Tilted Motor Planetary Drive for Forklift Chassis Mounting

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Solution Overview

Problem

Existing drive devices for industrial trucks require large slewing ring bearings, which demand a flat surface on the chassis, leading to potential distortion and increased length, and struggle to efficiently transmit torque with smaller pitch circle diameters.

Innovation Solution

A drive device with a drive motor arranged at an angle of 15 to 25 degrees relative to the vertical, using a planetary or reduced planetary gear, and a flange suspension for connection to the chassis, eliminating the need for a slewing ring bearing and allowing for a compact design with sufficient torque transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a slewing ring bearing is used to support the drive motor, then the drive device can accommodate larger weights and achieve optimal swivel radius, but the pitch circle diameter becomes large, increasing the overall length of the drive device

Engineering Contradiction:
Improveweight capacityVSAvoidoverall length of drive device
Core Design Contradiction:
ForceVSLength of moving object

Solution Approach 1:

The invention extracts and eliminates the slewing ring bearing from the drive device. Instead of using a slewing ring bearing to support the drive motor, the patent directly connects the drive motor to the planetary gear unit, thereby removing the source of the large pitch circle diameter and overall length increase while maintaining weight capacity through the planetary gear's inherent load-bearing capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the spatial arrangement by mounting the drive motor in a tilted position (at an angle of 15 to 25 degrees relative to the vertical) rather than in a conventional axial or transverse position. This dimensional change allows the motor to be compactly integrated with the planetary gear unit without requiring a large pitch circle diameter, thus reducing the overall length while maintaining torque transmission capability

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Length of moving object

If the pitch circle diameter of the slewing ring bearing is reduced, then the overall length of the drive device decreases, but the drive motor can no longer dip into the bearing, requiring a different mounting arrangement

Engineering Contradiction:
Improveoverall length of drive deviceVSAvoidmounting arrangement complexity
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The invention merges the drive motor directly with the planetary gear unit, eliminating the need for a separate slewing ring bearing mounting arrangement. The motor is integrated into the planetary gear housing, and the motor shaft is directly connected to the sun gear, simplifying the mounting arrangement while maintaining compact dimensions

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention employs a tilted mounting arrangement for the drive motor (at an angle of 15 to 25 degrees relative to the vertical) rather than a fixed axial or transverse position. This dynamic spatial arrangement allows the motor to be compactly integrated with the planetary gear unit, enabling the motor to effectively 'dip into' the gear housing without requiring a large pitch circle diameter

Inventive Principle:
Principle #15Dynamics

3Force

If a planetary gear with high reduction ratio is used, then sufficient torque is achieved, but the drive motor must be positioned at an angle to limit installation space height

Engineering Contradiction:
ImprovetorqueVSAvoidinstallation space configuration
Core Design Contradiction:
ForceVSShape

Solution Approach 1:

The invention employs an asymmetric mounting arrangement for the drive motor, positioning it at a tilted angle (15 to 25 degrees relative to the vertical) rather than in a symmetric axial or transverse position. This asymmetric configuration allows the motor to be compactly integrated with the planetary gear unit, achieving high torque through the planetary gear's reduction ratio while minimizing the height of the installation space

Inventive Principle:
Principle #4Asymmetry

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration enables efficient torque transmission, reduces the overall length and installation space, and simplifies the connection to the chassis, avoiding distortion and gear noise issues, while allowing for a smaller motor and reduced manufacturing costs.

Implementation Method 1

the at least one gear stage consisting of a planetary gear, reduced planetary gear, eccentric gear or Wolfrom gear

Methodology Applied
Scientific EffectPlanetary gear mechanism: Gear

Data Source

PatentEP3760463B1Drive device for an industrial truck with planetary gear
Publication Date: 2023.01.11 KORDEL ANTRIEBSTECHN
  • EP3760463B1 patent drawingFigure 1

AI summary

The invention relates to a drive device 1 for a forklift truck, comprising at least one gearbox housing 2 with at least one gearbox stage 3, 4 for driving at least one wheel 5 and a flange connection for a drive motor 6, wherein the at least one drive stage consists of a planetary gearbox, reduced planetary gearbox, eccentric gearbox or Wolfrom gearbox to transmit a small drive torque of the motor to a higher input speed, and wherein a simple means of connection to the chassis of a forklift truck is additionally provided. This is achieved by arranging the drive motor 6 at an angle to the vertical and connecting the gearbox housing 2 to the chassis of the forklift truck via a flange mounting 7.