New Piston Pumps From Parker

Diesel Progress North American Edition, July, 2001 by Mike Brezonick

P2 and P3 variable pumps designed for high pressure, low noise; "Supercharged" P3 designed for high self-priming speeds and high altitude performance

The concept of a "global product" -- one that can address the wide-ranging needs and requirements in nearly every market in the world -- has been a kind of Holy Grail for component manufacturers. Yet in most cases it's an elusive target, since nearly every region has its own particular operational or performance-related quirks that are difficult to accommodate in a single design.

But when Parker Hannifin decided to develop its newest piston pumps for mobile hydraulic applications, a global design was the key target. And thanks to an innovative design process that included personnel from Parker's U.S. and European operations, the company believes its new P2 and P3 series piston pumps will be able to meet the needs of mobile equipment manufacturers worldwide.

"Traditionally Parker America and Parker Europe were more like two satellites operated under different management and the product sold in the various countries were basically manufactured there," said Kjell Jansson, vice president, sales & marketing at Parker's Mobile Systems Division in Lincolnshire, Ill. "The American products were American developed and in Europe, we generally acquired companies and Parkerized the products. After we appointed global presidents for each Parker group a few years ago, we started the process to coordinate product development to some extent.

"About two years ago when we decided to make the world's best piston pump line, we said no more local products. From now on in the hydraulics group, every product we make has got to be global. The reasons are that our customers are global so we have to be able to go with global companies, wherever they go, and we can't have one shaft here and another one there. We also want to be able to manufacture the product anywhere in the world."

With the P2/P3 pumps, the first products to fall under the new global mandate, Parker assembled a design team unlike any it had formed in the past. "We realized that we had to have the full input from all over the world," Jansson noted, "otherwise it would seem like a global product but it would still be designed by Americans and maybe Germans.

"So we put a team together from various nationalities -- Swedish, German, Americans and others -- and brought together design engineering, manufacturing, procurement and marketing people. And a few of those people were not just pump people, they were systems people. So this is the first pump we truly designed to be a part of the mobile system rather than being another pump to beat competitor A or B or C."

The design team spent the first year of development in the U.S. and the following year in Europe, "so they were close to the product and systems engineering centers that were going to deal with this product later,,, Jansson explained.

The P2/P3 series pumps were officially unveiled at Bauma in Munich and they are available in seven basic frame sizes -- four for the P2 and three for the P3 -- with displacements ranging from 60 to 145 cc/rev for the P2 and 75 to 145 cc/rev for the P3 series. Maximum continuous operating pressure is 4600 psi, with peak pressures of 5200 psi.

The pumps incorporate a range of features designed to provide high performance and reduced noise in a wide range of mobile equipment applications. Among the most innovative of these features is the addition of a precompression or "ripple" chamber in the rear cover. The ripple chamber is engineered to absorb the pressure spikes that occur when the pump's pistons act against the fluid. "Every time the piston pumps, you get a pressure spike," said Jansson. "That happens in all piston pumps and it's where a lot of noise is generated.

"With the ripple chamber, part of that pressure spike is absorbed and doesn't go out into the system, which reduces the noise.

Bo Lindblom, manager, product support, Hydraulic Group, Europe, said that the noise reductions can be significant. "We reduce the pressure spike by 10 to 50 percent," he said. "That cuts down the hydraulic 'noise' being generated and sent out into the system.

"It's a proven solution," he added. "We have already been using that technology on our PV plus industrial pumps."

The P2/P3 series pumps also incorporate a rigid, cast iron housing, which is engineered to reduce vibration and noise transmission. The housing is statically sealed with O-rings, which minimizes the risk of external leakage, the company said.

The result is that the noise levels of the pumps at full flow (1800 rpm and 3600 psi) ranges from 74 to 80 dB(A), depending on the pump model.

The P3 pumps have the same features as the P2 units, with the addition of an impeller around the piston barrel. "The impeller increases the pressure at the valve plate, depending on rpm, between 0.5 to 1.5 bar," said Lindblom. "That allows us to increase the self priming speed approximately 10 percent. This pump will then work well at high altitudes or in applications that need a higher self-priming speed.