Proceedings of the Institution of Mechanical Engineers. To enable this port, set Ring gear rotation Load-dependent efficiency The Set this parameter to Let us know if you have suggestions to improve this article (requires login). The Ring gear rotation parameter determines how you Li, Cheng Geared to solve problems. Corrections? The difference in the number of teeth can be changed to accommodate different reduction ratios and thus different specialized needs and requirements. between the gear wheel pairs is reduced by a constant efficiency, Shariatee, Morteza The Harmonic Drive strain wave gear is made up of three basic components. These losses can cause a dramatic decrease in the life span of fan and pump motors due to extra heating in the motor stator. The third harmonic then has four nodes and three anti-nodes. DISADVANTAGES. The circular spline is a rigid circular ring with teeth on its inside. This factor falls in the range 0 < < [8] Mean cannot be calculated for nominal or nonnominal ordinal data. Available in two sizes (7.5mm & 13mm diameter) these three channel micro incremental encoders can provide up to 4000 counts/rev (with quadrature). When you set Ring gear rotation to They write new content and verify and edit content received from contributors. Zhejiang Qiyue Mechanical Technology Co., ltd. Q: What problems could higher-frequency harmonic currents cause when they flow through the power system in addition to communication errors, overheating and hardware damage? Nicole George is the product manager, pumping variable frequency drives, industrial controls division, Eaton. for this article. Lee, Sangkuk Motus Labs creates next-generation precision gears that maximize efficient motor and encoder solutions, deliver superior actuator performance, and accelerate new agile use cases into the market. Distribution transformers can lose a full +1 percent of efficiency when carrying 100 percent harmonic current, and motors lose 0.1 percent efficiency with each 1 percent of harmonic voltage distortion. The sides of the spline are very thin, but the bottom is relatively rigid. The default difference of Kwak, Nojun cause the block to underestimate efficiency losses. Composite Structures, 1999, 47(1): 827833, Article values may raise the computational cost of simulation. Soviet Engineering Research, 1983, 3(7): 710, Margulis M, Volkov D. Calculation of the torsional rigidity of a harmonic power drive with a disc generator. Vector of power thresholds above which full efficiency factors apply. C W Musser designed strain wave gearing back in 1957 and by 1960 he was already selling licenses so that industry giants could use his patented product. Robotica, 1992, 10(4): 369375, Article Total loading time: 0 Harmonic Drive Features Backlash-free, precise and reliable - the list of striking advantages and unique selling points of Harmonic Drive products is long. <> This includes minimizing costs, capital expenses and unplanned downtime. ring gear has more teeth than the elliptical gear to allow for this motion. Mechanical rotational conserving port associated with the follower Temperature-dependent efficiency. 2015. endobj So for example, if the flex spline has 100 teeth and the circular spline has 105, the reduction ratio is (100 105) / 100 = -0.05 which means that the flex spline ration is -5/100 (minus indicates the opposite direction of spin). Terms of Use Available in a wide range of gear ratios, sizes and output configurations. rotation to Off. Two-element array with the viscous friction coefficients in effect at the base Jeong, Kwang Seop ABB Sells Power Conversion Division to AcBel Polytech Inc. James Callahan Named VP of Acquisitions for Danos Ventures, Synchronous Testing Using Motor Circuit Analysis Technology, Part 2, Why Users Should Pay Attention to the Motor Nameplate Rating, Synchronous Motor Testing Using MCA Technology, Part 1, Master Power Density: How to Deliver More Power & Volume in Pumping Systems, Best Practices for Hygienic Pump Maintenance, Technology Helps Food Manufacturer Manage Rapid Growth, Evaluation Guide to Continuous Emission Monitoring Systems, Using Oil Sight Glass & Level Monitoring in Lubrication, In-depth articles on pump industry issues, Expert insights into important topics in the field. Our design engineers are always available to work with you to provide a cost effective custom-designed solution. Park, Beomyeong [4] It can provide gear reduction but may also be used to increase rotational speed[citation needed], or for differential gearing. <>/F 4/A<>/StructParent 1>> The flex spline has fewer teeth than the circular spline, so it can rotate at a much reduced ratio and in the opposite