The Necessity of Choosing and Improving the Claw Couplings for Pumps

Claw couplings for claw pumps are commonly used drive shafts in industrial pumps. Some adjustments may be required due to different working environments.Now we will give a comprehensive explanation on the necessity of selecting and improving the claw couplings for pumps.

Essentials and connection for selecting claw couplings for pumps

　　Essentials for selecting claw couplings for pumps:
①Permissible rated torque-is the allowable value of the torque that the claw coupling for pumps can withstand during actual use.
② Allowable torque-is the critical value for damage to the claw coupling for pump.
③Allowable speed-It is necessary to make sure that the speed of the motor is within this range when selecting the model.
④ Allowable eccentricity-the allowable value of the parallel deviation of the axis of the two shafts.
⑤ Allowable deflection angle-allowable value of mutual angle formed between two shafts.
⑥ Allowable axial deviation-the allowable value of the displacement of the two axes in the axial direction.
When starting, stopping, and switching between forward and reverse rotations, the motor will apply a load greater than the motor torque to the pump claw coupling. Therefore, when choosing a pump claw coupling, you should use the pump claw coupling The rated torque is greater than the torque of the motor.
Claw couplings for pumps are mechanical parts used to connect two shafts (driving shaft and driven shaft) in different mechanisms so that they can rotate together to transmit torque.In high-speed and heavy-duty power transmission, some claw couplings for pumps also have the functions of buffering, damping and improving the dynamic performance of the shafting.The claw coupling for pump is composed of two halves, which are respectively connected with the driving shaft and the driven shaft.Generally, the power machine is mostly connected with the working machine by means of a pump claw coupling.Therefore, sometimes in the process of installing the claw coupling for the pump, we must pay attention to the deviation in the process of connecting the shaft to the shaft.The claw coupling for pump is composed of two halves, which are respectively connected with the driving shaft and the driven shaft.Generally, the power machine is mostly connected with the working machine by means of a pump claw coupling.Therefore, sometimes in the process of installing the claw coupling for pump, we must pay attention to the deviation in the process of connecting the shaft to the shaft. It has a beautiful surface and good corrosion resistance. It does not need to go through surface treatment such as coloring, and exerts its inherent characteristics. Surface properties, a kind of steel used in many aspects, usually called stainless steel.High-alloy steels such as 13 chromium steel and 18-chromium nickel steel are representative of performance.From a metallographic point of view, because stainless steel contains chromium, a very thin chromium film is formed on the surface. This film isolates the oxygen from the intrusion of the steel and acts as a corrosion resistance.
In order to implement the basics of pump claw couplings, the universal standard claw couplings for chain pumps use a common chain to mesh with two parallel sprockets with the same number of teeth at the same time. Different structure types of chain pumps use claw couplings. The main difference is the use of different chains. Commonly used are claw couplings for double-row roller chain pumps, claw couplings for single-row roller chain pumps, claw couplings for toothed chain pumps, and nylon chain pumps. Use claw couplings, etc.The claw coupling for chain pump has a simple structure (composed of four pieces), convenient assembly and disassembly, no need to move the connected two shafts during disassembly, compact size, light weight, certain compensation capability, and low requirements for installation accuracy. Reliable work, long life, low cost, etc., are widely used in various important structural parts in quenching and tempering treatment, especially those connecting rods, bolts, gears and shafts that work under alternating loads.The rectangular spline is characterized by high centering accuracy and good centering stability.The taper hole is easy to install and disassemble relative to the ordinary shaft. The key link is safe and reliable. The claw coupling for pumps is a machine used to connect two shafts (driving shaft and driven shaft) in different mechanisms so that they can rotate together to transmit torque. Components.In high-speed and heavy-duty power transmission, some claw couplings for pumps also have the functions of buffering, damping and improving the dynamic performance of the shafting.
 

 

Improvement of claw coupling for pump

The expanded crystallization tank is the main machine for the production of expanded ammonium nitrate explosives. The ammonium nitrate is vacuum expanded in the dryer to form tiny pores and improve the sensitivity of ammonium nitrate, so that it can be directly detonated with a No. XNUMX detonator.

　　The expanded crystallization tank is the main machine for the production of expanded ammonium nitrate explosives. The ammonium nitrate is vacuum expanded in the dryer to form tiny pores and improve the sensitivity of ammonium nitrate, so that it can be directly detonated with a No. XNUMX detonator.
　　 1. Raising the problem
　　 When the ammonium nitrate is expanded and discharged in the expansion tank, the expansion tank is frequently positioned and started, forward rotation starts, forward rotation stops, and reverse rotation. At the moment of starting and stopping, the load of the machine is quite large, causing a huge impact Therefore, when the cycloidal pin gear reducer is screwed with the discharge hopper, a claw coupling for a pump is used to achieve the purpose of buffering and shock absorption.
　　 The expansion tank was put into production in October 1999, and by April 10, the claw coupling for the pump was scrapped due to severe fracture.Since the cooperation of the pump claw coupling with its shaft is an interference fit, it takes a lot of time, manpower and material resources during disassembly and assembly, delays the work plan, and affects the output.
　　 Observing the scrapped pump claw coupling, it is found that there are obvious cracks at the root of the unbroken claw, and the broken part of the broken claw is consistent with the location of the crack.Although it is cushioned by an elastic block, the back of the claw still breaks along these cracks.
　　 2. Failure reasons and technical improvement measures
　　 2.1 Causes of failure (1) The surface roughness of the claw-type coupling for the pump after being scrapped is too high
　　 (2) There is still a gap between the two halves of the claw couplings A and B for pumps after they are matched with the elastic block, causing reverse idle stroke and increasing impact.
　　 (3) The scrapped claw coupling for pumps uses ZG45 steel, which is sensitive to stress concentration.The higher the strength, the greater the stress concentration sensitivity and the lower the vibration damping.
　　 (4) The arc transition value between the claw and the root of the claw coupling for pumps is very small, almost close to a sharp angle of 90 degrees. This type of transition is prone to stress concentration and significantly reduces the stress. Under the action of impact, it is easy to Fatigue cracks are produced.
　　 2.2 Technical improvement measures
　　 (1) Reduce the surface roughness of the bonding surface.The pump claw coupling produces fatigue cracks under frequent positive and negative working conditions. The smaller the surface roughness value, the smaller the surface defect and the better the fatigue resistance. Change the surface roughness value to Ra3.2
　　 (2) Strictly control the clearance between the two halves of A and B and the elastic block to be less than 0.3mm to avoid the impact caused by the reverse stroke.
　　 (3) QT60-2 is used for parts material instead of cast steel ZG45.Nodular cast iron has low stress concentration sensitivity and good pin vibration performance, only slightly lower than gray cast iron. Its mechanical properties (strength, elasticity, plasticity) are slightly inferior to cast steel, and its wear resistance is good;
　　 (4) Increase the transition fillet at the root of the claw. When the structure permits, increasing the transition fillet is one of the important ways to reduce stress concentration. Change the 90 ° sharp angle to R10 arc transition.
　　 3 Conclusion
　　 Practice has proved that the improved claw coupling for pumps has been operating normally since it was installed in May 2001 and was scrapped at the end of 5.In three and a half years, the output of the workshop was nearly three times that of the previous year and a half of the improvement.The outsourcing processing cost of each pair of claw couplings for pumps saves nearly 2004 yuan compared with purchasing the original products. At the same time, it reduces the number of maintenance and ensures the normal production of the unit.
 

The above introduces the necessity of the selection and improvement of the claw couplings for pumps. I hope it will be helpful to everyone. Our website also organizes more relevant information. If you want to know more, please remember to collect it.