The heavy duty apron feeder is used for the continuous and uniform distribution and transfer of materials to the crusher, conveyor or other working machinery in a horizontal or inclined direction. It is especially suitable for transporting large, high temperature and sharp materials, and can work reliably in the open air and in wet and harsh environments. pron feeder is divided into heavy duty, medium duty and light duty. The quality of the reducer on the drive device is very critical to the service life of the whole machine. Many years ago, our transmission machinery research Institute developed and designed DT35, DT36, DT37, DT38 four series of retarders with reference to the technology of German Flanders Company, which are used for high-power and heavy-duty boards. However, the reducer on the small power heavy plate, medium plate and light heavy duty apron feeder drive device has always used the purchased planetary cycloidal pin wheel reducer.
We have also developed and designed the DT39 and DT40 with anchor connection, DT39K with hollow shaft connection,DT40K, DT39KNA with hollow shaft connection and backstop, DT40KNA and DT40KNA two kinds of output torque reduction gear.
Main technical parameters
DT39 series: Rated output torque: 60000N.m Shaft speed: 1000-1500r/min Transmission ratio: 280-500. DT40 series: Rated output torque: 30000N.m Shaft speed: 1000-1500r/min Transmission ratio: 280-4403. 3 Structure design The previous DT series reducer is composed of two separate reducer, one of which is a three-stage direct-alternating reducer, the other is GW type two-stage planetary reducer, the two reducer enclosures are connected by bolts, The advantage of this structure is that the three-stage direct reducer with different speed ratios and the two-stage planetary reducer with fixed speed ratios are assembled together to form a direct star reducer with different transmission ratios, but this structure also has drawbacks, one is easy to oil leakage at the joint, and the other is more troublesome to assemble. This design of the new DT reducer series is still based on this idea, but the structure has made the following changes:
1) Make the two retarders into one, reduce the two box walls, greatly reduce the weight, and solve the oil leakage problem and assembly trouble;
2) The speed ratio of the last two stages of the planetary transmission part is amplified as far as possible, so that the speed ratio of the direct transmission part is reduced, and the maximum speed ratio of 500 is achieved by using two stages of direct transmission plus two stages of planetary transmission. This structure increases the efficiency of the whole machine by two percentage points:
3) The most popular modular design method is adopted, and the footing is welded and connected with the box with bolts. It can be assembled into solid shaft type with footing and hollow shaft type without footing according to customer requirements:
4) The heavy duty apron feeder reducer with inclination requirements is also equipped with the most advanced built-in backcheck, which is beautiful and simplifies the structure of the main machine accessories, and does not increase the weight of the main machine.
The distribution of all levels of gear parameters is the key element of a reducer, the use of computer programming to simplify the design of a lot, after the selection of all levels of gear ratio, and then respectively calculate the contact strength and bending strength of all levels of gear, and finally determine the center and tooth parameters. The allowable strength is selected according to 20CMMo material, the industrial and mineral coefficient is 1.75, and the minimum safety coefficient is 1.5. Klingenberg helical bevel gear for the input stage. Parallel stage with helical cylindrical gear, helix Angle choose 10-12 degrees. The inner meshing Angle of the planetary transmission is between 17-18 degrees, and the outer meshing Angle is between 24-26 degrees. The principle of calculation is to make the strength of all levels close to each other, and the high-speed level is slightly higher than the low-speed level, so that the life of the machine is the highest. That is the best value for money. 5 Improvement of the internal structure of the planetary part of the original high-speed planetary part of the sun wheel and planetary frame are floating parts, and the front of the three-stage direct reducer is connected by floating gear sleeve, the new series of reducer in order to make the structure more compact, the former parallel stage fixed shaft lengthened into a gear shaft, the floating gear sleeve was cancelled, and the gear shaft was directly made into the sun wheel.
In order to make the series of reducer achieve different transmission ratio requirements, the first stage designed two speed ratios of bevel gear pairs, the second stage designed five speed ratios of cylindrical gear pairs so that seven transmission ratios.
The lubrication and sealing methods are calculated by thermal power
This series of heavy duty apron feeder reducer adopts splash lubrication. In order to discharge the residual oil in the box when the user changes the oil, a set of oil discharge system with a valve is added at the lowest point of the reducer. See Figure 2. Because the oil level of the reducer is relatively high, the input shaft forms a high-pressure area at the front end of the high-speed operation, and it is difficult to achieve no oil leakage with the general quality of the oil seal. In order to solve this problem, a small hole is opened between the oil seal and the bearing, and the external copper pipe is connected with the box. The test proved that the effect is very good. Originally this problem can be solved inside the box, but because the reducer is too small, can not be processed, had to use open pipe.
The advantages of this structure reducer to achieve full speed ratio at the same time to achieve compact structure, small size, light weight, reasonable use of internal and external meshing, power shunt principle to achieve high bearing capacity, high transmission efficiency, long service life, smooth operation, low noise. The installation size can be the same as the cycloidal reducer, the internal gear shaft and gear using 20 CrMnMo carburizing quenching and grinding, gear accuracy 6, internal gear gear shaper 7 precision, internal gear can also be made of hard tooth surface by nitriding according to strength requirements.
Economic benefits Compared with the same power of the planetary cycloidal pinion reducer DT39 series of the price of 25,000 yuan lower per unit, DT40 series of the price of 8,000 yuan lower per unit. Four years since the series of reducer has been put into use nine units so far running well.
