which is not even mentioned. How much energy is lost to friction in this system?
"Design concepts for hydraulic hybrids vary, but typically the car’s diesel or gas engine powers a hydraulic pump motor, which charges that high-pressure accumulator. The accumulator, in turn, drives one or more additional pump motors connected to the wheels. A second lower pressure accumulator typically completes the hydraulic circuit. Depending on the design, there may be one pump motor to drive a pair of wheels through a differential or one pump motor per wheel for an all-wheel-drive version with independent torque control. During braking, the pump motors on the wheels reverse themselves, re-charging the accumulator and capturing energy that would otherwise be lost to heat."
vs. to one with zero moving parts?
- Ultracapacitors perform well in cold weather, down to –40° Celsius, whereas, without heating, batteries do not operate reliably below 0° degrees Celsius. For transit busses,
- Ultracapacitors are a safe solution, as a pack with equalization is discharged over night.
- Ultracapacitors have a long life cycle, essentially lasting the lifetime of the machine into which they are incorporated. This low maintenance results in cost savings.
- Ultracapacitors are 85-95 percent efficient as compared to an average of 70% or lower for batteries in similar applications (as measured by ISE).
- Ultracapacitors are environmentally friendly, as they are 70 percent recyclable and do not include heavy metals.
- Ultracapacitors more than 10 times the power of batteries. In terms of vehicle acceleration, this is an essential attribute.
- Ultracapacitors provide a powerful energy storage solution, capable of capturing energy from one function, such as braking, and storing it for next energy requirement, such as acceleration.
http://www.evworld.com/article.cfm?archive=1&storyid=1138&first=5085&end=5084Maxwell Technologies to Design and Produce Ultracapacitors for Mercedes Hybrid Program
http://www.greencarcongress.com/2007/09/maxwell-technol.htmlEither Detroit can't think outside the mechanical box of pulleys, pumps, belts, and hoses -- or they make too much money from selling those items to even consider it.