Load On Screw Given Torque Required In Lowering Load With Trapezoidal Threaded Screw Calculator

Formula Used:

\[ W = \frac{Mt_{lo}}{0.5 \times d_m \times \frac{(\mu \times \sec(0.2618) - \tan(\alpha))}{(1 + (\mu \times \sec(0.2618) \times \tan(\alpha)))}} \]

Torque For Lowering Load (Mt_lo):

N·m

Mean Diameter Of Power Screw (d_m):

Coefficient Of Friction At Screw Thread (μ):

Helix Angle Of Screw (α):

rad

Load On Screw (W):

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1. What Is The Load On Screw Given Torque Required In Lowering Load With Trapezoidal Threaded Screw Formula?

The formula calculates the load on a trapezoidal threaded screw based on the torque required to lower the load, taking into account the screw's geometry and friction characteristics. It's essential for mechanical engineering applications involving power screws.

2. How Does The Calculator Work?

The calculator uses the formula:

\[ W = \frac{Mt_{lo}}{0.5 \times d_m \times \frac{(\mu \times \sec(0.2618) - \tan(\alpha))}{(1 + (\mu \times \sec(0.2618) \times \tan(\alpha)))}} \]

Where:

\( W \) — Load on screw (N)
\( Mt_{lo} \) — Torque for lowering load (N·m)
\( d_m \) — Mean diameter of power screw (m)
\( \mu \) — Coefficient of friction at screw thread
\( \alpha \) — Helix angle of screw (rad)
\( \sec(0.2618) \) — Secant of 15° (0.2618 rad)

Explanation: The formula accounts for the mechanical advantage and friction in trapezoidal threaded screws during load lowering operations.

3. Importance Of Load Calculation

Details: Accurate load calculation is crucial for designing screw mechanisms, ensuring proper torque requirements, and preventing mechanical failure in lifting/lowering applications.

4. Using The Calculator

Tips: Enter torque in N·m, mean diameter in meters, friction coefficient (dimensionless), and helix angle in radians. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is the sec(0.2618) term used in the formula?
A: The sec(0.2618) accounts for the 15° thread angle in trapezoidal threads, where 0.2618 radians equals 15 degrees.

Q2: What is the typical range for friction coefficient in screw threads?
A: Friction coefficients typically range from 0.1 to 0.3 for well-lubricated metal threads, depending on materials and lubrication.

Q3: How does helix angle affect the load calculation?
A: Larger helix angles generally reduce the mechanical advantage, requiring more torque to lift/lower the same load.

Q4: When is this formula most applicable?
A: This formula is specifically designed for trapezoidal threaded screws under load lowering conditions with known torque requirements.

Q5: What are the limitations of this calculation?
A: The formula assumes constant friction coefficients and doesn't account for wear, misalignment, or dynamic loading conditions.