Effective Length of Bush of Bushed Pin Coupling given Torque Calculator

Effective Length of Bush Formula:

\[ l_b = \frac{2 \times M_t}{D_b \times N \times D_{pin} \times p_m} \]

Torque Transmitted by Coupling (M_t):

N·m

Outer Diameter of Bush (D_b):

Number of Pins in Coupling (N):

Pitch Circle Diameter of Pins (D_pin):

Intensity of Pressure (p_m):

Tolerance:

Effective Length of Bush (l_b):

1. What is Effective Length of Bush of Bushed Pin Coupling?

Definition: The effective length of bush in a bushed pin coupling is the portion of the bush that actually transmits torque between the coupling flanges.

Purpose: This calculation ensures proper torque transmission while maintaining acceptable pressure levels between the bush and flange.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ l_b = \frac{2 \times M_t}{D_b \times N \times D_{pin} \times p_m} \]

Where:

\( l_b \) — Effective length of bush (meters)
\( M_t \) — Torque transmitted by coupling (N·m)
\( D_b \) — Outer diameter of bush (meters)
\( N \) — Number of pins in coupling
\( D_{pin} \) — Pitch circle diameter of pins (meters)
\( p_m \) — Intensity of pressure between flange (Pa)

Explanation: The formula balances torque transmission requirements with the pressure limits of the bush material.

3. Importance of Effective Length Calculation

Details: Proper bush length ensures:

Adequate torque transmission capacity
Acceptable pressure distribution
Long service life of the coupling
Prevention of premature bush failure

4. Using the Calculator

Tips:

Enter torque in N·m (convert from other units if needed)
Typical bush diameter: 0.035-0.050 m
Common number of pins: 4-8
Standard pressure intensity: 1-1.5 MPa for rubber bushes
Tolerance (±5% by default) accounts for manufacturing variations

5. Frequently Asked Questions (FAQ)

Q1: What happens if the bush length is too short?
A: Excessive pressure can cause premature wear or bush failure.

Q2: How does number of pins affect the calculation?
A: More pins allow shorter bush length for same torque, distributing load.

Q3: What's a typical pressure limit for rubber bushes?
A: Usually 1.0-1.5 MPa, but check manufacturer specifications.

Q4: Why include tolerance in the calculation?
A: Accounts for manufacturing variations and installation factors.

Q5: How does bush material affect the calculation?
A: Different materials have different allowable pressure (p_m) values.