1. Cleaning unit for an electric toothbrush having a motor, and wherein the cleaning unit comprises: a head part and a holder of movable contact elements having a range of motion relative to the head part, and wherein the holder of movable contact elements has a structure that allows receiving a driving motion from the engine through a drive mechanism comprising a drive shaft having a longitudinal axis, and the drive shaft is structured to transmit the motion generated by the engine to the movable contact holder； movable contact elements supported inside the movable contact holder； a gap located between the head and the movable contact element holder, while the width of the gap remains between about 0.1 mm and about 0.6 mm over the entire range of motion of the mobile contact element holder. 2. The cleaning unit according to claim 1, further comprising stationary contact elements supported inside the head portion such that when the movable contact element holder moves, the movable contact elements move relative to the stationary contact elements. The cleaning assembly of claim 2, wherein the movable contact elements and the stationary contact elements collectively define the field height of the contact elements； the needle part, the holder of movable contact elements, or both of these components: the head part and the holder of movable contact elements - determine the height of the support under the field of the contact elements； and the height of the field of the contact elements is greater than the height of the support. 4. Cleaning unit according to claim 1, c1. Чистящий узел для электрической зубной щетки, имеющей двигатель, и при этом чистящий узел содержит:головную часть и держатель подвижных контактных элементов, имеющий диапазон движения относительно головной части, и при этом держатель подвижных контактных элементов имеет структуру, обеспечивающую прием приводного движения от двигателя через механизм привода, содержащий приводной вал, имеющий продольную ось
