To ensure the accuracy and quality of the output shaft of the BWED10-595-0.37KW cycloid pin wheel reducer, the full process control is required from the four core links of material selection, processing technology, heat treatment control, and accuracy detection. Combined with the characteristics of this model 'small specifications, high transmission ratio (595), and low power (0.37KW)' (the output torque is small but the requirements for transmission stability are high), the specific measures are as follows:
1. Material and pretreatment: laying the foundation for quality
1. Adaptable material. Select the output shaft of this model. The transmission torque is small (0.37KW corresponding to the output torque is about 10-15N·m), but the stability of long-term operation is required. It is recommended to use 45 steel (economic and applicable) or 40Cr (higher strength requirements):
45 Steel: It is necessary to ensure that the chemical composition meets the standards (C: 0.42-0.50%, Si: 0.17-0.37%, Mn: 0.50-0.80%), and avoid impurities such as sulfur and phosphorus exceeding the standards (S≤0.035%, P≤0.035%), otherwise it is easy to cause processing cracking or insufficient strength.
40Cr: The Cr content needs to be controlled (0.80-1.10%) to ensure hardenability, and is suitable for scenarios with higher life requirements.
2. Forging and pretreatment
The blank is processed using die forging technology (rather than free forging) to ensure the continuous distribution of metal fibers and reduce internal looseness and pores (through ultrasonic flaw detection, defects of ≥φ2mm are not allowed).
After forging, spherical annealing is carried out (45 steel: 720-740℃ insulation for 3-4 hours, slow cooling to 600℃ air-cooling), reducing hardness (≤197HBW), improving cutting performance, and avoiding cracks during processing.
2. Processing technology: control key accuracy indicators
The core accuracy requirements of the output shaft include: journal cylindricality, surface roughness, keyway symmetry, and shoulder perpendicularity , which must be ensured through step-by-step processing:
1. Rough processing stage
Turning outer circle: reserve 2-3mm machining allowance, control the dimensional tolerance of the outer circle (such as φ18mm shaft journal, rough processing to φ20±0.1mm), to avoid deformation caused by uneven subsequent finishing allowance.
Drilling center hole: A-type central hole (with cone guard) is used to ensure that the coaxiality of the central holes at both ends is ≤0.05mm, and is used as the positioning reference for subsequent processing (the reference error will directly amplify the final accuracy error).
2. Semi-finishing stage
Precision car outer circle: The journal dimension tolerance is controlled at h6 level (such as φ18h6: upper deviation 0, lower deviation - 0.011mm), and the cylindricality is ≤0.003mm (tested with a dial gauge within the full axis length range).
Milling keyway: CNC milling machine is used to ensure the keyway width tolerance h9 level (such as 8h9: upper deviation 0, lower deviation - 0.036mm), and the symmetry is ≤0.02mm (using the keyway symmetry tester to detect), to avoid uneven stress after assembly.
3. Finishing stage
Grinding outer circle: Use a high-precision outer circle grinder (radial spindle jump ≤0.001mm), control the surface roughness of the journal below Ra0.8μm (tested with a roughness meter) to ensure good coordination with the bearing inner ring (reduce vibration and wear during operation).
Grinding the end face of the shaft shoulder: Ensure the perpendicularity between the shaft shoulder and the axis ≤0.005mm/100mm (tested with a right angle ruler and a dial gauge), to avoid axial bias during bearing installation.
3. Heat treatment: balance strength and accuracy stability
1. Tempering and quality processing (core process)
45 Steel: quenched at 840-860℃, tempered at 600-620℃, and the hardness is controlled at 220-250HBW (tested with a Rockwell hardness meter, the hardness difference on the same axis is ≤15HBW), ensuring the tensile strength ≥650MPa and the yield strength ≥360MPa.
After heat treatment, aging treatment is required (4-6 hours of insulation at 200-220℃) is required to eliminate internal stress and avoid deformation during subsequent processing or use.
2. Local hardening (optional) If the shaft journal and bearing fit require higher wear resistance, the shaft journal can be quenched at high frequency :
The quenching temperature is 880-900℃, the cooling medium is a water-based quenching liquid, the hardening layer depth is 0.5-0.8mm (detected by metallographic method), the surface hardness is 50-55HRC, and the transition between the hardening layer and the substrate must be smooth (avoid stress concentration).
