阅读说明：本技术 紧凑型行星差速器 (Compact planetary differential mechanism ) 是由 玛丽恩·杰克·英斯 钟归辉 于 2018-05-07 设计创作，主要内容包括：提供了一种紧凑型行星差速器，其包括驱动输入环形齿轮和行星齿轮承载架，该驱动输入环形齿轮具有外齿，该行星齿轮承载架具有第一轴向侧和第二轴向侧并以与驱动输入环形齿轮旋转固定的方式连接至驱动输入环形齿轮。在行星齿轮承载架的第一轴向侧上定位有第一行星齿轮，并且在第二轴向侧上定位有第二行星齿轮，其中，第一行星齿轮和第二行星齿轮布置为相互啮合对，并且行星齿轮承载架包括接口开口，行星齿轮的相应的相互啮合对通过该接口开口彼此接触。在行星齿轮承载架的第一轴向侧和第二轴向侧上分别定位有销板，其中，销板在第一行星齿轮中的每个第一行星齿轮和第二行星齿轮中的每个第二行星齿轮的位置处包括对准开口。小齿轮轴延伸穿过销板中的这些对准开口和行星齿轮承载架中的小齿轮轴开口。第一行星齿轮或第二行星齿轮中的单个行星齿轮以可旋转的方式支承在小齿轮轴中的各自相应的一个小齿轮轴上。小齿轮轴使销板夹紧靠向行星齿轮承载架。在行星齿轮承载架的第一轴向侧上定位有第一太阳齿轮并且第一太阳齿轮与第一行星齿轮接合。在行星齿轮承载架的第二轴向侧上定位有第二太阳齿轮并且第二太阳齿轮与第二行星齿轮接合。(A compact planetary differential is provided that includes a drive input ring gear having external teeth and a planet gear carrier having first and second axial sides and being connected to the drive input ring gear in a rotationally fixed manner with the drive input ring gear. A first planet gear is positioned on a first axial side of the planet gear carrier and a second planet gear is positioned on a second axial side, wherein the first and second planet gears are arranged in intermeshing pairs and the planet gear carrier comprises interface openings through which the respective intermeshing pairs of planet gears are in contact with each other. Pin plates are positioned on the first and second axial sides of the planet gear carrier, respectively, wherein the pin plates include aligned openings at the location of each of the first planet gears and each of the second planet gears. The pinion shafts extend through these aligned openings in the pin plate and pinion shaft openings in the planet gear carrier. Individual ones of the first or second planet gears are rotatably supported on respective ones of the pinion shafts. The pinion shaft abuts the pin plate clip against the planet gear carrier. A first sun gear is positioned on a first axial side of the planet gear carrier and is engaged with the first planet gears. A second sun gear is positioned on a second axial side of the planet gear carrier and is in engagement with the second planet gears.)

1. A compact planetary differential, comprising:

a drive input ring gear having external teeth;

a planet gear carrier having a first axial side and a second axial side, the planet gear carrier being connected to the drive input ring gear in a rotationally fixed manner with the drive input ring gear;

first and second planet gears, the first planet gears being located on the first axial side of the planet gear carrier, the second planet gears being located on the second axial side of the planet gear carrier, the first and second planet gears being arranged in intermeshing pairs, and the planet gear carrier comprising interface openings through which the respective intermeshing pairs of the first and second planet gears contact each other;

first and second pin plates located at the first and second axial sides of the planet gear carrier, respectively, the first and second pin plates including alignment openings at a location for each of the first and second planet gears;

a pinion shaft extending through the aligned openings in the first and second pin plates and a pinion shaft opening in the planet gear carrier, individual ones of the first or second planet gears being rotatably supported on a respective corresponding one of the pinion shafts;

a first sun gear located on the first axial side of the planet gear carrier, the first sun gear being engaged with the first planet gears; and

a second sun gear located on the second axial side of the planet gear carrier, the second sun gear being engaged with the second planet gears.

2. The compact planetary differential according to claim 1, wherein the coupling of the pinion shaft to the pin plate urges the pin plate clamp against the planet gear carrier.

