Forged steel Long spline shaft

This spline shaft is used for the transmission shaft of large dragline equipment, with a total length of 6.8 meters.

The production process includes forging, rough turning, UT flaw detection, quenching and tempering, semi-finishing turning, spline milling, finishing turning, inspection and packaging.

Some main production process for the large spline shaft.

Forging:

In the forging step,we design the best forging blank to reduce the raw material cost,thus save money for customer.The forging process of spline shaft is free forging, also called open forging, which is the process of hammering or pressing the metal block directly to achieve the desired shape without a prefabricated mold. This method is suitable for small batch production or the manufacture of large parts.

Rough machining：

Rough machining can cut off most of the surplus materials in a short time as possible, provide positioning precision benchmark for semi finish and finish machining, and find the blank defects in time.

Heat treatment

We strictly control the parameters of each product to ensure the accuracy.QT can adjust the properties and materials to a great extent, and its strength, plasticity and toughness are good.The quenching and tempering adopts the heating of the well-type electric furnace, the workpiece is placed vertically, the deformation is reduced, the heating is uniform, and the PAG synthetic medium is cooled to improve the hardenability of the workpiece, and the overall hardness reaches about HB300 to obtain better strength

Milling spline

Since the transmission shaft is too long to be hobbed using normal technology, our company uses CNC indexing milling to process the splines, and finally tests the various parameters of the splines to see if they meet the requirements of the drawings.

Painting and packaging

Finally, the long spline shaft is rust-proofed and painted, and then packaged according to customer requirements and ready for shipment.

Main types of spline shafts

1: Involute spline: This is the most common type, and its tooth profile follows an involute curve. This design allows the spline to run smoothly even with a certain amount of installation error, and has good self-centering performance.

2: Triangular spline: The tooth profile is triangular, suitable for applications that require smaller size but higher strength.

3: Rectangular spline: Both the teeth and the grooves are rectangular, usually used in light load conditions because they are easier to manufacture than involute splines.

4: Serve spline: One side of the teeth is vertical and the other side is inclined, suitable for applications with unidirectional loads.

Our advantage: From raw material control, strict control of each process

一、In Design

• 1. 40+ years of professional experience in producing large modulus gear / gear shaft, capable of providing rationalization suggestions or improvement programs;
• 2. Capable of providing site mapping and gear design；

二、In terms of Raw Material Control

• 1. Use refining furnace and other methods to reduce the content of sulfur, phosphorus, oxygen, hydrogen and other impurities;
• 2. Forging ratio > 5, higher than the international standard;
• 3. Provide raw materials according to European and American standards;

三、Excellent Heat Treatment Equipment & Supporting Equipment

• 1.  The vertical type electric furnace is used for heat treatment (German temperature control system, furnace temperature ±1℃;  Four kinds of quenching media can meet different quenching needs);
• 2.  The heat treatment workshop is close to the processing workshop, which make it more convenient for timely stress relief annealing of the workpiece;

四、Special processes for Key Points

• Coarse tooth before quenching and tempering

五、Inspection of Control Points

• 1. ultrasonic detection;
• 2. Magnetic particle detection was carried out on the tooth surface

六、Customized Products to Meet customer’s  Required

• According to the different needs of users, gear surface quenching, carburizing, nitriding treatment can be carried out.