Gears & Pinions
Segmented Arc Straight-Tooth Gear Rack
Segmented arc spur gear racks that bolt together into large-diameter gear rings for heavy-duty rotary drives. Made in 45# steel or 42CrMo, quenched and tempered with hardened teeth.
Segmented Arc Construction
Each piece is an arc-shaped straight-tooth rack segment with counterbored bolt holes on the back. Segments are fixed to a rotary table, machine base, or frame and joined end to end to build a complete gear ring at the required diameter; a worn segment can be replaced on its own instead of scrapping the full ring. The bolted, segmented design reduces machining, transport, and maintenance demands compared with a one-piece large ring.
Teeth, Materials, and Machining
The teeth are precision-milled straight spur teeth, normally with hardened tooth surfaces; the body is quenched and tempered before tooth machining. Standard material options include 45# steel and 42CrMo, with blanks from forgings or thick plate. As a gear manufacturing capability, the shop can machine parts up to Ø8,000 mm outside diameter and modules up to M60, and can produce straight, helical, herringbone, and internal tooth forms; the maximum hardening diameter is 8,000 mm.
Inspection and Order Confirmation
For gear orders, pitch, runout, hardness, and ultrasonic testing are checked in-house, and typical lead time is within 8–12 weeks. Final module, pitch, arc radius, arc angle, accuracy grade, tooth hardness, and section size are confirmed from the drawing or a measured sample before production.
Common Applications and Customization
These segmented racks are commonly used in large CNC rotary tables, construction machinery slewing mechanisms, shield tunneling cutterhead drives, heavy welding turntables, amusement ride rotation systems, and port machinery slewing drives. Segment length, hole pattern, material, heat treatment, and tooth form can be customized to the drawing; casting, forging, and rolled-ring blanks are available for gear production.
Specifications
- Typical materials
- 45# steel, 42CrMo
- Heat treatment
- Quenching and tempering; tooth-surface induction hardening
- Tooth profile
- Straight spur teeth
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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