US3792628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Torque proportioning and spin limiting differential
Assignee: Mack Trucks Inc
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Filing: 1972-07-03
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Granted: 1974-02-19
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Expires: 1992-07-03
Abstract
Abstract An inter-axle differential for multiple driving-axle vehicles divides the engine-transmission output torque between two axles or axle groups in proportion to the load distribution among the axles or axle groups. The differential is of the planetary-gear type, with one side gear coupled to one axle or group and the other side gear coupled to the other axle or group. The appropriate torque division between the axles is accomplished by sizing the side gears such that the ratio of their diameters approximates that of the respective axle or axle group loads. A spin limiting feature is also provided. A pinion cage is coupled to the engine-transmission system and retains a plurality of pinions on their outside diameters in hardened cylindrical bores which include longitudinally spaced cut away portions on generally opposite sides of the pinions. The two side gears mesh with the exposed portions of the pinion gears, so that when the pinions rotate in the bores, gear separation forces are developed between the pinions and the side gears that are productive of couples which act across the pinions and urge them against the bore walls, thereby transferring torque to the high load side of the differential.
Inventors
- 👤 R Stieg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:00
CPC Classifications
B; B60; B60K; B60K17/00; B60K17/34; B60K17/344; B60K17/346; B60K17/3462; B60K17/3465; F; F16; F16H; F16H48/00; F16H48/20; F16H48/28
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
276 words
In a vehicle having a front axle, a rear axle, a prime mover, a drive train drivably coupling the prime mover to the front and rear axles, and a differential in the drive train for dividing the prime mover-drive train output torque between the front axle and the rear axle in approximately the same proportion as the load distribution between the front and rear axles, the improvement in the differential comprising: a pinion gear; a rotatable pinion cage; means defining a cylindrical bore in the pinion cage for rotatably receiving the pinion gear, the wall of the bore having at least two longitudinally spaced cut away portions to expose corresponding portions of the pinion gear; means coupled to the drive train for rotatably driving the pinion cage, thereby transmitting torque to the differential; a first side gear meshing with one exposed pinion gear portion and further being operatively coupled to one of the front and rear axles; and a second side gear meshing with the other exposed pinion gear portion and further being operatively coupled to the other of the front and rear axle; the first and second side gears having different pitch diameters, whereby each side gear transmits torque from the pinion gage to the associated axle in proportion to the ratio of the pitch diameters; and whereby when one of the front and rear axles encounters low traction conditions relative to the other axle, gear separation forces acting between the rotating pinion gear and the first and second side gears urge the pinion gear against the bore wall thereby generating frictional forces therebetween which are effective to transfer additional torque to the other axle.
Claim 2
Dependent Claim
276 words
In a vehicle having a front axle, a rear axle, a prime mover, a drive train drivably coupling the prime mover to the front and rear axles, and a differential in the drive train for dividing the prime mover-drive train output torque between the front axle and the rear axle in approximately the same proportion as the load distribution between the front and rear axles, the improvement in the differential comprising: a pinion gear; a rotatable pinion cage; means defining a cylindrical bore in the pinion cage for rotatably receiving the pinion gear, the wall of the bore having at least two longitudinally spaced cut away portions to expose corresponding portions of the pinion gear; means coupled to the drive train for rotatably driving the pinion cage, thereby transmitting torque to the differential; a first side gear meshing with one exposed pinion gear portion and further being operatively coupled to one of the front and rear axles; and a second side gear meshing with the other exposed pinion gear portion and further being operatively coupled to the other of the front and rear axle; the first and second side gears having different pitch diameters, whereby each side gear transmits torque from the pinion gage to the associated axle in proportion to the ratio of the pitch diameters; and whereby when one of the front and rear axles encounters low traction conditions relative to the other axle, gear separation forces acting between the rotating pinion gear and the first and second side gears urge the pinion gear against the bore wall thereby generating frictional forces therebetween which are effective to transfer additional torque to the other axle.
Claim 3
Dependent Claim
87 words
The vehicle of claim 1 wherein: the at least two cut away portions of the bore wall are located on generally opposite sides of the bore; whereby the gear separation forces acting between the first side gear and the pinion gear are generally oppositely directed from those acting between the second side gear and the pinion gear and thereby form a couple across the pinion gear so as to provide frictional forces between the pinion gear and the bore wall proportional to the magnitude of the couple.
Claim 4
Dependent Claim
72 words
The vehicle of claim 1 wherein the improvement in the differential further comprises: a plurality of cylindrical bores in the pinion cage, the bores being symmetrically arranged about the rotational axis of the cage; a pinion gear rotatably received in each bore; and wherein the first side gear meshes with one exposed portion of each pinion gear and the second side gear meshes with the other exposed portion of each pinion gear.
Claim 5
Dependent Claim
23 words
The vehicle of claim 1 wherein the first side gear is a ring gear and the second side gear is a sun gear.
Claim 6
Dependent Claim
67 words
The vehicle of claim 4 wherein: a plurality of pinion gears are rotatably held by the pinion cage, the pinion gears being symmetrically arranged about the rotational axis of the pinion cagE with their axes of rotation generally parallel to said rotational axis; and the sun gear and the ring gear are positioned with their rotational axes coaxial with the rotational axis of the pinion gear cage.