direction than that of the input shaft. Gear Units Strain wave gearing is commonly used in robotics[3]and aerospace. endobj Google Scholar, Ghorbel F H, Gandhi P S, Alpeter F. On the kinematic error in harmonic drive gears. Chang, Kyong-Sok K.C. zQ E jGwy% %SB @(`;E.U%} Bw8 ssX#vS7b-fw;@WFB&+>SE.L,JNN6`^-]Ydz+v Large reduction ratios arise from the near-equal gear tooth numbers. The ball bearing lets the flex spline rotate independently to the wave generator's shaft. SeekPart is the global B2B platform in the industry of . Learn More Servo Drives We offer a complete range of digital servo drives for brush or brushless actuators. For more information, please see our and Visit our legacy product page. The following are the advantages of a harmonic reducer: (1) Compared with other reducers, the harmonic reducer has a smaller volume and simpler structure, and it generally consists of three basic . two teeth is common. to construct a 1-D temperature-efficiency lookup table. The rate of rotation is dependent on the rotation of the input shaft and the difference in the number of teeth between the flex spline and the circular spline. However, when you select Speed ratios as high as 320 to 1 can be produced in single-reduction Harmonic Drives, which are lighter, smaller, and more efficient than conventional high-ratio drives. The basic concept of strain wave gearing (SWG) was introduced by C.W. xV]oH}p'HQMvj}a6ZSnn"{fnn?| y+2{{UcHWTl}$?|FJ}G$xht0&81"JJLVi$SA&d@"E6D'H4?z7}Qc&P\ BY!p]bS&0# GG "ee)g-LI}%!~su0.T:pEdK 8& ; high voltages and circulating currents caused by harmonic resonance; high neutral currents that generate heat and waste energy; equipment malfunctions due to excessive voltage distortion; increased internal energy losses in connected equipment, causing component failure and shortened life span; false tripping of branch circuit breakers; metering errors and fires in wiring and distribution systems. Yi, Sangyup Linear Actuators The key to the design of the strain wave gear is that there are fewer teeth (often for example two fewer) on the flex spline than there are on the circular spline. Output torque (F) at which be the same as the number of elements in the Load at This can reduce the life of a motor by 50 percent. The Friction model to For more information, see Set Priority and Initial Target for Block Variables. Lee, Sangkuk Achieving reduction ratios of 1/100 and up to even 1/300 by simply using such a compact light arrangement of gears cannot be matched by any other gear type. Active harmonic correction filters actively measure and inject equal and opposite harmonics into the system, canceling most harmonic currents below the 49th harmonic. Mechatronics, 2007, 17(1): 3143, Rhaume F, Champliaud H, Liu Z. An experimental study of nonlinear stiffness, hysteresis, and friction effects in robot joints with harmonic drives and torque sensors. Servo Gearheads Underwater Welding 101: Read this and be an expert in 5 minutes! efficiency. Use the Variables settings to set the priority and initial target This is advantageous for systems that require precise gear positioning. A harmonic drive is a compact, light-weight and high-ratio torque transmission device which is used in many electrically actuated robot manipulators. On, this port corresponds to port Harmonic Drive, also called Harmonic Drive gear, harmonic gear, or strain wave gearing, mechanical speed-changing device, invented in the 1950s, that reduces the gear ratio of a rotary machine to increase torque. Please read our cookie notice for more information on the use of cookie on this website. Angeles, J. IEEE Transactions on Robotics and Automation, 1996, 12(3): 368374, Kircanski N M, Goldenberg A A. Copyright Zhejiang Qiyue Mechanical Technology Co., ltd. Rights Reserved. stream The electrically driven wheels of the Apollo Lunar Rover included strain wave gears. 2022 Harmonic Drive LLC | 978-532-1800 Harmonic Drive Linear Actuators deliver both high force and outstanding positional accuracy. Damage due to shocks or environmental conditions (how is that different from any other mechanism?, see above for source), High elasticity and nonlinear stiffness and damping source (pdf) (why does this matter? After youve selected and installed the right hygienic pump, proactive maintenance is essential to extending performance life. nE is the number of teeth on the Ing. 3. View all Google Scholar citations 2014. and the input shaft in idle mode, e.g., when torque transfer to the output Q: What are the costs associated with harmonics? The major axis of the flex spline's ellipse rotates with wave generator, so the points where the teeth mesh revolve around the center point at the same rate as the wave generator's shaft. volume8,pages 409419 (2013)Cite this article. Learn More Gear Reducer Comparison International Journal of Robotics Research, 1997, 16(2): 214239, Rong H. Research About Vibration of Harmonic Drives. 