US 4,727,770 A · Planetary gear set and assembly method

Abstract

A planet gear set and method of assembling the carrier on the sun and ring gear particularly suited for automation of the carrier assembly operation. The sun gear of the planetary set has a staging annulus formed on one end thereof defined between the addendum and dedendum circles of the sun gear teeth. The sun gear also has a frustoconical concentricity chamfer formed on the same end with one edge contiguous with dedendum circle edge of the staging annulus. The carrier, with the planet gears thereon, is aligned on the axis of rotation of the sun gear and advanced toward the same. If the sun gear is eccentric relative to its axis of rotation, the planet gears engage the concentricity chamfer and cam the sun gear to an aligned position which is achieved when the carrier achieves a staged position relative to the sun gear. In the staged position, the addendum circles of the planet gears are tangent to the dedendum circle edge of the staging annulus. The carrier is then mildly biased toward the sun gear and rotated, whereupon the teeth of the planet gears sequentially achieve meshing engagement with the sun gear teeth.

Drawings

Claims5

Dependent claims

In the assembly of a planetary gear set on a support defining a main axis,

said planetary gear set including
a sun gear having a plurality of gear teeth and disposed on said support for rotation about said main axis and for limited translation in a plane perpendicular to said main axis between aligned and eccentric positions relative to said main axis,
a ring gear having a plurality of gear teeth and disposed on said support for limited translation in a plane perpendicular to said main axis between aligned and eccentric positions relative to said main axis,
a plurality of planet gears each having a plurality of gear teeth adapted to mesh with said ring gear teeth and said sun gear teeth, and
a planet carrier supporting each of said planet gears for rotation about respective ones of a corresponding plurality of parallel planet axes of said planet carrier,
a method of timing said planet gears on one of said sun gear and said ring gear comprising the steps of:
forming a staging annulus in a plane perpendicular to said main axis on one end of said one gear having a first edge defined by the addendum circle of said gear teeth on said one gear and a second edge defined by the dedendum circle of said gear teeth,
said staging annulus being interrupted by the tooth spaces between said gear teeth on said one gear,
forming on said one gear a frustoconical concentricity chamfer having one edge contiguous with said second edge of said staging annulus,
aligning said carrier on said main axis and advancing said carrier toward said one gear until said carrier achieves a staged position relative to said one gear wherein said planet gears abut said one gear on said staging annulus with the addendum circles of each of said planet gears tangent to said second edge of said staging annulus,
at least one of said planet gears engaging said one gear on said concentricity chamfer when said one gear is in said eccentric position and camming said one gear to said aligned position when said planet carrier achieves said staged position on said staging annulus,
biasing said carrier toward said one gear, and
effecting relative rotation between said carrier and said one gear so that said planet gears sequentially achieve meshing engagement with said one gear.

10 more elements

A method of assembling a

planetary gear set on a support defining a main axis, said planetary gear set including
a sun gear having a plurality of gear teeth and disposed on said support for rotation about said main axis and for limited translation in a plane perpendicular to said main axis between aligned and eccentric positions relative to said main axis,
a ring gear having a plurality of gear teeth and disposed on said support for limited translation in a plane perpendicular to said main axis between aligned and eccentric positions relative to said main axis,
a plurality of planet gears each having a plurality of gear teeth adapted to mesh with said ring gear teeth and said sun gear teeth, and
a planet carrier supporting each of said planet gears for rotation about respective ones of a corresponding plurality of parallel planet axes of said carrier,
said method comprising the steps of:
forming a staging annulus in a plane perpendicular to said main axis on one end of one of said ring gear and said sun gear having a first edge defined by the addendum circle of said gear teeth on said one of said ring gear and said sun gear and a second edge defined by the dedendum circle of said gear teeth,
said staging annulus being interrupted by the tooth spaces between said gear teeth on said one of said ring gear and said sun gear,
forming on said one of said ring gear and said sun gear a frustoconical concentricity chamfer having one edge contiguous with said second edge of said staging annulus,
aligning said carrier on said main axis and advancing said carrier toward said one of said sun gear and said ring gear until said planet carrier achieves a staged position relative to said one of said sun gear and said ring gear wherein said planet gears abut said one of said sun gear and said ring gear on said staging annulus with the addendum circles of each of said planet gears tangent to said second edge of said staging annulus,
at least one of said planet gears engaging said one of said sun gear and said ring gear on said concentricity chamfer when said one gear is in said eccentric position and camming said one gear to said aligned position when said planet carrier achieves said staged position,
biasing said carrier toward said one of said sun gear and said ring gear,
effecting relative rotation between said carrier and said one of said sun gear and said ring gear so that said planet gears sequentially achieve meshing engagement with said one gear,
forming on one end of the other of said sun gear and said ring gear a frustoconical bevel surface overlapping the ends of said gear teeth on said other of said sun gear and said ring gear, and
further advancing said planet carrier toward said other of said sun gear and said ring gear and rotating said planet carrier to achieve substantially simultaneous meshing engagement between each of said planet gears and said other of said sun gear and said ring gear,
at least one of said planet gears engaging said other of said sun gear and said ring gear on said frustoconical bevel surface when said other gear is in said eccentric position and camming said other gear to said aligned position.

