Case Story- Rugged Industries Backpack Vacuum Cleaner

Rugged Industries Logo-AMETEK Case Study

For a quarter century, Sydney, Australia-based Rugged Industries has been designing and building commercial cleaning equipment—from vacuum cleaners to polishers to floor scrubbing machines. When they had an idea for their newest product, a backpack-mounted vacuum cleaner, they knew that the engineering of the device would be critical. For such a vacuum, weight, size and temperature rise of the motor are key for the comfort of the user—janitorial staff in commercial and industrial settings. And, of course, factors such as cost, power and flexibility are still critical aspects to finding the right solution. Plus, the company wanted the end product to be environmentally friendly in nature.

The company decided to focus on using swirl-tube cyclone technology, which would eliminate filter bags and maintain performance with no loss of suction. But they needed help on finding the right motor solution, and for that, they turned to the Shanghai office of Kent, Ohio-based AMETEK Dynamic Fluid Solutions.

Jin Wei, Motors Technology Manager for the company, realized that the Rugged project had some challenges. They were on a very tight time schedule, and wanted to launch mass production within 18 months. But Rugged wasn’t sure exactly what motor they wanted, as this backpack design was an entirely new one for them.

“They asked us for a ‘single stage, compact design, lightweight, high vacuum, low noise’ motor for their new backpack application,” said Wei. “With the very rough parameters for motor performance and physical characteristics, we realized that we didn’t have any existing motor that was close to their specification, but we told them we could develop a new model to meet their aggressive specs.”

This project grew to include the company’s Hong Kong office, as well as the Kent world headquarters, where Dave Gill, Senior Motor Design Engineer, led the motor platform design.

“We commonly do customized solutions for our customers,” said Gill. “This is where we offer value over selecting catalog motors.”

The AMETEK team held regular meetings with Rugged to track the project and discuss technical details. It was determined that a 120 in.-H2O sealed vacuum on a single-stage motor was necessary for the design, but AMETEK didn’t have a motor similar to those specifications.

Even so, Kent’s R&D team had created a 5.4-in. diameter motor/fan for a different customer about 10 years previously.

“While that project didn’t proceed, it was adapted in the intervening years to take advantage of the fan system, which is particularly quiet and efficient,” said Gill. “About four years ago, I started working to revive that project for a central vacuum solution. The potential air performance of this motor was appealing for the value end of this product line. As I worked on the program, I made a couple samples for another customer for a hand dryer application.”

Wei recalled those samples Gill had produced, and he asked Gill about possible adaptation for the Rugged project.  "It was a relatively easy task – we only had to redesign the windings and use correct brushes for Australian line voltage."

Six Sigma Methodology

The AMETEK team used a Design for Six Sigma methodology for implementing the project in five steps:

  • Rugged Industries Case Study AMETEK MotorDefine
  • Measure
  • Analyze
  • Design
  • Verify

Define included capturing initial voice of the customer perspectives and determining what items were critical to quality. The team also selected an initial benchmark motor.

For Measure, the engineers defined quantitative customer requirements, conducted a feasibility study and estimated a ballpark motor cost, to ensure that the finances would work out for the customer.

Analyze consisted of continually selecting and testing different benchmark motors, until finding the final one that was closest to the customer’s requirements. Here, AMETEK worked with Rugged to refine and justify their motor specifications.

In the Design portion, the actual motor base on the final benchmark motor was crafted. The AMETEK engineering team released the preliminary motor cost and worked with Rugged to refine, justify and make compromises to their motor specifications.

Lastly, Verify was where there additional testing and adjustment of the new motor’s design was performed until the motor passed Rugged’s specifications. Here, there was an update to the final motor cost, a pilot run and finally, customer approval.

The resulting motor has some special—not to mention patented—features. It boasts a quiet fan system, more so than most of AMETEK’s other products of similar power level, according to Gill. It also has the patented “Eternity” curved carbon brushes that give extra-long life.

“The new version Rugged is buying also employs one of our new motor lamination designs, optimized for high speed air moving applications,” said Gill.

Future versions of the vacuum

The AMETEK team is continuing to work with Rugged to improve the design. The backpack vacuum is very sensitive to motor weight, and AMETEK has done testing to replace brackets with lighter materials while maintaining the robust design. Some possible replacements have been found to degrade motor power and speed level, so the team continues to explore other avenues to lighten the design.

Rugged has already purchased 1,100 motors, with an outlook of 5,000 motors/year or more. The backpack has drawn a lot of attention and interest, and the company has received sample requests from many of their global customers. Rugged is currently working with AMETEK to develop a 220-V version for the Chinese market.

Wei said that almost all of the customer “wants” were met, and the only place where a compromise had to be made was on motor weight. But his team shared the whole process story of testing and reconfiguring things with Rugged to illustrate the undertaking from AMETEK’s engineering department.

“They were touched by our effort,” said Wei. “They visited our Shanghai office and expressed their appreciation, and promised that they wouldn’t work with other motor vendors for this project anymore—so AMETEK is now the sole vendor. I feel that our efforts established a stronger business and technical relationship with customer, resulting in their loyalty to us and their belief in our engineering expertise.”

Gill said that in the U.S., AMETEK is looking at expanding this new motor into more of the central vacuum market, structuring several power levels and features into the 5.4-in. family. It is also applicable in other vacuum cleaner applications, he explained.

“We’ve been selling some of these into the battery-operated backpack market in the U.S., and we are working to improve performance and efficiency,” he said. “The high-efficiency design is attractive in battery operated appliances, because it translates into longer run time on a charge.”

According to Rugged, the motor achieved a 1,005-hour life in the backpack vacuum.

“It is a truly great motor,” said Tibor Frei, Director at Rugged Industries Pty Ltd, Rugged Industries. “Configured in a cyclone vacuum delivering 250 max air watts of power, with no loss of suction, the amount of dust collection is unbelievable.”