US5169370A — End-thrust design for parallel-axis differential

Claim 1

Independent Claim 198 words

A differential assembly comprising: a housing; a pair of sun gears positioned in said housing for receiving a pair of respective axle ends for rotation therewith about a common axis, said sun gears having helical teeth; at least one pair of combination gears, each gear of said pair being supported in said housing (a) for axial movement in relation to and for contact with at least one bearing surface and (b) for rotation about a respective axis parallel to said common axis, and having a first engagement portion with helical teeth in mesh with a respective one of said sun gears and a second engagement portion in mesh with its paired combination gear; the meshing engagement of said sun and combination gears interconnecting said respective axle ends in a mutual driving relationship; and said first and second engagement portions of each combination gear having respective first and second gear tooth designs selected so that, when said combination gear is subjected to torque of a first direction, (a) said first engagement portion develops axial end thrust in a first direction against said bearing surface, and (b) said second engagement portion develops no axial end thrust in the opposite direction.

Claim 2

Dependent Claim 198 words

A differential assembly comprising: a housing; a pair of sun gears positioned in said housing for receiving a pair of respective axle ends for rotation therewith about a common axis, said sun gears having helical teeth; at least one pair of combination gears, each gear of said pair being supported in said housing (a) for axial movement in relation to and for contact with at least one bearing surface and (b) for rotation about a respective axis parallel to said common axis, and having a first engagement portion with helical teeth in mesh with a respective one of said sun gears and a second engagement portion in mesh with its paired combination gear; the meshing engagement of said sun and combination gears interconnecting said respective axle ends in a mutual driving relationship; and said first and second engagement portions of each combination gear having respective first and second gear tooth designs selected so that, when said combination gear is subjected to torque of a first direction, (a) said first engagement portion develops axial end thrust in a first direction against said bearing surface, and (b) said second engagement portion develops no axial end thrust in the opposite direction.

Claim 3

Dependent Claim 12 words

The assembly of claim 1 wherein second tooth design comprises spur teeth.

Claim 4

Dependent Claim 192 words

A gear differential having a planetary gearing arrangement comprising: a housing that is rotatable about a pair of axle shafts which share a common axis; a pair of sun gears positioned within said housing relative to respective bearing surfaces and adapted to be fixed to the respective ends of said axle shafts for rotation; at least one pair of planetary gears, each gear of the pair being mounted within said housing (a) for axial movement in relation to and for contact with at least one respective bearing surface and (b) for rotation about a respective axis which is parallel to said common axis; said sun and planetary gears having helical teeth and exerting axial end thrust against their respective bearing surfaces when subjected to torque; and each planetary gear having a first engagement portion with helical teeth for meshing with a respective one of said sun gears and a second engagement portion for meshing with its paired planetary gear, said first and second engagement portions having teeth designed so that said axial end thrust exerted by said planetary gears is at least equal to the end thrust exerted by said sun gears.

Claim 5

Dependent Claim 192 words

A gear differential having a planetary gearing arrangement comprising: a housing that is rotatable about a pair of axle shafts which share a common axis; a pair of sun gears positioned within said housing relative to respective bearing surfaces and adapted to be fixed to the respective ends of said axle shafts for rotation; at least one pair of planetary gears, each gear of the pair being mounted within said housing (a) for axial movement in relation to and for contact with at least one respective bearing surface and (b) for rotation about a respective axis which is parallel to said common axis; said sun and planetary gears having helical teeth and exerting axial end thrust against their respective bearing surfaces when subjected to torque; and each planetary gear having a first engagement portion with helical teeth for meshing with a respective one of said sun gears and a second engagement portion for meshing with its paired planetary gear, said first and second engagement portions having teeth designed so that said axial end thrust exerted by said planetary gears is at least equal to the end thrust exerted by said sun gears.

Claim 6

Dependent Claim 14 words

The gear differential of claim 3 wherein said second engagement portion comprises spur teeth.

Claim 7

Dependent Claim 188 words

A differential assembly comprising: a housing; a pair of sun gears positioned in said housing for receiving a pair of respective axle ends for rotation therewith about a common axis, said sun gears having helical teeth; at least one pair of combination gears, each gear of said pair being supported in said housing in relation to at least one bearing surface for rotation about a respective axis parallel to said common axis, and having a first engagement portion with helical teeth in mesh with a respective one of said sun gears and a second engagement portion in mesh with its paired combination gear; the meshing engagement of said sun and combination gears interconnecting said respective axle ends in a mutual driving relationship; and said first and second engagement portions of each combination gear having respective first and second gear tooth designs selected so that, when said combination gear si subjected to torque of a first direction, (a) said first engagement portion develops axial end thrust in a first direction against said bearing surface, and (b) said second engagement portion also develops axial end thrust in said first direction.

