NOVELTY - The assembly (10) has a vane motor (12) arranged within an outer casing (18). A drive section (14) is coupled to the vane motor. An output shaft is coupled to the drive section. The drive section comprises a drive hammer that is coupled to the vane motor. The vane motor engages the output shaft to provide rotation to the drive hammer. The drive section comprises a housing. Pins are attached to the housing that is in contact with the drive hammer such that the hammer pivots one of the pins to change a position within the housing.    USE - Motor assembly for a DTH drill assembly (claimed) in oil drilling, geothermal drilling and deep earth penetration applications.    ADVANTAGE - The assembly is provided with an engagement mechanism that provides high peak torque to the output shaft according to compact form factor, and can generate rotation during drilling process under extreme conditions such as high-temperature condition, without requirement of elastomeric components. The assembly avoids the need to utilize a gear set in a power delivery unit for transmitting power, thus realizing high torque generation operation in a compact package. The assembly adopts a compact packaging structure so as to ensure better directional controlling effect by utilizing a down-the-hole hammer (DTHH). The assembly utilizes a non-passage orifice that functions as a plug for preventing pressurized gas such as air, nitrogen or drilling foam, and pressurized liquid such as water, hydraulic fluid or oil, from entering a passage. The assembly is fixed with a hammer housing that is arranged with screws for improving safety performance of the pins within the housing by utilizing a welding, brazing or faster device. The assembly is formed with a protrusion that is prevented from engaging with a tab and arranged in sliding contact with the tab for allowing the hammer to rotate in an effective manner when torque can be transferred from the hammer to the tab, where amount of rotation of impulse bit depends on the reacting torque generated from an external load.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a down-the-hole (DTH) drill assembly.    DESCRIPTION OF DRAWING(S) - The drawing shows a partial cut-away view of a motor assembly.    Motor assembly (10)    Vane motor (12)    Drive section (14)    Bearing/shaft section (16)    Outer casing (18)