GB2127931A - Front wheel drive assembly for a vehicle - Google Patents

Front wheel drive assembly for a vehicle Download PDF

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Publication number
GB2127931A
GB2127931A GB08227450A GB8227450A GB2127931A GB 2127931 A GB2127931 A GB 2127931A GB 08227450 A GB08227450 A GB 08227450A GB 8227450 A GB8227450 A GB 8227450A GB 2127931 A GB2127931 A GB 2127931A
Authority
GB
United Kingdom
Prior art keywords
front wheel
gear case
wheel drive
drive assembly
cover
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB08227450A
Other versions
GB2127931B (en
Inventor
Tadao Nishihara
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Iseki and Co Ltd
Original Assignee
Iseki and Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Iseki and Co Ltd filed Critical Iseki and Co Ltd
Priority to GB08227450A priority Critical patent/GB2127931B/en
Publication of GB2127931A publication Critical patent/GB2127931A/en
Application granted granted Critical
Publication of GB2127931B publication Critical patent/GB2127931B/en
Expired legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K17/00—Arrangement or mounting of transmissions in vehicles
    • B60K17/30—Arrangement or mounting of transmissions in vehicles the ultimate propulsive elements, e.g. ground wheels, being steerable
    • B60K17/303—Arrangement or mounting of transmissions in vehicles the ultimate propulsive elements, e.g. ground wheels, being steerable with a gearwheel on the steering knuckle or kingpin axis
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K17/00—Arrangement or mounting of transmissions in vehicles
    • B60K17/04—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or kind of gearing
    • B60K17/043—Transmission unit disposed in on near the vehicle wheel, or between the differential gear unit and the wheel
    • B60K17/046—Transmission unit disposed in on near the vehicle wheel, or between the differential gear unit and the wheel with planetary gearing having orbital motion
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H1/00—Toothed gearings for conveying rotary motion
    • F16H1/006—Toothed gearings for conveying rotary motion the driving and driven axes being designed to assume variable positions relative to one another during operation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H1/00—Toothed gearings for conveying rotary motion
    • F16H1/28—Toothed gearings for conveying rotary motion with gears having orbital motion

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Arrangement And Driving Of Transmission Devices (AREA)

Abstract

A front wheel drive assembly for agricultural vehicle or the like comprises a front axle housing 2 accommodating a front wheel drive shaft 1. An inner gear case 3 is attached to the outer side of the front axle housing 2. An outer gear case 4 is steerably secured to the inner gear case 3. A planetary gear mechanism (13, 14, 18, 21a) is adapted to be driven by the front wheel drive shaft 1 through bevel gear mechanisms (12, 6, 7, 20), and is supported by an intermediate seat 17 which is fitted in the outer gear case 4. The arrangement is such that, when a cover 25 supporting the front wheel axle 24 is coupled to the outer side of the outer gear case 4, the front wheel axle 24 is automatically fitted to the output shaft 13c of the planetary gear mechanism (13, 14, 18, 21a). <IMAGE>

