As the automotive industry shifts towards new energy vehicles (NEVs), the performance of every component becomes critical. The water pump, a key part of the NEV cooling system, plays a vital role in maintaining optimal operating temperatures and ensuring vehicle reliability.
How NEV Water Pumps Work
The NEV water pump operates on the principle of centrifugal force. An electric motor drives the impeller, which spins and pushes coolant toward the edges of the impeller. Centrifugal force expels the liquid into the outlet passage, while a low-pressure zone at the center draws in new coolant from the inlet. This continuous cycle ensures effective cooling. In NEVs, these pumps typically run at high speeds to meet demanding cooling requirements.
Part Information & Customer Requirements
Part: Water Pump
Material: AlSi9Cu3
Machine: Vertical Machining Center (VMC)
Cooling: Internal Coolant
Machining Feature: Bearing Bore
Machining Challenges
-
Small Bore Diameter: The bore measures only ∅20.04mm, making indexable boring tools unsuitable. A solid, one-piece tool is required.
-
Tight Tolerances: The bore has a strict diameter tolerance of 0.03mm and a roundness requirement within 0.05mm, with a specific R-angle at the bottom.
-
Surface Finish Requirements: A surface roughness between Rz8 and Rz10 must be maintained—a challenge for conventional tooling.
Optimized Tooling Solution
To address these challenges, a specialized PCD (Polycrystalline Diamond) reamer with breaking teeth was developed.
Design Features:
-
Precision Micro-Adjustment Breaking Teeth: Enable fine control of the cutting process, ensuring consistent surface finish within the Rz8–Rz10 range.
-
Breaking Tooth Structure: Distributes cutting forces evenly, minimizing errors and improving roundness and diameter stability.
-
Multi-Tooth Design: Increases machining efficiency compared to single-point boring tools used during sampling, without compromising on quality.
Cutting Parameters:
-
Tool Diameter: D20.04
-
Spindle Speed: S2000
-
Feed Rate: F900
Conclusion
This custom PCD reamer with breaking teeth offers a reliable and efficient solution for machining high-precision bearing bores in NEV water pumps. By combining a multi-tooth layout, specialized breaking teeth, and fine-adjustment capabilities, it meets tight tolerances and surface finish requirements where standard tools fall short.
