The number of turns and winding density of the reducer motor coil are key factors that indirectly affect the torque output characteristics by influencing the electromagnetic energy conversion efficiency and magnetic circuit characteristics within the motor. Together, they determine the magnitude, stability, and compatibility of the motor's electromagnetic torque with the reduction mechanism. Based on the principle of electromagnetic induction, motor torque is essentially the torque generated by the electromagnetic force exerted on the reducer motor coil in the magnetic field when current is applied, driving the rotor to rotate. The strength of this torque is closely related to the number of turns and winding density of the reducer motor coil.
The impact of the number of turns of the reducer motor coil on torque output is primarily reflected in the regulation of magnetic flux. More turns in the reducer motor coil means more conductors cutting the magnetic field within the stator core slots. When current flows through the reducer motor coil, the small electromagnetic forces generated by each turn of the reducer motor coil add up to form a stronger total electromagnetic force, which in turn drives the rotor to generate a greater initial electromagnetic torque. However, this relationship isn't a simple linear progression, as increasing the number of turns simultaneously changes the reducer motor coil's resistance and back-EMF characteristics. Increasing the number of turns increases the total resistance of the reducer motor coil, which in turn reduces the loop current at the same supply voltage. If the current reduction exceeds the electromagnetic force effect caused by the increased number of turns, the electromagnetic torque may actually decrease rather than increase. Furthermore, the back-EMF increases with the number of turns, partially offsetting the supply voltage and further limiting the current increase. This requires careful consideration of the reduction ratio of the geared motor. If the motor's initial electromagnetic torque changes due to the adjustment of the number of turns, the final torque output to the load will also change after being amplified by the reduction mechanism. For example, the initial torque increase caused by an increase in the number of turns will translate into greater load torque at the same reduction ratio, while the reverse will result in a decrease in load torque.
The winding density primarily influences the stability and efficiency of torque output by optimizing the magnetic circuit structure. Winding density refers to how tightly the reducer motor coils are packed within the stator core slots. A higher density means more regular arrangement of the reducer motor coil conductors within the slots, and smaller air gaps between conductors and between the conductors and the core. The air gap is a region of high reluctance in the magnetic circuit. A smaller air gap reduces the overall reluctance of the magnetic circuit, minimizes magnetic field energy loss, and results in a more uniform magnetic flux distribution within the core. This uniform magnetic flux ensures a constant electromagnetic force on the reducer motor coils during rotor rotation, preventing periodic fluctuations in electromagnetic torque caused by magnetic flux fluctuations. This results in more stable torque output from the geared motor and reduced vibration and noise during operation. Conversely, if the winding density is too low, the air gaps within the slots increase, and the magnetic flux attenuates due to increased reluctance. This not only reduces the peak electromagnetic torque but also increases torque fluctuations. Especially under low-speed and heavy-load conditions, these fluctuations manifest as fluctuating torque at the load end, affecting the operating accuracy of the equipment.
Also, winding density indirectly affects torque stability by affecting heat dissipation. When the winding density is too high, the heat dissipation space between the reducer motor coil conductors is compressed. If the motor operates at high load for a long time, the heat generated by the reducer motor coil cannot be dissipated quickly. The increased temperature further increases the reducer motor coil resistance, resulting in a decrease in current and, consequently, a reduction in electromagnetic torque. While a low winding density allows for more heat dissipation space, the reduced magnetic circuit efficiency leads to lower motor energy efficiency. This reduces the ability to generate sufficient electromagnetic torque for the same input power, also impacting torque output. Therefore, winding density design requires a balance between magnetic circuit optimization and heat dissipation requirements to ensure that the motor maintains stable magnetic flux during long-term operation while avoiding torque degradation caused by overheating.
In practical applications, the balance between the number of turns in the reducer motor coil and the winding density is particularly critical. For example, when designing a high-torque reduction motor, the number of turns in the reducer motor coil is typically increased to boost initial electromagnetic torque, while the winding density is increased to reduce magnetic flux loss, ensuring that the increased number of turns effectively translates into increased torque. However, for high-speed, light-load applications, excessive turns can limit speed due to excessive back-EMF. In these cases, the number of turns should be reduced, and a reasonable winding density should be used to ensure magnetic circuit efficiency and avoid excessive torque degradation. Furthermore, the uniformity of the winding density can affect torque characteristics. If the reducer motor coils are partially loose or overlapped during winding, the magnetic flux of the stator reducer motor coils will be inconsistent across phases, causing uneven force on the rotor and generating additional torque. This additional torque can partially offset the effective torque, reducing actual output torque, increasing motor wear, and shortening motor life.
The number of turns in the reducer motor coil determines the baseline level of electromagnetic torque by regulating the electromagnetic force superposition effect and electrical parameters. The winding density ensures electromagnetic torque stability and conversion efficiency by optimizing the magnetic circuit and heat dissipation. The reasonable matching of the two is the core design link to ensure that the reduction motor can output the required torque under different working conditions and take into account both power and reliability.