Description

SPECIFICATION Front wheel drive assembly for a vehicle The present invention relates to a front wheel drive assembly for a vehicle, making use of a planetary gear mechanism as the final stage of the speed reduction.
Such front wheel drive assemblies have been known as making use of a planetary gear system as the final stage of the speed reduction, in order to minimise the size of the gear case while obtaining a sufficiently large speed reduction ratio. This kind of assembly is disclosed, for example, in the specification of the United States Patent No. 3469647. This type of front wheel drive assembly, however, is extremely difficult to assemble.For instance, in the known assembly disclosed in the above-mentioned specification, it is necessary to connect the front wheel axle to the output shaft of the planetary gear simultaneously with the assembling of the gears of the planetary gear mechanism, because the axial stopper for the front wheel axle is disposed in the vicinity of the inner side of the front wheel axle, i.e. in the vicinity of the point of meshing between the sun gear and the planetary gear. In consequence, the work has to be done in a restricted space and, in addition, the state of meshing of gears in the planetary gear mechanism can hardly be checked.
Accordingly, an object of the invention is to provide a front wheel drive assembly for vehicles, improved to overcome the abovedescribed problems of the prior art.
To this end, according to the invention, there is provided a front wheel drive assembly for a vehicle comprising: a front axle housing accommodating a front wheel drive shaft, an inner gear case attached to the outer end of the front axle housing, an outer gear case fitted to the inner gear case for free steering rotation, a planetary gear mechanism adapted to be driven by said front wheel driving shaft through a bevel gear mechanism and supported by an intermediate seat adapted to be fitted in the outer gear case, and a front wheel axle to which a front wheel is securable and supported by a cover, the front wheel axle being adapted to fit the output shaft of the planetary gear mechanism when the cover is coupled to the outer end of the outer gear case.
According to this arrangement, the planetary gear mechanism can be assembled before attaching the front wheel axle, so that it is possible to observe and check the state of meshing of the gears in the planetary gear mechanism. Furthermore, the work of coupling the front wheel axle to the output shaft is facilitated considerably. In addition, the size of the assembly as a whole can be reduced sufficiently while achieving a large speed reducing ratio, thanks to the combination of the bevel gear mechanism and the planetary gear mechanism. The planetary gear mechanism is disposed at a lateral side of the bevel gear mechanism and is made to have a height substantially equal to that of the bevel gear mechanism. In consequence, the sizes of the inner and outer gear cases are reduced to increase the road clearance to ensure safer driving on rough roads or the like.In addition, a closed driving case is formed by the front axle housing, inner gear case, outer gear case and the cover supporting the front wheel axle, so that the invasion by foreign matter such as water, mud and so forth is prevented even if the vehicle is used in muddy and wet ground such as a paddy field.
In order that the invention may be readily understood a preferred embodiment thereof will now be described by way of example with reference to the accompanying drawings in which Figure 1 is a vertical sectional front elevational view of a front wheel drive assembly in accordance with the invention; and Figure 2 is a sectional view taken along the line A-A of Fig. 1.
Referring to the drawings, a front axle housing 2 houses a front wheel drive shaft 1. An inner gear case 3 provided at its lower portion with a tubular journal boss 3a is attached to the outer side of the front axle housing 2. An outer gear case 4 has an upwardly opening gear room 4a, an upper journal hole 4b and a lower journal hole 4c. The upper journal hole 4b is rotatably fitted to a journal boss 5a on an upper cover 5 fitting to the upper end opening of the inner gear case 3, while the lower journal hole 4c is rotatably secured to a journal boss 3a. A steering central shaft 8 has bevel gears 6 and 7 fixed to the upper and lower ends thereof.The shaft 8 is supported through the bevel gear 6 by means of a bearing 9 on the inner gear case and by means of a bearing 10 on the outer gear case, in such a manner that the shaft 8 is coaxial with the upper journal boss 5a and the lower journal boss 3a. A bevel gear 1 2 is fixed to the outer portion of the front wheel drive shaft 1 supported by a bearing 11. The bevel gear 1 2 is engaged by the upper bevel gear 6 to form an uper bevel gear mechanism.
A carrier 1 3 has a central bore 1 3a and a spline hole 1 3b and carries at its peripheral portion a plurality of shafts 1 5 which carry planet gears 14. A bearing 1 6 has an inner race which fits around the output shaft 1 3c formed at the outside of the carrier 1 3. An intermediate seat 1 7 fitted to the outer race of the bearing 1 6 and an internally-toothed ring gear 1 8 are secured to the outer side of the outer gear case 4 by means of bolts 19.
According to this arrangement, the planet gears 14 and the carrier 1 3 are exposed to the gear space 4a. In addition, a sum gear shaft 21 integral with a sun gear 21a and fitting to a bevel gear 20 is supported by the inner wall of the gear space 4a by means of a bearing 22. in consequence, the bevel gear 20 meshes with the lower bevel gear 7 to form a lower bevel gear mechanism. When the carrier 1 3 is secured to the outer gear case 4 together with the ring gear 18 and the intermediate seat 17, the sun gear 21a meshes with the planet gears 1 4 thereby to form a planetary gear system consisting of the planet gears 1 4 meshing with the sun gear 21a and the ring gear 18, and the carrier 13.
