What damage can high operating temperature cause to the peripheral components of QJR-D400-20-2C reducer
QJR-D400-20-2C belongs to heavy-duty gear reducers, and its peripheral components include mechanical parts such as bearings, seals, couplings, as well as supporting motors, lubrication and cooling systems. Excessive operating temperature can cause multiple chain damages to these components, as follows:
1. Mechanical connections and supporting components
Bearing failure: The bearings of this reducer are mostly suitable for heavy load conditions, and the normal working temperature of commonly used bearing steel materials should be below 120 ℃. High temperature will accelerate the oxidation and hardening of lubricating grease inside the bearing, causing dry friction between the ball and the raceway after the oil film ruptures; At the same time, the bearing steel will undergo annealing, resulting in a significant decrease in hardness, which can lead to indentation, wear, or fatigue peeling of the raceway. In severe cases, the bearing may get stuck, and it may also drive the shaft system to move, affecting the overall transmission stability.
Coupling failure: High temperatures can cause thermal expansion of the gearbox housing, damaging the original alignment accuracy of the coupling. Moreover, the elastic components of the coupling, such as rubber pads, may weaken or even break due to high temperature aging and hardening, making it unable to cushion vibrations during transmission; If it is a metal diaphragm coupling, high temperature will also reduce the toughness of the diaphragm, which may cause cracks. In extreme cases, the coupling bolts may become loose or even break due to heat, resulting in power transmission interruption.
Loose and deformed box body and fasteners: The box body is mostly made of gray cast iron material, and high temperature can release internal stress, causing the joint surface to warp and deform, and the sealing performance to decrease. At the same time, the pre tightening force of bolts and other fasteners on the box will significantly decrease under high temperature. For every 100 ℃ increase in temperature, the pre tightening force of common bolts such as M10 may decrease by 15%. Long term high temperature will cause bolts to loosen, further exacerbating the problem of box leakage.
2. Sealing and lubrication related components
Aging and damage of seals: The skeleton oil seals at the input shaft and output shaft of the reducer are mostly made of rubber material, and their temperature resistance is usually between -40-120 ℃. High temperature can cause rubber seals to quickly harden, crack, lose elasticity, and wear the sealing lip edge, leading to lubricant leakage. And the leakage of lubricating oil will further exacerbate the insufficient lubrication of worm gears and bearings, forming a vicious cycle.
Deterioration of lubrication system performance: High temperature will accelerate the oxidation of gear oil, and the oxidation rate will increase by about twice for every 10 ℃ increase in oil temperature. Oxidized lubricating oil will generate acidic substances, sludge, and paint film, which will block the oil passage, not only preventing the lubrication system from supplying oil normally, but also corroding the surfaces of gears and bearings; At the same time, the viscosity of the oil will significantly decrease, and the thickness of the oil film will be insufficient to meet the lubrication load requirements under heavy load conditions.
3. Supporting electrical and heat dissipation components
Damaged supporting motor: The insulation system of the motor connected to the reducer is prone to collapse in high temperature environments. The insulation layer of motor enameled wire may crack due to high temperature carbonization, which may cause inter turn short circuit, surge current and burn out the coil; If it is a permanent magnet motor, high temperature may also cause demagnetization of the permanent magnet, resulting in a decrease in motor output torque and inability to provide stable power to the gearbox.
