Hydristor is a joining of the words 'hydraulic' and 'transistor'. The device invented by Tom Kasmer [1] in 1996 [2] and is based on the dual pressure balanced hydraulic vane pump invented by Harry F. Vickers in 1925.
Hydristor is a joining of the words 'hydraulic' and 'transistor'. The device invented by Tom Kasmer [1] in 1996 [2] and is based on the dual pressure balanced hydraulic vane pump invented by Harry F. Vickers in 1925.
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 fixed device 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'.
There are several problems with the historical design. The vane tips radially contact the cam ring elliptic surface and cause a significant friction as the rotor and vanes turn. This friction is both pressure dependent and speed squared dependent due to RPM-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'. Typically, vane pumps and motors 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.
Revolutions per minute is the number of turns in one minute. It is a unit of rotational speed or the frequency of rotation around a fixed axis.
Volumetric efficiency (VE) in internal combustion engine engineering is defined as the ratio of the mass density of the air-fuel mixture drawn into the cylinder at atmospheric pressure to the mass density of the same volume of air in the intake manifold. The term is also used in other engineering contexts, such as hydraulic pumps and electronic components.
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 energy to mechanical work through either linear or rotary motion. Linear motion can come from either a diaphragm or piston actuator, while rotary motion is supplied by either a vane type air motor, piston air motor, air turbine or gear type motor.
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.
There are 4 US and international patents on this device:
A patent is a form of intellectual property. A patent gives its owner the right to exclude others from making, using, selling, and importing an invention for a limited period of time, usually twenty years. The patent rights are granted in exchange for an enabling public disclosure of the invention. In most countries patent rights fall under civil law and the patent holder needs to sue someone infringing the patent in order to enforce his or her rights. In some industries patents are an essential form of competitive advantage; in others they are irrelevant.
The fixed relationships of the elliptic cam ring are replaced by 4 curved surface (cupped) movable pistons 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 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 is formed. This transmission can select any ratio in the forward direction and in the reverse direction without the need for any gears.
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 expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. In a pump, the function is reversed and force is transferred from the crankshaft to the piston for the purpose of compressing or ejecting the fluid in the cylinder. In some engines, the piston also acts as a valve by covering and uncovering ports in the cylinder.
Efficient energy use, sometimes simply called energy efficiency, is the goal 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. Installing LED lighting, fluorescent lighting, or natural skylight windows reduces the amount of energy required to attain the same level of illumination compared to using traditional incandescent light bulbs. Improvements in energy efficiency are generally achieved by adopting a more efficient technology or production process or by application of commonly accepted methods to reduce energy losses.
A continuously variable transmission (CVT), also known as a shiftless transmission, single-speed transmission, stepless transmission, pulley transmission, or, in case of motorcycles, a 'twist-and-go', is an automatic transmission that can change seamlessly through a continuous range of effective gear ratios. This contrasts with other mechanical transmissions that offer a fixed number of gear ratios. The flexibility of a CVT with suitable control may allow the input shaft to maintain a constant angular velocity even as the output speed varies.
A 2006 article for COE NewsNet [6] discusses a few details related to the design and test of the Hydristor. In this article, the Appendix provides some overarching concepts that are important for evaluation of the Hydristor and related technologies. As an infinitely variable transmission, the Hydristor could help extend car longevity 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.
Because the Hydristor is more easily packaged as a thin, large diameter device, it is easy to create a torque converter 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. As engine rpm is now variably decoupled from wheel speed, the engine can run at its most efficient point at all times. With the very fast response time of the Hydristor, a change in demand allows the engine to quickly hit the desired point without interrupting power flow.
The Hydristor torque converter can also accomplish total hydraulic braking and energy storage. 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 [7] already on the highways will create a hybrid vehicle which will out-perform the current crop of hybrids [ citation needed ], 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 [ citation needed ].
There are no independent tests to verify these claims for the Hydristor, and problems of excessive parts wear have yet to be overcome, making practical applications of this device unlikely.
Thomas E. Kasmer died on October 27, 2011, from a heart attack. [8] The Hydristor web site was shut down effective December 31, 2012, by the person who had been hosting it for him pro bono.
A pump is a device that moves fluids, or sometimes slurries, by mechanical action. Pumps can be classified into three major groups according to the method they use to move the fluid: direct lift, displacement, and gravity pumps.
An air compressor is a device that converts power into potential energy stored in pressurized air. By one of several methods, an air compressor forces more and more air into a storage tank, increasing the pressure. When tank pressure reaches its engineered upper limit, the air compressor shuts off. The compressed air, then, is held in the tank until called into use. The energy contained in the compressed air can be used for a variety of applications, utilizing the kinetic energy of the air as it is released and the tank depressurizes. When tank pressure reaches its lower limit, the air compressor turns on again and re-pressurizes the tank. An air compressor must be differentiated from a pump because it works for any gas/air, while pumps work on a liquid.
Fluid power is the use of fluids under pressure to generate, control, and transmit power. Fluid power is subdivided into hydraulics using a liquid such as mineral oil or water, and pneumatics using a gas such as air or other gases. Compressed-air and water-pressure systems were once used to transmit power from a central source to industrial users over extended geographic areas; fluid power systems today are usually within a single building or mobile machine.