3. The compact planetary differential of claim 1, wherein the first sun gear includes a first hub, a first web, and a first outer rim with a first inner ring gear, and the first inner ring gear is engaged with the first planet gears, the second sun gear includes a second hub, a second web, and a second outer rim with a second inner ring gear, and the second inner ring gear is engaged with the second planet gears, and the planet carrier includes at least one recess adjacent the first and second hubs, and at least one support bearing is positioned in the at least one recess, the at least one support bearing adapted to receive ends of first and second shafts extending through the first and second hubs.

4. The compact planetary differential of claim 1, wherein axially outward facing sides of the openings in the first and second pin plates are chamfered and ends of the pinion shafts are riveted in the openings, and/or the first and second hub portions include internal splines adapted to slidingly receive splined shaft ends.

5. The compact planetary differential of claim 1, wherein the axes of the first and second planet gears are radially located at an equal distance from the axis of the compact planetary differential, and the equal distance of the axes of the first and second planet gears from the axis of the compact planetary differential is less than 60% of the diameter of the input ring gear.

6. The compact planetary differential of claim 1, wherein at least one of the first and second sun gears is interchangeable, the first and second planet gears are interchangeable, or the first and second pin plates are interchangeable.

7. The compact planetary differential according to claim 3, further comprising annular recesses at the first and second axial sides of the planetary gear carrier that at least partially receive the first and second outer rims of the first and second sun gears, respectively, and preferably a first seal is positioned between the first outer rim and the recess at the first axial side of the planetary gear carrier, and preferably a second seal is positioned between the second outer rim and the recess at the second axial side of the planetary gear carrier.

8. The compact planetary differential of claim 1, wherein the planet gear carrier includes a first counterbore on the first axial side and a second counterbore on the second axial side, the first counterbore receives the first planet gear, the second counterbore receives the second planet gear, and the interface opening is formed by axial overlap of the first counterbore and the second counterbore.

9. The compact planetary differential according to claim 1, wherein the drive input ring gear is formed as a separate component from steel and is connected to the planet gear carrier.

10. The compact planetary differential of claim 1, wherein a radially innermost portion of each of the first and second planet gears is radially within 0.2 inches of a radially outer portion of the first and second hub portions to provide a radially compact arrangement.

Technical Field

The present invention relates to the field of drive trains for motor vehicles, and in particular to differentials.

Background

Motor vehicles typically include a drive train having a main drive, such as an internal combustion engine, paired with a transmission to provide different gear ratios from the engine to the drive wheels. Typically, the transmission is connected to a differential which transfers torque from the transmission to the output shaft, wherein the differential compensates for different rotational speeds of the wheels attached to the output shaft, e.g. occurring during cornering.

Differentials are also known in both spur and bevel gear differentials. Spur gear differentials offer the advantage of a substantial reduction in the axial length of the differential in the direction of the output axis, compared to bevel gear differentials. Spur gear differentials utilize a spur gear connected to a planet gear carrier, which is itself driven by the transmission output and which drives the output shaft via a sun gear engaged with the planet gears. Here the first set of planet gears is associated with a first sun gear and the second set of planet gears is associated with a second sun gear, wherein the first and second planet gears further mesh with each other via the first and second sets of planet gears axially overlapping and engaging. The number of teeth of the two sets of planet gears is equal, and the number of teeth of the first sun gear and the number of teeth of the second sun gear are also equal. Typically, the teeth of the first sun gear are arranged on an addendum circle having an addendum circle diameter different from an addendum circle diameter of an addendum circle on which the teeth of the second sun gear are arranged, such that the first set of planet gears mesh only with the first sun gear and the second set of planet gears mesh only with the second sun gear. Such a spur gear differential is known from US8,480,532, US8,480,532 is owned by the assignee of the present invention, and US8,480,532 is incorporated by reference in its entirety as if fully set forth herein.

Other experiments on spur gear differentials have been performed by the assignee of the present invention, together with the gear research center of the munich technical university and the general automotive power system germany ltd, where the sun gear is provided as a gear with internal ring teeth in engagement with planetary gears.

The bevel gear differential includes a carrier in which a pair of drive bevel gears are mounted, the pair of drive bevel gears being engaged with a pair of driven bevel gears having a common axis arranged perpendicular to the common axis of the drive bevel gears. The driven bevel gear is connected to the output shaft.

