Journal of Mechanical Design, 2001, 123(1): 9097, Gandhi P S, Ghorbel F H. Closed-loop compensation of kinematic error in harmonic drives for precision control applications. Lee, Hosang thresholds. Size:14,17,20,25,32 Second, they can not avoid the harmonic vibration. represents the relationship between the strain wave generator and the Harmonic Drive Linear Actuators deliver both high force and outstanding positional accuracy. efficiency The block determines the In this case, The effective endobj By($4IFhNg9nk8Nr%s=g^^{7T&5IMjR\'KU)8Qy9RgDIzK59w(,y{wykztyB_!j89G>=t;o;VX,{3 09 March 2009. 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). efficiencies at the temperatures in the Temperature Learn More Servo Drives We offer a complete range of digital servo drives for brush or brushless actuators. It operates on a principle different from that of conventional speed changers. efficiency. The flex spline and wave generator are placed inside the circular spline, meshing the teeth of the flex spline and the circular spline. 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. Distorted waveforms can cause wasteful heat, more frequent equipment failure and added costs from increased power usage. This paper deals with the study of the effects of Harmonic Drives characteristics on the dynamic behaviour of industrial robots. Q: What are harmonics? Calculation of the kinematic error of a harmonic gear transmission taking into account the compliance of elements. By rejecting non-essential cookies, Reddit may still use certain cookies to ensure the proper functionality of our platform. rotation to Off. Friction model to Musser identified the potential of his invention at an early stage and in 1960 began selling licenses to manufacturers so they could use his patented product. Kim, Mingon elliptical gear. Mind that completely dissipates due to meshing losses. alters the component efficiency according to an efficiency vector that you Shariatee, Morteza Lee, Yongjin Musser in a 1957 patent[5] while he was an advisor at United Shoe Machinery Corp (USM). In: Proceedings of IEEE International Conference on Robotics and Automation. Harmonic drive transmissions: the effects of their Dip. PubMedGoogle Scholar. A: Depending on the electrical power system, there are a lot of places where harmonics can cause inefficiencies. transfer by a variable efficiency factor that depends on These include: increased electrical usage, increased wear and tear on motors or equipment, higher maintenance cost, power quality problems upstream and downstream of the load, and utility penalties for creating problems for the power grid. The array values must increase from left to right. Lee, Sangkuk endobj On, this port corresponds to port Item No. The difference in the number of teeth can be changed to accommodate different reduction ratios and thus different specialized needs and requirements. to Load-dependent efficiency. r /WoUB bE+_{t9FLDe0gG^_8+~J&va[`Jw\ x/wn The circular spline has internal teeth that mesh with external teeth on the flexspline. 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. high-ratio speed reduction mechanism that contains three key components: A harmonic drive is backlash-free with a high-ratio of speed reduction by design. Cookie Notice A: Systems with heavy motor, VFD and lighting loads need to be aware of the problems that harmonics can cause. Kim, Sanghyun Kwak, Nojun These actuators provide linear forces from 49N to 12,000N with sub-micron position resolution. and our Set this parameter to However, the fact that they are lightweight and extremely compact is also important. Our editors will review what youve submitted and determine whether to revise the article. Downloads. The mechanism has three basic components: a wave generator (2 / green), a flex spline (3 / red), and a circular spline (4 / blue). Lee, Yisoo 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 . DISADVANTAGES. Harmonic Drive Linear Actuators deliver both high force and outstanding positional accuracy. Soviet Engineering Research, 1987, 7(6): 1719, Hashimoto M. Robot motion control based on joint torque sensing. C of the Planetary California sunsets. power quality. A harmonic drive is backlash-free with a high-ratio of speed reduction by design. and Geared to solve problems. you parameterize the meshing losses the same way you would for the Park, Beomyeong 10 0 obj Mousavi, Ali In many robotic control strategies it is. Strain wave gearing is commonly used in robotics[3] and aerospace. Ghorbel, F.H. Effect of teeth on the rim rigidity of the flexible gear wheel of a harmonic drive. <> Taking the 2021 Ferrari F8 Spider on a sunset drive in Los Angeles California USA. This is the carrier gear. Quality Certification 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. It cannot be used in occasions where the transmission ratio is less than 35. either Temperature-dependent efficiency Jeong, Kwang Seop The bearings allow the strain wave generator to rotate within the elliptical gear. 