Key Challenge 1: Clamping‑Induced Deformation of Thin‑Wall Stators
Symptom: Frameless stators are thin annular components with low radial rigidity. Conventional rigid tooling tends to deform stators into elliptical shapes during clamping. After welding, roundness specifications are exceeded, resulting in uneven air‑gap distribution inside the motor, aggravated torque ripple and elevated operating noise.
Root‑cause analysis: Ordinary fixtures deliver unadjustable clamping force with concentrated pressure at contact points. Elastic deformation occurs on thin‑wall structures, and permanent distortion remains after stress release upon welding completion.
Solution: Adopt multi‑point floating flexible clamping tooling equipped with a servo closed‑loop force‑regulation system. Clamping points are evenly distributed around the circumference to disperse stress. Reliable positioning is guaranteed while clamping‑caused deformation is minimized.
Key Challenge 2: Thermal‑Distortion Control for Circular‑Splicing Welding
Symptom: Local sharp temperature rise generates thermal stress during circular‑splicing welding of stator silicon‑steel laminations. Axial warpage and radial shrinkage appear after welding, making it hard to meet form‑and‑position‑tolerance requirements for high‑precision joint motors.
Root‑cause analysis: Conventional welding introduces high total heat input. Workpiece heating‑and‑cooling rates are uncontrolled; large temperature differences exist between weld seams and base material, leading to unbalanced stress distribution.
Solution: Deploy fiber laser with high‑speed galvanometer scanner and adopt time‑sharing & zone‑divided welding paths to reduce single‑shot heat input. A precision air‑cooling unit works simultaneously for in‑process temperature control to narrow workpiece temperature gradients. Post‑weld stator roundness deviation is controlled within 0.02 mm.
Key Challenge 3: Low Change‑over Efficiency for Multi‑specification Products
Symptom: Motors for different humanoid‑robot joints differ in inner diameter, stack thickness and slot geometry. Conventional dedicated equipment requires extensive mechanical‑tooling replacement and repeated parameter tuning for model switching. Long change‑over cycles conflict with the industry’s current multi‑variant, small‑batch production pattern.
Root‑cause analysis: Tooling is tightly coupled with machine hardware. Process parameters for different products lack standardized archiving; model change‑over heavily relies on individual engineer experience.
Solution: Implement modular quick‑change tooling design; only a small set of positioning components needs replacement for specification switching. Build a standardized process‑parameter library supporting one‑click parameter recall for different motor models. Total change‑over & commissioning time is reduced to less than one hour.
Key Challenge 4: Difficulty in On‑line Identification of Micro‑Defects
Symptom: Tiny weld porosity, incomplete fusion and subtle stator deformation can hardly be detected by manual visual inspection or conventional go‑no‑go gauges. Latent defects flow into downstream assembly processes, triggering rework and raising customer‑complaint risks.
Root‑cause analysis: Defect dimensions are extremely small; inspection criteria are difficult to quantify. Manual inspection suffers from unstable performance and low throughput.
Solution: Integrate high‑precision vision‑inspection units. After welding completion, stator roundness is automatically measured and weld‑seam morphology is analyzed. Algorithms automatically separate qualified and defective parts. All inspection data is permanently stored bound to individual product IDs to achieve full‑chain quality traceability.
Manufacturing frameless torque motors involves high process barriers. Manufacturers are recommended to finalize welding and circular‑splicing parameters using standalone machines first. Full‑line integration shall be carried out only after process validation is fully completed. Xingte Technology supplies dedicated laser circular‑splicing welding equipment for frameless stators together with full‑set process‑development support, helping enterprises finish process validation and achieve stable mass‑production launch.
