Speed reducer having self-locking function without ring gear, and self-locking method of speed reducer

A self-locking method of a speed reducer without a ring gear, wherein the speed reducer comprises:

• a carrier rotated as an input side, a first sun gear provided concentrically with the carrier, a first planetary gear engaged with the first sun gear, a second planetary gear engaged with the first planetary gear, a third planetary gear engaged with the second planetary gear, and a second sun gear concentric with the carrier, provided in parallel to the first sun gear, and engaged with the third planetary gear,
• wherein difference between the number of teeth of the first sun gear and the number of teeth of the second sun gear is at least one;
• the first, second, and third planetary gears are supported at different locations on one side of the carrier so as to be able to rotate and revolve and be disposed in n sets;
• the carrier is the input side;
• the second sun gear is a fixed side;
• the first sun gear is an output side;
• Z1 is defined as the number of teeth of the first sun gear;
• and Z2 is defined as the number of teeth of the second sun gear, wherein when Z1>Z7 and (Z1−Z2)<Z2 are satisfied, an output of the first sun gear is deceleration in the same direction;
• when Z1<Z2 and (Z2−Z1)<Z1 are satisfied, the output of the first sun gear is deceleration in a reverse direction;
• and when only one of the deceleration conditions is satisfied and the first sun gear is rotated by being changed to an input side, speed is not increased due to a self-locking function and a speed increase ratio is zero (a stationary state in which the sun gear used as the input side is not able to rotate).

A speed reducer having a self-locking function without a ring gear, the speed reducer comprising:

• a carrier rotated as an input side, a first sun gear provided concentrically with the carrier, a first planetary gear engaged with the first sun gear, a second planetary gear engaged with the first planetary gear, a third planetary gear engaged with the second planetary gear, and a second sun gear concentric with the carrier, provided in parallel to the first sun gear, and engaged with the third planetary gear,
• wherein difference between the number of teeth of the first sun gear and the number of teeth of the second sun gear is at least one;
• the first, second, and third planetary gears are supported at different locations on one side of the carrier so as to be able to rotate and revolve and be disposed in n sets;
• the carrier is the input side;
• the first sun gear is a fixed side;
• the second sun gear is an output side;
• Z1 is defined as the number of teeth of the first sun gear;
• and Z2 is defined as the number of teeth of the second sun gear, wherein when Z1<Z2 and (Z2−Z1)<Z1 are satisfied, an output of the second sun gear is deceleration in the same direction;
• when Z1>Z2 and (Z1−Z2)<Z2 are satisfied, the output of the second sun gear is deceleration in a reverse direction;
• and when only one of the deceleration conditions is satisfied and the second sun gear is rotated by being changed to an input side, speed is not increased due to the self-locking function and a speed increase ratio is zero (a stationary state in which the sun gear used as the input side is not able to rotate).

A speed reducer having a self-locking function without a ring gear, the speed reducer comprising:

• a carrier rotated as an input side, a first sun gear provided concentrically with the carrier, a first planetary gear engaged with the first sun gear, a second planetary gear engaged with the first planetary gear, a third planetary gear engaged with the second planetary gear, and a second sun gear concentric with the carrier, provided in parallel to the first sun gear, and engaged with the third planetary gear,
• wherein difference between the number of teeth of the first sun gear and the number of teeth of the second sun gear is at least one;
• the first, second, and third planetary gears are supported at different locations on one side of the carrier so as to be able to rotate and revolve and be disposed in n sets;
• the carrier is the input side;
• the second sun gear is a fixed side;
• the first sun gear is an output side;
• Z1 is defined as the number of teeth of the first sun gear;
• and Z2 is defined as the number of teeth of the second sun gear, wherein when Z1>Z7 and (Z1−Z2)<Z2 are satisfied, an output of the first sun gear is deceleration in the same direction;
• when Z1<Z2 and (Z2−Z1)<Z1 are satisfied, the output of the first sun gear is deceleration in a reverse direction;
• and when only one of the deceleration conditions is satisfied and the first sun gear is rotated by being changed to an input side, speed is not increased due to the self-locking function and a speed increase ratio is zero (a stationary state in which the sun gear used as the input side is not able to rotate).