minimum values. This contrasts with other mechanical transmissions that offer a fixed number of gear ratios...
, the Hydristor could help extend car longevity
Car longevity
Car longevity is of interest to many car owners and concerns several things: maximum service life in either miles or time , relationship of components to this lifespan, identification of factors that might afford control in extending the lifespan. Barring an accidental end to the lifespan, a car...
in the same way any other infinitely variable transmission can - by lowering the engine speed to a necessary minimum. As an example, recent Honda Civic IVT needs only 1400 engine RPM to travel at highway speeds.
Example use
Because the Hydristor is more easily packaged as a thin, large diameter device, it is easy to create a torque converterTorque converter
In modern usage, a torque converter is generally a type of hydrodynamic fluid coupling that is used to transfer rotating power from a prime mover, such as an internal combustion engine or electric motor, to a rotating driven load...
shape
which, with the proper adapters can fit any existing vehicle. Thus a few 'standard' Hydristors can be made which, with adapters will fit everything making the technology completely retrofittable into the entire highway fleet. By operating the engine near or at idle RPM, fuel economy is typically doubled. With the very fast response time of the Hydristor, a need for really quick acceleration is easily accomplished by 'ratioing' the Hydristor to allow the motor to race and make the desired power. The motor will last typically a half million miles due to greatly reduced engine revolutions per mile of travel. Emissions
Air pollution
Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere....
are also reduced due to slower engine speed.
Regenerative braking and hybrid vehicles
The Hydristor torque converter can also accomplish total hydraulic brakingHydraulic brake
The hydraulic brake is an arrangement of braking mechanism which uses brake fluid, typically containing ethylene glycol, to transfer pressure from the controlling unit, which is usually near the operator of the vehicle, to the actual brake mechanism, which is usually at or near the wheel of the...
and energy storage
Energy storage
Energy storage is accomplished by devices or physical media that store some form of energy to perform some useful operation at a later time. A device that stores energy is sometimes called an accumulator....
. Once a cruising speed has been achieved with front and rear Hydristors at some appropriate relative displacements, hydraulic braking is achieved by first simultaneously reducing both front and rear to zero displacement, then leaving the front Hydristor at zero (thus hydro mechanically disconnecting the engine from the torque converter hydraulic circuit and finally beginning to increase rear displacement as a braking function with the braking pressure and flow being directed to a hydraulic accumulator pressure tank. The decaying vehicle speed (kinetic energy), the rising tank pressure and the desired rate of deceleration determined by the driver all are variables which are easily managed by the Hydristor system. The stored braking energy can then be re-used for subsequent re-acceleration. With hydraulic storage capability, the acceleration at highway speeds can result in wheel spin.
The installation of a Hydristor torque converter into a typical car or truck already on the highways will create a hybrid vehicle
Hybrid vehicle
A hybrid vehicle is a vehicle that uses two or more distinct power sources to move the vehicle. The term most commonly refers to hybrid electric vehicles , which combine an internal combustion engine and one or more electric motors.-Power:...
which will out-perform the current crop of hybrids
Hybrid vehicle
A hybrid vehicle is a vehicle that uses two or more distinct power sources to move the vehicle. The term most commonly refers to hybrid electric vehicles , which combine an internal combustion engine and one or more electric motors.-Power:...
, thus adding other alternatives to that technology. One benefit of this approach is that the existing fleet can be re-configured thereby incurring monetary and natural resource savings .
Criticism
There are no independent tests to verify these claims for the Hydristor, according to some and problems of excessive parts wear have yet to be overcome, making practical applications of this device unlikely.External links
- Hydristor Corp
- Audio (13 May 2006, America's Car Show)
- ENR Podcast 20 February 2007 (Engineering News-Record, McGraw Hill)
- " CATIA Makes Possible a Solution to Global Warming" COE Article March, 2007
- Audio (26 May 2007, America's Car Show), Update