Core Components of Industrial Robots: Past and Present of RV Reducer
RV 减速机 ，到今天，中国仍然不具备设计和制造能力。 When we were looking forward to the era of robots infinitely, did you know that RV reducer , one of the most critical mechanical structures of robots , China still does not have the design and manufacturing capabilities. ” 时期，国家 “863” 计划将其列入重点攻克的技术瓶颈。 During the " Twelfth Five-Year Plan" period, the national "863" plan included it as a key technical bottleneck. The top domestic universities and scientific research institutions have only dealt with theses for a few years, and they have no real objects.
Among all the core parts of the robot, the reducer is the most critical.
成本结构大致如下：本体 22% 、伺服系统 25% 、 减速器 38% 、控制系统 10% 以及其他 5% 。 The cost structure of industrial robots is roughly as follows: 22% of the body , 25% of the servo system , 38% of the reducer , 10% of the control system, and other 5% . 6 轴工业机器人成本 ( 总成本 25 万元 ) ，可以看出减速器和 伺服电机 两项成本接近 13 万元，主要以进口为主。 Simply split the cost of the domestic 6- axis industrial robot (the total cost is 250,000 yuan ) . It can be seen that the two costs of the reducer and servo motor are close to 130,000 yuan, mainly imported.
RV 减速机的机械原理 First, the mechanical principle of RV reducer
· 勃朗于 1926 年创造性地提出了一种少齿差行星传动机构，它是用外摆线作为齿廓曲线的，这就是最早期的针摆行星传动，由于两个啮合齿轮其中之一采用了针轮的形式，这种传动也被称做摆线针轮行星齿轮传动。 The German Lorenz Bron creatively proposed a planetary transmission mechanism with little tooth difference in 1926. It uses an epicycloid as the tooth profile curve. This is the earliest pin-pendulum planetary transmission. One of the gears is in the form of a pinwheel. This transmission is also called a cycloid pinwheel planetary gear transmission.
RV transmission is a brand new transmission method. It is developed on the basis of traditional pin-and-pendulum planetary transmission. It not only overcomes the shortcomings of general pin-and-pendulum transmission, but also because of its small size, light weight, large transmission ratio range and long life A series of advantages such as stable accuracy, high efficiency and stable transmission.
The rotation of the input shaft is transmitted from the input gear to the spur gear and is decelerated by the gear ratio. This is the first reduction section.
2 减速部 … 差动齿轮减速机构 Second reduction section ... differential gear reduction mechanism
The spur gear is connected to the crank shaft and becomes the input of the second reduction section. RV 齿轮。 On the eccentric part of the crankshaft, an RV gear is mounted through a rolling bearing . RV 齿轮数多一个的针齿，以同等的齿距排列。 In addition, only one more pin tooth than the number of RV gears on the inner side of the housing is arranged at the same pitch.
RV 齿轮由于曲柄轴的偏心运动也进行偏心运动。 If the fixed housing rotates the spur gear, the RV gear also performs eccentric movement due to the eccentric movement of the crank shaft. RV 齿轮就会沿与曲柄轴相反的方向转动一个齿。 At this time, if the crankshaft rotates once, the RV gear will rotate one tooth in the opposite direction to the crankshaft. 2 减速部的轴。 This rotation is output to the shaft of the second reduction section. When the shaft is fixed, the housing side becomes the output side.
RV 减速机，轻载机器人第五关节和第六关节有可能使用谐波减速机。 All the first to fourth joints of the robot use RV reducers, and the fifth and sixth joints of light-loaded robots may use harmonic reducers. RV 减速机。 All joints of a heavy-duty robot require an RV reducer. 4.5 台 RV 减速器 。 On average, each robot uses 4.5 RV reducers . 18 万台，需使用减速机 90 万台。 In 2013 , 180,000 robots were sold worldwide, and 900,000 reducers were required .
的动力源一般为交流 伺服电机 ，因为由脉冲信号驱动，其伺服电机本身就可以实现调速，为什么工业机器人还需要减速器呢？ The power source of industrial robots is generally AC servo motors . Because they are driven by pulse signals, the servo motors themselves can achieve speed regulation. Why do industrial robots need reducers? Industrial robots usually perform repetitive actions to complete the same process; in order to ensure that industrial robots can reliably complete process tasks in production and ensure process quality, high positioning accuracy and repeated positioning accuracy are required for industrial robots. RV 减速器或谐波减速器。 Therefore, to improve and ensure the accuracy of industrial robots, RV reducers or harmonic reducers are required. Another role of precision reducers in industrial robots is to transmit greater torque. When the load is large, it is not cost-effective to blindly increase the power of the servo motor. You can increase the output torque through a reducer within a suitable speed range. In addition, the servo motor is prone to heat and low frequency vibration under low frequency operation, which is not conducive to ensuring accurate and reliable operation of industrial robots that work for a long time and periodically.
