Growing Trends in Electric Actuation · Identify the changing demands in the market for linear actuators and ... 20% until 2020 Increasing energy costs: Energy becomes the increasing

4/15/2014 | N. Davis (DCUS/SPF21) | © Bosch Rexroth AG 2014. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution,

as well as in the event of applications for industrial property rights.

Growing Trends in Electric Actuation

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Contents


Introduction

Electromechanical Drives

Replacing Fluid Power Energy Efficiency

Flexibility

Environment

Miniaturization Increased load capacities

Integrated servo motor and drive

Faster Cycle Times Linear motors

Reduction of moved mass

Standardization Mechanical connection interfaces

Open software interfaces

Increased Value-Add from

Suppliers Multi-axis systems and sub-

assemblies

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4/15/2014 | N. Davis, SPF2 | © Bosch Rexroth AG 2014. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as

in the event of applications for industrial property rights.

Introduction

Presenter:

Nathan Davis

Bosch Rexroth, Charlotte NC

Product Manager, Linear Systems and Screws

Presentation Objectives:

Identify the changing demands in the market for linear actuators and

the main drivers of these changes.

Present solutions to address these demands and gain a competitive

advantage.


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Electromechanical Drives replacing Fluid Power

Energy Efficiency

Energy consumption has a significant effect on Total Cost of Ownership

of plant and machinery: Energy consumption represents 20 – 30 % of

total costs, and with particularly energy-intensive applications, this share

is remarkably higher.

2 Simple Rules to Energy Savings:

1. Use as little energy as possible.

Mechanical efficiency

Idle time

2. Re-use what you’ve used.

Storage

Regeneration

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Energy Efficiency as Sustainable Competitive Factor

Legal framework conditions: Programs for reducing

the CO2 emission: 20% until 2020

Increasing energy costs: Energy becomes the

increasing cost factor

Ecologic awareness Self-commitment

of the companies

Products of machine and system engineering play a

decisive role in the energy use

Energy efficiency becomes a differentiation criteria and

a sustainable competitive factor

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1999 2001 2003 2005 2007 2009 2011

€ /

kW

h

+ 62 %

0,05

0,06

0,07

0,08

0,09

0,1

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€ /

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Selbstverpflichtung der Unternehmen

-25% CO2 per ton product (2020)

-10% per vehicle until (2012)

-20% in proportion to revenue (2011)

-12% CO2 absolute (2012)

- 20% CO2-Emissionen bis 2020

…………..

Self-commitment of the companies


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event of applications for industrial property rights. 5

Energy Efficiency

4/15/2014 | N. Davis, DCUS/SPF2 | © Bosch Rexroth AG 2014. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as

well as in the event of applications for industrial property rights.


Total

Efficiency

Control Drive Planetary Screw

driven Cylinder Servo Motor

1 0.99 0.9 0.8 0.7

1 0.9 0.85 0.95 0.4 0.6 0.95

Reservoir Motor (const. speed)

Hoses Proportional Valve (directional)

Cylinder Pump (var. displ.)

Electromechanical

Traditional Hydraulics

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Energy Efficiency




Total

Efficiency

Control Drive Planetary Screw

driven Cylinder Servo Motor

1 0.99 0.9 0.8 0.7

Electromechanical

Hydraulics with Variable Speed Drive

Control Drive Pump (fixed displ.)

Hoses Cylinder Servo motor

1 0.99 0.9 0.9 0.7 0.95 0.95

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Energy Efficiency

High efficiency throughout the drive

train

Energy on demand

Intelligent energy management allows

the recovery and temporary storage of

braking energy

Low energy consumption

compared to fluid driven

technology

Reduction of operating costs and

TCO




Drive units

Capacitive

energy

storage

Energy Exchange via DC-Bus

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Advantages: Electromechanical

Lower energy consumption compared to

pneumatics and traditional hydraulics Energy storage and regeneration

Higher mechanical efficiency

No oil or air leaks Fire and pollution hazard

Food industry

No hydraulic oil replacement and disposal

Lower noise

No special expertise needed to assemble or

maintain

Precise following of complex motion profiles

Quick changes to motion profiles

Synchronized motion

Electromechanical vs. Fluid Power




Advantages: Fluid Power

High forces and power density (hydraulics)

Maximum speeds

Long life span, no bearing wear

Better suited to handle shock loads and

vibrations

Overload capacity

Can operate in adverse environments High ambient temperatures

Dust, chips, dirt contamination

Wet

Conclusion:

The initial material cost of the electromechanical drive will usually be higher.

The specific advantages of the electromechanical drive and lower operating expenses

must be worth the additional up-front cost.

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Miniaturization

The desire to reduce the overall machine footprint is universal, but

especially present in the medical, electronic, and semiconductor

industries. Floor space is at a premium in clean room and laboratory

environments.

