The Durst Division of Regal-Beloit Corp. is introducing a completely new line of hydraulic pump drives intended for a wide range of mobile off-highway applications. The company has built hydraulic pump drives under the Regal, Federal and Terrell brand names, a range that over the years through development and acquisition, had grown to 22 models and myriad part numbers and configurations.

This completely new line, which will be sold under the Durst brand urine, is comprised of nine models covering horsepower ratings from 495 hp to 1025 hp.

There are four product groups within the new Durst line. The smallest, rated 495 hp at 2500 rpm, includes one-, two- and three pad drives with 6 in. and 6.5 in. gear centers. Above that is a family of 8 in. gear centers, two-, three- and four-pad models rated 725 hp at 2500 rpm. Next is a two- and three-pad family with 10.5 in. centers rated 950 hp at 2500 rpm. The largest pump drive in the new family is a 11.33 in., four-pad modal rated 1025 hp at 2500 rpm. An accompanying table includes more complete details, including ratios.

Durst is retaining a pair of smaller 460 hp direct-drive single-pump drives and a large six-pump drive model rated 600 hp. All of the new models and the existing models will be built at Durst's Shopiere, Wis., manufacturing operations which have recently been redesigned and expanded to manufacture the new pump drives.

The 6/6.5 in and 8 in. center drives will be available on April 1, with the 10.5 in. and 11.33 in. center models due by July 1. The other existing models will be phased out as the new models are introduced.

All are targeted at a wide range of global off-highway machines. In the construction markets this includes paving and compaction equipment, and hydraulic cranes; municipal applications such as sweepers, snow removal machines, in forestry, timber harvesting and processing equipment, as well as chippers and shredders.

Other potential applications include railway maintenance equipment, specialty ag equipment, ag sprayers, oilfield drilling and exploration equipment, including offshore, as well as workboats.

Overall this redesign program led to reducing 22 models to 12 modular drives, with simplicity being the key to the project from day one.

"This is an incredibly standardized product; gears, bearings, seals; the output groups, the input groups are all common in every model," said John Phillips, sales and marketing manager at Durst. "This is design for manufactability taken to the fullest extent possible." Further, the footprint of the new drives is interchangeable with Durst's former lines as well as competitive models.

"Cost and availability were the keys as we looked towards creating this new pump drive line," said Sam Finocchio, Durst's engineering project manager. "We wanted to come up with something that created common geometry across the different models, so we could have fewer parts and provide volume opportunities for manufacturing.

"That led us towards spur gears, ball bearings, all of which eliminate the time required for shimming, which at one time accounted for 50-60% of our assembly labor, especially on the larger models."

What resulted is an impressive new line that starts with modular design in which the bearings and gears are self contained within cast iron split housings. Input and output adapters are not required to retain the bearings, Finocchio said, and input and output adapters can be added or changed any time prior to installing the unit.

This, Phillips and Finocchio said, leads to greater flexibility for both distributors and equipment manufacturers. "We can sell these to a distributor as a module; housing and gears," Phillips said. "The distributor can stock pump adapters, engine adapters and drive plates and assemble a unit as a specific application dictates. If an OEM changes pumps or pump specs, the manufacturer or the distributor, now has more flexibility to make those changes."

The new Durst hydraulic pump drives all me AGMA Class 10 gears throughout, which Finocchio said are as quiet as helical gears. The drives include a solid-on-shaft, one-piece gear/shaft design that Finocchio said provides consistent and uniform alignment with bearings pressed on the gears, simplifying assembly. There are 31 gears that are totally interchangeable across the different models.