For example, the Stoeckicht system from 1940 solves this problem by making the annulus ring flexible while designing both it and the sun gear to float without bearings so that they are both supported by their respective mesh points. To share torque equally among all the planetary pinions, the utilization of flexible components in the design of a planetary gearbox shows promise.

Figure 2: Deviation of the actual configuration of the planet pinion axis of rotation O*p from its desired configuration Op In a rigid system, this condition imposes unbalanced loading among the planetary pinions. p of the planet pinion before any contact is made at the mesh points of the other planets (assuming the ring gear makes contact with all pinions at points K rg. Figure 2 shows in an exaggerated form that contact is made at the mesh point K sg. Load sharing and stress distribution at each mesh point are heavily influenced by global design configuration backlash tolerance component design tolerances manufacturing accuracy component deflection and thermal distortion. Furthermore, stress, too, is distributed invariably at mesh points. In the traditional epicyclical gearing system - i.e., where the distance between planetary pinion centerlines is specified by the design to be within a fixed range - it is widely recognized that load sharing is not evenly distributed among planetary gear meshes. The torsional wind-up of the carrier, position accuracy of the pins, machining tolerances of the planetary gear system components, and bearings clearances all can contribute to poor load sharing among the planetary pinions, as well as misaligned gear contacts in the deflected state. Planetary gearboxes with multiple planetary pinions enable a substantial reduction in the size and weight of the gear drive - concurrent with the number of pinions in the gearbox - and only when the transmitted load is equally shared among all the planet pinions.Įpicyclic gear systems have typically been equipped with straddle-mounted planetary pinions with pins supported on the input and output sides of the carrier. (An example of a five-pinion planetary gearbox is shown in Figure 1.) Figure 1: An example of a five-pinion planetary gearbox Planetary gearboxes are widely used in the industry examples are readily found in the automotive, aerospace, and other industries.

Overview of Equal Power Sharing in Planetary Gearboxes Therefore, a need continues to exist for a load-equalizing mechanism for planetary pinions. Enhanced accuracy in the machining of the components is a straightforward, less-than-economical approach to equalizing the load share in planetary gearboxes. Typically due to manufacturing errors, displacements under operating load, or other factors, planetary pinions share power disproportionately. This paper relates to the load-equalizing capabilities of planetary gearboxes, and more generally, addresses the load-equalizing capabilities of multi-flow gear trains, that is, gear trains that feature two or more flows of transmitted power.

Freedom planet torque levels