Sealed worm gear type finger joint unit

A sealed worm gear finger joint unit, comprising:

• a worm;
• a rotary actuator for rotatably driving a worm shaft of the worm, the worm shaft is a worm shaft section which is formed by extending a rotating shaft of the rotary actuator so as to pass through a shaft hole in the worm;
• a worm wheel that meshes with the worm;
• a joint shaft that protrudes coaxially from the worm wheel;
• and
• a gearbox case in which the worm, the worm shaft, the worm wheel, and the joint shaft are housed, wherein at least one shaft end section of the joint shaft protrudes outward from the gearbox case;
• a tool engagement section for engaging a tool for turning the worm shaft is formed in a shaft end section of the worm shaft, the shaft end section of the worm shaft in which the tool engagement section is formed is a shaft end section at the distal end of the rotating shaft;
• an opening that makes the tool engagement section accessible from the outside is formed in the gearbox case, the opening being sealable by a removable lid;
• a first case section in which the worm and the worm shaft section are attached;
• and
• a second case section in which the worm wheel and the joint shaft are attached, wherein
• an exposed face in which the external peripheral face of the worm is exposed in the first case section, and an exposed face in which the external peripheral face of the worm wheel is exposed in the second case section, lie on both sides of a shim plate and are joined together, whereby the gearbox case is assembled, and
• a center distance between the worm shaft section and the joint shaft is adjusted by the shim plate.