Staff Mechanical Engineer, Sealing Systems

Mainspring Energy, Inc.; Menlo Park (CA); On-site; USD 180,000 - 240,000; Full time

Job summary

Mainspring Energy, Inc. is seeking a Staff Mechanical Engineer to own a major portion of the Rings team's challenging piston and ring system development. You will lead design efforts, advance from concept to production, and tackle multi-domain problems with a systems approach.

The role requires strong CAD/FEA skills, 2D drawings with GD&T, and a track record of delivering high‑quality precision parts in R&D-to-production cycles. Excellent collaboration in a dynamic team is essential.

Qualifications

• Master's degree in Mechanical Engineering or PhD with relevant experience.
• 8+ years of industry experience (5+ years if PhD) in related field.
• Experience designing high‑performance, precision parts from R&D to production.
• Proficient in SolidWorks; familiarity with FEA tools (Ansys a plus).
• Ability to generate 2D drawings for manufacturing with GD&T.

Responsibilities

• Lead ring and piston development, including setting requirements and scope, developing designs, reviewing colleagues' work, and planning production introductions.
• Design complex moving parts for piston and ring systems from concept to detailed design and testing.
• Root cause analysis of failures involving thermal, structural, materials, and fluids interactions.
• Design and run test campaigns using benchtop rigs and in-generator experiments to validate designs.
• Define requirements on subsystems to improve performance and collaborate with the team to implement solutions.
• Work in a fast-paced, iterative environment with cross-disciplinary collaboration.

Skills

Collaborative work style

Designing precision parts

Systems thinking

Structural mechanics

Heat transfer

Problem solving

Education

Master's degree in Mechanical Engineering

Ph.D. in Mechanical Engineering

Tools

SolidWorks

Ansys

GD&T

Job description

Job Overview

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. Progressing the ring service interval is one of the most important development programs at Mainspring. As a Staff Mechanical Engineer on this team, you will take ownership of a significant piece of that challenge.

Responsibilities

• Lead ring and piston development projects, including setting requirements and scope, developing novel designs, reviewing colleagues' designs and analyses in detail, and building production introduction plans
• Design complex moving parts in the piston and ring system, from originating ideas through detailed design, build, test, and evaluation of performance
• Assess and root cause failures that involve coupled thermal, structural, materials, and fluid interactions, balancing analysis with hands-on physical intuition
• Design and run effective test campaigns, using both benchtop rigs and in-generator experiments, to validate designs and accelerate learning
• Discover and define requirements on surrounding subsystems to improve ring and piston performance
• Collaborate closely with a talented engineering team in a fast-paced, iterative environment to find the best solutions

Qualifications

• 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
• A systems approach to problem solving: Prefers to look at the whole system to identify negative interactions and opportunities for improvement

Bonus Qualifications

• Excellent understanding of thermodynamics, experience interacting with a complex thermodynamic system. Power generation, energy storage, and aerospace (especially turbomachinery or propulsion) are all extremely relevant
• Experience designing for high-cycle fatigue and high-pressure, high-temperature environments. Experience with super alloys is a plus
• Fluency in Python programming for data analysis, and experience developing and validating simplified models of systems and subsystems to inform failure analysis and design

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses and identifying potential inconsistencies or verification signals in application materials based on available information. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.