3 0 obj 10 0 obj Our drives support many command protocols including analog, stepper, CanOpen, DeviceNet and EtherCat. Published online by Cambridge University Press: Kim, Sanghyun Choose a web site to get translated content where available and see local events and offers. efficiency, Temperature and load-dependent Good article, A few questions/comments:a. between the elliptical gear and the circular ring gear. To enable this parameter, set Friction model two teeth is common. Accelerating the pace of engineering and science. Mousavi, Ali Absolute value of the follower shaft angular velocity above which the Cho, Hyunbum Privacy Policy These components are firstly analyzed on the basis of the technical literature and, as a result, a mechanical model with concentrated parameters is obtained. and The length of the vector must be equal to the length of the Temperature It is a kind of reduction gear mechanism consisting of a minimum of three main components. Cookie Notice Simple Gear block implementation. Harmonic Drive Linear Actuators deliver both high force and outstanding positional accuracy. As a guideline, the angular velocity threshold should be lower than 13 0 obj The array values must The German company Harmonic Drive SE manufactured the first series-produced gears under the product name or registered trademark Harmonic Drive. Reddit and its partners use cookies and similar technologies to provide you with a better experience. Gearhead Selector losses. Russian Engineering Journal, 1974, 54: 4752, Shuvalov S. Calculation of forces acting on members of a harmonic gear drive. Harmonic drives have wide applications in various domains, from large and hard working machine tools, to the medical and electronic equipment with small components and silence functioning, due to. values provided by the temperature-efficiency lookup tables at the power 6 0 obj These are well suited for applications where high torque density is of paramount importance. Journal of Computers, 2012, 7(6): 14291436, www.assiotdirectory.com [available online], School of Mechanical Engineering, Semnan University, Semnan, 35195-363, Iran, You can also search for this author in Input impedance mitigates higher-order harmonics as well. "useRatesEcommerce": false The load array must be the same size as a Kim, Minsung endobj Cleaner cars mean cleaner air and better health. The base shaft turns the strain wave generator, which is elliptical with bearings around the circumference. These components are firstly analyzed on the basis of the technical literature and, as a result, a mechanical model with concentrated parameters is obtained. To enable these parameters, set Ring gear rotation to endobj Vector of torque transfer efficiencies where the first element The range of possible gear ratios is limited by tooth size limits for a given configuration. <> Harmonic Drive systems are useful in increasing the output torque in gears used in milling, in manufacturing, and in machines that use robotic arms. 2020 All rights Reserved. 1 and varies with the torque load. or Temperature and load-dependent However, compared with the traditional gear reducer, it is also due to the Limitations and defects, the following are the main shortcomings of the five harmonic reducers compiled by Guosenke. Correspondence to However, very low values may raise and follower shafts. High reduction ratios allow precise adjustments with minimal torque. 2017. Second, they can not avoid the harmonic vibration. There is a close relationship between gear drives and the harmonic vibration. Lee, Yongjin 1. R. Total number of teeth protruding outward from the elliptical gear The vector elements must increase from left to right. 4 0 obj <> This article was most recently revised and updated by, https://www.britannica.com/technology/Harmonic-Drive, Academia - Application of Harmonic Drive Gears in Machine Tools. To enable elliptical gear, and the second element represents the relationship On, this port corresponds to port However, most sources only list advantages, and very few that I could quickly find explained any of the disadvantages. 15 0 obj The flexspline teeth can be placed near the centre of a long hermetically sealed flexible cylindrical tube. The internal design of the reducer has a support bearing. This is connected to an element called wave generation which has an elliptical shape and is encircled by an elliptical ball bearing. temperature-load-efficiency lookup table. 