32.3.1.3. Constraint Bearing

A Constraint bearing is defined between two bodies. The created position types are five:

  • Engine Block & Shaft Main (EB_SM)

  • Shaft Pin & Connecting Rod (SP_CR)

  • Connecting Rod & Piston Pin (CR_PP)

  • Piston Pin & PisTon (PP_PT)

  • Engine Block & Balancing Shaft (EB_BS)

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Figure 32.123 Constraint bearing

32.3.1.3.1. Modeling Options

  1. Click the Constraint icon of the Crank Connector group in the Crank tab. The user can see the Crank Component Bearing – Constraint Bearing dialog box.

  2. The user can choose the following types in Component Type and select the position where the constraint bearing is created in Component Index.

    ../_images/image1852.png

    Figure 32.124 Crank Component Bearing – Constraint Bearing dialog box

  3. Click OK

32.3.1.3.2. Properties

Click the right mouse button on the constraint bearing component to choose Properties of constraint bearing. The user can modify the property of a constraint bearing in following dialog box.

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Figure 32.125 Constraint Bearing property page

  • Type: Spherical Joint, Cylindrical Joint and Revolute Joint Type.

    The user can refer the following table for each constraint bearing.

    ../_images/image1872.png

    Table 1 Constraint bearing characteristics

  • Please refer to the Friction types in below.

    • Standard Friction

    1. Select Friction Coefficient in the combo box

      ../_images/image1883.png

      Figure 32.126 Coulomb Friction

      • Journal Radius: shaft radius attached bearing inside

    1. Click More and enter the values to define Coulomb Friction

      ../_images/image1634.png

      Figure 32.127 Friction Definition dialog box

      ../_images/image1891.png

      Figure 32.128 Standard Friction

    • Empirical Formula

    1. Select Empirical Formula in the combo box.

      ../_images/image1903.png

      Figure 32.129 Empirical formula Friction

      ../_images/image1913.png

      Figure 32.130 Journal Radius & Radial Clearance

    1. Click More and enter the values to define Empirical formula friction

      ../_images/image1684.png

      Figure 32.131 Empirical Formula Friction dialog box

    • Friction Torque

      ../_images/image1923.png

      Figure 32.132 Parameters for SOMMERFELD number

      ../_images/image1932.png

      Figure 32.133 Each Lubrication region is decided by SOMMERFELD number

      \(\text{Friction Torque}:T=\sum {_i} \eta_i F_i R_i\)

    • Friction Force

      ../_images/image1952.png

      Figure 32.134 Parameters for Dimensionless Duty Parameter

      ../_images/image1961.png

      Figure 32.135 Each Lubrication region is decided by Dimensionless Duty Parameter

      \(\text{Friction Force}:F=\sum {_i} \eta_i F_i\)

Position information of Constrain Bearing

  • Engine Block & Shaft Main (EB-SM)

    ../_images/image1983.png

    Figure 32.136 Position information of Constraint Bearing between Engine Block & Shaft Main

  • Shaft Pin & Connecting Rod (SP-CR)

    ../_images/image1993.png

    Figure 32.137 Position information of Constraint Bearing between Shaft Pin & Connecting Rod

  • Connecting Rod & Piston Pin (CR-PP)

    ../_images/image2002.png

    Figure 32.138 Position information of Constraint Bearing between Connecting Rod & Piston Pin

  • Piston Pin & Piston (PP-PT)

    ../_images/image2013.png

    Figure 32.139 Position information of Constraint Bearing between Piston Pin & Piston

    The position of Constraint Bearing is decided by following formulation

    \(\pm Dist_z=\frac{BossSpacing}{2}+\frac{PinLength-BossSpacing}{4}\)

  • Engine Block & Balancing Shaft (EB-BS)

    ../_images/image2032.png

    Figure 32.140 Position information of Constraint Bearing between Engine Block & Balancing Shaft