Technical requirements for plum blossom couplings and precautions for hot mounting

Published: 2018-08-03

Plum couplingIt is a widely used coupling, also called elastic claw coupling, which is composed of two metal claw discs and an elastic body.The two metal claws are generally made of 45 gauge steel, but aluminum alloys are also useful when load sensitivity is required.The elastomer is made of high-elastic polyurethane material, which has the function of cushioning and shock absorption.The life of the coupling is also the life of the elastic.Since elasticity is under compression, it is obviously under tension.The life of the general elastomer is 10 years.Because elasticity has the function of buffering and damping vibration, it is used more in situations with strong vibration.The performance temperature of the elastomer determines the operating temperature of the coupling, which is generally -35 to +80 degrees.Commonly used plum blossom couplings are divided into two types, one is a clamped fixed plum blossom coupling, mostly made of aluminum alloy, and the other is a keyed plum blossom coupling, which is mostly made of 45 steel.According to the type of elastomer, it can be divided into star-shaped elastic coupling and plum blossom-type elastic coupling.

The plum blossom coupling belongs to the category of general machinery parts. It is composed of four parts: the driving end, the driven end, the damping pad and the top wire. Its accessories include gears and sleeve connections (there is a common gear sleeve for bilateral gears) , Rubber ring bolt hole connection (single-sided perforation and double-sided cross perforation), plum blossom pad butt connection, nylon rod hole connection, and gears directly drive the machine.The matching hole of the half coupling and the shaft can be made circular.It can be used to connect two mechanical parts in different mechanisms (the driving shaft and the driven shaft) so that they can rotate together to transmit torque.

When assembling the quincunx coupling, clamp the petal part of the quincunx-shaped elastic member on the end face of the two halves of the coupling. The convex teeth are staggered and inserted into the tooth side space formed by the high-speed and heavy-duty power transmission in order to work in the coupling It plays a role of buffering and damping vibration.Strict coaxiality of the two axes, so that no unilateral load is generated during operation, so as to maintain balance and reduce vibration. The requirements for concentricity of different types of installation are 0.2.Under normal circumstances, it is just fine to loosely match and then tighten the screws. You can also choose a plum coupling with a keyway!It is also keyed to the motor, screw, or other shaft end, even if you don't tighten the screw, it will not loosen.

The plum blossom coupling has many structural forms, a wide range of applications, and a variety of material choices.It is one of the most frequently selected models in flexible couplings.Commonly used materials for plum couplings are gray iron, cast steel and aluminum alloy.The plum blossom coupling is simple in structure, does not require lubrication, is convenient for maintenance, easy for inspection, maintenance-free, and can run continuously for a long time.Polyurethane elastic elements are resistant to oil, have large carrying capacity, and have a long service life.Work stably, with good vibration damping, buffering and electrical insulation properties.It has large axial, radial and angular compensation capabilities.The structure is simple, the radial dimension is small, the weight is light, and the moment of inertia is small, suitable for medium and high speed occasions.

Plum blossom flexible coupling has the following characteristics:

1. The operation is stable and reliable, with excellent vibration damping, buffering and electrical insulation functions.

2. The design is simple, the radial dimension is small, the weight is light, the migration and transformation inertia is small, and it is suitable for medium and high speed working conditions.

3. It has a large axial, radial and angular compensation force.

4. Polyurethane elastic parts are resistant to oil, with strong load-bearing strength, long service time and reliable insurance.

5. The coupling does not need to be smooth, the maintenance operation is small, and it can continue to run all the time.

Technical requirements of plum coupling:

1. The amount of operating compensation refers to the two-axis phase offset formed by comprehensive factors such as manufacturing errors, installation errors, and changes in working load caused by vibration, shock, and temperature changes in the working state.

2. The surface of half coupling, flange coupling, flange half coupling, brake wheel, brake wheel half coupling is not allowed to have cracks, shrinkage holes, air bubbles, slag inclusion and other defects that affect strength. The surface of the brake wheel should be quenched, the hardness is 45~55HRC, and the hardened layer is greater than 3mm.

3. The shape of the elastic part should be smooth and flat, and the working surface should not have pitting, and there should be no defects such as impurities, bubbles, cracks, etc. inside.

4. The shaft hole tolerance of the semi-coupling is in accordance with the provisions of GB/T3852-1997, and the surface roughness Ra value of the shaft hole is not less than 1.6um.

5. Before the coupling leaves the factory, carry out trial assembly. The relative trial assembly position between the half coupling and the elastic part shall be no less than two positions, which should be convenient for assembly and disassembly.

6. The coupling used under high-speed working conditions should undergo a balance test with the main shaft system.

7. The coupling should be cleaned before packaging, and the coupling surface should be coated with anti-rust agent, and the non-coupling surface should be coated with paint or other anti-rust treatment.

Precautions for hot mounting plum coupling:

1. Before heating, check whether the plum blossom coupling is paired with another coupling, especially if several units of the same unit are installed, find out the pair number or mark.

2. There should be no defects such as burrs and scratches on the mating surface of the plum coupling.

3. Always record the temperature rise and current value, and the temperature rise should not exceed 30°C per hour.

4. After the temperature rises to 100°C, the inspectors should pay attention to it.

5. When measuring the aperture value with the sample rod, power off the operation.

6. Fire fighting equipment should be provided in the heating area.

7. After the plum blossom coupling is hot-mounted on the shaft, use cold water to pour the journal to cool it to prevent the heat from spreading to the armature and affecting the insulation.