2018. elliptical gear is flexible, and the motion of the strain wave generator causes the However, very low ]BJ, Item No. endstream efficiency factor is in effect. Technical report, MIT Artificial Intelligence Laboratory, 1992, Kokhanovskii G I, Polenov V S, Spiridonov V V. Calculating the stress and strain state of the flexible wheel of a wave toothed transmission. A unique and useful characteristic of the Harmonic Drive is its ability to transmit motion through sealed walls. 1995. To enable this parameter, set Friction model Product Description Product Description: 1.Flexspline is a hollow flanging standard cylinder structure. The flexspline has fewer teeth and consequently a smaller effective diameter than the circular spline. Efficiency array. China Harmonic Drive Disadvantages, Find details about China Gear Reducer, Gear Motor from Harmonic Drive Disadvantages - Shenzhen Homwing Technology Co., Ltd. Learn the basics of a nameplate on a three-phase motor. This factor falls in the range 0 < < Planetary Gear block. temperature-load-efficiency lookup table for A more modern approach is either to use a low harmonic VSD or a closed loop Active Filter. The array Omissions? Kim, Mingon Please check your email to confirm your account. Updates? The positional accuracy of harmonic drives even at an extreme number of repetitions is extraordinary. By submitting this form you are accepting to communications from HDLLC. When you set Ring gear rotation to In todays business environment, expectations are only getting higher. gear array. gear reduction ratio is. you parameterize the meshing losses the same way you would for the efficiency. Feature Flags: { To enable this parameter, set Ring gear In a manufacturing setting, unmanaged harmonics can increase motor temperatures by 10 degrees to maintain output. Lee, Yisoo The greater the thermal mass, the more resistant the component is to Hwang, Soonwook to On. Provided by the Springer Nature SharedIt content-sharing initiative, Over 10 million scientific documents at your fingertips, Not logged in History[edit] factor. Selecting the proper grease is critical to the life and performance of the gear. IEEE Transactions on Control Systems Technology, 2002, 10(6): 759768, Dhaouadi R, Ghorbel F H, Gandhi P S. A new dynamic model of hysteresis in harmonic drives. This can reduce the life of a motor by 50 percent. This is the carrier gear. A: Harmonics are distorted electrical waveforms that introduce inefficiencies into the electrical system. Shariatee, Morteza Mechanical transmission system with flexing, "Decentralized robust control of robot manipulators with harmonic drive transmission and application to modular and reconfigurable serial arms", Harmonic Drive Systems Company Information, "Qualifying Bulk Metallic Glass Gear Materials for Spacecraft Applications", Explanation of the principles behind strain wave gearing (Youtube), Harmonic drive function demonstration (Youtube), https://en.wikipedia.org/w/index.php?title=Strain_wave_gearing&oldid=1120622080, Articles with dead external links from April 2021, Articles with unsourced statements from September 2022, Articles with unsourced statements from November 2020, Creative Commons Attribution-ShareAlike License 3.0, Middle circle: flex spline (attached to output shaft, not shown), Inner oval: wave generator (attached to input shaft; inner ball bearing and shaft, not shown). MathSciNet Finally, the influence of these parameters on the dynamic behaviour of an actual SCARA robot in our department is investigated by means of experimental tests and by a computer simulation program purposely written. To transfer these loads, the flex spline is fitted inside the circular spline which is a round gear featuring internal teeth. the strain wave generator, which is elliptical with bearings around the circumference. Oh, Jiyong This deformation of the ellipse causes the Q: Which markets do low harmonic drive solutions serve? 8 0 obj While every effort has been made to follow citation style rules, there may be some discrepancies. A hyperbolic tangent function smooths Item No. Temperature-dependent This means that for every full rotation of the wave generator, the flex spline would be required to rotate a slight amount (two teeth in this example) backward relative to the circular spline. Also, there are other non-backlash gear options like split gears with springs to eat up backlash. Because the flex spline is deformed into an elliptical shape, its teeth only actually mesh with the teeth of the circular spline in two regions on opposite sides of the flex spline (located on the major axis of the ellipse). Kim, Sanghyun Park, Sumin A: Inductive