Drum-shaped hob for hobbing internal gear

The drum-type cutter with spiral tooth edges and retracting grooves addresses the inefficiencies of conventional gear cutting machines by enabling flexible and efficient cutting of internal gears with adjustable spiral angles and directions, particularly for large and extra-large gears.

CN120306735AInactive Publication Date: 2025-07-15冯明东
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Patent Information

Application Number
CN202311756584.0
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2023-12-20
Publication Date
2025-07-15
Estimated Expiration
Not applicable · inactive patent

AI Technical Summary

Technical Problem

Existing gear hobbers cannot efficiently process internal gears, and the gear inserter has difficulties in machining helical teeth and super-large gears.

Method used

The drum-shaped hob is used to move the workpiece in the inner side to cut. A number of toothed blades and anti-chip grooves are distributed on the waist of the drum-shaped hob. The toothed blades are part of the cylindrical gear and are distributed in a spiral shape. There are mounting holes on the end surface.

Benefits of technology

The gear hobbing machine can process internal gears, expand the machining range, and improve machining efficiency and accuracy.

✦ Generated by Eureka AI based on patent content.

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Abstract

A drum-shaped hob for hobbing an internal gear is characterized in that a plurality of tooth-shaped blades are spirally distributed on the waist part of the drum-shaped hob, a chip removal groove is reserved on the waist part of the drum-shaped hob, back angles are shoveled on the tooth-shaped blades, and mounting holes are formed in the end surface of the drum-shaped hob. The hob is installed on the gear hobbing machine, generating motion is conducted on a machined inner gear to machine the inner gear, and the limitation that the gear hobbing machine cannot machine the inner gear is broken through. The hobbing cutter is simple in structure, low in production cost, high in production efficiency and particularly suitable for hobbing large and ultra-large straight-tooth and helical-tooth inner gears.
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Description

Technical Field

[0001] The present invention belongs to machine tool equipment, and particularly relates to gear processing equipment. Background Art

[0002] Currently, internal gears are generally processed by gear shapers. Gear shaper machining is generally for straight teeth. When machining helical teeth, special guide rails and cutters are required, and the helix angle and helix direction of the gear to be machined cannot be changed arbitrarily, so the application range is not wide. When machining large or extra-large gears, it will be very difficult. Hobbing machines have high efficiency in machining gears, a wide application range, and high precision, and can machine extra-large gears, but they cannot machine internal teeth. Summary of the Invention

[0003] The present invention uses a method in which a helical tooth-shaped cutting edge is provided on the waist surface of a drum hob, and a generating motion is performed with the workpiece on the inner side of the workpiece for cutting. The problem that the current hobbing machine cannot machine internal gears is solved. The solution adopted by the present invention is that a plurality of tooth-shaped cutting edges and chip flutes are distributed on the waist surface of the drum hob. The tooth-shaped cutting edge is a part of the tooth shape of a cylindrical gear and has a back angle ground. The tooth-shaped cutting edges are spirally distributed on the waist surface of the drum hob, and there are mounting holes on the end face of the hob. The drum hob rotates on the inner side of the workpiece to form a generating motion with the workpiece, and continuous cutting of the workpiece is performed through the cutting edges.

[0004] The present invention is further described below with reference to the accompanying drawings: Figure 1 It is the end face of the drum hob Figure. Figure 2 It is a sectional view of the tooth-shaped cutting edge on the waist surface of the drum hob. Figure 3 It is for the drum Schematic diagram of the helix of the tooth-shaped cutting edge of the hob. In the figure: 1 Tooth-shaped cutting edge 2. Chip flute, 3. Fixing hole. Detailed Embodiment Figure 1 In the illustrated embodiment: A plurality of tooth-shaped cutting edges (1) and chip flutes (2) are distributed on the waist portion of the drum hob, and a central hole is provided on the end face for mounting the drum hob. The tooth-shaped cutting edge (1) is provided with a high back angle.

[0005] Figure 2 In the illustrated embodiment: The tooth shape on the end face of the tooth-shaped cutting edge (1) is a part of the tooth shape of the end face of a cylindrical gear, and the number of teeth of the cylindrical gear is less than the number of teeth of the internal gear to be machined.

[0006] Figure 3 In the illustrated embodiment: The tooth-shaped cutting edge (1) is spirally distributed on the waist of the drum hob.

Claims

1. A drum hob for hobbing internal gears, which has a plurality of tooth-shaped cutting edges and chip-breaking grooves distributed in the waist of the drum hob. The tooth-shaped cutting edges are provided with back angles, and mounting holes are provided on the end face.

2. The drum hob for hobbing internal gear according to claim 1, wherein The tooth profile on the end face of the tooth-shaped cutting edge is a part of the tooth profile of the end face of a cylindrical gear, and the number of teeth of the cylindrical gear is less than the number of teeth of the internal gear to be machined.

3. The drum hob for hobbing internal gears according to claim 1 is characterized in that, The tooth-shaped cutting edges are spirally distributed in the waist of the drum hob.