The automotive field continues to seek additional ways to reduce the weight of motor vehicles to improve efficiency. Furthermore, modularizing the parts of the drive train to more easily install and remove the engine, transmission, and differential is also a consideration in order to reduce assembly costs.

It would be beneficial to reduce the weight of the drive train of a motor vehicle and to reduce the installation space. It would also be advantageous to reduce manufacturing costs. This should be achieved in its entirety without sacrificing functionality or reliability.

Disclosure of Invention

A compact planetary differential is provided that includes a drive input ring gear having external teeth and a planet carrier having first and second axial sides, the planet carrier being connected to the drive input ring gear in a rotationally fixed manner with the drive input ring gear. A first planet gear is positioned on a first axial side of the planet gear carrier and a second planet gear is positioned on a second axial side of the planet gear carrier, wherein the first and second planet gears are arranged in intermeshing pairs and the planet gear carrier comprises interface openings through which the respective intermeshing pairs of the first and second planet gears contact each other. First and second pin plates are positioned on first and second axial sides of the planet gear carrier, respectively, wherein the first and second pin plates include aligned openings at the location of each of the first and second ones of the first planet gears. The pinion shaft extends through the aligned openings in the first and second pin plates and the pinion shaft opening in the planet gear carrier. Individual ones of the first or second planet gears are rotatably supported on respective ones of the pinion shafts. The pinion shaft is preferably connected to the pin plate and clamps the pin plate against the planet gear carrier. On a first axial side of the planet gear carrier there is located a first sun gear, which preferably has a first hub, a first web and a first outer rim with a first inner ring gear, and which is preferably in engagement with the first planet gears by means of a first inner ring gear by mutual meshing contact. Thus, the first sun inner ring gear orbits the first planetary gear. On a second axial side of the planet gear carrier there is located a second sun gear, preferably having a second hub, a second web and a second outer rim with a second inner ring gear, and the second sun gear is engaged with the second planet gears by intermeshing contact, preferably with a second inner ring gear. Thus, the second sun inner ring gear orbits the second planet gears. Preferably, the planet carrier includes at least one recess adjacent the first and second hub portions and at least one support bearing is located in the at least one recess and adapted to receive the ends of the first and second shafts extending through the first and second hub portions. This arrangement provides a more compact planetary differential than known prior art spur gear differentials or planetary differentials. Furthermore, the first and second planet gears, the first and second sun gears and the first and second pin plates are preferably interchangeable, respectively, thereby reducing the number of different components that need to be manufactured, which reduces costs and simplifies assembly. Further, the arrangement of the pin plates at each end of the pinion shaft provides a mechanically stable assembly that improves reliability and service life.

In one preferred arrangement, the compact planetary differential further comprises a respective needle bearing between each of the first and second planet gears and the respective pinion shaft. This increases the service life and reduces internal friction.

Preferably, the at least one recess includes first and second recesses on first and second axial sides of the planet gear carrier, respectively, and the at least one support bearing includes first and second support bearings. A first support bearing is located in the first recess and a second support bearing is located in the second recess. In order to reduce friction and increase service life, the support bearing is preferably a rolling bearing.

In a preferred embodiment, the axially outwardly facing sides of the openings in the first and second pin plates are chamfered, and the ends of the pinion shaft are riveted in the openings. The pinion shaft may also be retained by other methods.

Preferably, the first and second hub portions include internal splines adapted to slidingly receive the splined shaft end portions.

In a preferred arrangement of the compact planetary differential, the axes of the first and second planet gears are located radially at equal distances from the axis of the compact planetary differential. Preferably, the axes of the first planet gears and the axes of the second planet gears are equidistant from the axis of the compact planetary differential less than 60% of the diameter of the input ring gear.

To reduce manufacturing costs, the first and second sun gears may be forged to net shape, and the teeth are preferably hardened. The sun gear may also be machined and hardened. The sun gear may also be cast or formed by powder metallurgy depending on the application and the load carried.

In a preferred arrangement, annular recesses are provided on the first and second axial sides of the planet gear carrier, which annular recesses at least partially receive the first outer rim of the first sun gear and the second outer rim of the second sun gear, respectively. This may provide a guard arrangement to prevent debris from entering the gear area. A first seal may also be provided between the first outer rim and the recess in the first axial side of the planet gear carrier, and a second seal may be provided between the second outer rim and the recess in the second axial side of the planet gear carrier. However, this arrangement is not necessary, and the entire compact planetary differential may be located in the housing and run in a gear oil bath.

