Mechanical Engineer – Rings

Mainspring Energy is revolutionizing power generation with the world’s most flexible and adaptable onsite power generator, the Mainspring Linear Generator. Commercial, industrial, and utility leaders are choosing Mainspring over traditional options like engines, turbines, and fuel cells to quickly and reliably deliver local power for EV charging, commercial facilities, data centers, and grid-scale operations. The Mainspring Linear Generator is fuel flexible, ramps up and down to meet demand, and utilizes a flameless technology with near-zero NOx emissions.

Backed by top-tier investors such as Khosla Ventures, Bill Gates, American Electric Power, and Lightrock, Mainspring designs, manufactures and delivers its products to customers across the U.S. today, and we’re quickly scaling for international expansion.

Inspired by our vision of the affordable, reliable, net-zero carbon grid, Mainspring is rapidly expanding within the $816B global electricity equipment market, and we’re hiring the best talent to meet growing customer demand around the globe. We welcome a broad range of backgrounds, experiences, and talents to bring fresh perspectives and ongoing innovation to our customers.

We are looking to build relationships with people who share our values:

• Pragmatic Optimism. Building a new category of world-class power generation requires the optimism of ambition and creativity, balanced with practicality to solve problems efficiently. The challenges that arise are opportunities for growth.
• Excellence without Ego. We bring expertise and commitment to creating the best customer experience, from sales to deployment and service, just as we apply deep technical rigor to building and delivering world-class products. We strive for excellence and behave as leaders with the humility to acknowledge our challenges, both collectively and as individual contributors.
• Proactive Collaboration. The integration and cross-disciplinary nature of Mainspring’s business requires intentionally seeking out others who bring different skills, perspectives, and priorities. Our culture of inclusion and respect extends beyond our team to interactions with our partners and customers.

Mainspring is based in Menlo Park and has partnered with top-tier investors and utilities such as Khosla Ventures, Bill Gates, Next Era, and American Electric Power. More information can be found at

One core innovation in the Linear Generator is the use of a piston and ring system without liquid lubricant, which dramatically reduces emissions and O&M costs. This person will work on the challenging design of these solid lubricant systems, involving complex 3D shapes with sliding seals, high pressure and temperature, materials optimization, with complex fluid dynamics, heat transfer and structural mechanics.

This person needs to be a fast learner, who can take on a leadership role and lead development projects, design parts and do hands-on work in the lab to analyze performance and failure modes.

• Lead ring development projects, including developing project requirements and scope, developing novel designs, reviewing in detail the designs and analyses of colleagues, and developing production introduction plans
• Design complex moving parts in the piston and ring system of the Linear Generator, from originating creative ideas, executing the design and build, testing and then evaluating performance
• Assess failure modes that involve complex thermal/structural/materials/fluids interactions
• Develop system models to drive component design development in response to field observations
• Develop accelerated life tests in the lab on benchtop and in-generator experiments

• Masters in Mechanical Engineering or equivalent with at least ten years experience or PhD in Mechanical Engineering or equivalent with at least seven years experience
• Self-starter who thrives in a fast-paced dynamic environment and can lead projects and optimize solutions across different teams.
• Design experience with high performance parts that have been released into the market
• Expert in Solid Works or comparable CAD package, including structural FEA
• Solid physical understanding of…