German INA coupling INA model INA price

INA coupling slider is ring-shaped, made of steel or wear-resistant alloy. Oldham couplings are suitable for transmissions with lower speeds and higher torque transmission. Slider couplings consist of two hubs and a center slider. The center slider, as a torque-transmitting element, is usually made of engineering plastics; in special cases, other materials such as metals can be selected.

INA coupling introduction

Consists of two hubs and a thin-walled metal tube, connected by welding or bonding. Although many other materials are available, stainless steel and nickel are the most commonly used metal tube materials. Nickel tubes are produced by electrodepositing. This method first involves machining a solid mandrel into a corrugated shape, electroplating nickel onto the mandrel, and then chemically dissolving the mandrel to obtain the nickel bellows. This method controls the precision of the bellows wall thickness and achieves thinner walls than other manufacturing methods. These thin-walled bellows give the coupling high sensitivity and rapid response, making it ideal for applications in extremely small and precise instruments.

INA coupling features and applications

1) Bellows couplings are backlash-free and highly sensitive. 2) High elasticity provides better equipment protection. 3) Capable of absorbing vibration and compensating for radial, angular, and axial misalignments. 4) Oil-resistant and highly corrosion-resistant. 5) Torsionally rigid, with identical clockwise and counterclockwise rotation characteristics. 6) Commonly used in industrial machinery such as CNC machine tools and indexing tables. The elastic element of bellows couplings is a precision metal bellows, available in flexible and rigid series. The flexible series offers greater elasticity and is often used in micro-applications such as encoders and sensors, while the rigid series is mainly applied in servo motors and CNC machine tools (machining centers).

INA coupling troubleshooting

From the coupling structure, it is known that the coupling transmits power to the power output shaft (gearbox shaft) via a clamping hub interference fit, and to the power input shaft via a clamping collar. Power is transmitted between the clamping end and the interference fit end of the coupling through the bellows, which are bonded to the interference fit end and the clamping collar. The fault location is at the clamping collar and the bellows. Two pre-deformation slots are machined radially into the clamping collar, with a slot width of approximately 2mm. On the side with the clamping screw, the slot is through in the diametrical direction but not fully open in the depth direction at the connection with the bellows, featuring a beveled cross-section; the other slot is not open radially, but its longitudinal section at the connection with the bellows is also not fully open, featuring a beveled cross-section. During clamping, the clamping screws are tightened to the specified value using a torque wrench, eliminating the clearance between the bore and the shaft through the deformation of the clamping collar to achieve clamping. As seen from the cross-sectional view, due to the presence of the two pre-deformation slots, the cross-section at this location is weaker, and deformation primarily occurs at these slots. The cross-sectional area of the pre-deformation slot on the side with the clamping screw is the smallest, making it the weakest point. Permanent figure-eight deformation marks at its end indicate that the stress in this area during clamping is significant, exceeding the yield limit of super-hard aluminum. According to the stress distribution diagram, once the bevel gear box and main gearbox are assembled and clamped, the stress value at the bonded interface of the pre-deformation slot on the clamping screw side is 164Mpa, with a deformation magnitude of 0.027mm. During launcher operation, the coupling is subjected to alternating composite stresses, causing even greater stress and deformation at this location. If minor defects such as voids, inclusions, or flaws exist at the bonded interface during manufacturing, micro-cracks will first form at the defective areas within the region of highest stress on the coupling's bonded surface when the alternating stress exceeds the bond strength, creating a fatigue source. Due to stress concentration at the crack tip, the crack gradually propagates with increasing stress cycles and prolonged exposure to constant stress. As the crack spreads, the bonded interface is progressively weakened, leading to fatigue failure when the crack reaches a certain size. The coupling functioned normally during initial testing, but as usage time increased, the cracks gradually propagated, causing failure even under low loads. The presence of stress at the bonded joint is a potential hidden cause of failure. To avoid high stress generation in the clamping collar during clamping, annular grooves are generally cut into the clamping collar for stress relief.

Weidou Intelligent Technology specializes in selling German INA rigid couplings, INA flexible couplings, INA safety couplings, INA universal joints, INA diaphragm couplings, INA jaw couplings, INA flange couplings, INA Oldham couplings, INA slider couplings, INA gear couplings, INA tire couplings, INA elastic couplings, INA bellows couplings, INA roller chain couplings, INA spring couplings, INA original imports from Germany. Customers are welcome to inquire and order.