The first and second shafts may be provided separately from the compact planetary differential or together. The shafts include splined ends that engage in respective first and second hub portions. The first and second shafts are preferably aligned with an axis of the compact planetary differential, and a cylindrical support portion extends from the splined end, and the at least one support bearing is located on the cylindrical support portion.

In a preferred arrangement, the first planet gears and the second planet gears axially overlap by at least about 25% of the axial tooth dimension of the first planet gears and the second planet gears.

Preferably, the planet gear carrier includes a first counterbore on the first axial side and a second counterbore on the second side, the first counterbore receiving the first planet gear, the second counterbore receiving the second planet gear, and the interface opening is formed by axial overlap of the first counterbore and the second counterbore.

To reduce weight and manufacturing costs, the drive input ring gear may be formed as a separate component made of steel, which is then connected to the planet gear carrier. The planet gear carrier may be machined or otherwise formed from a lower grade alloy steel or aluminum or any other suitable material.

In a preferred arrangement, the radially innermost portion of each of the first and second planet gears is radially within 0.2 inches of the radially outer portion of the first and second hub portions to provide a radially compact arrangement. This arrangement of the planet gears as close as possible to the axis of the compact planetary differential results in an overall reduction in the radial dimensions compared to the known prior art.

As one of ordinary skill in the art will appreciate from the present disclosure, the above-mentioned features may be used alone or in various combinations to provide a low cost, reduced size and weight differential for various motor vehicle applications.

Drawings

The foregoing summary, as well as the following detailed description of preferred embodiments of the invention, will be best understood when read in conjunction with the appended drawings, which illustrate a preferred embodiment of the invention. In the drawings:

FIG. 1 is a side view of a compact planetary differential with some components removed for clarity.

FIG. 2 is a cross-sectional view through the compact planetary differential of FIG. 1 taken along line 2-2 in FIG. 1.

Fig. 3 is an exploded cross-sectional view showing components of the compact planetary differential of fig. 1 and 2.

FIG. 4 is a cross-sectional view of the compact planetary differential similar to FIG. 2 showing the insertion of two axles.

FIG. 5 is a side view of the planet gear carrier and drive input ring gear.

Fig. 6 is a cross-sectional view taken along line 6-6 in fig. 5.

Fig. 7 is a side view of the planetary gear.

Fig. 8 is a cross-sectional view taken along line 8-8 in fig. 7.

Fig. 9 is a side view of the pin plate.

Fig. 10 is a cross-sectional view taken along line 10-10 in fig. 9.

Fig. 11 is a side view of a pinion shaft for supporting the planetary gear.

Fig. 12 is an end view of the pinion shaft shown in fig. 11.

Fig. 13 is a side view looking into the interior of the sun gear.

Fig. 14 is a cross-sectional view taken along line 14-14 in fig. 13.

FIG. 15 is a partial side view showing the first and second intermeshing planet gears located on the pin plate.

FIG. 16 is a partial cross-sectional view showing the intermeshing first and second planet gears located in the planet gear carrier and held in place on the pinion shafts connected to two of the pin plates.

Fig. 17 is a view of the compact planetary differential of fig. 1-3 including some preferred overall dimensions, the view being shown with some elements removed for clarity.

FIG. 18 is a view of an alternative arrangement of a compact planetary differential having a further reduced radial dimension and a slightly larger axial dimension.

Fig. 19 is an envelope diagram showing known overall dimensions of a prior known spur gear differential.

Detailed Description

Certain terminology is used in the following description for convenience only and is not limiting. The words "front", "rear", "upper" and "lower" designate directions in the drawings to which reference is made. The words "inwardly" and "outwardly" refer to directions toward and away from the parts referred to in the drawings. The term "about" means within typical manufacturing tolerances of the preferred amounts or ranges. These terms and terms having similar meanings are for ease of description when referring to the drawings and should not be considered limiting. "axially" refers to a direction along the axis of a shaft or similar object. A reference to a list of items referenced as "at least one of a, b, or c" (where a, b, and c represent listed items) refers to any single one or combination of the items a, b, or c.

