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In this video we look at the structure and functional principle of a cycloidal gear. A cycloidal gear is usually used for the precise control of moving parts of robots. The heart of the cycloidal gear is the cam disk (cycloid disk). This is driven by an eccentric shaft. Fixed bolts are arranged in a ring around the eccentric shaft, into which the recesses of the cam disk engage. If the eccentric shaft rotates, the cam disk is rotated around these bolts by the eccentric movement. The cam disk itself rotates about its axis of symmetry, but against the direction of rotation of the drive shaft and much slower. There are holes in the cam disk. The rollers of a roller disk behind it engage in these holes. In this way, the cam disk drives the roller disk. The output shaft is attached to the roller disk coaxially to the drive shaft. The shape of the cam disk is based on the cycloid. This is created by a rolling circle rolling on a base circle. In practice, shortened cycloids are often used to keep the unbalance low. 00:00 Structure of a cycloidal gear 02:46 Rolling a disk on a plane 03:16 Rolling a disk on the outside of a circle 04:20 Rolling a disk on the inside of a circle 05:27 Kinematics of the cycloidal gear 06:41 Gear ratio 07:34 Use of a cam disk (cycloidal disk) 08:21 Cam disks with a normal cycloid 09:31 Manufacturing the cam disk with a milling cutter 09:59 Cam disks with a shortened cycloid 11:53 Comparison of cam disks with a normal and shortened cycloid 12:25 Construction of the cam disk (cycloidal disk) 13:38 Determination of the rolling circle diameter 14:40 Determination of the base circle diameter 16:04 Determination of the hole diameter of the cycloidal disk 16:49 Parameter representation of the cam disk 18:05 Avoiding imbalances 18:43 Advantages and disadvantages of cycloidal gears vs. planetary gears