Gears & PinionsRing gears
Integral Internal/External Spur Ring Gear
One-piece ring gear combining external spur teeth with an internal spur ring, used in heavy-duty planetary drives and reducers.
One part, two meshes
The ring is cut from a single annular blank: large-module straight teeth on the outside diameter and a small-module internal spur ring in the bore. There is no bolted or press-fit joint between the two tooth sets, so both stay concentric and square to the end faces by virtue of the part itself.
The outer teeth take power from a driving pinion; the inner ring acts as the ring gear of a planetary train, working with the sun gear and planet carrier for reduction and torque multiplication. Two transmission stages in a single component shorten the axial length of the housing.
Machining scope in our shop
Internal and external gear cutting is done in-house on rings up to Ø10 000 mm outside diameter and modules up to M60. Tooth forms cover spur, helical, herringbone and internal teeth; hardening is available up to Ø10 000 mm.
End-face bolt holes, locating shoulders and fits are machined from the tooth axis as the reference, so the mounting holes and the two tooth sets stay tied to one datum.
Material and heat treatment
Blanks are normally forged from 42CrMo or 40CrNiMo; cast and rolled-ring blanks are also possible. Normalizing and quench-and-temper pre-treatment keep the core tough, after which the tooth flanks are induction hardened or case hardened for surface hardness and wear resistance.
Tooth pitch, runout, hardness and ultrasonic testing can all be checked in our own plant, with reports issued per batch.
What you specify
Module, number of teeth, pressure angle, accuracy grade, flank hardness, overall dimensions and bolt-hole pattern are made to your drawing, with both tooth sets cut from one reference. Typical lead time is within 90 days, depending on size and quantity.
Specifications
- Structure
- One-piece, integral external and internal teeth
- External teeth
- Straight (spur) teeth, large module
- Internal teeth
- Spur ring, small module, in the bore
- Typical materials
- 42CrMo, 40CrNiMo (forged blanks)
- Heat treatment
- Normalizing and quench-and-temper; induction or case hardening of tooth flanks
- Mounting
- Evenly spaced bolt holes on the end face
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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