1) Title of the invention
Integrated planet pinion & spherical bearing for application in helicopter planetary gear system.
2) Field of invention
It comes in the gear box where gear reduction ratio is more and weight plays a major role i.e. in the aerospace field.
3) Use of invention
This invention finds application in planetary gear system of helicopters.

4) Prior art
In the previous design, the planet pinion and bearing are separate parts. The bearing will have inner race and outer race with a cylindrical rolling elements in between. The inner race will seat on the shaft and outer race will seat on the planet pinion inner diameter, This design needs a bearing retainer to lock the bearing inner and outer race. Planet pinion will have step in bore on one side, to lock the bearing outer race and a set of threaded holes on the face of other side of the hole to mount the bearing retainer plate. Also Screws to mount the bearing retainer plate on pinion and shaft.
5) Draw backs of prior art
There are few shortcomings in the earlier design which is mentioned below.
• More space.
• More weight.
• More number of parts.
• Less reliability
6) Comparison between prior art and present invention
Due to cylindrical rollers in bearing there is no flexibility in the planetary system to take misalignments. The present design-uses-spherical roller bearing which permits the flexibilityjto slight misalignment. Pinion have spherical surface as internal diameter, but prior design pinion have internal diameter of cylindrical surface. Also present design permits less space by avoiding extra parts, thereby reducing the weight of assembly.
7) Aim of the invention
The prime objective is to provide angular misalignment and reduce the overall size & weight of the gearbox without impairing the functionality of helicopter.
8) Summary of the present invention
The present invention involves a configuration of integrated planet pinion & spherical bearing as shown in Figurel & 2. It consists of 2 rows of spherical rollers running in the race ways ground in the inner and outer races. The rollers are held in position by the cages. The outer race has the raceways ground in the inner diameter for guiding the rollers and the planet pinion spur gear in the outer diameter for meshing with the sun gear & ring gear of the planetary gear system.

9) Brief description of drawings
The Figurel illustrates the sectional view of integrated planet pinion and spherical bearing. The Figure 2 illustrates the isometric view of integrated planet pinion and spherical bearing. The Figure 3 depicts the position of integrated planet pinion and spherical bearing in a planetary gearing system of rotor craft.
10) Statement of invention
The present invention of integrated planet pinion and spherical bearing can take misalignment due to manufacturing tolerances. Integrated planet pinion and spherical bearing act as a single unit, reducing no of part & weight than prior art and thus increasing reliability of planetary gearing system.
11) Detailed description of invention
The main gear box is used in helicopters to transfer the power from engine to Main rotor. The required speed reduction from engine to rotor is achieved by main gear box, with required number of stages and type of gearing system. Planetary gearing system is one of the speed reduction type used in helicopters. This planetary gearing system consists of a sun gear, ring gear, planet pinion and a planet carrier. As explained below with reference to the figure 3.
The integrated planet pinion and spherical bearing comprises of planet pinion 101 and spherical bearing 107, located in Main gear box of helicopter. It is mounted on one or more lugs on the planet carrier 103. One or more planet pinion 101 is driven by a sun gear 104, which gets power from prior stage gearing. The gear teeth on these planet pinions 101 meshes with teeth of the fixed ring gear 102 and drives the planet carrier 103, which is mounted on a bearing 106.
The present invention involves the configuration of integrated planet pinion & spherical bearing as shown in Figurel & 2. It consists of 2 rows of spherical rollers running in the race ways ground in the inner and outer races. The rollers are held in position by the cages. The outer race has the raceways ground in the inner diameter for guiding the rollers and the planet pinion spur gear teeth in the outer diameter for meshing with the sun gear & ring gear of the planetary gear system.