Input key - Uchikomiki

...A type of wedge that is inserted between two parts, with a groove (keyway) in both the shaft and shaft hole, or just in the shaft hole, into which the key is inserted (Figure). The most commonly used is the square sink key that is inserted across the groove between the shaft and the shaft hole. There are two types of keys: a set key, in which the key is first inserted into the keyway of the shaft and then the shaft hole is pushed in, and a drive key, in which the shaft hole is inserted onto the shaft and then the key is driven in. Keys that only have a keyway in the shaft hole include flat keys, which are used with part of the shaft flattened, and saddle keys, which have a recess in the key to fit the shaft....

*Some of the terminology explanations that refer to "typing keys" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…両者の間に差し込む一種のくさびであり，軸と軸穴部の両方，または軸穴部のみに溝(キー溝)を設け，これにキーを挿入する(図)。最もよく利用されるのは，軸と軸穴部の溝にまたがって挿入する角形の沈みキーで，これにはあらかじめ軸のキー溝にキーをはめてから軸穴部を押し込む植込みキーと，軸穴部を軸にはめた後にキーを打ち込む打込みキーとがある。軸穴部のみにキー溝を設けるものには，軸の一部を平らにしておいて用いる平キー，逆にキーのほうに軸と合うようにくぼみを設けるくら(鞍)キー(サドルキーともいう)などがある。…

※「打込みキー」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報