The existence of a precision reducer enables the servo motor to run at a suitable speed, and accurately reduces the speed to the speed required by various parts of the industrial robot, improves the rigidity of the mechanical body, and outputs a larger torque. Compared with general reducers, robot joint reducers require short transmission chains, small size, high power, light weight, and easy control.
RV 减速器和谐波减速器。 There are two main types of reducers used in articulated robots: RV reducers and harmonic reducers. RV 减速器具有更高的刚度和回转精度。 Compared with harmonic reducer, RV reducer has higher rigidity and turning accuracy. RV 减速器放置在机座、大臂、肩部等重负载的位置；而将谐波减速器放置在小臂、腕部或手部；行星减速器一般用在直角坐标机器人上。 Therefore, in articulated robots, the RV reducer is generally placed at a heavy load such as the machine base, the boom, and the shoulder; the harmonic reducer is placed on the forearm, wrist or hand; the planetary reducer is generally used On Cartesian robots.
RV 减速机较机器人中常用的谐波传动具有高得多的疲劳强度、刚度和寿命，而且回差精度稳定，不像谐波传动那样随着使用时间增长运动精度就会显着降低，故世界上许多国家高精度机器人传动多采用 RV 减速器，因此，该种 RV 减速器在先进机器人传动中有逐渐取代谐波减速器的发展趋势。 At the same time, the RV reducer has much higher fatigue strength, stiffness and life than the harmonic drive commonly used in robots, and the return accuracy is stable. Unlike the harmonic drive, the motion accuracy will decrease significantly with the use of time. Therefore, many countries in the world use RV reducers for high-precision robot transmission . Therefore, this type of RV reducer has gradually replaced the harmonic reducer in the development of advanced robot transmission.
RV 减速机发展编年史 3. Chronicle of RV reducer development
1926 年德国人劳伦兹 · 勃朗于创造性地提出 RV 减速机原理 1. In 1926 , the German Laurenz Brown creatively proposed the principle of RV reducer
1931 年劳伦兹 · 勃朗在德国慕尼黑创建了 “ 赛古乐 ” 股份有限公司，最先开始了摆线减速器的制造和销售 2. In 1931 , Lorenz Blanc established " Segura " Co., Ltd. in Munich, Germany , and first started to manufacture and sell cycloid reducers.
1939 年，日本住友公司和 “ 赛古乐 ” 公司签定了技术合作协议，并生产销售； 3. In 1939 , Japan's Sumitomo Corporation and " Segura " signed a technical cooperation agreement and produced and sold it;
1944 年，日本帝人精机成立，这个未来的 RV 减速机霸主，在飞机制造、纺织机械、机床等多个行业硕果累累； 4. In 1944 , Teijin Seiki Japan was established. This future RV reducer overlord has achieved fruitful results in a variety of industries such as aircraft manufacturing, textile machinery, and machine tools;
1950 年 -1960 年，摆线磨床的出现，解决了摆线齿形的精度不高的难题，使摆线传动得到了进一步的发展。 5. From 1950 to 1960 , the emergence of cycloidal grinders solved the problem of low accuracy of cycloidal tooth profile, and further developed the cycloidal transmission.
1956 年，日本纳博克公司发售全球第一个自动门，在市场上展露头角。 6. In 1956 , Japan's Nabog company sold the world's first automatic door, showing its presence in the market.
1980 年左右，日本帝人精机提出 RV 传动理论，着手应用于机器人行业。 7. Around 1980 , Teijin Seiki proposed the theory of RV transmission, and began to apply it to the robot industry.
1986 年，日本帝人精机 RV 减速机正式大规模生产，取得成功； 8. In 1986 , the Teijin Seiki RV reducer was officially mass-produced with success;
2003 年，帝人精机和纳博克合并组成 Nabtesco( 纳博特斯克 ) 公司，并取得快速发展，现在已成为 RV 减速机行业的领头羊，占据了 60% 以上的市场，特别在中 / 重负荷机器人上，其 RV 减速机市场占有率高达 90% 。 9. In 2003 , Teijin Seiki and Nabok merged to form Nabtesco , and achieved rapid development. Now it has become a leader in the RV reducer industry, occupying more than 60% of the market, especially in China / On heavy-duty robots, its RV reducer market share is as high as 90% .