Two ways to minimize the size of your machine:

Carry the same load on smaller components

Integrate the drive (amplifier) and servo motor

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Miniaturization

Increased Load Capacity

Linear Guides

Changing the linear bearing type from a roller or bushing on round shaft

or a plastic sliding guide to a profiled rail will allow the same load to be

carried in a smaller package.

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Miniaturization


Comparison of Linear Guide Sizes

Minimum size needed to carry a 350 lb force (without moment loads)

to a 500 million inch expected life

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A

H

A

H

A

H

Cam Roller Size 42

Ball Bushing 40mm

Ball Rail Size 15

Width A (mm) 116 108 34

Height H (mm) 39 94 24



Miniaturization


Screws

Planetary screws have more bearing contact area and can carry heavier

loads than the same size ball screw.

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Miniaturization


Comparison of Screw Sizes

Minimum size needed to push with a 2100 lb thrust force to a 500

million inch expected life

Ball Screw 80x10

Planetary Screw 30x10

Diameter D (mm) 105 64

Length L (mm) 95 85

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L

D

L

D

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Miniaturization

Integrated Servo Motor and Drive

Eliminates the power and control electronics from the cabinet

Reduces the cabinet volume by up to 90 %

Decreases the cabling effort up to 90 %

Eliminates the power losses in the cabinet up to 90 %

For smaller numbers of axes: may be able to mount cabinet on

machine, making it possible to easily move & reducing floor space



+ =




Faster Cycle Times

Cycle time is usually limited by:

Critical speed (harmonic vibration) of a screw drive

Stiffness (settling time) of a toothed belt drive

One solution to these limitations is to use a synchronous linear motor

drive.

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Ironless Core Type Iron Core Type



Faster Cycle Times

Linear Motors

Advantages of Linear Motors:

High speed – usually limited by acceleration/deceleration distance or the

maximum speed of the linear guide

Backlash free

Wear free

Maintenance free

Smooth motion

Long lengths possible

Highly accurate and repeatable due to linear position measurement

Multiple independent moving primaries (carriages) possible

Disadvantages:

Higher price due to extensive use of rare earth magnets

Limited thrust forces due to thermal constraints of the motor

Not suitable for environments with ferromagnetic contaminants

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Faster Cycle Times

Linear Motors

Available in pre-assembled linear stages including linear guides, cable

chain, switches, and linear scale.

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Ironless Core Type Iron Core Type



Faster Cycle Times

Reduction of Moved Mass

By reducing the amount of mass that a linear actuator has to move,

acceleration and deceleration rates can be increased.

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Moving mass = Payload + Thrust Rod

Main Body, Motor

Mount are fixed

Telescoping Ball Screw Actuator Belt Driven Linear Axis

Gear Reducer,

Motor, and Belt

Pulleys are fixed

Moving mass = Payload + Main Body




Standardization

Industry standards have been established for mounting dimensions, and

are mostly followed, for the following linear motion products:

Ball and Roller Rail

Ball Screws

Electromechanical Cylinders (inherited from pneumatic & hydraulics)

Industry standards have not been established for linear modules (pre-

assembled axes) or aluminum structural framing elements.

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Standardization

Mechanical Connection Interfaces

Some vendors are creating standard mounting interfaces within their

own product lines.

Advantages: Minimum design effort, fast assembly

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Standardization

Open Software Interfaces

Software demands a higher share of engineering effort now than ever

before. Machine builders are demanding more flexible and open

software tools to become more productive.

Advantages:

Engineers can use language and

development environment

they already know

Easier implementation of

interfaces on different

platforms (PC, smart device,

browser)

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(Ross Systems and Controls)

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Standardization

Open Software Interfaces

Wind River

Workbench Visual Studio Eclipse Xcode

C++ VB/C#/C++

… Java Objective-C

LabVIEW

G

Individual

function

(Real-time)

Motion

Controller

vxWorks

IT

Automation

PC

Windows

Mobile App

Smart Device

Google

Android

Apple

iOS

Rapid Prototyping

Simulation

MATLAB

MATLAB

SIMULINK

SIMULINK

MATLAB

MS Visual

Studio

C++ / C#

Microsoft

Windows RT

Development

environment

Application

High level

language

Device

platform

Operating

system






Increased Value Add From Suppliers

Due to ever increasing demands on smaller design departments,

machine builders are looking to vendors to add more value to their

products.

An example would be purchasing a multi-axis sub-assembly instead of

individual framing elements, linear axes, cable management, connection

brackets, etc.

Advantages:

Faster time to market

Designs are proven

Service and support

Single point of contact

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Thank you for your attention!

Questions?




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Documents

Growing Trends in Electric Actuation · Identify the changing demands in the market for linear actuators and ... 20% until 2020 Increasing energy costs: Energy becomes the increasing