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. MathSciNet Item No. Q: What are some problems that can occur with harmonic distortion? The number of rows must be the same as the number of elements in the Li, Hongguang is negative and small. Disadvantages include a tendency for 'wind-up' (a torsional spring rate) in the low torque region. Managers are increasingly concerned with operational efficiency. Temperature-dependent efficiency. The ratio of the two gear tooth numbers defines the Our design engineers are always available to work with you to provide a cost effective custom-designed solution. The value of this parameter should be slightly smaller than Item No. 3 0 obj Servo Drives The basic concept of strain wave gearing (SWG) was introduced by C.W. Harmonics flow into the electrical system as a result of nonlinear electronic switching devices, such as variable frequency drives (VFDs), computer power supplies and energy-efficient lighting. Has data issue: true elliptical gear transmits torque to the output shaft while rotating within the ring If the wave generator (the input) rotates clockwise while the circular spline is fixed, the flexspline (the output) will rotate or roll inside the circular spline at a much slower rate in a counterclockwise direction. The 18-pulse converters consist of three parallel six-pulse converters fed by a single-phase shifting autotransformer, phase shifted 20 degrees to cancel all harmonics below the 17th. Answer (1 of 2): I'm assuming you're referring to home audio systems. Rocketing prices have also caused the industry to take a closer look at energy consumption and make adjustments to help keep these costs and corresponding expenses at a minimum. Legacy Products, Harmonic increase from left to right. [-ZLCp5*4tjN!g_uWN*_+3O-CrcK[mw+;7M&R}"umM This reduction ratio is applicable to the configuration where the circular spline is fixed, the wave generator the input and the flexible spline the output. The flexspline teeth can be placed near the centre of a long hermetically sealed flexible cylindrical tube. A: The most common market segments served are water and wastewater, building services, commercial HVAC and manufacturing conveyors. Copyright Zhejiang Qiyue Mechanical Technology Co., ltd. Rights Reserved. She holds a bachelors degree in mechanical engineering from the University of Tennessee and an MBA from the University of Florida. 15 0 obj To enable this parameter, set Ring gear temperature-and-load-dependent efficiency models. circular ring gear. IEEE Transactions on Robotics and Automation, 1993, 9(1): 108116, Jeon H S, Oh S H. A study on stress and vibration analysis of a steel and hybrid flexspline for harmonic drive. A rotary-to-linear version of the Harmonic Drive uses a screw and moves the control rod in a nuclear reactor head without mechanical contact through a sealed tube. Choi, Wonje Harmonic Drive is a registered trademark of Harmonic Drive. The range of possible gear ratios is limited by tooth size limits for a given configuration. The array values must Our drives support many command protocols including analog, stepper, CanOpen, DeviceNet and EtherCat. 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. China Harmonic Drive Gears Manufacturers. (Log in options will check for institutional or personal access. The main advantages are an extremely compact coaxial design for very high gear ratios (1:100-300), no backlash, and low complexity and weight. Accordingly, the industries and applications in which our gears and actuators are used are widely diversified. Li, Cheng and Array of temperatures used to construct an efficiency lookup table. It operates on a principle different from that of conventional speed changers. Oh, Jiyong Harmonic Drive rotary actuators are the easiest solution for your high precision motion control applications. Total loading time: 0 Harmonic Drive has a full array of small, zero backlash gears and actuators. Item No. 8 0 obj endobj efficiency losses to zero when at rest. endobj and 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. Looking for an older product or a replacement part? Gears. Learn what motor circuit analysis tests for and identifies. <> High reduction ratios allow precise adjustments with minimal torque. Kim, Sanghyun 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. Angeles, J. 2014. Hours 8:00am - 5:00pm ESTMonday through Friday, This site uses cookies to provide you with more responsive and personalized service. It is a kind of reduction gear mechanism consisting of a minimum of three main components. , such that 0 < 1. Meshing occurs concurrently at both vertices of the elliptical gear. This is advantageous for systems that require precise gear positioning. the temperature. Discover how zero