RV 减速机方面，我国从二十世纪五十年代起开始研究行星齿轮传动装置，六十年代从国外引进，尽管在理论和仿制方面取得了一些成果，但与日本的同类最新产品相比，我们研制的摆线针轮 减速器 从整体性能、使用寿命、传动精度、承载能力到新产品的进一步开发升级都存在着相当多的不足之处。 As for the RV reducer, China has been studying planetary gear transmission since the 1950s and was introduced from abroad in the 1960s. Although some achievements have been made in theory and imitation, compared with the latest Japanese similar products, There are quite a few shortcomings in the cycloid pinwheel reducer we have developed from the overall performance, service life, transmission accuracy, load carrying capacity to the further development and upgrade of new products.
ABB 、 Kuka 、安川等国际巨头采购价为 3 万元 ~5 万元，卖给我国企业约 7 万元，普通企业约 12 万元，我国企业采购精密减速机的成本比国际巨头贵一倍还多。 The purchase price of a precision reducer ABB , Kuka , Yaskawa and other international giants is 30,000 to 50,000 yuan, which is sold to Chinese enterprises for about 70,000 yuan, and ordinary enterprises for about 120,000 yuan. Giants are more than twice as expensive.
机器人产业 研究所 (GRII) 数据统计，国内有 353 家 机器人 企业，其中研究减速器的只占到 13 家，研究 RV 减速器的只有 5 家。 According to the statistics of the Institute of Industrial Robot Industry (GRII) , there are 353 robot companies in China, of which only 13 are studying reducers, and only 5 are studying RV reducers .
( 机器人 ) 传动核心部件 RV 减速装置以及系列交流 伺服电机 ，投入批量生产，更获得市场广泛认可。 In 2010 , Nantong Zhenkang Welding Electromechanical Co., Ltd. developed a series of RV reduction gears and a series of AC servo motors that can be used in high-end industrial applications ( robots ) as transmission core components . 200 多台。 In 2013, it produced more than 200 units.
7 月 20 日，武汉市精华减速机制造有限公司总经理余运清透露，自主研发的一种精密减速机刚获得检验通过，有望替代进口，降低工业机器人国产化成本。 On July 20 , 2014 , Yu Yunqing, general manager of Wuhan Jinghua Reducer Manufacturing Co., Ltd. revealed that a precision reducer independently developed by the company has just passed inspection and is expected to replace imports and reduce the cost of domestic production of industrial robots.
7 月，秦川发展发布公告称，计划投资 1.94 亿元进行 9 万套 ( 一期 ) 工业机器人关节减速器技术改造项目建设。 In July 2014, Qinchuan Development announced that it plans to invest 194 million yuan in the construction of a 90,000 ( Phase 1 ) industrial robot joint reducer technology renovation project. RV 减速器的研发制造推进了人们的视野。 This move has promoted the development and manufacture of domestic robotic RV reducers and pushed people's horizons.
With the economic transformation and upgrading and the aging of China's population, the development of the robot industry has ushered in a stage of rapid development of demand. 3.7 万台，约占全球销量的 1/5 ，总销量超过了日本，位居全球第一。 In 2013 , nearly 37,000 industrial robots were sold in the Chinese market , accounting for about one fifth of global sales . The total sales surpassed Japan and ranked first in the world. 2016 年成为全球最大的 机器人市场 ，保有量将超过 15 万台。 It is expected that China is expected to become the world's largest robot market in 2016 , with its holdings exceeding 150,000 units. 都计划投资近 50 亿日元在中国新建工厂，自 2016 年起投产制造工业机器人用的核心零部件 -RV 减速机，计划每年产量 10 万台， 2020 年达 20 万台。 Nabtesco plans to invest nearly 5 billion yen to build a new plant in China. Starting in 2016 , RV reducers, the core components for industrial robots , will be produced. The annual output is planned to reach 100,000 units and reach 20,000 units by 2020 .
With such a large market demand, at present, it seems that it has almost no chance with Chinese companies. We look forward to Chinese companies being able to break through technical bottlenecks and win the market at an early date.