Making the Torque-Transfer Transition

Amsted Automotive Group saw the EV revolution coming and has the ‘means’ to deliver greater driveline efficiency. AAG’s top engineers talk next-gen technology.

Means Industries’ Dynamic Controllable Clutch delivers multi-mode functionality and actuation to the EV driveline. It is shown here in planar configuration. (AAG)

A reckoning has arrived at suppliers whose product portfolios, engineering resources, and R&D activities are not aligned with the EV horizon. The challenge of pivoting their focus to electrification, while sustaining the incumbent business, has been particularly vexing for many Tier 2s and Tier 3s rooted in “legacy” powertrain supply, as S&P Global analyst Michael Robinet has noted in his Supplier Eye column in this publication.

Growing sophistication of EV propulsion systems and demand for increased vehicle efficiency are driving product development and manufacturing synergies across AAG’s business units. (AAG)

But for Means Industries, whose clutch-technology IP is inside most automatic transmissions made worldwide, balancing today’s business with tomorrow’s propulsion opportunities has been part of the company’s strategic roadmap for years.

“The OEMs have shifted their spend from ICE into EVs, which are inevitable,” said Jeremy Holt, the veteran engineering executive and president of Means Industries’ parent company, Amsted Automotive Group (AAG). “But if the shift takes longer than is forecasted, we have a business plan that’s agnostic to that. We can survive with a rapid transition to EVs, and we can also do well in an extended-ICE scenario.”

Founded in early 2021, employee-owned AAG consolidates the synergies of Means (mechatronic clutches, driveline disconnects, e-motor housings), powder-metal pioneer Burgess-Norton, and SWM Manufacturing, a leader in advanced cold-forming and precision machining processes. The company’s 16 engineering and manufacturing facilities in North America, Asia and Europe are engaged in EV programs with both legacy and start-up OEMs looking to expand their new vehicles’ torque-transfer capabilities and overall efficiency.

A solid book of business in “the surviving engines and transmissions” chunk of the industry, as Holt calls it, is expected to sustain revenues and ongoing product development for at least the next decade until EVs reach mainstream volume.

Needing a 25,000-rpm clutch

For the past six years, Means Industries has aimed its evolving R&D program to “address the unvoiced needs of EV propulsion—the greater efficiencies that the OEMs have not yet realized,” Holt explained. The Saginaw, Michigan-based company leverages the proprietary materials and metal-forming expertise of the sister AAG units, along with Means’ expanding muscle in mechatronic engineering, control software, and electro-magnetic actuation.

Anticipating the steep curve in research and testing required for electric drivelines meant the company had to replace and reconfigure laboratory equipment “for going from ICE engine speeds to electric motor speeds,” observed Carl Beiser, director of advanced engineering. “We’ve been listening to the customer about their needs for things like a 25,000-rpm clutch. We’re putting those learnings into our advanced R&D portfolio work so we can generate unique IP that can then be applied.” AAG’s investments in virtual design and simulation toolsets is paying off in “exponential progress” in actuation development, Beiser said. NVH analysis is another vital focus. And the company is even doing its own coil winding, he added.

While the first generation of EVs are relatively basic in terms of propulsion and gearing, Holt’s team believes the second and third generations will require significantly greater transmission and driveline sophistication in the quest for higher overall efficiency.

“The transition into EV transmission and driveline architectures is a natural evolution for us,” said Jeff Prout, AAG’s VP of product technology. He noted that next-gen EV drivelines will feature more multiple-motor layouts, multi-axis torque delivery, disconnect axles and “unique combinations in the differential” and even multi-speed gearing. All require the “smart” torque-transfer approaches now being prototyped by Means and in some cases evaluated by its customers. Faster driveline response times and more precise control are a must, he asserted, to reduce internal parasitics and deliver the refined actuation that OEMs and EV buyers demand.

Rivian Automotive is among the new-wave EV makers that have engineered AAG technology into its production vehicles, SAE Media has learned from publicly available resources. The novel R1T is equipped with an electro-mechanical axle system with disconnect functionality, enabled by Means Industries’ Dynamic Controllable Clutch (DCC) and Burgess-Norton powder metal processes. The patented DCC is a keystone technology that enables the rapid (<20 ms) and smooth decoupling/recoupling of the electric pickup’s drive axles and rear drive module, via electro-magnetic actuation and engagement. Devoid of hydraulics, the compact mechanism contributes a range increase for R1T of more than 10%, according to engineers.

