Artemis Intelligent Power demostrates hydraulic hybrid BMW 530i w/Video
The concept of a hydraulic hybrid powertrain is not a new one, and a number of companies have developed prototypes. The latest to show off a vehicle so equipped is Artemis Intelligent Power in the UK. The company has put together a BMW 530i demonstrator using its Digital Displacement pump/motor technology. The layout is very similar, in principal, to that used by FEV on its experimental UPS delivery vans. In this configuration, there is no direct connection between the engine and drive wheels. Instead, the engine drives a hydraulic pump that charges a hydraulic pressure accumulator in a series hybrid layout. The pressurized fluid stored in the accumulator is used to drive a pair of hydraulic motors at the rear axle that actually drive the wheels.
Like an electric hybrid, under braking, the drive motors are used to pressurize the accumulator. The company claims this is a more cost-effective solution than batteries. While the system can capture kinetic energy quickly - like an ultracapacitor - the energy storage capacity of the accumulators is unfortunately limited, making this configuration less useful for cars, particularly in highway driving. The series hydraulic hybrid is best suited to urban-use trucks like delivery vans or buses where there is more room for the accumulators. Artemis claims a 50 percent reduction in urban fuel consumption on its demonstrator vehicle. The key difference that Artemis is claiming for its version is the design of the hydraulic pump motor which is claimed to provide greater efficiency and more precise control. You can check out a video after the jump.
[Source: Artemis Intelligent Power]
Reader Comments (Page 1 of 1)
Chris M 6:27PM (2/26/2009)
I'd have to agree, the limited energy storage makes it of marginal value for regular cars, but it would be very well suited for large trucks, and for vehicles that already need and use hydraulic systems, like bucket loaders and other construction equipment, tractors and other farm equipment.
Reply
spdracerut 11:31AM (2/27/2009)
I does not make sense for a vehicle driven mostly in free flowing trafffic, but in a lot of stop and go traffic, it should be very effective. Hydraulic hybrid systems would do very well for the typical LA commuter that is constantly speeding up and slowing down between 10-40mph. The system just needs to recovery enough energy from one decel to help on the next acceleration.
GoodCheer 11:51AM (2/27/2009)
For city use I don't think you need all that much storage.
Let's say you have a 2000kg car, and you want to be able to accelerate from a stop to ~40mph (18m/s) twice on your stored energy.
2*(1/2 m v^2) = 648 kJ = 0.18 kWh.
Granted, there are some losses, even at low speed, not accounted for in that math.
I didn't find their estimates of stored energy, but 180 Wh of energy is only about 15% of the battery in a Prius.
jpm 9:38PM (2/26/2009)
Looks neat...
how's that accumulator work?
is it economical?
Reply
Herm 7:35AM (2/27/2009)
a hydraulic accumulator stores energy by compressing a plastic bladder filled with nitrogen.. on the other side of the bladder is oil.. the whole thing is inside a steel container. Supposedly well proven tech, the revolutionary part is the computer controlled hydraulic motor.
Essentially a very good transmission, should be very rugged and efficient, infinitely variable and low parts count.
This video is about 3 years old, any other news from this company?
Reply
Ruckus 10:56AM (10/26/2009)
Saying only for heavy trucks is wrong thinking. Any vehicle takes exactly the same energy to go as to stop. This is basic physics. If 70% of braking can be recovered, then you save 50-70% on acceleration energy, regardless of weight.
Reply