The same reference numerals are used for the same elements or elements having the same function of the present invention. The embodiments shown merely represent examples of how a device according to the invention may be equipped. The embodiments shown do not represent a definitive limitation of the invention.

Referring to fig. 1-4, a first embodiment of a compact planetary differential 10 is shown. The compact planetary differential 10 includes a drive input ring gear 12 having external teeth 14. A planet gear carrier 16 having a first axial side 17 and a second axial side 18 is connected to the drive input ring gear 12 in a rotationally fixed manner with the drive input ring gear 12. The drive input ring gear 12 and the planet gear carrier 16 may be integrally formed, for example, by machining from a single piece of material, or the drive input ring gear 12 and the planet gear carrier 16 may be separately formed from two different materials, wherein the ring gear 12 is made of steel and has at least hardened teeth 14. In this case, the planet gear carrier 16 may be made of a lower grade steel, aluminum, or other suitable material and connected to the ring gear 12, for example, via welding, bolts, rivets, or any other suitable connection.

The first planet gears 22A to 22C are located on a first axial side 17 of the planet gear carrier 16. The second planet gears 26A-26C are located on the second axial side 18 of the planet gear carrier 16. The first planetary gears 22A-22C preferably have teeth 24 and the second planetary gears 26A-26C preferably have teeth 28. The first and second planet gears 22A-22C and 26A-26C are arranged in intermeshing pairs and the planet gear carrier 16 includes an interface opening 30, respective intermeshing pairs 22A, 26A of the first and second planet gears 22A-22C and 26A-26C; 22B, 26B; 22C, 26C contact each other through the interface opening 30. The planet gears 22A-22C, 26A-26C are preferably made of steel and may be machined, forged, manufactured by casting, or the planet gears 22A-22C, 26A-26C may be made of other materials, such as by powder metallurgy or any other suitable forming method, to provide the teeth 24, 28 with a desired profile and suitable tolerances for a particular application. As shown in fig. 1 and 3, the axes of the first planetary gears 22A to 22C and the axes of the second planetary gears 26A to 26C are located at an equal distance R from the axis of the compact planetary differential. In a preferred arrangement, the first and second planet gears 22A-22C and 26A-26C are interchangeable. Detailed drawings showing preferred planetary gears 22A-22C, 26A-26C are provided at fig. 7 and 8. As shown most clearly in fig. 2 and 16, the first planetary gears 22A to 22C and the second planetary gears 26A to 26C overlap by at least 25% of the axial tooth sizes W of the first planetary gears 22A to 22C and the second planetary gears 26A to 26C.

As shown in detail in fig. 2 and 3 and 5 and 6-fig. 5 and 6 show details of the planet gear carrier 16 and the drive input ring gear 12-preferably the planet gear carrier 16 includes a first counterbore 19 on the first axial side 17 and a second counterbore 20 on the second axial side 18, the first counterbore 19 receiving the first planet gears 22A-22C and the second counterbore 20 receiving the second planet gears 26A-26C. The interface opening 30 is formed by the axial overlap of the first counterbore 19 with the second counterbore 20.

Although in the preferred embodiment, 3 intermeshing pairs 22A, 26A of first and second planet gears are shown; 22B, 26B; 22C, 26C, one skilled in the art will recognize that the number of intermeshing pairs of first and second planet gears may vary. Preferably, there are at least two intermeshing pairs and there are intermeshing pairs of planet gears that are equally spaced in the circumferential direction.

Still referring to fig. 1-4, first and second pin plates 32 and 34 are positioned on the first and second axial sides 17 and 18, respectively, of the planet gear carrier 16. The first and second pin plates 32, 34 include aligned openings 36, 38 at the location of each of the first and second planet gears 22A-22C, 26A-26C. Details of a preferred pin plate are shown in fig. 9 and 10. Preferably, the first pin plate 32 and the second pin plate 34 are interchangeable. However, the first pin plate 32 and the second pin plate 34 may be provided as reversed components. In a preferred embodiment, the pin plates 32, 34 are made of steel. However, other materials may be used depending on the particular application.

