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Unique positive displacement pump questions

Unique positive displacement pump questions

Unique positive displacement pump questions


I have a few unique questions for pump designers for a racing application. I design racing shocks, I've never designed a pump and will begin looking for a technical partnership after I hopefully get a few questions answered.

The micro "pump" will be inside a damper and won't actually be pumping anything (more of a slave) and the pressures will typically be very low. The main damper piston will be pushing the light shock oil through the pump. Very small weights will be attached to the pump output shaft. As you can imagine the damper shaft can change direction from compression to rebound at a very high frequency in some cases and the pump will need to react just as quickly. So there is a sense of scale, the entire pump housing needs to fit inside a 2" body cap. Before you say I'm a whacko what I'm trying to accomplish has already been done with a micro spur gear pump and I'm trying to improve on it.

Sliding vane pumps - thinking about a balanced design with two inlets and outlets
  1. Can sliding vane pumps work as well as spur gear pumps with regards to the rapid change of direction?
  2. Can the sliding vanes be designed to maintain a seal at short bursts to 10,000 RPM? I'm thinking perhaps the vane may not be able to follow the wall as the chamber expands.
  3. I've found a manufacturer that makes carbon composite rotors, vanes, and housings. If you have any experience with this material I'd like to hear about it.
Micro spur gear pumps
  1. I'm trying to wrap my head around whether a gear pump with different size drive and driven gears will work. Each gear will displace the same amount of volume per shaft rotation, just one faster than the other. Is there a reason this won't work? I've certainly never seen it before. I like this option because it eliminates a secondary gear set to increase the speed of the weights, I would simply attach them to the smaller gear.
  2. Is there a significant benefit to relieving pressure between the meshed gears. I've seen groove details on the end faces that allow pressure to escape to the outlet.

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