Understand the fundamentals, formulas, and applications for precise drive design.
How do I calculate the fundamental torque of a motor?
The fundamental torque (M) is the product of the force (F) acting on a lever and the length of the lever arm (r), so M = r x F. However, for electric motors, the calculation based on power and speed is more relevant in practice.
Which formula is crucial for calculating motor torque from power and speed?
The central formula for calculating motor torque (M) in Newton-meters (Nm) from power (P) in kilowatts (kW) and speed (n) in revolutions per minute (RPM) is: M [Nm] = (P [kW] * 9550) / n [RPM].
Why is the factor 9550 so important in the torque formula?
The factor 9550 is a conversion factor, which harmonizes the different units of power (kW), speed (RPM), and the resulting torque (Nm). Ignoring it can lead to significant miscalculations of 10-15% .
How does a gear box affect torque and what role do losses play?
A gear box increases the torque according to its ratio (e.g. 10:1 ratio = 10 times torque). However, gear losses, often between 5% and 15% per stage, reduce the effective torque available at the output. These losses must be considered for accurate design.
What difference does the motor type make for the torque, e.g. at startup?
Different motor types exhibit strongly varying torque-speed characteristics. A wound rotor motor, for instance, can provide 2.5 times the rated torque at startup , while a standard asynchronous motor often only reaches 1.5 times. The selection must fit the specific requirements of the application.
What are the advantages of direct drives (torque motors) regarding torque and efficiency?
Direct drives, also known as torque motors, transmit torque without an intermediate gear box.This prevents gear losses, resulting in higher system efficiencies of over 90% . They often provide very high torque in a compact design.
My motor is not delivering the expected torque – what are common causes?
Common causes include a insufficient power supply (a voltage drop of 10% can reduce the torque by almost 20%), winding errors in the motor, or unexpectedly high mechanical loads or increased friction in the system.
How can ATEK Drive Solutions assist in selecting the right motor and calculating torque?
ATEK Drive Solutions offers as a system provider for the complete industrial drive train comprehensive consulting. With decades of experience and a modular system, we help you find the optimal combination of motor, gear box, and brake for your specific torque requirements and calculate them precisely.
Die precise calculation of motor torque with the formula M [Nm] = (P [kW] * 9550) / n [RPM] is fundamental to avoid miscalculations of 10-15% and ensure the optimal drive performance. Gear losses, often
Getriebeverluste, oft 5-15% per stage, reduce the effective torque, while direct drives can achieve system efficiencies of over 90% and thus reduce energy costs .
The selection of the right motor type and consideration of all system factors are crucial; ATEK’s system competence for the entire drive train can enhance the overall system efficiency by 5-10% und minimize interface risks..Discover the key formulas, practical applications, and expert tips for calculating the ideal torque for your motor. Avoid costly missteps and optimize your drive systems!
The correct calculation of torque is critical for selecting the right motor. This article provides you with a comprehensive guide. Do you need personalized consulting? Contact us now Contact with our experts!
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Basics of torque: What you need to know
The correct determination of motor torque is an important factor in selecting the optimal drive for your application. An inaccurate torque calculation can lead to inefficiency or system failures. This article explains how to calculate motor torque accurately and thus choose a suitable drive solution to optimize your drive design.
What is torque and the associated basic formula?
Torque, also known as moment of force, describes the rotational effect of a force (F) on a body around a pivot point multiplied by the lever arm (r). The basic formula is M = r x F. Here, the perpendicular distance of the lever to the force direction is particularly relevant: A small inaccuracy in determining this can affect the entire calculation, for example by 10% in the design of robotic arms.
How is torque actually generated in electric motors?
In electric motors, like our efficient gear motors, torque results from the interaction of magnetic fields. Lorentz forces act on current-carrying conductors between the stator and rotor. The amount of this torque, for example 50 Nm in a compact servo motor, is a crucial factor for the motor’s performance and efficiency.Formulas for torque calculation: How to calculate correctly
The central formula: Torque from power and speed
The required drive torque can be determined from the motor power (P) in kilowatts and the speed (n) in RPM. The commonly used formula to calculate the motor torqueis: M [Nm] = (P [kW] * 9550) / n [RPM]. The factor 9550 is an important conversion factor for harmonizing units; ignoring it can lead to miscalculations of 10-15%.
