Sinoascend EIRO Synchronizer sleeve production process:

1. Material selection

Common materials: low carbon alloy steel (such as 20CrMnTi, 20CrMo), medium carbon steel (such as 45 steel), which must meet the requirements of high strength, wear resistance and toughness.

Heat treatment process: carburizing and quenching (surface hardness HRC58-62, core maintains toughness) or high-frequency induction quenching.

2. Main processing flow

Making: bar cutting (sawing or precision forging blank).

Rough machining: turning the outer circle, inner hole, end face, and reserving finishing allowance (0.3-0.5mm).

Heat treatment: carburizing and quenching or nitriding treatment to ensure surface hardness and wear resistance.

Finishing:

Fine turning: high-precision CNC lathe processing of internal and external contours to ensure dimensional tolerance (IT6-IT7 level).

Grinding: precision grinding of outer circle/inner hole (Ra 0.4-0.8μm) to ensure the smoothness of the mating surface.

Tooth processing: Use gear shaping, hobbing or broaching to process internal/external splines, and the tooth profile accuracy must meet DIN 5480 or GB/T 3478 standards.

Deburring: Electrolytic or manual deburring to avoid assembly interference.

Surface treatment: Phosphating, copper plating or DLC coating (reduce friction coefficient and improve wear resistance).

Cleaning and testing: Ultrasonic cleaning, 100% dimensional and appearance inspection.

3. Sinoascend EIRO Key process control points

Spline processing: Use high-precision broaches or CNC gear shaping machines, and the cumulative pitch error is ≤0.02mm.

Heat treatment deformation control: Compensate for deformation through fixture shaping or subsequent straightening processes.

Dynamic balancing test: High-speed rotating parts require dynamic balancing correction (if applicable).

2. Precision requirements

1. Dimensional accuracy

Internal/external splines:

Tooth pitch error: ±0.01mm;

Tooth tolerance: 0.015-0.025mm;

Tooth profile tolerance: in accordance with DIN 5480 6H/7h grade.

Mating surface:

Inner hole diameter tolerance: H7 (±0.015mm);

Outer circle diameter tolerance: h6 (±0.01mm).

Coaxiality: Inner and outer circle coaxiality ≤0.02mm.

2. Geometric tolerance

End face runout: ≤0.03mm;

Verticality between spline and reference surface: ≤0.02mm/100mm;

Tooth surface roughness: Ra ≤0.8μm (mating surface needs to be ≤0.4μm).

3. Functional testing

Assembly test: the clearance with the synchronizer ring and gear (usually 0.05-0.15mm);

Durability test: simulate the shift cycle (≥100,000 times without abnormal wear);

Noise test: verify the abnormal shift noise in the transmission assembly.

III. Sinoascend EIRO Advanced process technology

Precision stamping: some thin-walled sleeves are formed by multi-station stamping to reduce material waste.

Laser measurement: online laser scanning to detect tooth shape and contour accuracy (such as Gleason gear detector).

Intelligent manufacturing: CNC machine tools integrate automatic compensation system to correct tool wear errors in real time.

IV. Sinoascend EIRO Common problems and countermeasures

Tooth surface roughening: optimize the broach coating (TiN/AlCrN) or reduce the cutting speed.

Heat treatment deformation: use vacuum carburizing or controlled atmosphere furnace.

Assembly jamming: strictly control the spline symmetry and chamfer accuracy (C0.3-C0.5).

All copyrights belong to Sinoascend