[{"data":1,"prerenderedAt":126},["ShallowReactive",2],{"\u002Fen\u002Fglossary\u002Fjoint-motor":3},{"id":4,"title":5,"alternateName":6,"body":7,"description":116,"extension":117,"keywords":118,"meta":119,"navigation":120,"path":121,"seo":122,"stem":123,"updated":124,"__hash__":125},"glossary\u002Fglossary\u002Fen\u002Fjoint-motor.md","Joint Motor","关节电机 \u002F Robot Actuator",{"type":8,"value":9,"toc":110},"minimark",[10,15,24,29,83,87,103],[11,12,14],"h1",{"id":13},"what-is-a-joint-motor","What Is a Joint Motor?",[16,17,18,19,23],"p",{},"A ",[20,21,22],"strong",{},"joint motor"," (also called a robot joint module or integrated actuator) packs a frameless torque motor, gearbox, encoders, driver, and bearings into one compact unit. Mounted directly at a robot's joints, it outputs controlled torque and rotation — the \"muscle\" of humanoid robots, quadrupeds, and robotic arms.",[25,26,28],"h2",{"id":27},"core-components","Core Components",[30,31,32,39,51,62,72],"ul",{},[33,34,35,38],"li",{},[20,36,37],{},"Frameless torque motor",": generates raw torque and sets the power ceiling.",[33,40,41,44,45,50],{},[20,42,43],{},"Gearbox",": trades speed for torque; common choices are the ",[46,47,49],"a",{"href":48},"\u002Fen\u002Fglossary\u002Fplanetary-gearbox","planetary gearbox"," and harmonic drive.",[33,52,53,56,57,61],{},[20,54,55],{},"Encoders",": measure joint angle for closed-loop control; high-end designs use ",[46,58,60],{"href":59},"\u002Fen\u002Fglossary\u002Fdual-absolute-encoder","dual absolute encoders",".",[33,63,64,67,68,61],{},[20,65,66],{},"Bearing",": carries loads while preserving rotational precision; load-bearing joints typically use a ",[46,69,71],{"href":70},"\u002Fen\u002Fglossary\u002Fcrossed-roller-bearing","crossed roller bearing",[33,73,74,77,78,82],{},[20,75,76],{},"Driver",": runs current\u002Fvelocity\u002Fposition loops and receives commands over CAN\u002FCANFD buses (see ",[46,79,81],{"href":80},"\u002Fen\u002Fglossary\u002Fmit-protocol-can","MIT protocol",").",[25,84,86],{"id":85},"key-specifications","Key Specifications",[16,88,89,90,93,94,97,98,102],{},"The parameters that matter most are ",[20,91,92],{},"rated torque"," (continuous output), ",[20,95,96],{},"peak torque"," (short-term ceiling), weight, envelope dimensions, reduction ratio, and communication interface. A humanoid robot typically needs 20–40 joint motors across several torque tiers — the BXI Elf 3, for example, runs 31 ",[46,99,101],{"href":100},"\u002Fen\u002Fmotors\u002Fadvanced-motors","85\u002F70\u002F50-series joint motors"," spanning 25–150 N·m peak torque.",[16,104,105,106,61],{},"For a sizing methodology, see the ",[46,107,109],{"href":108},"\u002Fen\u002Fblog\u002Fjoint-motor-selection-guide","joint motor selection guide",{"title":111,"searchDepth":112,"depth":112,"links":113},"",2,[114,115],{"id":27,"depth":112,"text":28},{"id":85,"depth":112,"text":86},"A joint motor is an integrated robot actuator combining a frameless motor, gearbox, encoders, and driver in one unit, mounted directly at a robot joint — the core power component of humanoid robots and robotic arms.","md","joint motor, robot actuator, integrated actuator, robot joint module",{},true,"\u002Fglossary\u002Fen\u002Fjoint-motor",{"title":5,"description":116},"glossary\u002Fen\u002Fjoint-motor",null,"x9EEPuA3LvSXMHvXgBzkE8Esmeqaip4sfS4pTLlHaL8",1783425867261]