Speed reducing device and drive device

A speed reducing device comprising:

• three speed reducer units arranged in parallel;
• and
• an output rotating body configured to rotate by power received from an output side of each of the three speed reducer units,
• wherein each of the three speed reducer units includes:
• a casing having a peripheral wall with inner teeth disposed on an inner periphery of the peripheral wall;
• and
• a speed reducing mechanism unit meshing with the inner teeth to reduce a speed of input rotation,
• wherein the peripheral wall of the casing of each of the three speed reducer units is disposed in contact with the peripheral walls of the casings of the other two speed reducer units, and
• wherein in at least one of the peripheral walls of the casings contacting with each other, a thickness of a contact portion is smaller than a thickness of other portions in a circumference of the same peripheral wall.

A drive device comprising:

• a speed reducing device;
• and
• a drive source for transmitting a driving force to the speed reducing device,
• wherein the speed reducing device includes:
• a plurality of speed reducer units arranged in parallel and configured to receive power from the drive source;
• and
• an output rotating body configured to rotate by power received from an output side of each of the plurality of speed reducer units,
• wherein each of the plurality of speed reducer units includes:
• a casing having a peripheral wall with inner teeth disposed on an inner periphery of the peripheral wall;
• and
• a speed reducing mechanism unit meshing with the inner teeth to reduce a speed of input rotation,
• wherein at least two of the plurality of speed reducer units are disposed adjacent to each other such that outer surfaces of the peripheral walls of the casings thereof are in contact with each other, and
• wherein in at least one of any two of the peripheral walls contacting with each other, a thickness of a contact portion is smaller than a thickness of other portions in a circumference of the same peripheral wall.