Giordano Buio – giordano.buio@studenti.unipd.it

Product

The Schmidt-Kupplung coupling is a compactly built coupling for precise torque transmission of extremely radially offset shafts. The shaft offset can be changed both at rest and while running under load, to any value within the required permissible swivel range. In this process, permanent angle-synchronous transmission is ensured regardless of the shaft offset height. From one drive to the other, they operate permanently in synchronisation, with no phase shift.

The Schmidt-Kupplung coupling is composed by three discs:

Input disc
Intermediate disc
Output disc

These discs are connected by six links. This ensure compactness and torsionally stiff work.

The Schmidt-Kupplung coupling is used in the following application fields:

Roller and calender drivers
Forming
Roller feeds
Coating systems
Profiling systems
Printing and packaging machines

Objectives

The purpose of the kinematic analysis of The Schmidt-Kupplung coupling is to verify angle-synchronous transmission while shaft offset changes.

Modelling

Bodies

9 bodies are imported in ADAMS VIEW as a parasolid file (*.x_t) after settings:

Units MKS
Global WY working grid
No gravity

The model without constrains has 9 x 6 = 54 DOF

Constraints

The Schmidt-Kupplung coupling is modelling only whit 13 revolute joints that locks 5 DOF each.

Using Gruber equation DOF = 9 x 6 – 13 x5 = -11

There are 14 redundant constraint equation.

System DOF = DOF (Gruber eq.) + Redundant_constraint = -11 + 14 = 3

Simulation

To study the Schmidt-Kupplung coupling behaviour 2 motions are used:

Input_motion: a rotational joint motion that simulates constant angular velocity of ruota_input

alpha_x = 360° t

Input_traslations: General point motion apply to ruota_output. It constrains Y and Z displacement as follow:

y = 0.04 sin(pi/4*t)

z = 0.06 |sin(pi/4*t)|

The system’s DOF are updates to DOF = 0

Results

The model has beensimulated for 3 seconds with 0.001 seconds steps size. This simulation permits to obtain position, velocity and acceleration data of each 9 bodies.

Graphic 1 shows the two input motions:

angular velocityof ruota_input

omega_x = 360°/s

Y and Z displacements of ruota_output

y = 0.04 sin(pi/4*t)

z = 0.06 |sin(pi/4*t)|

Graphic 2 shows angle-synchronous transmission while shaft offset changes. Marker_10 is related to ruota_input and Marker_38 to ruota_output. Both augular velocity are equal to 360°/s.

Graphic 3 shows velocities and acceleration of Marker_38 related to ruota_output. Observe that translational velocity doesn’t change angular velocity.