Belt drive pulley
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| C | |
| in the palette | on the schematic |
The block is designed to simulate interaction of the rotating pulley and the translatory moving belt.
- vA and vC – linear speeds of the belt at the port "A" and the pulley at the port "C", m/s
- ω – angular speed of the pulley, rad/s
- R – pulley radius, m
- μ 0 – friction factor taking into account the type of the belt
- θ – angle of belt contact, rad
- vth – linear speed threshold value used to achieve the stability of the numerical solution by reducing the friction force at a slip speed below the threshold, rad/s
- FA and FB – belt tension forces at ports "A" and "B", respectively, N
- Fmin – minimum belt pressing force applied to the pulley
- Fcent – centrifugal force, N:
where M – mass of the belt section in contact with the pulley, kg, v – belt speed, m/s
As the pulley rotation speed increases, the belt pressure force on the pulley decreases due to centrifugal force, but it cannot fall below the minimum pressure force specified in the block properties.
- For a flat belt:
where μ – coefficient of contact friction
- For a v-belt:
where φ – belt wedge angle, rad; N – number of belts
The block allows you to change the direction of belt end motion and the sign of the belt tension force. Belt end motion in the same direction means that the belt end speeds will have the same sign. The sign of the belt tension force indicates when the force at the port "A" will be considered belt tension force. The table (Table 1) schematically shows the ways of connecting the pulley to other blocks. Vector S indicates the positive direction of the velocity vectors v and force vectors F. Vectors vA and vB indicate the coincidence or mismatch of the signs of the velocities of the ends of the belt.
| Tension force | |||
|---|---|---|---|
| Positive | Negative | ||
| Motion direction of the belt ends | Same direction | 1 |
2 |
| Opposite direction | 3 |
4 |
|
The block allows you to set the coincidence or mismatch of the directions of rotation of the pulley and the belt end A motion. When the directions of rotation and movement coincide, the positive rotation speed will correspond to the positive speed of the belt end A, regardless of the relative direction of movement of the belt ends and the sign of the tension force.
The block allows you to simulate linear motion of the pulley. In this case the port "C" receives the profile of the pulley rotation axis linear motion.
Inputs
| Name | Description | Connection line type |
|---|---|---|
| A | Port for connecting model blocks to the belt end A | Translatory mechanics |
| B | Port for connecting model blocks to the belt end B | Translatory mechanics |
| R | Port for connecting model blocks to the pulley shaft (rotor) | Rotary mechanics |
| C | Port for connecting model blocks to the pulley axis (case). The port is available with the property "Consider linear motion of the pulley” enabled | Translatory mechanics |
Outputs
None.
Properties
| Name | Parameter | Description | By default | Data type |
|---|---|---|---|---|
| Belt | A group of properties that define the belt parameters | |||
| Belt type | BType | Allows you to set the belt type. The possible values are: "Flat", "V-belt" | Flat | Перечисление |
| Number of belts | N | Number of belts. The property is available when you select the type of the belt as "V-belt”. | 3 | Целое |
| Belt wedge angle, deg. | Fi | Belt wedge angle. The property is available when you select the type of the belt as "V-belt”. | 40 | Вещественное |
| Mass of the belt per unit length, kg/m | M | Mass of 1 meter of the belt | 0.05 | Вещественное |
| Belt initial speed, m/s | V0 | Belt initial speed from the end A | 0 | Вещественное |
| Belt initial position, m | S0 | Belt initial position from the end A | 0 | Вещественное |
| Pulley | A group of properties that define the pulley parameters | |||
| Pulley radius, m | R | Pulley radius | 1 | Вещественное |
| Angle of belt contact, deg | Teta | Angle of belt contact | 180 | Вещественное |
| Coefficient of bearing friction, Nm·s/rad | B | Coefficient of bearing friction | 0 | Вещественное |
| Friction | A group of properties that define the friction parameters | |||
| Speed threshold, m/s | Vth | The slip speed of the belt, below which the friction force is reduced to achieve the stability of the numerical solution | 1 | Вещественное |
| Coefficient of contact friction | Mu | Coefficient of contact friction | 0.5 | Вещественное |
| Minimum pressing force applied to the pulley | Fmin | The value of the minimum belt pressing force on the pulley used to achieve the stability of the numerical solution | 10 | Вещественное |
| Fine settings | A group of properties that define the fine settings | |||
| Consider the linear motion of the pulley | Translation | Allows you to take into account the linear motion of the pulley | None | Двоичное |
| Direction of rotation and motion direction of the belt | RotationDir | Allows you to set the direction of rotation and the motion direction of the belt. The possible values are: "Same direction", "Opposite direction" | In the same direction | Перечисление |
| Motion direction of the belt ends | BeltsDir | Allows you to set the motion direction of the belt ends. The possible values are: "Same direction", "Opposite direction" | In the same direction | Перечисление |
| Belt tension force | ForceSign | Allows you to set the sign of the belt tension force. The possible values are: “Positive", "Negative" | Positive | Перечисление |
Parameters
| Name | Parameter | Description | Data type |
|---|---|---|---|
| Belt slip,m/s | V_Rel | Belt slip speed on pulley | Вещественное |
| Port R | A group of parameters displaying the parameters at the port "R" | ||
| Angular speed of the pulley, rad/s | W | Angular speed of the pulley | Вещественное |
| Torque at the pulley, Nm | T | Torque at the pulley | Вещественное |
| Port A | A group of parameters displaying the parameters at the port "A" | ||
| Belt linear speed, m/s | V_A | Belt end A linear speed | Вещественное |
| Belt tension force, N | F_A | Belt end A tension force | Вещественное |
| Port B | A group of parameters displaying the parameters at the port "B" | ||
| Belt linear speed, m/s | V_B | Belt end B linear speed | Вещественное |
| Belt tension force, N | F_B | Belt end B tension force | Вещественное |
| Port C | A group of parameters displaying the parameters at the port "C" | ||
| Pulley linear speed, m/s | V_C | Pulley linear speed. The value is zero if the property "Consider the linear motion of the pulley" is disabled | Вещественное |
| Pulley tension force, N | F_C | Pulley tension force. The value is zero if the property "Consider the linear motion of the pulley" is disabled | Вещественное |