# Dynamics of Mechanisms with Superior Couplings
## 4 Discussion  
In this paper, the authors briefly present the basic dynamic aspects that appear in mechanisms with superior couples, used for hundreds of years in various machines and mechanisms, in mechanical transmissions, automations, automatic processing machines, industrial installations, medical equipment, control, and measurement in the automotive industry, in household appliances, and in many other fields. Today, robots frequently use such mechanical transmissions for servomotors. Mechanisms with superior couples are extremely robust and reliable, withstand millions of dynamic cycles at high speeds and powers, transmit very high forces and moments for a long time, without breaks, without wear, and without repairs, while the mechanisms of Equivalent replacement tried so far may not cope with the breakage very quickly, for example, those with electrical coils and rod. For this reason, mechanisms with superior couples are also used in the medical industry in operating rooms, in the operation of industrial robots, in medical equipment, in control and measurement devices, in pacemakers, in mobile prostheses, and in other fields. The laws of motion that have been used since ancient times in mechanisms with superior couples are now used in industrial robots, to obtain optimal laws for passers-by, for how to tread the sole of the robot as naturally as possible, but at the same time, such lifting laws also use the command and control of industrial robots, the trajectory of the deserter who must follow the correct laws of motion in the movement between two distant working points, to optimize the general movement of the robot and its arms, so the dynamics of movement must be smooth, but fast without noises, without vibrations, without interruptions, with higher speeds but constantly as high as possible, without unevenness, without breaks, without shocks, and without wear. From ancient times, optimized polynomial laws have been used for this purpose: various, with as many factors as possible, to impose as many conditions at the border. Today there are other convenient laws that can be used in industrial robots, which are first synthesized by authors in hard memory mechanisms and then taken over and transposed for use in passing robots, as well as in all anthropomorphic industrial robots, which represent about 80-90% of all industrial robots, for optimizing their trajectories. The authors started from the classic mechanisms with superior couples with cam and follower (adept; Figure 1), that worked with mechanical yields of about 3-4%, and gradually increased them to 10-12%, then to 18-24%, so that, in the end, they would even reach 30-40%, especially for roller modules [55; 56; 57; 58; 59; 60; 61; 62; 63]. Figure 17: Cam profile at module B. C4P law, \(n=5500\) [rot/min] \(\varphi_{u}=80\) [degree], \(r_{0}=13\) [mm], \(r_{b}=3\) [mm], \(h_{T}=6\) [mm]. Mechanisms with superior couple type Maltese cross or Geneva driver (Figure 2) have also been studied by the authors and it has been found that even they can increase mechanical efficiency even when using modern mechanisms inputs and many transverse channels that will no longer have only four channels, but many small ones, the guide on the channel being very short for the drive screw, so as to permanently change the drive screw and the driven channel, which leads to efficiencies over 90-95%. Gears are also mechanisms with superior couples by multiplying the cams. The great advantage of the gear mechanism is to present permanent operating efficiencies, high power transmissions, forces, and moments, at high speeds, without wear, without shocks, and without noises or vibrations. Today, they are still very well calibrated constructively from the stage of design [58]. For the precise theoretical determination of the efficiency of a cylindrical gear, it must be taken into account that it will have several pairs of teeth engaged simultaneously, i.e., the degree of coverage of the gear must also be taken into account.