Friends who have just come into contact with the mechanical industry often feel confused when faced with a wide variety of reducers, unable to distinguish between different types of WPWDV135,WPWDV155,WPWDV175,WPWDV200,WPWDV250 reducers
What are the differences between speed reducers, as well as their main structures and functions? This has caused a lot of confusion for those engaged in related work, especially those engaged in mechanical sales. Below, we will analyze the structures and characteristics of two different types of speed reducers to explain how to distinguish them. We hope that readers can learn to distinguish different types of speed reducers by drawing inferences from each other.
Planetary gear reducer: The main transmission structure is: planetary gear, sun gear, and outer gear ring
Due to structural reasons, planetary reducers have a minimum single stage reduction of 3 and a maximum reduction of generally no more than 10. The common reduction ratio is 3.4.5.6.8.10, and the number of stages of the reducer generally does not exceed 3. However, some large reducers have a 4-stage reduction compared to customized reducers
Compared to other reducers, planetary reducers have the characteristics of high rigidity, high accuracy (up to 1 point per stage), high transmission efficiency (97% -98% per stage), high torque/volume ratio, and lifelong maintenance free
Due to these characteristics, most planetary reducers are installed on stepper and servo motors to reduce speed, increase torque, and match inertia
The rated input speed of the reducer can reach a maximum of 18000rpm (depending on the size of the reducer itself, the larger the reducer, the lower the rated input speed). The output torque of industrial grade planetary reducers generally does not exceed 2000Nm, and specially designed super large torque planetary reducers can reach a maximum of 10000Nm. The working temperature is generally around -25 ℃ to 100 ℃, and its working temperature can be changed by changing the lubricating grease
Several concepts about planetary reducers:
Series: The number of sets of planetary gears. Due to the inability of a set of star gears to meet a larger transmission ratio, sometimes 2 or 3 sets are needed to meet the requirements of supporting a larger transmission ratio. As the number of star gears increases, the length of the 2nd or 3rd stage reducer will increase and the efficiency will decrease
Return clearance: Fix the output end and rotate the input end clockwise and counterclockwise to generate+-2% of the rated torque at the input end
When torque is applied, there is a small angular displacement at the input end of the gearbox, which is the return clearance. The unit is "minute", which is one sixtieth of a degree. Some people also call it the back clearance
Planetary cycloidal pinwheel reducer: All transmission devices can be divided into three parts: input part, deceleration part, and output part. On the input shaft, there is a double eccentric sleeve with a misalignment of 180 °. On the eccentric sleeve, there are two roller bearings called rotating arms, forming the H mechanism. The center holes of the two cycloidal gears are the raceways of the rotating arm bearings on the eccentric sleeve, and the cycloidal gears mesh with a group of circular arranged needle teeth on the needle gear to form an internal meshing reduction mechanism with a tooth difference of one tooth, In order to reduce friction, in reducers with low speed ratios, needle teeth are equipped with needle teeth sleeves. When the input shaft rotates with an eccentric sleeve for one cycle, due to the characteristics of the tooth profile curve on the cycloidal gear and its limitation by the needle teeth on the needle gear, the motion of the cycloidal gear becomes a plane motion with both revolution and rotation. When the input shaft rotates in the forward direction, the eccentric sleeve also rotates for one cycle, and the cycloidal gear rotates in the opposite direction by one tooth to achieve deceleration. Then, with the help of the W output mechanism, the low-speed rotation motion of the cycloidal gear is transmitted to the output shaft through the pin shaft, This results in a lower output speed.
Characteristics of cycloidal gear reducers
High speed ratio and high efficiency single stage transmission can achieve a reduction ratio of 1:87, with an efficiency of over 90%. If multi-stage transmission is used, the reduction ratio is even greater.
Due to the use of planetary transmission principle, the input and output shafts are on the same axis line, resulting in a compact structure and small size for its model.
Smooth operation, low noise, large number of meshing teeth of cycloidal needle teeth, large overlap coefficient, and mechanism of machine component balance, which limits vibration and noise to the minimum extent.
Reliable use and long service life. The main components are made of high carbon chromium steel material, which has been quenched (HRC58-62) to obtain high strength. Additionally, some transmission contacts use rolling friction, making them durable and have a long service life Reasonable design, convenient maintenance, easy disassembly and installation, minimum number of parts, and simple lubrication.
