Universal Joint

Rotary coupling between two cardan shafts.

blockType: Engee1DMechanical.Elements.Rotational.UniversalJoint

Path in the library:

/Physical Modeling/1D Mechanical/Couplings & Drives/Universal Joint

Description

Block Universal Joint It is a rotary coupling between two cardan shafts. The coupling transmits torque between the shafts, so that they rotate as a unit under the action of a load. Two rotational degrees of freedom, internal to the coupling, allow the shafts to be connected at an angle. This intersection angle varies depending on the signal coming from port A. Additional compliance, made in the form of a parallel set of spring shock absorbers, allows the clutch to deform under load.

Block Universal Joint It can be used as a connection between two rotating drive components, for example, between the drive and driven shafts in an automotive transmission. universal joint 1 en

The ratio of the angular velocities of the shafts depends on two parameters: the angle of intersection of the two shafts and the angle of rotation of the drive shaft. The input physical signal determines the angle of intersection, while the parameter of the property inspector determines the initial angle of the drive shaft. These two angles determine the ratio of the two angular velocities of the shaft according to the nonlinear equation

Where

— angular velocity of the driven shaft around its longitudinal axis;
— angular velocity of the drive shaft around its longitudinal axis;
— the angle of rotation of the drive shaft around its longitudinal axis;
— the angle of intersection of the drive and driven shafts relative to the neck of the drive shaft.

The two diagrams in the figure illustrate the parameters of the equation. In each diagram, the left shaft corresponds to the drive shaft, and the right shaft corresponds to the driven shaft. The diagram on the right shows a coupling, the same as in the diagram on the left, but after turning the shafts by 90° around their longitudinal axes (dashed lines).

universal joint 2

The figure shows the intersection angle — this is the angle between the two shafts relative to the neck of the drive shaft. The absolute value of this angle must be in the range `0 ≤ A < Maximum intersection angle'. The angle of inclination of the drive shaft is the angle of inclination of the drive shaft relative to its longitudinal axis. The angle of inclination of the drive shaft is also the time integral of the angular velocity of the drive shaft .

Ports

Input

# A — Intersection angle
scalar

Details

The physical signal input port for the intersection angle.

Data types	`Float64`
Complex numbers support	I don’t

Conserving

# B — drive shaft
rotational mechanics

Details

Preservation of the rotary port connected to the drive shaft.

Program usage name

base_flange

# F — driven shaft
rotational mechanics

Details

Preservation of the rotary port connected to the driven shaft.

Program usage name

follower_flange

Parameters

# Maximum joint angle — maximum angle of intersection of shafts,
deg | rad | rev | mrad

Details

The maximum intersection angle that the coupling allows. This angle measures the rotation between the drive and driven shafts around the neck of the drive shaft. The value of this angle should be in the range I’m glad.

Units	`deg` \| `rad` \| `rev` \| `mrad`
Default value	`0.7853981633974483 rad`
Program usage name	`max_angle`
Evaluatable	Yes

# Joint compliance — the malleability model

Details

Compliance model for the block:

the checkbox is not checked by default — stiffness and shock absorption are not modeled;
if the check box is checked, stiffness and shock absorption are simulated.

Default value	`false (switched off)`
Program usage name	`enable_compliance`
Evaluatable	Yes

# Initial base shaft angle — the initial angle of inclination of the drive shaft
deg | rad | rev | mrad

Details

The angle of rotation of the drive shaft around its longitudinal axis at the beginning of the simulation.

Units	`deg` \| `rad` \| `rev` \| `mrad`
Default value	`0.0 rad`
Program usage name	`phi_base_start`
Evaluatable	Yes

Details

Linear spring stiffness of the connection. The spring stiffness takes into account the accumulation of elastic deformation energy in the joint due to the malleability of the material.

Dependencies

To use this option, select the check box next to the option Joint compliance.

Units	`HP_DIN/rpm` \| `Nm/rad` \| `Ws/rad` \| `mmN/rad` \| `HP_DINs/rad` \| `ft*lbf/rad`
Default value	`1.0e6 N*m/rad`
Program usage name	`k`
Evaluatable	Yes

# Joint damping — damping coefficient
N*m/(rad/s) | ft*lbf/(rad/s)

Details

Linear damping coefficient in the connection. The damping coefficient takes into account the energy dissipation in the joint due to the malleability of the material.

Dependencies

To use this option, select the check box next to the option Joint compliance.

Units	`Nm/(rad/s)` \| `ftlbf/(rad/s)`
Default value	`1000.0 N*m/(rad/s)`
Program usage name	`C`
Evaluatable	Yes

# Initial torque from base to follower shaft — initial torque
N*m | mN*m | lbf*ft

Details

The torque that the drive shaft transfers to the driven shaft at the beginning of the simulation. This torque determines the initial state of compliance of the material in the joint. Set this value to greater than zero to preload the shafts with torque. Changing this value changes the initial transient mode due to the malleability of the material.

Dependencies

To use this option, select the check box next to the option Joint compliance.

Units	`Nm` \| `mNm` \| `lbf*ft`
Default value	`0.0 N*m`
Program usage name	`T_start`
Evaluatable	Yes