13 more elements

In a planetary gear set in an automotive transmission having a transmission case defining a main axis of said transmission,

said planetary gear set including
a sun gear having a plurality of gear teeth and disposed on said transmission case for rotation about said main axis and for limited translation in a plane perpendicular to said main axis between aligned and eccentric positions relative to said main axis,
a ring gear having a plurality of gear teeth and disposed on said transmission case for limited translation in a plane perpendicular to said main axis between aligned and eccentric positions relative to said main axis,
a plurality of planet gears each having a plurality of gear teeth adapted to mesh with said sun gear teeth and said ring gear teeth,
a planet carrier, and
means mounting each of said planet gears on said planet carrier for rotation about respective ones of a plurality of parallel planet axes of said carrier,
the combination comprising:
means on one end of said sun gear defining a staging annulus in a plane perpendicular to said main axis having a first edge defined by the addendum circle of said sun gear teeth and a second edge defined by the dedendum circle of said sun gear teeth,
said staging annulus being interrupted by the tooth spaces between said sun gear teeth,
means on said sun gear defining a frustoconical concentricity chamfer having one edge contiguous with said second edge of said staging annulus,
at least one of said planet gears engaging said sun gear on said concentricity chamfer when said sun
gear is in said eccentric position and when said carrier is aligned on said main axis and advanced toward said sun gear,
said planet gears camming said sun gear to said aligned position when said planet carrier achieves a staged position relative to said sun gear wherein said planet gears abut said sun gear on said staging annulus with the addendum circles of each of said planet gears tangent to said second edge of said staging annulus, and
means on said ring gear defining a frustoconical bevel surface extending from the addendum circle of said ring gear teeth to beyond the dedendum circle of said ring gear teeth,
at least one of said planet gears engaging said ring gear on said frustoconical bevel surface when said ring gear is in said eccentric position and camming said ring gear to said aligned position when said carrier is aligned on said main axis and advanced toward said ring gear.

12 more elements

A method of assembling a planetary gear set on a support defining a main axis,

said planetary gear set including
a sun gear having a plurality of gear teeth and disposed on said support for rotation about said main axis and for limited translation in a plane perpendicular to said main axis between aligned and eccentric positions relative to said main axis,
a ring gear having a plurality of gear teeth and disposed on said support for limited translation in a plane perpendicular to said main axis between aligned and eccentric positions relative to said main axis,
a plurality of planet gears each having a plurality of gear teeth adapted to mesh with said ring gear teeth and said sun gear teeth, and
a planet carrier supporting each of said planet gears for rotation about respective ones of a corresponding plurality of parallel planet axes of said carrier,
said method comprising the steps of:
forming on one end of said sun gear a staging annulus in a plane perpendicular to said main axis having a first edge defined by the addendum circle of said sun gear teeth and a second edge defined by the dedendum circle of said sun gear teeth,
said staging annulus being interrupted by the tooth spaces between said sun gear teeth,
forming on said sun gear a frustoconical concentricity chamfer having one edge contiguous with said second edge of said staging annulus,
aligning said carrier on said main axis and advancing said carrier toward said sun gear until said planet carrier achieves a staged position relative to said sun gear wherein said planet gears abut said sun gear on said staging annulus with the addendum circles of each of said planet gears tangent to said second edge of said staging annulus,
at least one of said planet gears engaging said sun gear on said concentricity chamfer when said sun gear is in said eccentric position and camming said sun gear to said aligned position when said planet carrier achieves said staged position,
biasing said carrier toward said sun gear,
effecting relative rotation between said carrier and said sun gear so that said planet gears sequentially achieve meshing engagement with said sun gear,
forming on one end of said ring gear a frustoconical bevel surface overlapping the ends of said ring gear teeth, and
further advancing said planet carrier toward said ring gear and rotating said planet carrier to achieve substantially simultaneous meshing engagement between each of said planet gears and said ring gear,
at least one of said planet gears engaging said ring gear on said frustoconical bevel surface when
said ring gear is in said eccentric position and camming said ring gear to said aligned position.

