Abstract: The present invention is a pneumatic grinder, with a housing, an air chamber stand, and a rotor. The air chamber stand includes a cylinder, an upper cover and a lower cover. The cylinder is fitted with an inlet hole and an exhaust hole. There is a lateral exhaust hole assembled on the upper cover or lower cover or both covers and provided with a vertical internal borehole section linking the air chamber within the air chamber stand, and a transverse external borehole section. The air exhaust capacity of the air chamber stand is increased, markedly reducing turbulence and improving rotational speed and strength of the rotor. The vibration of rotor is efficiently reduced for the users, thereby improving significantly the torque, performance and quality of the pneumatic grinder with better applicability.

Abstract: The present invention provides an improved structure of pneumatic grinder, the housing of pneumatic grinder comprises an air chamber stand to assemble rotor; the air chamber stand comprising a cylinder, an upper cover and lower cover; the cylinder is fitted with inlet hole and exhaust hole; the major feature of the present invention lies in: a lateral exhaust hole is assembled on the upper cover and/or lower cover; said lateral exhaust hole is provided with a vertical internal borehole section linking air chamber within air-chamber stand, and also provided with a transverse external borehole section protruding from the edge of upper cover and/or lower cover; with the lateral exhaust hole, it is possible to increase air exhaust capacity of air chamber stand, reduce markedly the turbulence in air chamber stand, and improve the rotational speed and strength of rotor.

Abstract: The rotor blade structure for the pneumatic devices includes a blade mounted into the preset chamber of a drive rotor of a pneumatic device. The blade with predefined edge and thickness has an assembly side, an external side and two windshield surfaces. At least one windshield surface is provided with a recessed portion. There may be a single recessed portion or a plurality of recessed portions. Hence, the recessed portion could increase the compression area of blade's windshield surface, thus improving the driving force of the blade and torsion of drive rotor with higher practicability.

Abstract: An improved structure of an air sander grinder with air chamber mounting and eccentric mounting, and the cylinder air chamber mounting is placed inside the air sander grinder, and an air chamber is placed in the center of the air chamber mounting the sides of which has air inlet and air outlet openings the eccentric mounting includes a mandrel and an eccentric component, and the top of the mandrel has a drive section that is placed in the air chamber of the air chamber mounting, and the bottom of the mandrel has a linkage section connected with the eccentric component; the feature of the present invention is that the air chamber mounting is made by the inner metal ring with an outer plastic ring on the outside; the mandrel of the eccentric mounting is metal mandrel, and the eccentric component is a plastic eccentric component; the eccentric component is formed at the bottom of the metal mandrel.