Wolfrom planetary transmission

Transmission concept for high reduction ratios with dedicated planet support

A stepped planet gear, two axially adjacent ring gears and direct radial support form the core of the described operating principle.

Official patent title

Planetengetriebe (Planetary Gear)

Engineering challenge

In Wolfrom planetary gear sets, radial forces and tilting moments act on the planet gears during torque transmission. The patent specification describes a structural radial support for the stepped planet gear.

Underlying engineering principle

A stepped planet gear meshes with a sun gear and two axially adjacent ring gears. The tip-circle outer surface of the second, helically toothed section is supported on a cylindrical section coaxial with the first shaft.

Operating principle

The sun gear on the first shaft meshes with the first toothed section of the stepped planet gear.

This first toothed section also meshes with the first ring gear.

The second, helically toothed section meshes with the second ring gear.

The outer surface at the tip circle of the second toothed section runs on the coaxial cylindrical support section and provides radial support for the stepped planet gear.

Depending on the embodiment, support washers and thrust bearings provide additional axial guidance and accommodate tilting moments.

Design features

• stepped planet gear between the sun gear and two axially adjacent ring gears

• two coupled toothed sections on the stepped planet gear

• helically toothed second gear section

• cylindrical support section coaxial with the first shaft

• depending on the embodiment, supplementary support washers and thrust bearings

These features alone do not establish any application-specific performance values.

Potential applications

The patent specification refers to applications requiring a high reduction ratio with low backlash; robotics is cited as one example. Suitability for any industrial application must be assessed against the specific engineering requirements.

Patent and register information

Official German title: Planetengetriebe
Inventor: Prof. Dr.-Ing. Bernd-Robert Höhn
Registered proprietor: Höhn GmbH, Gräfelfing

German application: DE 10 2020 111 001.4 · filed 22 April 2020
Publications: DE102020111001A1 (28 October 2021); DE102020111001B4 (5 May 2022)
German register status: “anhängig/in Kraft”, checked on 21 October 2026.

International family: PCT/EP2021/060277; WO2021214085A1. Other grant publications include US11781619B2 (10 October 2023) and JP7300786B2 (30 June 2023). The current status of these national rights has not been independently confirmed here. A PCT publication is not a worldwide patent.

German register — current status · Original German patent — PDF · WIPO international publication · US patent — PDF

The patent claims and relevant national registers govern the scope and status of protection. Licensing and third-party rights require a separate review.

Technical animations

English animation — Wolfrom planetary transmission · Deutsche Animation · Höhn GmbH YouTube channel

Engineering by Höhn GmbH

Höhn GmbH supports industrial companies in assessing the operating principle for a specific application, comparing it with alternative transmission concepts and defining appropriate next development steps.

Statements regarding availability and licensing are made only following a separate legal review.

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