14 more elements

In a planetary gear set in an automotive transmission having a transmission case defining a main axis of said transmission,

said planetary gear set including
a sun gear having a plurality of gear teeth and disposed on said transmission case for rotation about said main axis and for limited translation in a plane perpendicular to said main axis between aligned and eccentric positions relative to said main axis,
a ring gear having a plurality of gear teeth,
a plurality of outer clutch discs spline connected to said transmission case,
a plurality of inner clutch discs disposed between respective pairs of said outer clutch discs and spline connected to said ring gear radially outboard of said ring gear teeth whereby said ring gear is disposed on said transmission case for limited translation in a plane perpendicular to said main axis between aligned and eccentric positions relative to said main axis,
a plurality of planet gears each having a plurality of gear teeth adapted to mesh with said sun gear teeth and said ring gear teeth,
a planet carrier, and
means mounting each of said planet gears on said planet carrier for rotation about respective ones of a plurality of parallel planet axes of said carrier,
the combination comprising:
means on one end of said sun gear defining a staging annulus in a plane perpendicular to said main axis having a first edge defined by the addendum circle of said sun gear teeth and a second edge defined by the dedendum circle of said sun gear teeth,
said staging annulus being interrupted by the tooth spaces between said sun gear teeth,
means on said sun gear defining a frustoconical concentricity chamfer having one edge contiguous with said second edge of said staging annulus,
at least one of said planet gears engaging said sun gear on said concentricity chamfer when said sun gear is in said eccentric position and when said carrier is aligned on said main axis and advanced toward said sun gear,
said planet gears camming said sun gear to said aligned position when said planet carrier achieves a staged position relative to said sun gear wherein said planet gears abut said sun gear on said staging annulus with the addendum circles of each of said planet gears tangent to said second edge of said staging annulus, and
means on said ring gear defining a frustoconical bevel surface extending from the addendum circle of said ring gear teeth to beyond the dedendum circle of said ring gear teeth,
at least one of said planet gears engaging said ring gear on said frustoconical bevel surface when said ring gear is in said eccentric position and camming said ring gear to said aligned position when said carrier is aligned on said main axis and advanced toward said ring gear.

13 more elements

Dependencies are inferred from the claim text.

Description2,750 words

Summary835 words

#The subject matter of this application relates to the subject matter of copending U.S. patent application Ser. No. 707,391 now U.S. Pat. No. 4,640,294, filed Mar. 1, 1985 by Richard A. Ordo and assigned to the assignee of this invention.

#1. Field of the Invention

#This invention relates generally to planetary gear type automotive transmissions and, more particularly, to a planetary gear set and method of assembling the same in an automated operation.

Brief description of the drawings2 figures

#FIG. 1 is an elevational view of a planetary gear set according to this invention undergoing assembly by the assembly method according to this invention; and

#FIG. 2 is a sectional view taken generally along the plane indicated by lines 2--2 in FIG. 1.

Detailed description1,871 words

#Referring now to the drawings, a planetary gear set 10 according to this invention is to be assembled onto a supporting structure 12, such as a transmission case, which defines a main axis 14 fixed relative to the case. The planetary gear set 10 includes a sun gear 16, a ring gear 18, a plurality of planet gears 20a-d and a planet carrier 22. The ring gear 18 is connected to the case 12 through a disc clutch 24.

#The disc clutch 24 includes a clutch pack 25 consisting of a plurality of outer discs 26 and a plurality of inner discs 28 interleaved between the outer discs. Each outer disc has a circumferential array of outer spline teeth 30 slidably engaged in a corresponding plurality of spline grooves 32 in the case 12 centered about the axis 14. Each of the inner discs 28 has an internal circumferential array of spline teeth 34 slidably engaged in a corresponding plurality of spline grooves 36 in the ring gear which are parallel to the axis 14 when the ring gear is centered about or aligned on the axis. Each of the inner discs 28 has a friction lining 38 on each face of the disc which slidably engages an opposing face on the adjacent one of the outer discs 26.

#The clutch pack 25 is stacked against an annular backing plate 40 on the case 12 and engaged by an annular piston, not shown, which compresses the clutch pack against the backing plate. When the clutch is thus engaged, the ring gear 18 is held stationary relative to the case and when the clutch is released the ring gear is freely rotatable relative to the case as the inner discs 28 rotate relative to the stationary outer discs 26. The ring gear and the attached inner discs 28 are free to translate in planes perpendicular to the axis 14 by an amount corresponding generally to the clearance between the inner diameters of the outer discs 26 and the outer diameter of the ring gear which circumscribes the spline grooves 36.

Planetary gear set and assembly method

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Planetary gear set and assembly method

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims5

Description2,750 words

Drawings

Classification3 codes

Life of this patent

Description2,750 words