This paper describes the development and 3D modeling of a spindle head (SH) with an integrated drive equipped with an innovative belt transmission. The kinematic and layout features of the head design for a multi-purpose machine tool, taking into account the mounting of interchangeable modular tooling, are analyzed. A preliminary design is completed, and the main components and structure of the drive unit are defined. The spindle clamping mechanism, its disc spring, and clamping amplifier are calculated. 3D modeling of the SH head in the integrated CAD environment of Creo Parametric is performed, utilizing a set of applications for designing various mechanical drive transmissions. The disc spring in Creo Ansys Simulation is modeled. Rendering and drive explode tools were used to represent the designed structure and its competitiveness more realistically. An innovative version of a sectional belt drive is proposed as a synthesis of a V-belt (the elastic element of the section) and metal elements that have the design features of chains. An analytical basis for a calculation method for assessing the durability of sectional V-belts was developed. Durability indicators for the innovative belt drive design were calculated and compared with those of a drive with a standard V-belt. A compromise solution, characterized by a significant reduction in the maximum stress in the contact zone and a slight increase in the belt pretension force, is considered. The proposed drive design for a multi-operation machine tool has the potential to improve operational reliability during the machining of complex machine parts.