3D printed gear cutting tools with capillaries for minimum quantity lubrication, gas or liquid

A gear forming tool comprising:

• an outer sleeve having an outer sleeve aperture;
• an inner sleeve having an inner sleeve aperture disposed within the outer sleeve and in fluid communication with the outer sleeve aperture;
• a tool holder disposed within the inner sleeve and rotatable relative to the inner sleeve about a rotational axis of the tool holder, wherein the tool holder has a plurality of fluid channels, each fluid channel having a respective inlet open to an exterior of the tool holder and a respective outlet open to the exterior of the tool holder, each fluid channel extending independently of each other fluid channel through the tool holder from the respective inlet to the respective outlet of that fluid channel, wherein the inlets are spaced apart from each other in a circumferential direction about an exterior surface of the tool holder such that the inlets are configured to, sequentially, intermittently be in fluid communication with the inner sleeve aperture as the tool holder rotates relative to the inner sleeve, wherein the exterior surface extends between a first end surface and a second end surface, and the exterior surface is a continuous, uninterrupted cylindrical surface from the inlets to the second end surface, wherein the outlets are located in the second end surface, wherein each of the outer sleeve and the inner sleeve cover a majority of the exterior surface of the tool holder;
• and
• a gear cutting tool coupled to the tool holder for common rotation about the rotational axis, the gear cutting tool including a head portion and a cutting portion,
• wherein the head portion defines a plurality of capillary inlets open through an exterior end surface of the head portion,
• wherein the cutting portion has a plurality of tool cutting edges and a plurality of capillaries, each capillary extending to a corresponding one of the capillary inlets to receive fluid therefrom,
• wherein each outlet is in fluid communication with a corresponding subset of capillary inlets of the plurality of capillary inlets, each subset of capillary inlets includes at least two of the capillary inlets,
• wherein each subset of capillary inlets is independent of each other subset of capillary inlets by being grouped into respective recessed pockets in the exterior end surface of the head portion and each subset of capillary inlets, via the corresponding capillaries, are configured to provide lubrication to a corresponding subset of tool cutting edges of the plurality of tool cutting edges such that rotation of the tool holder relative to the inner sleeve, sequentially, intermittently provides lubrication to each subset of tool cutting edges, wherein each subset of tool cutting edges includes at least two of the tool cutting edges.