The invention provides a curtain body braking mechanism of a curtain without a pulling
rope. Motion of a transmission
rope is controlled mainly by a one-way
clutch unit. The one-way
clutch unit is provided with a wheel shaft base, a wheel shaft, a
clutch wheel and two planetary gears. The wheel shaft is fixed to the wheel shaft base and provided with two spaced
brake blocks, a rolling groove is formed between the two
brake blocks, the clutch wheel is arranged on the wheel shaft in a sleeving and rolling mode and provided with an inner annular
tooth part, the inner annular
tooth part surrounds the peripheries of the two
brake blocks, and the planetary gears are arranged in a brake groove of the wheel shaft and meshed with the inner annular
tooth part of the clutch wheel in a rolling mode, so the planetary gears are driven by the inner annular tooth part of the clutch wheel and clamped with or separated from the brake blocks of the wheel shaft. Thus, when the planetary gears are clamped to the brake blocks, the transmission
rope cannot be stretched, and positioning of a curtain body is finished.