A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor.
In internal combustion engines, variable valve timing (VVT) is the process of altering the timing of a valve lift event, and is often used to improve performance, fuel economy or emissions. It is increasingly being used in combination with variable valve lift systems. There are many ways in which this can be achieved, ranging from mechanical devices to electro-hydraulic and camless systems. Increasingly strict emissions regulations are causing many automotive manufacturers to use VVT systems.
A variable displacement pump is a device that converts mechanical energy to hydraulic (fluid) energy. The displacement, or amount of fluid pumped per revolution of the pump's input shaft can be varied while the pump is running.
Hydraulic machines are machinery and tools that use liquid fluid power to do simple work, operated by the use of hydraulics, where a liquid is the powering medium. In heavy equipment and other types of machine, hydraulic fluid is transmitted throughout the machine to various hydraulic motors and hydraulic cylinders and becomes pressurised according to the resistance present. The fluid is controlled directly or automatically by control valves and distributed through hoses and tubes.
Turbomachinery, in mechanical engineering, describes machines that transfer energy between a rotor and a fluid, including both turbines and compressors. While a turbine transfers energy from a fluid to a rotor, a compressor transfers energy from a rotor to a fluid.
Adjustable speed drive (ASD), also known as variable-speed drive (VSD), describes equipment used to control the speed of machinery. Many industrial processes such as assembly lines must operate at different speeds for different products. Where process conditions demand adjustment of flow from a pump or fan, varying the speed of the drive may save energy compared with other techniques for flow control.
An axial piston pump is a positive displacement pump that has a number of pistons in a circular array within a cylinder block. It can be used as a stand-alone pump, a hydraulic motor or an automotive air conditioning compressor.
A rotary vane pump is a positive-displacement pump that consists of vanes mounted to a rotor that rotates inside a cavity. In some cases these vanes can have variable length and/or be tensioned to maintain contact with the walls as the pump rotates. It was invented by Charles C. Barnes of Sackville, New Brunswick, who patented it on June 16, 1874. There have been various improvements, including a variable vane pump for gases (1909)
A rotary-screw compressor is a type of gas compressor, such as an air compressor, that uses a rotary-type positive-displacement mechanism. They are commonly used to replace piston compressors where large volumes of high-pressure air are needed, either for large industrial applications or to operate high-power air tools such as jackhammers and impact wrenches.
A hydraulic motor is a mechanical actuator that converts hydraulic pressure and flow into torque and angular displacement (rotation). The hydraulic motor is the rotary counterpart of the hydraulic cylinder as a linear actuator. Most broadly, the category of devices called hydraulic motors has sometimes included those that run on hydropower—namely, water engines and water motors—but in today's terminology the name usually refers more specifically to motors that use hydraulic fluid as part of closed hydraulic circuits in modern hydraulic machinery.
Hydraulic pumps are used in hydraulic drive systems and can be hydrostatic or hydrodynamic. A hydraulic pump is a mechanical source of power that converts mechanical power into hydraulic energy. It generates flow with enough power to overcome pressure induced by the load at the pump outlet. When a hydraulic pump operates, it creates a vacuum at the pump inlet, which forces liquid from the reservoir into the inlet line to the pump and by mechanical action delivers this liquid to the pump outlet and forces it into the hydraulic system. Hydrostatic pumps are positive displacement pumps while hydrodynamic pumps can be fixed displacement pumps, in which the displacement cannot be adjusted, or variable displacement pumps, which have a more complicated construction that allows the displacement to be adjusted. Hydrodynamic pumps are more frequent in day-to-day life. Hydrostatic pumps of various types all work on the principle of Pascal's law.
A positive displacement meter is a type of flow meter that requires fluid to mechanically displace components in the meter in order for flow measurement. Positive displacement (PD) flow meters measure the volumetric flow rate of a moving fluid or gas by dividing the media into fixed, metered volumes. A basic analogy would be holding a bucket below a tap, filling it to a set level, then quickly replacing it with another bucket and timing the rate at which the buckets are filled. With appropriate pressure and temperature compensation, the mass flow rate can be accurately determined.
In aviation, a power transfer unit (PTU) is a device that transfers hydraulic power from one of an aircraft's hydraulic systems to another in the event that second system has failed or been turned off.
A rotodynamic pump is a kinetic machine in which energy is continuously imparted to the pumped fluid by means of a rotating impeller, propeller, or rotor, in contrast to a positive displacement pump in which a fluid is moved by trapping a fixed amount of fluid and forcing the trapped volume into the pump's discharge. Examples of rotodynamic pumps include adding kinetic energy to a fluid such as by using a centrifugal pump to increase fluid velocity or pressure.
PumpLinx is a 3-D computational fluid dynamics (CFD) software developed for the analysis of fluid pumps, motors, compressors, valves, propellers, hydraulic systems and other fluid devices with rotating or sliding components.
The yaw system of wind turbines is the component responsible for the orientation of the wind turbine rotor towards the wind.
A cam engine is a reciprocating engine where, instead of the conventional crankshaft, the pistons deliver their force to a cam that is then caused to rotate. The output work of the engine is driven by this cam.