A front wheel axle 24b is provided at its outer end with a seat 24a for mounting a wheel disc 23 and also with a male screw thread 24b and a spline boss 24c. The front wheel axle 24 is inserted into the cover 25 and is fitted into the inner race of a bearing 26 which has an outer race fitting in the cover 25. A nut 27 is screwed to the male screw thread 24b thereby to fix the inner race of the bearing 26 with respect to the cover 25.
When the cover 25 is coupled to the outer end of the gear case 4 by means of bolts 28, the outer end portion of the sun gear shaft 21 is supported by the inner side of the wheel axle 24 through a bearing 29 and, at the same time, the spline boss 24c of the wheel axle 24 is fitted in the spline hole 1 3b of the output shaft 13c.
In the illustrated embodiment of the invention, the planetary gear mechanism is constructed to have a height substantially equal to the upper and lower bevel gear mechanism. The arrangement is such that, when the cover 25 is coupled to the outer side of the outer gear case 4, the inner peripheral surface 25a of the inner end of the cover 25 projects outwardly from the outer side of the gear case 4 to facilitate the achievement of axial alignment between the sun gear shaft 21 and the front wheel axle 24, and between the output shaft 1 3c and the front wheel axle 24.
In addition, where the cover 25 has been secured to the outer gear case 4, the inner side portion of the nut 27 abuts the outer side of the output shaft 13c, so that the nut 27 plays the double role of axial stopper for the output shaft 1 3c and axial stopper for the bearing 26. A rim 31 mounting a front wheel 30 is secured to the outer periphery of the wheel disc 23. A reference numeral 32 denotes stopper rings by which the shafts 1 5 are fixed to the carrier 13, while 33 denotes a needle bearing. A numeral 34 denotes a thrust bearing, while numerals 35, 36 and 37 denote oil seals.
Therefore, as a knuckle arm (not shown) secured to the outer gear case 4 is steered by a steering mechanism, the outer gear case 4, front wheel axle 24 and the front wheel 29 secured to the latter are swung around the upper journal boss 5a, lower journal boss 3a and the steering center shaft 8. As the front wheel drive shaft 1 is driven through a front differential gear (not shown), the sun gear shaft 21 is driven through the upper and lower bevel gear mechanism so that the carrier 1 3 is rotated at a speed much lower than the speed of rotation of the sun gear shaft 21 due to the meshing of the planet gears 14 with the ring gear 1 8. In consequence, the front wheel axle 24 and, hence, the front wheel 29 are rotated at a sufficiently reduced speed.
In the front wheel driving device of the invention, as has been described, the planetary gear mechanism is supported by the intermediate seat 1 7 which in turn is fitted in the outer gear case 4. When the cover 25 supporting the front wheel axle 24 is coupled to the outer side of the outer gear case 4, the front wheel axle 24 just fits in the output shaft 1 3c of the planetary gear mechanism. It is, therefore, possible to observe and check the state of the gears of the planetary gear mechanism before the outer end of the outer gear case 4 is closed by the cover 25.
Namely, it is possible to easily check the state of meshing of the planet gears 14 and the ring gear 1 8 and so forth visually so that the adjustment of meshing condition is facilitated advantageously. Since the coupling of the front wheel axle 24 to the output shaft 1 3c of the planetary gear mechanism is completed by fitting the cover 25 to the outer gear case 4, the assembling of the device as a whole is made in quite an easy manner. The size of the device as a whole is remarkably reduced and, hence, the weight and cost are reduced while attaining a large speed reduction ratio, thanks to the combination of the bevel gear mechanisms and the planetary gear mechanism.In addition, since the front axle housing 2, inner gear case 3, outer gear case 4 and the cover 25 supporting the front wheel axle 24 in combination form a closed case, water and mud are prevented from coming into the device even if the vehicle runs on wet and muddy ground such as a paddy field.
In the case where the installation height of the planetary gear mechanism is made substantially equal to that of the upper and lower bevel gear mechanisms, the configuration of the outer gear case 4 and the cover 25 accommodating these parts are made substantially flat and positioned substantially at the same height. This conveniently increases, in combination with the reduced size of the device as a whole, the height of the lower most portion of the device. This means that the road clearance during running is decreased so that the vehicle can safely clear a ridge in the paddy field.
In the embodiment in which the cover 25 is coupled to the outer gear case 4 while being guided by the outer peripheral surface 1 7a of the intermediate seat 17, it is possible to easily attain the axial alignment between the sun gear shaft 21 and the front wheel axle 24 and between the output shaft 1 3c and the front wheel axle 24, so that the assembling of the shafts is very much facilitated. Furthermore, in the embodiment in which the nut 27 screwed to the front wheel axle 24 serves as an axial stopper for the bearing 26 by which the front wheel axle 24 is supported on the cover 25 and an axial stopper for the output shaft 13c, the axial stopping of the front wheel axle 24 in relation to the output shaft 1 3c is directly achieved by the coupling of the cover 25 to the outer gear case 4. This remarkably simplifies the assembling work as compared with the conventional device in which the axial stopper has to be positioned in the vicinity of the inner side of the front wheel axle.

