Orientation-free planetary pin for lubrication of planetary bearings
A planet pin for use in a planetary gear system and a gear system including a planet pin are disclosed. The inventive planet pin provides a plurality of radial passages in fluid communication with an axial passage which can advantageously eliminate, or substantially reduce, the need to orient a planet pin in a planetary gear system.
1. A planetary pin for use in a planetary gear system, the planetary pin comprising:
a cylindrical body having an axial passage defined by an inner cylinder wall and a wall thickness between the inner cylinder wall and an outer cylinder wall; and
a plurality of radial passages through the wall thickness configured such that axes of radially adjacent ones of the radial passages are offset by less than 180° when viewed along an axis of the axial passage,
wherein the plurality of radial passages provide a corresponding plurality of fluid paths between the axial passage and the outer wall,
wherein a first set of the plurality of radial passages lie in a first circumferential plane of the cylindrical body and a second set of the plurality of radial passages lie in a second circumferential plane of the cylindrical body, the first circumferential plane is axially offset from the second circumferential plane of the cylindrical body, and an axis of each radial passage of the first set of the plurality of radial passages is circumferentially offset from an axis of a radially adjacent radial passage of the second set of the plurality of radial passages.
2. The planetary pin of claim 1 , wherein the axes of at least some of the plurality of radial passages are perpendicular to the axis of the axial passage.
3. The planetary pin of claim 1 , wherein each of the plurality of radial passages is in one of the first set or the second set.
4. The planetary pin of claim 1 , wherein an axis of radially adjacent ones of the radial passages are circumferentially offset by 60°.
5. A planetary gear system comprising:
a centrally located sun gear having outwardly directed gear teeth;
a ring gear concentric with, and circumscribed about, the sun gear, the ring gear having inwardly directed gear teeth; and
a planet gear disposed between an inner diameter of the ring gear and an outer diameter of the sun gear, the planet gear having outwardly directed gear teeth configured to concurrently engage the outwardly directed gear teeth of the sun gear and the inwardly directed gear teeth of the ring gear,
wherein the planet gear is supported for rotation about a planet pin on a planetary bearing, the planet pin fixed against rotation, the planet pin comprising:
a cylindrical body having an axial passage defined by an inner cylinder wall and a wall thickness between the inner cylinder wall and an outer cylinder wall; and
a plurality of radial passages through the wall thickness configured such that axes of radially adjacent ones of the radial passages are circumferentially offset by less than 180° when viewed along an axis of the axial passage,
wherein the plurality of radial passages provide a corresponding plurality of fluid paths between the axial passage and the outer wall,
wherein a first set of the plurality of radial passages lie in a first circumferential plane of the cylindrical body and a second set of the plurality of radial passages lie in a second circumferential plane of the cylindrical body, and the first circumferential plane is axially offset from the second circumferential plane of the cylindrical body, and an axis of each radial passage of the first set of the plurality of radial passages is circumferentially offset from an axis of a radially adjacent radial passage of the second set of the plurality of radial passages.
6. The planetary gear system of claim 5 , wherein an orientation of the plurality of radial passages is such that the axial passage is in fluid communication with the planetary bearing through one of the plurality of radial passages regardless of a rotational position of the planet pin.