# Staff Mechanical Engineer, Sealing Systems at Mainspring Energy

- Company: Mainspring Energy
- What the company does: Local power generation for data centers, utilities, industrial & enterprise applications. Fuel-flexible, fast to deploy, high-efficiency, low NOx power. Backed by General Catalyst and Khosla.
- Company website: https://www.mainspringenergy.com/
- Type: Startups
- Level: Senior
- Location: Menlo Park, CA
- Work setup: On-site
- Pay: $172K to $230K base salary per year (USD)
- Posted: 2026-09-18
- Apply by: 2026-11-02
- Apply: https://jobs.lever.co/mainspringenergy/c18aae73-9391-461a-9639-993be8a8839c
- Page: https://www.1752.vc/careers/jobs/mainspring-energy-staff-mechanical-engineer-sealing-systems-2/

## About the role

The Rings team owns one of the hardest technical problems in the Linear Generator: a piston and ring system that seals without liquid lubricant. Getting this right is foundational to the product’s low emissions and maintenance business model. The design space is demanding, with complex sealing geometry, demanding thermal and pressure conditions, and material performance and system behavior that all need to be considered simultaneously.

## What they're looking for

- Master's degree in Mechanical Engineering or equivalent with at least eight years of experience, or a Ph.D. with at least five years of experience
- A proactive and collaborative work style suited for a dynamic R&D environment where priorities can evolve as you learn, including comfort with problems that cross team boundaries and engineering disciplines
- Experience designing high-performance, precision parts from R&D through to production release
- Fluency in SolidWorks or a comparable CAD package. Comfortable using structural and thermal FEA as a design tool (Ansys is a plus)
- Ability to generate 2D drawings for manufacturing, including comfort with GD&T
- Excellent physical understanding and intuition in structural mechanics and heat transfer, strength in tribology, fluid mechanics, or thermodynamics is a plus

Tags: Mechanical Engr