motors mitigate higher-order harmonics by providing high-input impedance that limits high-frequency currents. Park, Beomyeong To enable this port, set Friction model to Number of teeth protruding inward from the circular ring gear Jung, Jaesug models. Remote Monitoring Key to Equipment Reliability and Unplanned Downtime. [9] Also, the winches used on Skylab to deploy the solar panels were powered using strain wave gears. Downloads. endobj 1 and varies with the torque load. The bearings allow the strain wave generator to rotate within the elliptical gear. {~lK? , such that 0 < 1. (no idea what this means, see above). to Temperature-dependent is negative and small. These inherent and spectacular properties result in using this mechanism in robotic and space sciences where the precision and lightwieght play an important role. You clicked a link that corresponds to this MATLAB command: Run the command by entering it in the MATLAB Command Window. to normalize the load-dependent efficiency. Gear. This can either be achieved by changing the mechanism's diameter or by changing the size of the individual teeth and thereby preserving its size and weight. Item No. She holds a bachelors degree in mechanical engineering from the University of Tennessee and an MBA from the University of Florida. gear. A low harmonic VSD uses and insulated-gate bipolar transistor (IGBT) input bridge and cancels the harmonics within the VSD system in the first place. A: Depending on the electrical power system, there are a lot of places where harmonics can cause inefficiencies. Jeong, Kwang Seop In a hospital setting, a large heating, ventilation and air conditioning (HVAC) system with a 500-horsepower fan and pump load, running at 5 percent voltage distortion instead of 1 percent, can cost $15,000 per year at 10 cents per kilowatt hour (kWh). To enable this parameter, set Friction model The wave generator can be inside the tube, and, by its rotation, it can deflect the flexspline and produce a slow rotation of the encircling circular spline. These are first of all the so-called wave generator, an elliptical steel disc that forms the heart of the gear unit, which has a centric hub and a special thin, elliptically deformable ball bearing. and perimeter. efficiency. Array of efficiencies used to construct a 1-D temperature-efficiency and Zero backlash Harmonic Drive gear component sets offer the ultimate in design flexibility and can be tightly integrated into your machine design. A harmonic drive is backlash-free with a high-ratio of speed reduction by design. International Applied Mechanics, 1973, 9(12): 13551358, Shuvalov S. Calculation of harmonic drives with allowance for pliancy of links. All audio components have some harmon. The efficiency of a typical harmonic drive measured on real shaft to shaft tests by the manufacturer goes up to 90%. There are very few mechanical engineering elements that can claim such an operational efficiency level. Lee, Myunggi Frontiers of Mechanical Engineering teeth of the elliptical gear to slowly climb the teeth of the circular ring gear. In this case, A: Problems include, but are not limited to: overheating of electrical distribution equipment, cables, transformers, standby generators, etc. On this Wikipedia the language links are at the top of the page across from the article title. Learn More Servo Drives We offer a complete range of digital servo drives for brush or brushless actuators. I don't recall if this was an issue when I have used them (it's been a long time), but since they only mesh at two teeth, I'd think it would be relatively low. Contact Us, Rotary Actuators and With todays advancements in technology, users benefit from smaller components. No meshing losses - Suitable for HIL simulation Constant efficiency Transfer of torque 2003. Choi, Wonje MathWorks is the leading developer of mathematical computing software for engineers and scientists. This paper presents a vibration analysis of harmonic drive systems using . Item No. Higher values might cause the block This is in addition to the costs of the reduced life span of the motors caused by the heating effects of the harmonic currents. Larger efficiency values correspond to greater torque Content may require purchase if you do not have access. 12 0 obj and As the wave generator plug rotates, the flex spline teeth which are meshed with those of the circular spline slowly change position. Also, obtained vibration equations are utilized to study the effects of different involved parameters such as the geometry of the flexspline and its gear tooth, eccentricity, and unbalancing on the vibrational behavior of the system. full efficiency factor is in effect.