Claim 8

Dependent Claim 188 words

A differential assembly comprising: a housing; a pair of sun gears positioned in said housing for receiving a pair of respective axle ends for rotation therewith about a common axis, said sun gears having helical teeth; at least one pair of combination gears, each gear of said pair being supported in said housing in relation to at least one bearing surface for rotation about a respective axis parallel to said common axis, and having a first engagement portion with helical teeth in mesh with a respective one of said sun gears and a second engagement portion in mesh with its paired combination gear; the meshing engagement of said sun and combination gears interconnecting said respective axle ends in a mutual driving relationship; and said first and second engagement portions of each combination gear having respective first and second gear tooth designs selected so that, when said combination gear si subjected to torque of a first direction, (a) said first engagement portion develops axial end thrust in a first direction against said bearing surface, and (b) said second engagement portion also develops axial end thrust in said first direction.

Claim 9

Dependent Claim 28 words

The assembly of claim 5 wherein the second engagement portions of said combination gears are each divided into two separate meshing areas which straddle said first gear portion.

Claim 10

Dependent Claim 32 words

The assembly of claim 6 wherein said separate meshing areas of said second engagement portions have helical teeth of the same hand and said sun gears have helical teeth of opposite hand.

Claim 11

Dependent Claim 32 words

The assembly of claim 6 wherein said separate meshing areas of said second engagement portions have helical teeth of opposite hand and said sun gears have helical teeth of the same hand.

Claim 12

Dependent Claim 69 words

The assembly of claim 5 further comprising: spring means associated with each said combination gear for biasing the ends of the gears away from contact with said bearing surface, and wherein the end thrust developed by the engagement portions of the gear is sufficient to overcome said spring bias and to cause contact between the gear and said bearing surface whenever the gear is subjected to a predetermined torque.

Claim 13

Dependent Claim 26 words

The assembly of claim 5 wherein said second tooth design comprises helical teeth but of opposite hand to the gear teeth of said first tooth design.

Claim 14

Dependent Claim 180 words

A gear differential having a planetary gearing arrangement comprising: a housing that is rotatable about a pair of axle shafts which share a common axis; a pair of sun gears positioned within said housing relative to respective bearing surfaces and adapted to be fixed to the respective ends of said axle shafts for rotation; at least one pair of planetary gears, each gear of the pair being mounted within said housing in relation to at least one respective bearing surface for rotation about a respective axis which is parallel to said common axis; said sun and planetary gears having helical teeth and exerting axial end thrust against their respective bearing surfaces when subjected to torque; and each planetary gear having a first engagement portion with helical teeth for meshing with a respective one of said sun gears and a second engagement portion for meshing with its paired planetary gear, said first and second engagement portions having teeth designed so that said axial end thrust exerted by said planetary gears is greater than the end thrust exerted by said sun gears.

Claim 15

Dependent Claim 180 words

A gear differential having a planetary gearing arrangement comprising: a housing that is rotatable about a pair of axle shafts which share a common axis; a pair of sun gears positioned within said housing relative to respective bearing surfaces and adapted to be fixed to the respective ends of said axle shafts for rotation; at least one pair of planetary gears, each gear of the pair being mounted within said housing in relation to at least one respective bearing surface for rotation about a respective axis which is parallel to said common axis; said sun and planetary gears having helical teeth and exerting axial end thrust against their respective bearing surfaces when subjected to torque; and each planetary gear having a first engagement portion with helical teeth for meshing with a respective one of said sun gears and a second engagement portion for meshing with its paired planetary gear, said first and second engagement portions having teeth designed so that said axial end thrust exerted by said planetary gears is greater than the end thrust exerted by said sun gears.

Claim 16

Dependent Claim 31 words

The gear differential of claim 11 wherein the gear teeth of said second engagement portion are also helical but of opposite hand to the gear teeth of said first engagement portion.

Claim 17

Dependent Claim 42 words

The gear differential of claim 11 wherein the second engagement portion of each planetary gear is divided into two separated areas which straddle said first engagement portion, said separated areas being in mesh with the separated areas of a paired planetary gear.

Claim 18

Dependent Claim 22 words

The gear differential of claim 13 wherein said separated areas of the second engagement portion have helical teeth of the same hand.

Claim 19

Dependent Claim 21 words

The gear differential of claim 13 wherein said separated areas of the second engagement portion have helical teeth of opposite hand.

Claim 20

Dependent Claim 77 words

The gear differential of claim 11 further comprising: spring means associated with each said planetary gear for biasing the gear away from said bearing surface, and wherein the end thrust developed by the engagement portions of the gear is sufficient to overcome said spring bias and to cause contact between the gear and the bearing surface whenever the gear is subject to a predetermined torque from one of its respective sun gear and its paired planetary gear.

Claim 21

Dependent Claim 110 words

The gear differential of claim 16 wherein: said spring means biases each planetary gear away from contact with bearing surfaces located in proximity to each of its respective ends; and said end thrust is in a first direction when said housing is rotated in a first direction about said common axis, and said end thrust is in a second direction when said housing is rotated in a second direction about said common axis; the end thrust in each direction being sufficient to overcome said spring bias and to cause contact between the gear and a respective one of said bearing surfaces whenever the gear is subject to said predetermined torque.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1995-12-08	1996-06-08	1996-12-08	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1999-12-08	2000-06-08	2000-12-08	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2003-12-08	2004-06-08	2004-12-08	$7700.00	Window Closed / Lapsed

End-thrust design for parallel-axis differential

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