Functional SafetyH1B060-250 Product Reliability Data
Revision historyTable of revisions
DateChangedRev
February 2015First editionAA
270159250 • Rev AA • February 2015
Functional SafetyH1B060-250 Product Reliability Data
Contents
Overview
Danfoss Component
H1 Bent Axis Motor (060-250 cm³/rev)..................................................................................................................................... 5
Standards and Assumptions
Component Information and Calculations
F1: Safe Controllability (Motor at Demanded Displacement).......................................................................................... 7
References
List of References..............................................................................................................................................................................8
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Functional SafetyH1B060-250 Product Reliability Data
Overview
This MTTF data has been compiled by the engineering team responsible for the H1B Bent Axis Motor.
These are professionals at Danfoss, who have the authority and technical knowledge to calculate the
MTTF Data for this product based on the standards set in place by both the industry and/or Danfoss.
The purpose of this document is to assist in the transfer of MTTF information for the given product from
Danfoss to the appropriate party in a way which will result in a clear understanding and documentation
on how we derived it. This MTTF information is provided to assist in calculating the overall MTTF of a
complete or partially complete piece of machinery.
Danfoss cannot be held responsible for the suitability of these calculated MTTF values for use in the
calculation of the overall machinery MTTF values. The MTTF values for the H1B Bent Axis Motor are based
on a specific machine use, operating environment, and/or duty cycle as stated by the standards set in
place by both the industry and/or Danfoss. This communication along with any attached Danfoss
drawings, sketches, or data is transmitted in confidence.
No information stated in this document or any attachments or supplements may be reproduced or
disclosed in whole or in part without written permission of Danfoss. Further, neither these documents
nor any attachments are a warranty of any sort by Danfoss or a guarantee of machine suitability for its
intended purpose. It remains the responsibility of the machine manufacturer to ensure overall machine
functionality and overall machine safety.
We recommend consulting the functional safety cross BA team before applying the document to the
customer.
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Functional SafetyH1B060-250 Product Reliability Data
Danfoss Component
H1 Bent Axis Motor (060-250 cm³/rev)
The H1 family of closed circuit variable displacement bent axis motors is designed for use with all existing
Danfoss hydraulic motors for the control and transfer of hydraulic power. H1 motors are compact and
high power density where all units utilize an integral electro-hydraulic or hydraulic servo control that
controls the speed and torque of output shaft speed for the flow provided by a pump. Shaft speed
direction is defined through the hydraulic flow direction controlled by the pump. H1 motors are
specifically compatible with the Danfoss family of PLUS+1® microcontrollers for easy Plug-and-Perform
installation.
H1 motors can be used together in combination with other Danfoss pumps and motors in the overall
hydraulic system. Danfoss hydrostatic products are designed with many different displacement, pressure,
and load-life capabilities. Go to the Danfoss Power Solutions website or applicable product catalog to
choose the components that are right for your complete closed circuit hydraulic system.
Intended Use
The H1 variable displacement bent axis motors are intended for closed circuit applications. The speed
rate is proportional to the motor input flow and displacement.
The displacement can infinitely be controlled between zero and maximum displacement.
Output shaft speed direction is reversed by reversing the hydraulic flow direction at the pump.
Details regarding intended use, such as application examples and operating conditions, are available in
Technical Information documents on our Danfoss page
http://powersolutions.danfoss.com/literature/
For any intended use other than the above you are invited to contact your local Danfoss representative
for advice.
Introduction
Results
This technical report states the MTTFd for an H1 motor configuration. The motor configuration is
discriminated between a motor with feedback system and without a feedback system. The calculation of
the MTTFd values of each function is described in Component Information and Calculations on page 7.
The following table shows the MTTFd values of motor configurations and special functions.
Results of MTTFd on motor level
IDMotor ConfigurationMTTFd [years]
1Motor with electrical control>150
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Functional Safety
Standards and Assumptions
H1B060-250 Product Reliability Data
The calculations are performed with reference to the Danfoss Global Standard GS-0078. The standard
GS-0078 defines the following options for how to determine the MTTF/MTTFd value for a specific
component or product. The process/algorithm selected will depend on:
•
Whether the component is purchased or manufactured
•
The availability of Danfoss field usage history
•
The availability of industry standard field usage history (primarily for electronic components)
•
Similarity of design to existing products
•
Knowledge of the design process
Some calculation options are listed below:
•
The methods outlined in ISO 13849-1 2006 Annexes C and D
•
Comparison to similar products already in production
•
Industry MTTF databases for widely available components (i.e. electronics)
MIL-HDBK-217
‒
Siemens SN29500
‒
Manufacturer’s Information
‒
•
MTBF data from Verification testing in PDLP
•
Danfoss design practices and procedures for hardware and software design
•
Defects data from Danfoss CQAR database and/or customer data
•
Information on sold products originates from Danfoss SAP
•
Information on application profiles originates from Danfoss technical support knowledge
•
Safety function = Not certified safety functions (no CE)
The assumptions and raw data of the calculation are listed in an internal document “MTTFd for
H1B060-250_internal_Danfoss.docx”. This document is stored in the H1 database (Link access is needed).
