Cascon applies a wide range of technologies to the design and manufacture of custom solutions for its customers. Gerotors and other positive-displacement rotary pumping devices are at the core of many of our products and Cascon’s engineering staff has decades of experience designing real-world solutions using their expertise. Our engineers capitalize on the flexibility of these technologies, matching the right gear design with the right application to optimize the resulting product.
Cascon currently serves aerospace, chemical, gas turbine, industrial, mission-critical and mobile markets – although specialized pumps and gears have countless applications.
Range and Experience
Although Cascon has achieved success engineering a variety of hydraulic devices, we have a unique depth and range of experience applying gerotors and IGR rotor technology to solve difficult problems. The names of Cascon engineers are on a variety of patents related to these devices, some of which date back to the initial wide spread commercial introduction of the gerotor in the 1970’s. These devices can handle an extremely wide range of fluids, from water and refrigerants to high viscosity chemicals. We can design pumps which effectively manage flows ranging from a few cc/min to over 300 gallons per minute, with operating pressures up to 2000 psi. Beyond pumping technology, we also integrate valves, electric drive motors, control electronics and other devices into our custom products.
The gerotor is a simple yet elegant device used to pump a wide variety of fluids in automotive, industrial and aerospace applications. Cascon engineers are among the most experienced in the world at applying this well-established technology.
The gerotor consists of just two components: an inner and outer element, each supported by the structure of the pump. Its principle of its operation is very simple and easily understood through the illustration below. As the two elements rotate, an expanding “pocket” is formed to draw fluid in through the pump inlet. Fluid is forced out through the pump outlet as the pocket contracts. Porting contained in the adjacent housings provides for the inlet and outlet timing necessary to keep the two sealed from one another.
The geometry of the device requires that the inner and outer rotate on different fixed centers, one element driving the other much like a gear set. This offset, or eccentricity as it is called, combined with the form geometry provides for continuous contact and matched velocity at each mating point resulting in smooth, efficient motion. Many of the concepts used to understand involute gearing are applicable to the gerotor.
The internally generated rotor, or IGR, is a close cousin of the gerotor and is based on a very similar set of generating equations but with a term or two reversed. The gerotor outer element is comprised of a series of semi-circular forms while the inner element has a continuously changing radius of curvature. The IGR reverses this arrangement; the outer element has a continuously changing radius of curvature and the inner carries the conjugate circular forms. In the IGR, these circular forms are replaced with cylindrical rolls carried by the inner element. While more expensive than a Gerotor, this arrangement gives the IGR useful advantages in certain challenging applications. Its principle of operation is identical to that of the gerotor.
There are some applications where spur gears offer advantage over Gerotor or IGR technology and Cascon engineers are adept at designing with them in these cases. One example is a low-volume aerospace application where ceramic materials were needed for the pump rotors. Rather than develop a new manufacturing capability to produce ceramic gerotors, spur gears were chosen to utilize an established gear grinding technology and achieve a less expensive program overall.
Integral Valves and Other Hydraulic Devices
In many cases ancillary devices such as relief valves, pressure control valves, checks, burst plugs, filters, or sensors can be integrated into the product design to provide an optimum system-level solution. Our engineers can accommodate third-party devices into a new product or provide custom designs when needed.
In addition to the conventional pump or motor shaft with a spline or key drive arrangement, a gear interface can be provided either on the pump or motor shaft or designed to be integral with the pump rotor set as in the transmission pump shown below.
Electric Drive Motors and Electronics
We also have extensive experience designing electric drive motors and related electronics into product solutions. These have included AC, DC, and high-speed brushless DC type motors. In several cases we have developed application specific drive control electronics to provide the highest level of integration. This highly integrated approach can offer our customers considerable benefits in size, weight, reliability and cost.