Parking braking mechanism for speed reducer of pure electric vehicle

The invention discloses a parking braking mechanism for a speed reducer of a pure electric vehicle, and relates to the technical field of parking devices in power transmission systems of electric vehicles, the parking braking mechanism comprises a braking ratchet wheel, a parking spring support, a parking braking shaft, a cam sector plate and a parking pawl shaft, the parking spring support is fixedly mounted on the parking braking shaft, and the cam sector plate is fixedly mounted on the parking braking shaft; firstly, multiple states of parking braking can be achieved through the difference value of spring force, the braking mechanism can be converted into the braking state from the pre-braking state through compression of the buffer spring, in the braking process, the braking limiting piece fully absorbs impact vibration generated when the parking pawl is clamped into a tooth groove of the braking ratchet wheel, and therefore the braking effect is improved. The brake ratchet wheel has the advantages that t