If we talk about the backstage mechanism, then you should start with the fact that the "backstage" is a French word that can be translated into our language as a "detail" or "link".
general information
From a technical point of view, a rocker mechanism is understood to mean a device whose task is to convert rotational or swinging motion into reciprocating. However, this mechanism can also perform the inverse function. If we talk about the general classification of this device, then it can be of three types - a rotating type, a swinging type, or moving in a straight line. However, if you understand the essence of the rocker mechanism, it becomes clear that any of its kind can be attributed to the lever type of devices. In addition, it is important to note that the backstage work is paired with another part called the slider. This part is also a rotating part in the overall design of the mechanism.
Benefits and Material
The main advantage of this mechanism is the provision of a rather high speed of the slider, which it develops when performing the reverse stroke. This advantage has led to the fact that such a device has become very widely used in equipment that has an idle reverse stroke. Moreover, if we compare the rocker mechanism with the crank mechanism, for example, the first is able to transmit much less effort compared to the second.
Most often, the rocker device is used to convert the uniform rotational movement of the crank as efficiently as possible into the rotational movement of the wings directly. It is worth noting that this movement is uneven. However, there are times when the backstage movement will still be uniform. Most often this happens if the distance between the supports of the crank and its wings is equal to the length of the crank itself. In such a system, the link mechanism will simultaneously be also a crank mechanism, which is equipped with a link with uniform movement.
The design and distribution of the mechanism
To date, the four-link is the most common backstage design. In addition, all structures of this type can be classified into several groups depending on what type of third link in the device. There are such classes as: two-link, rocker-slide, rocker-rocker, crank-rocker.
These mechanisms are most often used in various kinds of machines, such as gear-shaping, cross-planing and other machines, which can be attributed to metal-cutting types. The essence of the rocker mechanism is that this is one of the many varieties of the crank. The use of a mechanism with a backstage is resorted to if there is a need for equipment to convert rotational motion to reciprocating. In planing types of machines, a swinging type of rocker is used, and in mortising machines a rocker of a rotating type is installed.
Four link mechanism design
A four-link rocker mechanism with a rocker stone is a system that can be considered with the example of a planer, where this type of device is used. The operation of this system can be described as follows. The crank carries out a circular motion around the axis through the rocker, thereby causing the rocker to make a rocking movement. However, at the same time, if you look at the movement of the rocker relative to the rocker, it will already make a reciprocating movement. This type of device is also often used in hydraulic pumps, which have rotary-type mechanisms with rotating blades. In addition, the four-link mechanism has found its application among various hydraulic and pneumatic drives. In this case, the design involves an input piston on the connecting rod, which slides in a rotating or swinging cylinder.
Rocker Slider
This model of the mechanism is most often used in laboratory conditions, and is also used for training and familiarization with this device in the conditions of educational laboratories in such disciplines as applied and theoretical mechanics.
It is worth mentioning that the widespread multi-link rocker-slider mechanism is quite large. This is due to the fact that the design of the second connecting rod with the slider is lower than the straight-line arrangement of the backstage shaft. This design feature suggests that the start of the connecting rod will be lower than the rocker-link device itself. This, in turn, suggests that such a mechanism should have a high foundation or bed, and this means that it will be necessary to spend more money on its creation, since the excess material goes to create such a bed. It is worth noting that it is this factor that is considered the biggest problem and the main drawback of the whole system as a whole.
Rocker Arm
The linkage mechanism is an invention that has found its application in the field of mechanical engineering. The main objective of this system is to convert reciprocating motion into all-wheel drive rotational. The purpose with which this mechanism was invented was to increase the service life of the system, as well as to increase its efficiency, or efficiency. In addition, goals were also pursued, such as expanding opportunities in the field of kinematics, due to the fact that the system was supplied with a second wings, and also the links of the system were performed differently.
Crank mechanism
After the invention of this system, it began to be referred to as articulated lever mechanisms that have hydraulic devices or pneumatic devices, and the purpose of their use was ventilation in warehouses. The design of this mechanism is quite simple, and it contains three main elements: it is a stand, crank and wings. The task posed to the inventors of this device is to improve reliability while simplifying the mechanism in terms of design. The prototype for the invention of this model was hydraulic or pneumatic mechanisms, which also used a backstage with translational movement. In addition, the structure also included a stand, a slider, a crank.
Repairs
Like any other mechanism, the rocker also has its own service life. After this service life, the time comes to repair the linkage mechanism. However, it also happens that the device goes out of service ahead of schedule. Most often, in this mechanism, parts of it such as the link, the rocker, the gear wheel, the screws and nuts to move the sprocket, as well as the spider itself with a finger, wear out or wear out. If the surface of the grooves of the backstage got more than 0.3 mm wear, and also there are deep scuffs on them, then milling with the subsequent scraping operation is used as a repair. If the wear is not too strong, you can get around only by scraping, without milling.
If the backstage wears out, then the walls of the groove are first put in order as a repair. When carrying out work, they most often focus on those areas that are less worn out than others.