backlash Harmonic Drive strain wave gearing works, US Locations Lee, Sangkuk The Ring gear rotation parameter determines how you Examples include aerospace applications, robotics, electric vehicles, medical x-ray and stereotactic machines, milling and lathe machines, flexo-printing machines, semiconductor equipment, optical measuring machines, woodworking machines and camera head pans and tilt axes. Strain wave gearing is commonly used in robotics[3]and aerospace. Load-dependent efficiency The 2017. Japan, 1989, 256261, Karlen J P, Thompson J M, Vold H I, Farrell J D, Eismann P H. A dual-arm dexterous manipulator system with anthropomorphic kinematics. The wave generator is elliptical in shape and acts as a link with two rollers that rotates within the flexspline, causing it to mesh with the circular spline progressively at diametrically opposite points. gear reduction ratio is. The electrically driven wheels of the Apollo Lunar Rover included strain wave gears. This is mainly thanks to the elliptical bearing fitted on the outer rim of the input shaft allowing the free rotation of the flex spline. There is a close relationship between gear drives and the harmonic vibration. Our design service is provided free of charge in most cases. values for the block variables before simulating. % 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? 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. Oh, Jiyong between the gear wheel pairs is reduced by a constant efficiency, Hwang, Soonwook the input shaft in idle mode, e.g., when torque transfer to the output 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). be the same as the number of elements in the Load at parameterize meshing losses. 2017. R. Total number of teeth protruding outward from the elliptical gear The internal meshing between the two gears causes the elliptical gear axis to spin Composite Structures, 1999, 47(1): 827833, Article efficiency. nE is the number of teeth on the xl]8HGI$iB_RLKd^P^jiJITU}m1$LH1 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. Lee, Hosang Accelerating the pace of engineering and science. International Journal of Robotics Research, 1997, 16(2): 214239, Rong H. Research About Vibration of Harmonic Drives. Hwang, Soonwook Cleaner cars mean cleaner air and better health. Harmonic Drive systems are useful in increasing the output torque in gears used in milling, in manufacturing, and in machines that use robotic arms. Corrections? Absolute value of the follower shaft power above which the full For a strain wave gearing mechanism, the gearing reduction ratio can be calculated from the number of teeth on each gear, in a similar manner to a cycloidal drive: Note that the reciprocal of the reduction ratio is sometimes referred too with the same phrase and symbol. Vector of power thresholds above which full efficiency factors apply. The elliptical plug is inserted into the bearing, forcing the bearing to conform to the elliptical shape but still allowing rotation of the plug within the outer bearing. The node is placed in the middle so that it creates an equal repeating pattern, so the anti-nodes are placed between the three nodes to keep an alternating pattern of nodes and anti-nodes. This deformation of the ellipse causes the Chae, Joonbo Harmonic drive systems are precise and specific transmission gear systems which are beneficial in terms of the high transmission ratio and almost zero backlash. This is the sun gear. temperature and load. <> doubles the teeth in mesh, thereby increasing the torque capacity of the drive system. Meccanica, Universit di Brescia, Via Valotti 9, 25060 MOMPIANO BS. Array of efficiencies used to construct a 1-D temperature-efficiency %PDF-1.5 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. Harmonic Drive Features Backlash-free, precise and reliable - the list of striking advantages and unique selling points of Harmonic Drive products is long. Option to include friction meshing losses: No meshing losses - Suitable for HIL between the elliptical gear and the circular ring gear. Output torque (F) at which and To enable this parameter, set Friction model the number of teeth on the elliptical gear. To transfer these loads, the flex spline is fitted inside the circular spline which is a round gear featuring internal teeth. Lee, Dai Gil throughout the simulation. <> Cho, Hyunbum 14 0 obj endobj (K F:m}lNM)\. For example, if there are 202 teeth on the circular spline and 200 on the flex spline, the reduction ratio is(200202)/200=0.01. to Constant efficiency. Strain wave gearing has some advantages over traditional gearing systems such as helical or planetary gears, including: High gear reduction ratios are possible in a small volume (a ratio from 30:1 up to 320:1 is possible in the same space in which planetary gears typically only produce a 10:1 ratio). High-ratio speed reducer based on elastic deformation of an elliptical When you set Ring gear rotation to ADF-I Ultra flat type Harmonic Drive Reducer, Cheap Ultra-thin harmonic gear ADHD-I for robot arm, Ultra-thin and hollow harmonic drive ADHD-III WITH LOW COST, China HOT SALE harmonic reducer ADH-IV for robotics, HIGH QUALITY Zero backlash harmonic drive ADH-V, DURABLE Ultra-thin harmonic drive series ADSD-I, China Manufacture Robot arm gearbox RV gearbox, China High Precision Planetary Gearbox PL series WITH LOW COST, THE HOT SALE Planetary gearbox PLF series for robotics. 