The invention relates to a novel radial piston motor mechanism. The novel radial piston motor mechanism includes a casing, wherein an eccentric shaft is arranged at the center of the casing; one end of the eccentric shaft is connected with the casing through a thrust bearing; a needle bearing is arranged at the other end of the eccentric shaft; an adjusting gasket and an elastic disc spring are arranged on the inner side of the thrust bearing; an oil seal is arranged at the position, on the outer side of the thrust bearing, of the eccentric shaft; the oil seal is fixed through an inner snap spring I; a rear cover is arranged at the outer part of the needle bearing, and is connected with the casing through a lock screw; a seal ring is arranged on the joint face of the rear cover and the casing; an oil distribution disc is arranged between the rear cover and the eccentric shaft; oil holes are formed in the oil distribution disc and the end face of the eccentric shaft connected with the oil distribution disc; oil grooves are formed in the position, corresponding to the oil holes, of the rear cover,; and a slide shoe plunger component is arranged at the middle part of the eccentric shaft. The novel radial piston motor mechanism is flexible in operation, low in noise, and convenient to mount; and a plunger does not need to perform rotation along with a rotating shaft.