Slewing Assist System for Heavy Equipment Motor Reduction

Solution Overview

Problem

Existing slewing systems in heavy equipment, such as excavators and cranes, require oversized motors to handle heavy loads, leading to high initial and operational costs, and pose challenges in retrofitting older machines for dredging operations, as they do not efficiently reduce motor size or provide adequate slewing assistance.

Innovation Solution

A slewing assist system comprising a central rotation member, a slip member, and a lever arm with a pin that moves between retracted and expanded positions, assisted by an actuating element and a controller, which engages with the central rotation member to provide additional slewing assistance, allowing for more efficient rotational movement and reducing the need for oversized motors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If an oversized motor is used to handle heavy loads, then the machine can operate under heavy loads and dredging operations, but the initial purchasing cost, operating cost, and repairing cost increase

Engineering Contradiction:

Improveload handling capabilityVSAvoidoperating cost

Core Design Contradiction:

StrengthVSLoss of energy

Solution Approach 1:

The slewing system is segmented into two functional components: a base slewing drive for normal operations and an auxiliary slewing assist system activated only during heavy load conditions. This segmentation allows the main motor to be sized for typical operations while the assist system provides supplemental power when needed, reducing overall energy consumption and operating costs.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The slewing assist system dynamically engages and disengages based on load conditions. The pins automatically engage with the rack gear when heavy loads are detected and disengage when normal operating conditions return, allowing the system to adapt its power output to match actual operational needs rather than continuously operating at maximum capacity.

Inventive Principle:

Principle #15Dynamics

2Strength

If an oversized motor is used to handle heavy loads, then the machine can operate under heavy loads and dredging operations, but the initial purchasing cost increases

Engineering Contradiction:

Improveload handling capabilityVSAvoidinitial purchasing cost

Core Design Contradiction:

StrengthVSQuantity of substance

Solution Approach 1:

The slewing system is segmented into two functional components: a base slewing drive for normal operations and an auxiliary slewing assist system activated only during heavy load conditions. This segmentation allows the main motor to be sized for typical operations while the assist system provides supplemental power when needed, reducing overall energy consumption and operating costs.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The auxiliary slewing assist system serves multiple functions: it enables heavy load operations, allows dredging operations on older machines, and can be retrofitted to existing equipment. This multi-functionality justifies the additional component cost by providing versatile capability across different operational scenarios.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Strength

If an oversized motor is used to handle heavy loads, then the machine can operate under heavy loads and dredging operations, but the probability of retrofitting existing or older machines decreases

Engineering Contradiction:

Improveload handling capabilityVSAvoidretrofitting capability

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The slewing system is segmented into two functional components: a base slewing drive for normal operations and an auxiliary slewing assist system activated only during heavy load conditions. This segmentation allows the main motor to be sized for typical operations while the assist system provides supplemental power when needed, reducing overall energy consumption and operating costs.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The auxiliary slewing assist system is nested within the existing slewing mechanism, utilizing the same central rotation member and rack gear. The pins engage with the existing rack gear teeth, and the lever arms connect to the existing slewing bearing, allowing the retrofit to integrate seamlessly with older machine designs without requiring complete system replacement.

Inventive Principle:

Principle #7Nested doll (Nesting)

4Device complexity

If a traditional slewing motor system is used, then the structure is simple, but the system cannot provide adequate slewing assistance for heavy loads and dredging operations

Engineering Contradiction:

Improvesystem structureVSAvoidslewing power

Core Design Contradiction:

Device complexityVSPower

Solution Approach 1:

The auxiliary slewing assist system acts as a counterbalance to the limitations of the base slewing drive. By providing supplemental force in the opposite direction of the load resistance, the pins engaging with the rack gear create additional torque that offsets the insufficient power of the originally sized motor during heavy load conditions.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

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

The slewing assist system reduces the power requirements of the slew drive, enabling smaller motor designs, lowers initial capital costs, and allows retrofitting of older machines for heavy-duty operations, enhancing efficiency and versatility in handling heavy slewing movements.

Implementation Method 1

A first end and a second end of an actuating element are coupled to the lever arm and the upper structure. The slewing assist system provides additional slewing assist to the upper body structure through the lever arm by engaging the slip member and the central rotation member through the at least one pin.

Methodology Applied

Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

A lever arm is fixedly coupled to the slip member. The slewing assist system provides additional slewing assist to the upper body structure through the lever arm by engaging the slip member and the central rotation member through the at least one pin.

Methodology Applied

Scientific EffectMechanical Advantage: Mechanical Advantage

Implementation Method 3

The pin may be actuated to engage with teeth of the rack gear. The pin movable between a retracted position and an expanded position. The at least one pin engages the slip member with the central rotation member in the expanded position such that the central rotation member and the slip member rotate together.

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS10260214B2Slewing assist system

Publication Date: 2019.04.16 CATERPILLAR INC

AI summary

A slewing assist system for a machine having an upper body structure supported on an undercarriage structure includes a central rotation member. The central rotation member is rotatably coupled to undercarriage structure. A slip member is concentrically coupled to central rotation member and allows a relative rotational motion. At least one pin is coupled to slip member and engages slip member in expanded position such that central rotation member and slip member rotate together. A lever arm is fixedly coupled to slip member. A first end and a second end of an actuating element are coupled to lever arm and upper structure, respectively. The slewing assist system provides additional slewing assist to upper body structure by engaging slip member and central rotation member through pin. The slewing assist system assists in a first and a second rotational direction by extending and retracting second end of actuating element, respectively.