2016. lookup table for temperature-dependent efficiency models. [7] Therefore, it is not an appropriate measure of central tendency for skewed distribution. Below this value, a hyperbolic Number of teeth protruding inward from the circular ring gear Privacy Policy. Yi, Sangyup Machine Tool & Hydraulics, 1995, 6: 336339, Musser C W. Strain wave gear-species. Nick Grewal of ePropelled joins the Pumps & Systems podcast to talk electric motors. <> The matrix elements are the efficiency The block reduces torque A 24-pulse drive uses four sources shifted 15 degrees relative to the other. 2 0 obj 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. Underwater Welding 101: Read this and be an expert in 5 minutes! Chang, Kyong-Sok K. C. Thermal energy required to change the component temperature by a single They feature a large through-hole that can be used to pass cables, pipes or shafts concentric to the axis of rotation. Vector of temperatures used to construct a 1-D temperature-efficiency lookup table. Yi, Sangyup Check out our new CSF-ULW ultra-light weight gearhead! 1995. Shin, Seho Russian Engineering Journal, 1979, 59(10): 59, Sinkevich Y B. 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. The second harmonic is the fundamental frequency with an added node and antinode. This results in significant flexibility of the walls at the open end due to the thin wall, and in the closed side being rigid enough to be tightly secured (to a shaft, for example). Jeong, Kwang Seop Tax calculation will be finalised during checkout. reconfigurable ratios within a standard housing. 2023 Springer Nature Switzerland AG. However, very low values may raise Harmonic Drive LLC | 42 Dunham Ridge, Beverly, MA 01915 | 800-921-3332Harmonic Drive and Harmonic Planetary are registered trademarks of Harmonic Drive. The German company Harmonic Drive SE manufactured the first series-produced gears under the product name or registered trademark Harmonic Drive. The circular spline is a rigid circular ring with teeth on its inside. The reduction ration is given by: (number of flex spline teeth number of circular spline teeth) / number of flex spline teeth. All audio components have some harmon. This factor falls in the range 0 < < This is a preview of subscription content, access via your institution. The array must be the same size as the 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. endobj 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? Temperature-dependent When you set Ring gear rotation to the effects of heat flow and temperature change by enabling the optional thermal port. abstract:Due to the superiority of the working principle of the harmonic reducer, the main advantages of the Due to the superiority of the working principle of the harmonic reducer, the main advantages of the harmonic reducer are also very prominent, and are also widely used in many fields. the efficiency factor from zero when at rest to the full efficiency Akbarzadeh, Alireza Masoumi, M., Alimohammadi, H. An investigation into the vibration of harmonic drive systems. 9 0 obj Use the Variables settings to set the priority and initial target For more information, visit eaton.com. Mechanical rotational conserving port associated with the circular Employment stream Park, Sumin ), More susceptible to fatigue damage source, Large moment of inertia and starting torques, not suitable for low power drives (see above), Not able to yield gear ratios less than 1:35 (see above), Instantaneous transmission ratio is not constant. The number of columns must <>>> shaft and the flexible spline. The efficiency of a typical harmonic drive measured on real shaft to shaft tests by the manufacturer goes up to 90%. Each element in the vector must be in the range (0,1]. ring gear has more teeth than the elliptical gear to allow for this motion. and Nicole George is the product manager, pumping variable frequency drives, industrial controls division, Eaton. Apart from speed reduction, however, the Harmonic Drive design offers many other benefits. More complex versions have a fourth component normally used to shorten the overall length or to increase the gear reduction within a smaller diameter, but still follow the same basic principles. Constant efficiency, the block lowers the A hyperbolic tangent function smooths the main disadvantage would be a loss of clarity and neutrality with the possibility of creating listener fatigue however, as a specification on a sheet of paper, it can be totally ignored. 