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Functional SafetyH1B060-250 Product Reliability Data
Component Information and Calculations
The following table lists the MTTFd for each individual motor function. Please refer to F1: Safe
Controllability (Motor at Demanded Displacement) on page 7 for further understanding of functions and
Customer is responsible for correct port selection due to input signal.
F1: Safe Controllability (Motor at Demanded Displacement)
An input signal to the control solenoids C1, C5, and C6 will lead to a certain displacement of the motor
and based on the system flow through the motor a certain output speed at the motor shaft (e.g., vehicle
speed) results out of that. The following table describes the failures and failed parts that can lead to a
failure of the function.
Detailed boundaries to ensure safe controllability:
•
Control: Proportional control C1 (Input current is either constant or changes according to the defined
ramps)
•
Control: 2-Position control C1 (Input current / voltage are switched either on or off)
•
Control: Proportional pressure control override (Prop.-PCOR) (Input current is either constant or
changes according to the defined ramps)
•
Control: 2-Position pressure control override (PCOR) (Input current / voltage are switched either on or
off)
•
Control: Brake pressure defeat (BPD) (Input current / voltage are switched either on or off)
See TI manual for specification/
performance of function and
boundaries shown in
Current/voltage
supply C1/C5/C6
[years]
Motor speed> 150
d
It is the customer's responsibility to consider how to deal with a loss of SAFE CONTROLLABILITY during
analysis of the functional safety concept for the complete system.
Listed below are potential causes for failures that are impacting SAFE CONTROLLABILITY. These are
considered in the MTTFd calculation.
FailureFailed PartDescription
Motor not at demanded
displacement
Controller (wrong signal)Motor output speed cannot be
Broken wire to solenoid
Solenoid coil defect
Sticky control spool/solenoid
armature
Broken connection servo system to
valve segment
controlled as demanded
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Functional SafetyH1B060-250 Product Reliability Data
References
List of References
ISO 13849-1,2Safety of machinery – Safety-related parts of control systems
GS-0078MTTF calculations for Danfoss products
CQARCustomer Quality Action Report. Danfoss global tool based process for managing defects on
2800 East 13th Street
Ames, IA 50010, USA
Phone: +1 515 239 6000
Danfoss
Power Solutions
(Shanghai) Co., Ltd.
Building #22, No. 1000 Jin Hai Rd
Jin Qiao, Pudong New District
Shanghai, China 201206
Phone: +86 21 3418 5200
Products we offer:
Comatrol
www.comatrol.com
Schwarzmüller-Inverter
www.schwarzmuellerinverter.com
Turolla
www.turollaocg.com
Valmova
www.valmova.com
Hydro-Gear
www.hydro-gear.com
Daikin-Sauer-Danfoss
www.daikin-sauer-danfoss.com
Bent Axis Motors
•
Closed Circuit Axial Piston
•
Pumps and Motors
Displays
•
Electrohydraulic Power
•
Steering
Electrohydraulics
•
Hydraulic Power Steering
•
Integrated Systems
•
Joysticks and Control
•
Handles
Microcontrollers and
•
Software
Open Circuit Axial Piston
•
Pumps
Orbital Motors
•
PLUS+1® GUIDE
•
Proportional Valves
•
Sensors
•
Steering
•
Transit Mixer Drives
•
Danfoss Power Solutions is a global manufacturer and supplier of high-quality hydraulic and
electronic components. We specialize in providing state-of-the-art technology and solutions
that excel in the harsh operating conditions of the mobile off-highway market. Building on
our extensive applications expertise, we work closely with our customers to ensure
exceptional performance for a broad range of off-highway vehicles.
We help OEMs around the world speed up system development, reduce costs and bring
vehicles to market faster.
Danfoss – Your Strongest Partner in Mobile Hydraulics.
Go to www.powersolutions.danfoss.com for further product information.
Wherever off-highway vehicles are at work, so is Danfoss. We offer expert worldwide support
for our customers, ensuring the best possible solutions for outstanding performance. And
with an extensive network of Global Service Partners, we also provide comprehensive global
service for all of our components.
Please contact the Danfoss Power Solution representative nearest you.
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products already on order provided that such alterations can be made without changes being necessary in specifications already agreed.
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