The pinion shaft 40 extends through the aligned openings 36, 38 in the first and second pin plates 32, 34 and the pinion shaft opening 44 in the planet gear carrier 16. The pinion shaft openings 44 in the planet gear carrier 16 are shown in detail in fig. 5 and 6. Individual ones of the first planetary gears 22A to 22C or the second planetary gears 26A to 26C are rotatably supported on respective corresponding ones of the pinion shafts 40. The connection of the pinion shaft 40 to the pin plates 32, 34 preferably clamps the pin plates 32, 34 against the planet gear carrier 16. In a preferred embodiment, a respective needle bearing 42 is positioned between each of the first and second planet gears 22A-22C and 26A-26C and the respective pinion shaft 40. As shown in detail in fig. 4, two adjacent needle bearings 42 may be provided for each of the first and second planet gears 22A-22C, 26A-26C, depending on the particular configuration and load on the planet gears 22A-22C, 26A-26C.

In a preferred embodiment, the axially outwardly facing sides of the openings 36, 38 in the first and second pin plates 32, 34 include chamfers 37, 39, as shown in detail in fig. 9 and 10. As shown in detail in fig. 2 and 16, the ends of the pinion shaft 40 are preferably roller staked in the openings 36, 38 and enlarged to lock into the chamfers 37, 39. Alternatively, the connection between the pinion shaft 40 and the pin plates 32, 34 may be by welding or any other suitable connection means such as press fitting. Axial washers or bearings may be positioned between the planet gears 22A-22C, 26A-26C, the sides of the planet gear carrier 16, and the pin plates 32, 34 to reduce friction. These washers or bearings are not shown and are optionally used in one or more of the noted positions to ensure that the planet gears rotate freely.

Still referring to fig. 1-4, a first sun gear 50 is positioned on the first axial side 17 of the planet gear carrier 16, the first sun gear 50 having a first hub portion 52, a first web 54, and a first outer rim 56 with a first inner ring gear 58. The first inner ring gear 58 is engaged with the first planetary gears 22A to 22C. A second sun gear 60 is positioned on the second axial side 18 of the planet gear carrier 16, the second sun gear 60 also being provided with a second hub portion 62, a second web 64 and a second outer rim 66 with a second inner ring gear 68. The second inner ring gear 68 is engaged with the second planetary gears 26A to 26C. The first and second sun gears 50, 60 are preferably forged to net shape and are preferably interchangeable, thereby reducing the total number of parts. One preferred form of sun gear 50, 60 is shown in fig. 13 and 14. As shown in detail in fig. 3, 4, 13 and 14, the first and second hub portions 52, 62 preferably include internal splines 53, 63, the internal splines 53, 63 being adapted to slidably receive splined shaft ends. This is illustrated in FIG. 4, where the first and second shafts 81, 82 are shown as having respective splined ends 85, 86, the splined ends 85, 86 including splines adapted to slidingly engage the internal splines 53, 63 of the first and second hub portions 52, 62.

The planet gear carrier 16 includes at least one recess 72, 74 adjacent the first and second hub portions 52, 62, as best shown in fig. 2, 3 and 4. At least one support bearing, and preferably a first support bearing 76 and a second support bearing 78, are positioned in the at least one recess 72, 74 and are adapted to receive ends of the first and second shafts 81, 82 extending through the first and second hub portions 52, 54 formed as cylindrical support portions 83, 84.

In one preferred arrangement, the first and second shafts 81, 82 including the splined ends 85, 86 may be provided with the compact planetary differential 10, with the splined ends 85, 86 engaged in the respective first and second hub portions 52, 54. These first and second shafts 81, 82 are aligned with the axis of the compact planetary differential 10, and cylindrical support portions 83, 84 extend from splined ends and support the planet gear carrier 16 via support bearings 76, 78 located on the cylindrical support portions 83, 84 of the shafts 81, 82.

As shown, in the preferred embodiment, the at least one recess 72, 74 includes a first recess 72 and a second recess 74 on the first axial side 17 and the second axial side 18 of the planet gear carrier 16, respectively. Thus, the at least one support bearing includes a first support bearing 76 and a second support bearing 78, with the first support bearing 76 being located in the first recess 72 and the second support bearing 78 being located in the second recess 74. The first and second support bearings 76, 78 are preferably rolling bearings and include an outer race formed of bearing grade steel. Preferably, the cylindrical bearing portions 83, 84 of the shafts 81, 82 ride directly on the rollers of these bearings.

