The drive reducer of the belt conveyor often encounters situations where the input shaft of some drive reducers breaks, which has a certain impact on the production of users. When the shaft is broken, only the input shaft is usually broken, and the output shaft is rarely broken. In severe cases, continuous input shaft breakage may occur on several belt conveyors. This situation may occur when all the gearboxes that experienced shaft breakage are from the same belt conveyor supplier. When the axle is broken, the stubble at the crack on the rear axle is usually flush, and the cross-section is usually perpendicular to the length direction of the axle. Shaft breakage occurs on both belt conveyors on mobile machinery and ground belt conveyors.
The primary external factors causing a broken shaft should include the following aspects:
1.1 The bearing capacity of the selected belt conveyor reducer is not sufficient. The drive reducer of the belt conveyor is selected too small. When the practical application power of the reducer exceeds the bearing capacity of the reducer, the drive reducer of the belt conveyor will break within a certain period of time;
1.2 Hydraulic couplings and brake wheels are usually installed between the motor shaft and the reducer shaft. When the dynamic balance between the brake wheels and the hydraulic couplings is poor and severe, it can cause significant vibration during the operation of the belt conveyor. When the vibration load reaches a certain level, it causes excessive stress on the output shaft of the gearbox and cracks;
The concentricity error of the equipment is too large. Assuming that the concentricity between the reducer and motor shaft should be carefully adjusted when using the hydraulic coupling and brake wheel between the equipment motor and reducer, even if the difference is too large, the coupling and brake wheel may vibrate excessively during operation, resulting in shaft breakage.
1.4 Defects in the gearbox plan caused the input shaft to break. This situation occurs when selecting a gearbox based solely on the request of the gearbox supplier to plan the belt conveyor. Although the selected gearbox meets the requirements of the gearbox supplier, the phenomenon of shaft breakage still occurred.
The internal elements of a broken shaft in a reducer mainly include the following aspects:
2.1 Excessive stress at the cracked shaft during gearbox planning;
2.2 Failure to fully consider the curvature radius of the transition fillet and modify the curve at the shoulder of the input shaft of the reducer resulted in severe stress convergence and fatigue damage;
2.3 The reducer adopts a vertical axis method, and the top input shaft is the umbrella gear shaft. Severe stress convergence occurs at the transition shoulder of the umbrella gear support bearing, leading to fatigue damage;
2.4 The reducer is a hard tooth surface reducer, and the input shaft diameter of the reducer is relatively thin. Although the strength is calculated, due to the thinness of the shaft itself, stress concentration is severe and fatigue damage occurs at the point where the shaft diameter is changed;
2.5 The heat treatment quality of the input shaft is not qualified;
2.6 Improper material selection for input shaft.
3 Methods and techniques to avoid and reduce shaft breakage in gearboxes
3.1 Revise the plan for the gearbox;
3.2 During equipment and repair, pay attention to adjusting the concentricity of the motor and reducer to meet the customary requirements;
When using a parallel axis reducer, it is best not to use a vertical axis reducer;
3.4 When selecting a reducer, consider or calculate the radial load that the reducer can withstand;
3.5 When selecting the motor speed, it is advisable to choose a six pole motor as much as possible. A motor with a synchronous speed of 1000 revolutions per minute should be used as the driving motor to reduce the vibration of the coupling and brake wheel during high-speed rotation. Especially for belt conveyors with higher power, such as those with a power greater than 90 kW, it is best to choose a low-speed motor. At this time, the motor price will be correspondingly higher than that of a four pole motor;
3.6 Try to reduce or control the magnitude of the unbalanced torque between the hydraulic coupling and the brake wheel.
The above methods can basically identify or address the issue of broken input shafts in the drive reducer of the belt conveyor. Necessary spare parts for reducers should be properly equipped in the belt conveyor system for repeated operations, in order to replace them in a timely manner to avoid affecting normal production.