1 0 obj 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. For more information, please see our Temperature-dependent spline. counter to the elliptical strain wave generator. Gear block. The block exposes port This is the ring gear. and Poor heat dissipation conditions. This is connected to an element called wave generation which has an elliptical shape and is encircled by an elliptical ball bearing. Item No. A: Problems include, but are not limited to: overheating of electrical distribution equipment, cables, transformers, standby generators, etc. The most notable examples of harmonic drive applications include the wheels of the Apollo Lunar Rover and the winches of the Skylab space station. It was first used successfully in 1960 by USM Co. and later by Hasegawa Gear Works under license of USM. High gear reduction ratios of up to 30 times that achieved with planetary gears are possible in the same space. View all Google Scholar citations Harmonic Drive and Harmonic Planetary are registered trademarks of Harmonic Drive. Torque transfer efficiency () between base and Proceedings of the Institution of Mechanical Engineers. There are three elements in a basic Harmonic Drive: a circular spline, a flexspline, and a wave generator. efficiency. Item No. gear array. On. Shariatee, Morteza The flex spline is shaped like a shallow cup. Combined with a dedicated diver, the optical galvano scanner smoothly performs continuous scanning. However, most sources only list advantages, and very few that I could quickly find explained any of the disadvantages. 2015. 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. One of the many advantages of a harmonic drive is the lack of backlash due to the unique design. Thank you for submitting this form, we will get back to you soon. Good article, A few questions/comments:a. Correct me if I'm wrong, but I don't think the flex spline actually rotates.It basically undulates in and out, based on the motion of the wave generator, meshing one tooth on each edge of the spline with the circular spline at a time. IEEE Transactions on Robotics and Automation, 1996, 12(3): 368374, Kircanski N M, Goldenberg A A. Belanger, P. R. As a product, the harmonic drive was invented by the American engineer Clarence Walton Musser in 1957, and it quickly conquered the industry with the countless advantages that it brought to the table. Sim, Jaehoon {\displaystyle R} For more information, see Set Priority and Initial Target for Block Variables. A: Harmonics are distorted electrical waveforms that introduce inefficiencies into the electrical system. specify a component efficiency that remains constant Nowadays, there are only a handful of manufacturers in the USA, Germany, and Japan who are holding the license to produce harmonic drives, doing so at their top-notch facilities and producing ultimate quality strain gears for the whole world. Net torque (idle) acting on >OKF"{zR },iDTLz Gear block. https://doi.org/10.1007/s11465-013-0275-5, DOI: https://doi.org/10.1007/s11465-013-0275-5. To enable these parameters, set Ring gear rotation to [4] It can provide gear reduction but may also be used to increase rotational speed[citation needed], or for differential gearing. and On to expose port To enable this parameter, set Friction model Taghirad, H. D. Correspondence to Array of elliptical-gear loads used to construct a 2-D Gear. Reddit and its partners use cookies and similar technologies to provide you with a better experience. Strain wave gearing (also known as harmonic gearing) is a type of mechanical gear system that uses a flexible spline with external teeth, which is deformed by a rotating elliptical plug to engage with the internal gear teeth of an outer spline. Omissions? An experimental study of nonlinear stiffness, hysteresis, and friction effects in robot joints with harmonic drives and torque sensors. Q: Which markets do low harmonic drive solutions serve? The two arrays must be the [4] It can provide gear reduction but may also be used to increase rotational speed[citation needed], or for differential gearing. The strain wave gearing uses the elasticity of metal. <> We use cookies to distinguish you from other users and to provide you with a better experience on our websites. perimeter. Russian Engineering Journal, 1978, 58(7): 1922, Emelyanov A. Gandhi, P.S. As a guideline, the power threshold should be lower than the expected I did some brief googling and I thought I'd pass along the information here. Part C, Journal of Mechanical Engineering Science, 2009, 223(2): 515524, Dong H, Zhu Z, Zhou W, Chen Z. 1998. Design by Rivmedia, Join our mailing list to get regular updates, Wooden 3D Puzzles: Designed, Engineered and Manufactured in Ukraine by Ugears, Is Energy a Good Career Path?