diff --git a/gear transmission/gear transmission.js b/gear transmission/gear_transmission.js
similarity index 100%
rename from gear transmission/gear transmission.js
rename to gear transmission/gear_transmission.js
diff --git a/planetary gear/planetary gear.js b/planetary gear/planetary_gear.js
similarity index 100%
rename from planetary gear/planetary gear.js
rename to planetary gear/planetary_gear.js
diff --git a/rolling bearing/rolling bearing.js b/rolling bearing/rolling_bearing.js
similarity index 100%
rename from rolling bearing/rolling bearing.js
rename to rolling bearing/rolling_bearing.js