- The central formula for calculating torque is: M [Nm] = (P [kW] * 9550) / n [RPM].
- The factor 9550 serves to harmonize the units and is critical for accuracy.
- Ignoring the factor 9550 can lead to miscalculations of 10-15%.
- The gear ratio increases the torque, but only theoretically.
- Gear losses, often between 5% and 15% per stage, reduce the effective output torque.
- Accurate consideration of losses is essential for the proper design of drive systems. Gear ratios and losses should not be forgotten!
Getriebeübersetzung und Verluste nicht vergessen!
A motor with 10 Nm torque and a gear box with a 10:1 ratio theoretically delivers 100 Nm. In practice, however, gear losses, which often range from 5% to 15% per stage, reduce the actual output torque. When selecting, drive systems. this precise consideration is required. A careful assessment of losses is necessary for the accurate determination of motor torque.Decisive influencing factors on motor torque
motor type and the characteristic torque-speed curve
For applications such as conveyor belts that require high starting torque, the choice of motor type is significant. Different motor types, such as squirrel cage or wound rotor, have significantly differing torque-speed curves. For example, a wound rotor can offer 2.5 times the rated torque at startup, whereas a standard asynchronous motor often only reaches 1.5 times. The suitable motor speed also plays a role.
Friction, efficiency, and the often underestimated advantage of direct drives
In complex systems with multiple gear stages, up to 20% of the generated drive torque can be lost due to friction in the drive train. Direct drives, also known as torque motors, avoid gear losses and can thereby achieve system efficiencies of over 90%, leading to a significant reduction in energy costs.Torque in practice: Correct selection and troubleshooting
Application examples and critical criteria for motor selection
The torque requirements vary greatly depending on the application, whether it is a CNC machine with a precision requirement of 0.01 mm or a drive in material handling. Besides the torque value, speed range, duty cycle (e.g. S1 continuous operation), and environmental conditions are important selection criteria. Oversizing the motor by 20% can already lead to unnecessarily increased procurement and operating costs.
- Application-specific torque requirements must be determined precisely (e.g. for CNC machines or material handling).
- Important selection criteria besides torque are speed range, duty cycle (e.g. S1 continuous operation), and environmental conditions.
- Oversizing the motor, for example by 20%, can lead to unnecessarily increased procurement and operating costs.
- In case of torque issues, the power supply of the motor should be checked first.
- A voltage drop of just 10% can reduce the torque of an asynchronous motor by almost 20%.
- Other possible causes for insufficient torque are winding errors or unexpectedly high mechanical loads.
- A detailed analysis of the causes is essential for troubleshooting.
Dealing with torque issues: Causes and solutions
If a motor does not deliver the expected torque, for example 75 Nm, the power supply should first be checked before assuming a defect. A voltage drop of 10% can nearly decrease the torque of an asynchronous motor by 20%. This underscores how important it is to calculate the motor’s torque correctly and consider all influencing factors. Possible further causes are winding errors or increased mechanical loads, which necessitate a thorough analysis.ATEK Drive Solutions: Your partner for optimal drive systems
System competence for the entire industrial drive train
ATEK Drive Solutions GmbH offers gear boxes, brakes, and motors as matched system solutions from a single source. This system competence can contribute to optimal performance and minimize interface risks, often enabling an efficiency improvement of 5-10% in the overall system.
Modular diversity and customer-specific precision for your application.
For applications that require a specific drive torque of 123 Nm at an exact speed of 47 rpm, our modular system offers a variety of configurations and enables quick delivery times. In special cases, such as in medical technology, customized special solutions are developed that focus on precision and a balanced price-performance ratio.
A careful calculation of the motor torque is fundamental for efficient and reliable drive solutions. Understanding how to calculate the torque for a motor while considering all influencing factors and system losses is crucial. With the appropriate expertise and an experienced partner, the right choice can be made. ATEK Drive Solutions GmbH is available for tailored advice on your drive optimization.