As shown in detail in fig. 2 and 3, in one preferred arrangement, annular recesses 90, 91 are provided on the first and second axial sides 17, 18 of the planet gear carrier 16, the annular recesses 90, 91 at least partially receiving the first and second outer rims 56, 66 of the first and second sun gears 50, 60, respectively. As indicated by the dashed lines in fig. 3, a first seal 92 is positioned between the first outer rim 56 and the recess 90 on the first axial side 17 of the planet gear 16, and a second seal 93 is positioned between the second outer rim 66 and the recess 91 on the second axial side 18 of the planet gear carrier 16. The seals 92, 93 may be formed as pressure seals or any other suitable sealing arrangement. Additionally, seals may be located at the radial peripheries of the first and second sun gears 50, 60 and in contact with the first and second axial sides 17, 18 of the planet gear carrier 16.

To ensure a compact size of the compact planetary differential 10, it is preferred that the equal distance R of the axes of the first and second planet gears 22A-22C and 26A-26C from the axis of the compact planetary differential is less than 60% of the diameter D of the input ring gear 12. For one preferred embodiment of the compact planetary differential 10, this diameter D is shown in fig. 17. In an alternative embodiment shown in fig. 18, dimension D is reduced even further.

In addition, to optimize the reduced radial envelope of the compact planetary differential 10, the radially innermost portion of each of the first and second planet gears 22A-22C and 26A-26C is radially within a small clearance distance from the radially outer portions of the first and second hub portions 52, 62 of the first and second sun gears 50, 60. The radial gap dimension is preferably within about 0.2 inches of the radially outer portions of the first and second hub portions 52, 62. However, the dimensions may be reduced according to the particular tolerances of the components of the compact planetary differential 10.

The compact size provided by the compact planetary differential 10 in comparison to a known prior art spur gear differential is illustrated in fig. 17, 18, and 19, where fig. 19 illustrates an envelope with known dimensions of a prior art spur gear differential. As shown in the embodiment of fig. 17, by positioning the axes of the first and second planet gears 22A-22C and 26A-26C at a common distance R from the planet differential axis, the dimension of which is less than 60% of the diameter D of the input ring gear 12, the overall radial dimension of the compact planetary differential is greatly reduced. Referring to fig. 18, here the radial dimension is even further reduced by allowing an increase in the axial dimension, which may be suitable for a particular application.

The compact differential 10 provides excellent differential functionality in a more compact size than previously available, thereby meeting today's modern motor vehicle design requirements.

In each of the above embodiments, all of the rotating components will be supported via suitable bearings or bushings, and these devices will be enclosed in a housing to allow lubrication. These items are not described in further detail since they are conventional in the art.

Having thus described the invention in detail, it will be appreciated and will be apparent to those skilled in the art that numerous physical variations are possible without departing from the inventive concepts and principles embodied herein, only a few of which are exemplified in the detailed description of the invention. It should also be appreciated that numerous embodiments are possible which incorporate only a portion of the preferred embodiments and which do not alter the inventive concepts and principles embodied herein relative to those portions. The present embodiments and alternative configurations are therefore to be considered in all respects as illustrative and/or illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all alternative embodiments and modifications of the embodiments which fall within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

List of reference numerals

10 compact planetary differential mechanism

12 drive input ring gear

14 outer tooth

16 planetary gear carrier

17 first axial side

18 second axial side

19 first counter bore

20 second counter bore

22A-22C first planetary gear

24 teeth

26A-26C second planetary gear

28 teeth

30 interface opening

32 first pin plate

34 second pin plate

36 aligned with the opening

37 chamfer

38 aligned with the opening

39 chamfer angle

40 pinion shaft

42 needle roller bearing

44 pinion shaft opening

50 first sun gear

52 first hub portion

53 internal spline

54 first hub part

56 first outer rim

58 first inner ring gear

60 second sun gear

62 second hub part

63 internal spline

64 second hub part

66 second outer rim

68 second inner ring gear

72 recess

74 recess

76 first support bearing

78 second support bearing

81 first axis

82 second axis

83 cylindrical bearing part

83 cylindrical bearing part

85 splined end

86 splined end

90 annular recess

91 annular recess

92 first seal

93 second seal