Article from: Foshan assembly line http://m.e-testing.net.cn/ Introduction to the treatment method for shaft breakage of belt conveyor drive reducer
The drive reducer of the belt conveyor often encounters situations where the input shaft of some drive reducers breaks, which has a certain impact on the production of users. When the shaft is broken, only the input shaft is usually broken, and the output shaft is rarely broken. In severe cases, continuous input shaft breakage may occur on several belt conveyors. This situation may occur when all the gearboxes that experienced shaft breakage are from the same belt conveyor supplier. When the axle is broken, the stubble at the crack on the rear axle is usually flush, and the cross-section is usually perpendicular to the length direction of the axle. Shaft breakage occurs on both belt conveyors on mobile machinery and ground belt conveyors.
The primary external factors causing a broken shaft should include the following aspects:
1.1 The bearing capacity of the selected belt conveyor reducer is not sufficient. The drive reducer of the belt conveyor is selected too small. When the practical application power of the reducer exceeds the bearing capacity of the reducer, the drive reducer of the belt conveyor will break within a certain period of time;
1.2 Hydraulic couplings and brake wheels are usually installed between the motor shaft and the reducer shaft. When the dynamic balance between the brake wheels and the hydraulic couplings is poor and severe, it can cause significant vibration during the operation of the belt conveyor. When the vibration load reaches a certain level, it causes excessive stress on the output shaft of the gearbox and cracks;
The concentricity error of the equipment is too large. Assuming that the concentricity between the reducer and motor shaft should be carefully adjusted when using the hydraulic coupling and brake wheel between the equipment motor and reducer, even if the difference is too large, the coupling and brake wheel may vibrate excessively during operation, resulting in shaft breakage.
1.4 Defects in the gearbox plan caused the input shaft to break. This situation occurs when selecting a gearbox based solely on the request of the gearbox supplier to plan the belt conveyor. Although the selected gearbox meets the requirements of the gearbox supplier, the phenomenon of shaft breakage still occurred.
The internal elements of a broken shaft in a reducer mainly include the following aspects:
2.1 Excessive stress at the cracked shaft during gearbox planning;
2.2 Failure to fully consider the curvature radius of the transition fillet and modify the curve at the shoulder of the input shaft of the reducer resulted in severe stress convergence and fatigue damage;
2.3 The reducer adopts a vertical axis method, and the top input shaft is the umbrella gear shaft. Severe stress convergence occurs at the transition shoulder of the umbrella gear support bearing, leading to fatigue damage;
2.4 The reducer is a hard tooth surface reducer, and the input shaft diameter of the reducer is relatively thin. Although the strength is calculated, due to the thinness of the shaft itself, stress concentration is severe and fatigue damage occurs at the point where the shaft diameter is changed;
2.5 The heat treatment quality of the input shaft is not qualified;
2.6 Improper material selection for input shaft.
3 Methods and techniques to avoid and reduce shaft breakage in gearboxes
3.1 Revise the plan for the gearbox;
3.2 During equipment and repair, pay attention to adjusting the concentricity of the motor and reducer to meet the customary requirements;
When using a parallel axis reducer, it is best not to use a vertical axis reducer;
3.4 When selecting a reducer, consider or calculate the radial load that the reducer can withstand;
3.5 When selecting the motor speed, it is advisable to choose a six pole motor as much as possible. A motor with a synchronous speed of 1000 revolutions per minute should be used as the driving motor to reduce the vibration of the coupling and brake wheel during high-speed rotation. Especially for belt conveyors with higher power, such as those with a power greater than 90 kW, it is best to choose a low-speed motor. At this time, the motor price will be correspondingly higher than that of a four pole motor;
3.6 Try to reduce or control the magnitude of the unbalanced torque between the hydraulic coupling and the brake wheel.
The above methods can basically identify or address the issue of broken input shafts in the drive reducer of the belt conveyor. Necessary spare parts for reducers should be properly equipped in the belt conveyor system for repeated operations, in order to replace them in a timely manner to avoid affecting normal production.
Article from: Foshan assembly line
http://m.e-testing.net.cn/