US 11,982,339 B2
Electro-hydraulic linear lead screw actuator
Shu Wang, Yorkville, WI (US); and Matthew Schoenberg, Kenosha, WI (US)
Assigned to ZOOMLION HEAVY INDUSTRY NA, INC., Yorkville, WI (US); and ZOOMLION HEAVY INDUSTRY SCIENCE AND TECHNOLOGY CO. LTD., (CN)
Filed by Shu Wang, Yorkville, WI (US); and Matthew Schoenberg, Kenosha, WI (US)
Filed on Jan. 26, 2023, as Appl. No. 18/101,604.
Application 18/101,604 is a continuation in part of application No. 17/863,945, filed on Jul. 13, 2022, granted, now 11,773,949.
Prior Publication US 2024/0019017 A1, Jan. 18, 2024
Int. Cl. F16H 25/20 (2006.01); F15B 15/14 (2006.01); F16H 25/22 (2006.01)
CPC F16H 25/2204 (2013.01) [F15B 15/14 (2013.01); F15B 2015/1495 (2013.01); F16H 2025/2062 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An electro-hydraulic linear lead screw actuator, comprising:
an electric motor;
a hydraulic tube;
an actuator lead screw is rotatably retained in said hydraulic tube, said actuator lead screw is rotated by said electric motor;
an actuator screw nut includes a piston portion formed on an outside perimeter thereof, a lead screw thread is formed through said actuator screw nut to threadably receive the actuator lead screw, a screw relief cavity is formed in said actuator screw nut, said screw relief cavity includes a perimeter that is greater than an outer perimeter of said actuator lead screw, a first hydraulic chamber is formed in said hydraulic tube between said electric motor and a first end one end of said piston portion, a second hydraulic chamber is formed beyond a second end of said piston portion, at least one oil passage extends from a second end of said piston portion to said screw relief cavity, wherein hydraulic oil is pumped from said second hydraulic chamber through said actuator screw nut to said first hydraulic chamber by rotation of said actuator lead screw; and
an actuator rod extends from an end of said actuator screw nut, wherein rotation of said actuator lead screw causes said actuator rod to extend or retract.