Gears & PinionsSpur gears
Herringbone Gear with Internal Spline Connection
One-piece double-helical gear body with a high-precision internal spline bore, made for heavy-duty gearboxes and reducers where high torque and smooth, quiet running are required.
Double-Helical Tooth Form
The gear carries two helical tooth sets of opposite hand that meet in a herringbone pattern. This keeps the high contact ratio, smooth running and low noise of a helical gear while the two hands cancel the axial thrust that a single helical gear pushes into the bearings, so the design suits high-speed, high-torque and shock-loaded drives.
Teeth are cut and then ground, giving a hardened tooth surface with the profile accuracy and surface finish needed for long service under alternating and impact loads.
Internal Spline Hub
The bore is an involute internal spline that mates with an external spline shaft for circumferential fixing and torque transmission. Compared with a parallel key, the spline gives better centering, spreads load over more teeth and carries higher torque, while still allowing limited axial adjustment during assembly.
A thick, reinforced hub section keeps the body rigid so the gear holds its shape when transmitting large loads.
Machining and Heat Treatment
Gear bodies can be produced from cast, forged or rolled-ring blanks. On our gear line the maximum outside diameter is Ø10 000 mm and the maximum module is M60, with straight, helical, herringbone and internal tooth forms available.
Heat treatment covers quenching and tempering as well as high-frequency tooth-surface hardening, with a maximum hardening diameter of Ø10 000 mm. Hardened parts are finished by precision hobbing and grinding to balance core toughness against tooth-surface hardness.
Inspection and Delivery
Tooth pitch, runout, hardness and ultrasonic testing are all carried out in house, and reports are issued with the batch. Dimensions and geometry follow the drawing or the mating gearbox requirements.
Typical lead time is within 90 days. Tooth count, module, helix angle, accuracy grade, tooth-surface hardness and spline size are confirmed against the drawing or by measurement before production.
Specifications
- Typical materials
- 42CrMo / 20CrMnTi alloy structural steel
- Heat treatment
- Quenching and tempering or carburizing
- Tooth surface
- Hardened and ground
Common questions
- Can you machine this part to my drawing?
- Yes. Every part is quoted from the drawing. Send a PDF, DWG, DXF, STEP or IGES file with the material, quantity and any inspection requirements, and we reply within one working day.
- How are the material and heat treatment decided?
- They follow your drawing. The specification table shows the range normally used for this part type; the final material and heat treatment are confirmed with the quotation.
- What lead time and inspection come with the part?
- Lead time is set in the quotation and depends on material, size, quantity and inspection scope. Material verification, in-process checks and final inspection records are archived with the part, and any extra certification is agreed before production.
- How is the part packed for export?
- Export parts are rust-proofed and packed for the transport method and destination confirmed in the quotation, with lifting points and markings agreed before dispatch.
Every part is quoted from the drawing itself, not from a size band. Send it over and we answer with the process, the lead time and the tolerance we can hold.
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