Beiser argues that traditional dog clutches and friction-type clutches can be a compromised solution for electric propulsion systems, notably in efficiency, size and cost. He cited Means’ consistent innovation in 1-way mechanical diode (MD) clutch development, progressing to the CMD (controllable mechanical diode) and recently to the DCC. (CMDs are capable of transmitting torque in reverse and first gear using a set of locking elements, thus eliminating the need for the low/reverse clutch pack.) CMD benefits in an automatic transmission include reduced spin loss, smaller size and mass and potentially lower systems cost.

The multi-mode DCC brings faster actuation and disengagement. “We first presented publicly on EV technologies in 2018, and at the time the DCC was more of a shifting element than a disconnect,” Beiser noted. “But when you figure out how to control it, it’s agnostic to the systems that it can be used in. It can be a shifting element and it can be a disconnect. It’s multi-mode functionality depending on how you actuate it.” Ongoing development includes the potential for greater torque density, new control strategies, “and functionality that a dog clutch doesn’t offer; functionality that the customer hasn’t really thought about yet. It’s that ‘unvoiced need,’” he offered.

Increasingly sophisticated clutch actuation is core to the IP that AAG is generating. Holt stressed the importance of building a strong team in mechatronic engineers and directing R&D investment to that space. “We have some future technologies that we’ve been experimenting with that are heading for customer evaluation,” he said.

Mechatronics muscle

Cell manufacturing at Means Industries’ Saginaw facility. (AAG)

The EV trend and the rise of the mechatronics and software disciplines is affecting changes in Amsted’s hiring of engineers, according to Prout. “For context, ten years ago we were a group of mechanical engineers, and we did some FEA. When we added our first electrical engineer, he spent most of his time out in the test lab keeping the test equipment running! It wasn’t until about five years ago that we started looking for mechatronic and electrical engineers. Now we have a team of them, and I’d say one-third to half of our R&D projects are being driven by the mechatronics team.”

Beiser surmised that nearly 100% of AAG’s advanced R&D activities with customers are related to electrification. Asia seems to be more focused on hybrids in the last 18 months. And what of advanced R&D in the legacy-powertrain arena? “If there is a new automatic transmission platform being developed, we’re not aware of it,” he stated.

Amsted Automotive executive engineers from left: Jeff Prout, Jeremy Holt and Carl Beiser. (Lindsay Brooke)

A robust co-op program for engineering students is keeping Mean Industries in the hunt for new talent, within today’s super-competitive market. “The young engineers coming out of university are more versed in electrical and mechanical today,” Prout said, “and the importance of electrical engineering now is at an all-time high. If you’re studying electrical engineering or software, your opportunities will grow immensely” as the industry moves into electrification at the component, tiered supplier, and vehicle levels, he advised.

As the industry begins to usher in the next generation of EVs, Holt’s teams are already seeing differences in collaborating with their incumbent-OEM customers versus those at the EV startups who tend to have leaner organizations and internal capabilities.

“We recently launched a new disconnect with a start-up,” Prout reported. “They leaned very heavily on us, where typically when we go into an OEM they will have already sketched in some sort of mechanical or friction-based clutching device. Not only did the start-up come in with a blank sheet of paper--‘this is the box, we need something here’--but they also gave us half the amount of time to do it in! That was quite challenging. But I’d say we had a lot more design and engineering freedom working with the start-up.”

From all of AAG’s customers, however, the three words they hear most often in EV program meetings related to systems performance are fast, smooth and quiet. “Fast is relative to the OEM in question, but smooth -- that’s a table stake!” Beiser exclaimed. “So, the challenge becomes, increasing the disconnect speed without sacrificing smoothness. And that opens the door for control software.”

“You can smooth things out with friction clutches, but you can’t have friction clutches in an efficient EV drivetrain,” Holt concluded. “It’s the perfect place for highly efficient, multi-mode clutches that have the ability to lock, to do regen and disconnect, and don’t create waste energy in the shifting process, all within one controllable device.” Unvoiced needs to be met.