Claims (5)

1. A front wheel drive assembly for a vehicle comprising: a front axle housing accommodating a front wheel drive shaft, an inner gear case attached to the outer end of the front axle housing, an outer gear case fitted to the inner gear case for free steering rotation, a planetary gear mechanism adapted to be driven by said front wheel driving shaft through a bevel gear mechanism and supported by an intermediate seat adapted to be fitted in the outer gear case, and a front wheel axle to which a front wheel is securable and supported by a cover, the front wheel axle being adapted to fit the output shaft of the planetary gear mechanism when the cover is coupled to the outer end of the outer gear case.
2. A front wheel drive assembly for a vehicle according to claim 1, wherein the planetary gear mechanism is disposed laterally of the bevel gear mechanisms substantially at the same installation height as the latter.
3. A front wheel drive assembly for a vehicle according to claim 1 or 2, wherein said cover is adapted to be coupled to the outer gear case while being guided by the outer peripheral surface of the intermediate seat.
4. A front wheel drive assembly for a vehicle according to claim 1, 2 or 3, further comprising a nut screwed to the front wheel axle, the nut serving as an axial stopper for a bearing by which the front wheel axle is supported by the cover and also as an axial stopper for the output shaft.
5. A front wheel drive assembly substantially as herein described with reference to the accompanying drawings.
GB08227450A 1982-09-27 1982-09-27 Front wheel drive assembly for a vehicle Expired GB2127931B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08227450A GB2127931B (en) 1982-09-27 1982-09-27 Front wheel drive assembly for a vehicle

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB08227450A GB2127931B (en) 1982-09-27 1982-09-27 Front wheel drive assembly for a vehicle

Publications (2)

Publication Number Publication Date
GB2127931A true GB2127931A (en) 1984-04-18
GB2127931B GB2127931B (en) 1986-01-08

Family

ID=10533173

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08227450A Expired GB2127931B (en) 1982-09-27 1982-09-27 Front wheel drive assembly for a vehicle

Country Status (1)

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GB (1) GB2127931B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2144086A (en) * 1983-07-28 1985-02-27 Kubota Ltd Axle reduction apparatus for tractors
US6557189B2 (en) * 2000-07-06 2003-05-06 Arjo Limited Invalid positioning device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2144086A (en) * 1983-07-28 1985-02-27 Kubota Ltd Axle reduction apparatus for tractors
US6557189B2 (en) * 2000-07-06 2003-05-06 Arjo Limited Invalid positioning device

Also Published As

Publication number Publication date
GB2127931B (en) 1986-01-08

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19920927