Cooper Standard chooses DuPont™ Zytel® HTN PPA for all-plastic coolant pump meeting the needs of new genearation powertrains and vehicle electrification.
Rapid advances in the way today’s automobiles move — from advanced internal combustion engines (I.C.Es) through hybrid electric vehicles (HEVs) to battery electric vehicles (BEVs) — depend, for peak efficiency, on equally rapid advances in powertrain components.
Cooper Standard of Novi, Michigan, USA, a leading global supplier of automotive body sealing, fuel, brake and emissions products, and thermal management and anti-vibration systems, is at the forefront of developments in coolant pumps for I.C.Es, HEVs and BEVs.
Advances in coolant pump technology at Cooper Standard have enabled an unprecedented level of coolant control and improvements in pumping efficiency, to meet the demands of new generation powertrains.
State-of-the-art is the Cooper Standard Series 4 Brushless Pump, made with DuPont™ Zytel® HTN PPA. This is the company’s latest all-plastic pump which controls movement of coolant in a wide range of operating environments within the vehicle, both for improved powertrain performance and increased occupant comfort.
Cooper Standard chose DuPont™ Zytel® HTN PPA for its new all-plastic Series 4 Brushless Pump to reduce weight, withstand 100 g-force shocks, resist salt environments and lifetime contact with glycol coolants, and operate at high temperatures.
The series 4 pump is an enhancement of the Cooper Standard Series 1 pump — winner of the 2005 US SPE “Most Innovative Use of Plastics” award — which has been well proven since that time in the Ford Escape and Fusion HEVs, and the Nissan pathfinder SUV.
Since its introduction in 2010, Series 4 pumps have been adopted as standard equipment in several advanced propulsion vehicles in development, or already on the road. These include the Citroën DS4, the Peugeot (PSA) 3008, Renault’s Fluence and Kangoo, the luxury Nissan Fuga, and the ground-breaking Nissan Leaf, the first mass-produced 100 percent electric car from a major manufacturer, launched in Fall 2010.
“Based on its pulse width modulation (PWM) commutation design, Cooper Standard’s Series 4 pump enables more precise control by the on board vehicle computer than either the Series 1 pump or other competitive pumps on the market today,” said Patrick Bielman, Director Commercial Planning at Cooper Standard. “It is a high-volume, highly efficient solution enabling automakers to better control thermal management systems for improved vehicle operation and passenger comfort.”
The Series 4 pump of DuPont™ Zytel® HTN PPA offers three key design benefits:
- Low current draw: The new pump reduces electrical consumption by using source voltage more efficiently. This is achieved via improvements in hydraulics, electronics and motor design leading to approximately 15 percent greater operating efficiency, up to 25 percent less current draw, and increased HEV fuel economy and EV range due to amperage reduction, compared to similar pumps.
- Variable speed: The pump is designed with a PWM communication interface for precise thermal control, allowing customers to optimize flow output by varying revolutions per minute (RPM). This variation maximizes flow against the system pressure, while keeping the current draw to a minimum level. Complex systems with several fluid circuits are controlled to specific RPM’s to achieve the maximum benefit at minimum cost.
- Auto reversing: the Series 4 Pump detects non-rotating conditions and adopts an auto-reversing mode to clear the impeller when blocked by foreign debris.
The innovative design of the Series 4 pump incorporates 11 discrete components into one integrated assembly, enabling weight to be cut by one-third and motor life expectancy to be increased by up to 500 percent, compared with conventional metal pumps.
Performance data drawn from flow, pressure and source voltage testing, based on inputs from the vehicle control module on a test rig at Cooper Standard, indicate how the new all-plastic pump meets a wide range of flow and pressure requirements (see Charts 1 and 2).
Chart 1. Flow vs. pressure characteristic
Chart 1 highlights flow vs. pressure characteristic of the pump on test, and illustrates the variable range that separates the Series 4 design from its competitors.
Chart 2. Pump efficiency
Chart 2 illustrates the efficiencies of the pump at different signal inputs.
Findings from the test data demonstrate that Cooper Standard’s Series 4 Pump addresses a key customer concern — how to modulate (or provide variable flow controls) at high efficiencies through a wide range of inputs, including overall efficiency at various pressures.
“We made the decision several years ago to design with plastic instead of metal,” said Bielman. “Using plastic allows Cooper Standard to remove significant weight, and the resin provides a toughness that withstands harsh shocks — up to 100 g-force — with flexibility to prevent cracking during drop testing. It also allows us to use self-tapping threads into the plastic. The glycol-resistant nature of the plastic enables the material to withstand lifetime contact with the coolant. Another key characteristic of the material is its excellent performance in calcium chloride testing.”
Key members of the team at Cooper Standard that developed the all-plastic Series 4 Brushless Pump of DuPont™ Zytel® HTN PPA include (from l to r) Gary Klinger, Engineer; Russ Rombach, Principle Engineer and Chris Stockman, Program Engineer.
“Designing with plastics, such as Zytel® HTN PPA, allows a longer life in a salt environment than typical metal components without significant plating processes. Also, the operating temperature range of the material exceeds that which the electronics can withstand,” Bielman confirmed.
The development team at Cooper Standard forecasts that all future coolant pump housings will be designed and produced from plastic, in a trend that is expected to extend to other fluid management components such as water valves and electric thermostats.
“Based on our satisfaction with the performance of DuPont™ Zytel® HTN PPA resin in the coolant pump application, and also in our 3-way and 4-way valves, we are planning further generations of our pump family which will most likely be produced using this material,” Bielman concluded.
Engineering plastics, such as Zytel® , are making an important contribution to emissions reduction by enabling auto manufacturers to take weight out of key components, without any loss of strength or heat and fluids resistance. The heat, chemical and moisture resistance of Zytel® allows the material to perform well in tougher under hood applications, enabling design engineers to move beyond metals and design without the constraints of traditional materials — facilitating complex moldings that open the way to a high level of integration of multiple functions.
Zytel® is not only lighter than the metals it replaces but is also capable of delivering significant cost and performance improvements. For more information on Zytel®, and on working with DuPont to provide materials solutions for your automotive applications, contact us .