The function of the transmission system is between the prime mover and the working machine in the machine, and it mainly transmits the movement and power of the prime mover to the working machine, where it mainly plays a decelerating role and coordinates the speed and torque of the two.
The characteristics of the transmission scheme: the transmission has a simple structure, high efficiency, easy manufacture, long service life, and convenient maintenance.Due to the parallel arrangement of the motor, the reducer and the drum, the lateral size is large and the machine is not compact, but the position of the gears is asymmetrical. The high-speed gears should be arranged far from the torque input end to make the shaft torsionally deformed under the action of torque. This part offsets the bending deformation of the shaft under the action of the bending moment, so as to reduce the uneven load distribution along the tooth width.The installation position of the motor and the working machine, the motor is installed at the end far away from the high-speed shaft gear, and the working machine should be installed at the end far away from the low-speed shaft gear.
1. Combination of gears, shafts and bearings
The pinion and the shaft are made into one body, called the gear shaft. This structure is used when the diameter of the gear is not related to the diameter of the shaft. If the diameter of the shaft is d and the diameter of the gear root circle is df, then when df- When d≤6～7mn, this structure should be adopted.When df-d>6～7mn, the gear and the shaft are separated into two parts, such as the low-speed shaft and the large gear of the reducer. At this time, the gear and the shaft are connected with a fixed flat key in the circumferential direction, and the parts on the shaft are used The shaft shoulder, shaft sleeve and bearing cover are axially fixed.Both shafts use deep groove ball bearings.This combination is used to bear radial load and small axial load.When the axial load of the reducer is large, the combined structure of angular contact ball bearings, tapered roller bearings or deep groove ball bearings and thrust bearings should be adopted.The bearing uses the thin oil splashed when the gear rotates. When the reducer is lubricated, the lubricating oil in the oil pool in the box seat is splashed and splashed on the inner wall of the box cover by the rotating gear, and flows along the inner wall to the groove of the sub-box surface. Flow into the bearing through the oil guide groove.When the circumferential speed of the oil-soaked gear υ ≤ 2m/s, grease should be used to lubricate the bearing. In order to avoid the possibility of splashing thin oil from washing away the grease, an oil retaining ring can be used to separate it.In order to prevent the loss of lubricating oil and external dust from entering the box, a sealing element is installed between the bearing end cover and the extension shaft.
2. Cabinet
The box is an important component of the reducer.It is the base of the transmission parts and should have sufficient strength and rigidity.
The box is usually made of gray cast iron, and cast steel box can also be used for the reducer with heavy load or impact load.In order to simplify the process and reduce the cost of the reducer produced by a single body, a steel plate welded box can be used.
Gray cast iron has good casting performance and vibration damping performance.In order to facilitate the installation and disassembly of the shaft components, the box is made into a horizontal split type along the axis line.The upper box cover and the lower box body are connected by bolts into one body.The connecting bolts of the bearing seat should be as close as possible to the bearing seat hole, and the boss next to the bearing seat should have enough bearing surface to place the connecting bolts and ensure the wrench space required when tightening the bolts.In order to ensure that the box body has sufficient rigidity, support ribs are added near the bearing hole.In order to ensure the stability of the reducer placed on the foundation and minimize the machining area of the box base plane, the box base generally does not adopt a complete plane.
3. Reducer accessories
In order to ensure the normal operation of the reducer, in addition to paying enough attention to the structural design of the gear, shaft, bearing combination and box body, consideration should also be given to filling and draining the lubricating oil pool of the reducer, checking the oil level, processing and Reasonable selection and design of auxiliary parts and components such as precise positioning of box cover and box seat, hoisting, etc. during disassembly, assembly and maintenance. 1) The inspection hole is to check the meshing of the transmission parts and to pour lubricating oil into the box.The inspection hole is set on the top of the upper case cover to directly observe the gear meshing part.Usually, the cover plate of the inspection hole is fixed on the box cover with screws!