	US 11,750,065 B2
	Integrated linear generator system
Matt Svrcek, Redwood City, CA (US); David DeGraaff, Mountain View, CA (US); Kevin Walters, Redwood City, CA (US); Cameron Wylie, Oakland, CA (US); John Powers, Menlo Park, CA (US); John Lawler, Portland, CA (US); Sam Sherman, San Francisco, CA (US); Jodie Prudhomme, San Francisco, CA (US); and Scott Coakley, Naples, ID (US)
Assigned to Mainspring Energy, Inc., Menlo Park, CA (US)
Filed by Mainspring Energy, Inc., Menlo Park, CA (US)
Filed on Jun. 24, 2022, as Appl. No. 17/848,926.
Application 17/848,926 is a continuation of application No. 16/719,916, filed on Dec. 18, 2019, granted, now 11,404,937.
Claims priority of provisional application 62/781,586, filed on Dec. 18, 2018.
Prior Publication US 2022/0399784 A1, Dec. 15, 2022
Int. Cl. H02K 7/18 (2006.01); F02B 63/04 (2006.01); F02B 71/04 (2006.01); H02P 9/08 (2006.01)

CPC H02K 7/1884 (2013.01) [F02B 63/041 (2013.01); F02B 71/04 (2013.01); H02P 9/08 (2013.01)]

18 Claims

1. A frame for a linear generator, the linear generator comprising two free-piston assemblies, the frame comprising: a plurality of structural members to mount and laterally align: a central cylinder arranged along an axis; two linear electromagnetic machines (LEMs), each arranged along the axis on a respective side of the central cylinder; and two gas spring cylinders that form respective gas springs, each arranged along the axis outboard of a respective LEM, wherein the two free-piston assemblies are to move along the axis relative to the laterally aligned central cylinder and two gas spring cylinders without mechanical linkages, and wherein at least one structural member of the plurality of structural members is to counteract axial forces from pressure in the respective gas springs caused by the respective free-piston assembly; and at least one tie rod in tension to provide a compressive pre-load on the frame along the axis.