The “drive arm” tooling allows for simultaneous machining of internal and external keyways on a vertical milling machine. This method eliminates outsourcing, enhances product quality, and improves production schedules, providing a model for similar parts.
Demand analysis of keyway
Oil logging equipment primarily consists of pipe fittings with various internal and external features, including threads, sealing grooves, and keyways (see Figure 1).

Machining internal keyways has been challenging. The traditional method involves electrical discharge machining (EDM), which lengthens cycles and raises costs due to electrode production and outsourcing. The current workflow is: turning → milling → EDM → clamping.
EDM requires specialized electrodes and machines, which are costly and may cause delays. Using a vertical milling machine for keyway processing could save significant time and expense.
Functional analysis of tooling structure
The “drive arm” design addresses production needs by enabling keyway machining on a vertical milling machine (see Figure 2).

This tooling mounts on the milling machine’s power head. Its cantilevered shape allows access to the part’s internal keyway. It features a straight-tooth external meshing gear system, comprising 12 key components, including gears and a D8 end milling cutter.
The machine spindle connects to gear shaft A, driving the “drive arm.” Power is transmitted through three cylindrical gears to the milling cutter.
To use the system, secure gear A on gear shaft A, attach it to the spindle, and adjust its length. The sleeve bracket is fixed to the power head, providing stable support. The bar bracket is attached to ensure proper gear meshing. When the spindle starts, the assembly accurately positions the workpiece, allowing smooth cutting with the milling cutter.
Analysis of the use effect
The use of a “drive arm” in the vertical milling machine processing hole keyway (see Figure 3) after the success of the existing process is adjusted to: car → milling → clamp, in addition to removing the EDM process. In the new process, the processing of the keyway in the hole from EDM to the vertical milling machine with the workpiece “drive arm” processing, while the workpiece clamping position remains unchanged, directly with the “drive arm” on the keyway milling cutter processing of the outer keyway, so that in the same step on the completion of the inner and outer keyway. In this way, the machining of the inner and outer keyway can be completed in the same work step, which improves the machining positional accuracy of the parts, and at the same time ensures the machining progress and saves the machining cost.