Claim 7
Dependent Claim
220 words
An unequal torque proportioning differential for use with vehicles having multiple driving axles comprising: a pinion gear; a rotatable pinion cage; means defining a cylindrical bore in the pinion cage for rotatably receiving the pinion gear, the wall of the bore having at least two longitudinally spaced cut away portions to expose corresponding portions of the pinion gear; means adapted to be coupled to the vehicle drive train for rotatably driving the pinion cage so as to transmit torque to the differential; a first side gear meshing with one exposed pinion gear portion and being operatively coupled to a first driving axle; and a second side gear meshing with the other exposed pinion gear portion and being operatively coupled to a second driving axle; the first and second side gears having different pitch diameters, whereby each side gear transmits torque to its associated driving axle in proportion to the ratio of the pitch diameters of the first and second side gears; and whereby when one of said first or second axles encounters low traction conditions relative to the other axle, gear separation forces acting between the rotating pinion gear and the first and second side gears urge the pinion gear against the bore wall thereby generating frictional forces therebetween which are effective to transfer additional torque to the other axle.
Claim 8
Dependent Claim
220 words
An unequal torque proportioning differential for use with vehicles having multiple driving axles comprising: a pinion gear; a rotatable pinion cage; means defining a cylindrical bore in the pinion cage for rotatably receiving the pinion gear, the wall of the bore having at least two longitudinally spaced cut away portions to expose corresponding portions of the pinion gear; means adapted to be coupled to the vehicle drive train for rotatably driving the pinion cage so as to transmit torque to the differential; a first side gear meshing with one exposed pinion gear portion and being operatively coupled to a first driving axle; and a second side gear meshing with the other exposed pinion gear portion and being operatively coupled to a second driving axle; the first and second side gears having different pitch diameters, whereby each side gear transmits torque to its associated driving axle in proportion to the ratio of the pitch diameters of the first and second side gears; and whereby when one of said first or second axles encounters low traction conditions relative to the other axle, gear separation forces acting between the rotating pinion gear and the first and second side gears urge the pinion gear against the bore wall thereby generating frictional forces therebetween which are effective to transfer additional torque to the other axle.
Claim 9
Dependent Claim
84 words
The differential of claim 6 wherein: the at least two cut away portions of the bore wall are located on generally opposite sides of the bore; whereby the gear separation forces acting between the pinion gear and the first side gear are generally oppositely directed from those acting between the pinion gear and the second side gear, thereby forming a couple across the pinion gear which develops frictional forces between the pinion gear and the bore in proportion to the magnitude of the couple.
Claim 10
Dependent Claim
57 words
The differential of claim 7 wherein: a plurality of pinion gears are rotatably held by the pinion cage, the pinion gears being arranged symmetrically about the rotational axis of the pinion cage with their axes of rotation generally parallel to said rotational axis; and each of the pinion gears meshes with the first and second side gears.
Claim 11
Dependent Claim
23 words
The differential of claim 7 wherein the first side gear comprises a ring gear and the second side gear comprises a sun gear.
Claim 12
Dependent Claim
267 words
A differential for resisting differential spinout comprising: a pinion cage having an axis of rotation and being rotatably driven by means supplying input torque to the differential, the pinion cage having a cylindrical bore provided therein with a longitudinal axis parallel to the axis of rotation of the pinion cage; an elongate pinion gear having an axis of rotation positioned in the cylindrical bore whereby the pinion gear is retained by the wall of the bore; the wall of the bore having at least two longitudinally spaced portions cut away to expose the pinion gear positioned therein, the cut away portions being positioned on generally opposite sides of the bore; a first side gear operatively coupled to a first output shaft and positioned to mesh with the pinion gear through one cut away portion of the bore wall; and a second side gear operatively coupled to a second output shaft and positioned to mesh with the pinion gear through the other cut away portion; whereby the torque applied to the pinion cage generates gear separation forces between the pinion gear and first side gear and the pinion gear and second side gear at their respective meshes when one of the output shafts is connected to a low traction load and the other output shaft to a high traction load, which forces form a couple across the pinion gear which urge the pinion gear against the bore wall opposite the respective meshes, so that frictional forces are developed between the pinion gear and the bore wall which are effective to transfer additional torque to the high traction side.
Claim 13
Dependent Claim
267 words
A differential for resisting differential spinout comprising: a pinion cage having an axis of rotation and being rotatably driven by means supplying input torque to the differential, the pinion cage having a cylindrical bore provided therein with a longitudinal axis parallel to the axis of rotation of the pinion cage; an elongate pinion gear having an axis of rotation positioned in the cylindrical bore whereby the pinion gear is retained by the wall of the bore; the wall of the bore having at least two longitudinally spaced portions cut away to expose the pinion gear positioned therein, the cut away portions being positioned on generally opposite sides of the bore; a first side gear operatively coupled to a first output shaft and positioned to mesh with the pinion gear through one cut away portion of the bore wall; and a second side gear operatively coupled to a second output shaft and positioned to mesh with the pinion gear through the other cut away portion; whereby the torque applied to the pinion cage generates gear separation forces between the pinion gear and first side gear and the pinion gear and second side gear at their respective meshes when one of the output shafts is connected to a low traction load and the other output shaft to a high traction load, which forces form a couple across the pinion gear which urge the pinion gear against the bore wall opposite the respective meshes, so that frictional forces are developed between the pinion gear and the bore wall which are effective to transfer additional torque to the high traction side.
Claim 14
Dependent Claim
23 words
The differential of claim 10 wherein the first side gear comprises a ring gear and the second side gear comprises a sun gear.
Claim 15
Dependent Claim
46 words
The differential of claim 10 wherein: a plurality of the cylindrical bores are provided in the pinion cage; an elongate pinion gear is positioned in each bore; and the first and second side gears mesh with each pinion through the cut away portions of said bores.
Claim 16
Dependent Claim
45 words
The differential of claim 12 wherein: the cylindrical bores and associated pinion gears are arranged symmetrically about the axis of rotation of the pinion cage; and the first and second side gears are positioned with their axes coaxial with the axis of the pinion cage.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |