Accident Reconstruction Network > News > March 2005 >03/14/05

Accident Reconstruction News Article

TROY, Mich., March 14 /PRNewswire-FirstCall/ -- ArvinMeritor, Inc. (NYSE: ARM - News) and Meritor WABCO Vehicle Control Systems announced today their new Premium Hydraulic Braking System for medium-duty truck and bus applications. The package includes Meritor WABCO's Hydraulic Power Brake (HPB) -- the next-generation of its hydraulic actuation and anti-lock braking system (ABS), and the Meritor® Quadraulic(TM) hydraulic disc brake. Combined, these two brake technologies offer unparalleled stopping and performance capabilities.

The premium package is available immediately to North American original equipment manufacturers' vehicles.

"The new HPB system offers significant advancements. It incorporates many industry-first features that will positively impact motor carriers' vehicle performance," said Denny Sandberg, president and general manager of Meritor WABCO Vehicle Control Systems. "Together, the HPB and Quadraulic disc brakes achieve unrivaled stopping performance, providing motor carriers' added safety to vehicle operators."

"Our hydraulic disc brake has been proven in hundreds of thousands of miles since it entered the market in 1997," said Pedro Ferro, vice president and general manager of Worldwide Braking Systems and Commercial Vehicle Emissions, ArvinMeritor. "Combining it with the advanced HPB takes this complete system to a whole new level in stopping power for medium-duty applications."

Together, the new HPB and Quadraulic disc brake offer numerous benefits over current systems on the market today. One collective advantage for the industry is shorter stopping distances. Drivers will appreciate pedal "feel" similar to that of a passenger car, while fleets and owner-operators will benefit from longer lining life, fewer aftermarket parts and single-source shopping.

HPB System

The HPB is a braking and vehicle control system for vehicles in classes four through seven, and buses that are equipped with hydraulic brakes. The system provides three important functions:

* does not require the use of an external source to provide power assist to achieve a low pedal effort as required in a conventional hydraulic braking system;

* brake control functions, including ABS, automatic traction control (ATC), and electronic brake force distribution (EBD); and

* optional auto-apply electronic parking brake control.

The hydraulic energy required to actuate the brakes and control these functions is stored in hydraulic accumulators. When the vehicle's ignition is turned on, internal pumps are activated and fill both accumulators with pressurized hydraulic brake fluid. When the brake pedal is applied, the small master cylinder provides a hydraulic signal to the relay valve. Proportional to that signal, the accumulators provide pressure to the brake calipers. When the pedal is released, brake fluid returns to the reservoir from the brake calipers. For ABS and ATC activation, pressure at the wheel is individually modulated by ABS and ATC solenoid valves in the hydraulic modulator assembly. When required, hydraulic pressure is supplied and released to the appropriate foundation brake to achieve the desired functional effect.

"The enhanced stopping performance delivered by the new HPB is accomplished through faster reaction time when compared to other available hydraulic braking systems," said Alan Korn, chief engineer, Meritor WABCO Vehicle Control Systems. "This improved reaction time is a direct result of the stored energy in the accumulators, which are features distinct to this system."

HPB also has the advantage of serving as an enabling platform, allowing for custom tailoring to meet the needs of various OEMs and fleet applications. In addition to ATC, the system can accommodate the stability enhancement capability which has never before been available to the medium-duty market. It also serves as the foundation for future advanced features.

EBD (electronic brake force distribution) is another key development of the HPB system. This function provides constant review of the vehicle's load status and monitoring of each wheel end. Based on wheel slip observed by the HPB system during braking, braking forces at the axles are automatically adjusted to achieve a balanced, efficient use of the brakes. This results in improved stopping performance and allows the vehicle to adjust for consistent brake feel independent of the load.

The new HPB provides further advantages via its parking brake Auto-Apply function. When a vehicle's automatic transmission is placed in Park position, the park brake will automatically apply. The Auto-Apply will also function when the ignition key is switched off.

"HPB represents a breakthrough in braking control for hydraulically-braked vehicles," commented Korn. "This system delivers substantial benefits for the operator while providing a more comfortable driving experience."

Quadraulic Hydraulic Disc Brake

With a fixed caliper opposed four piston brake, the Quadraulic disc brake is designed to package within the 19.5 x 6.75 inch and 22.5 inch wheel sizes. It is available in two piston sizes -- 4 x 64 mm and 4 x 70 mm.

The Quadraulic disc brake provides several performance and maintenance benefits as a result of its unique design. The fixed caliper eliminates a main concern often associated with rail slider or pin slider designs -- external environment factors. Reduced affects of external influences result in longer lining life and reduced vehicle maintenance costs.

The enhanced robustness of this brake is complemented by simplified maintenance. When lining changes are required, only the lining retention bolt needs to be removed and the new linings can be dropped into the caliper. An absence of caliper swing due to the fixed caliper design allows for the brake hose to remain untouched during the lining replacement process eliminating the possibility of hose damage.

"Since its introduction several years ago, the Quadraulic disc brake has gained wide acceptance as a standard brake, on various vocational vehicles, providing premium results," said Prakash Jain, business unit director, Wheel End and Hydraulic Brakes, ArvinMeritor. "Motor carriers appreciate its easy- to-maintain design, fewer service parts, lower maintenance costs, added durability, and superior stopping performance."

In addition to the design advantages, the brake caliper sizes can be used inter-changeably by utilizing the same torque plates and rotors, reducing aftermarket parts requirements. Reducing inventory requirements even further, the two caliper sizes available with this brake (4 x 64 mm and 4 x 70 mm), use common brake pads (no unique inner/outer or directional pads), torque plates, hubs/rotors, and fasteners to attach the caliper to torque plate and rotor to hub.

WABCO, the vehicle control systems business of American Standard Companies, is the world's leading producer of electronic braking, stability, suspension and transmission control systems for heavy duty commercial vehicles. WABCO products are also increasingly used in luxury cars and sport utility vehicles (SUVs). Customers include the world's leading commercial truck, trailer, bus and passenger car manufacturers. Founded in the US 136 years ago as Westinghouse Air Brake Company, WABCO was acquired by American Standard in 1968. Headquartered in Brussels, Belgium, the business today employs nearly 6700 people in 30 office and production facilities worldwide. In 2004, WABCO contributed US$1.72 billion to American Standard's total sales of US$9.50 billion. Website: http://www.wabco-auto.com .

Meritor WABCO(1) is a joint venture of ArvinMeritor, (NYSE: ARM - News) and the WABCO Automotive Products Group of American Standard Companies Inc. (NYSE: ASD - News).

ArvinMeritor, Inc. is a premier $8 billion global supplier of a broad range of integrated systems, modules and components to the motor vehicle industry. The company serves light vehicle, commercial truck, trailer and specialty original equipment manufacturers and related aftermarkets. Headquartered in Troy, Mich., ArvinMeritor employs approximately 31,000 people at more than 120 manufacturing facilities in 25 countries. ArvinMeritor common stock is traded on the New York Stock Exchange under the ticker symbol ARM. For more information, visit the company's Web site at: http://www.arvinmeritor.com .

(1) Meritor WABCO products are available in the United States, Mexico and Canada.

Source: ArvinMeritor, Inc.

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