GB2497416A - A gear train with direct drive between input and output - Google Patents
A gear train with direct drive between input and output Download PDFInfo
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- GB2497416A GB2497416A GB1221790.7A GB201221790A GB2497416A GB 2497416 A GB2497416 A GB 2497416A GB 201221790 A GB201221790 A GB 201221790A GB 2497416 A GB2497416 A GB 2497416A
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- 238000005755 formation reaction Methods 0.000 description 1
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Classifications
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- 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
- F16H3/00—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion
- F16H3/02—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion without gears having orbital motion
- F16H3/08—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion without gears having orbital motion exclusively or essentially with continuously meshing gears, that can be disengaged from their shafts
- F16H3/087—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion without gears having orbital motion exclusively or essentially with continuously meshing gears, that can be disengaged from their shafts characterised by the disposition of the gears
- F16H3/091—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion without gears having orbital motion exclusively or essentially with continuously meshing gears, that can be disengaged from their shafts characterised by the disposition of the gears including a single countershaft
- F16H3/0915—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion without gears having orbital motion exclusively or essentially with continuously meshing gears, that can be disengaged from their shafts characterised by the disposition of the gears including a single countershaft with coaxial input and output shafts
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- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
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Abstract
A gear train 10, for a single lay shaft automotive gearbox, comprises a main shaft 12 and a lay shaft 14 arranged parallel to one another. A plurality of gear pairs 42, 44, 46, 48 are spaced axially along the main and lay shafts 12, 14, each gear pair 42,44,46,48 comprising main and output shaft gears 42a, 44a, 46a, 48a and lay shaft gears 42b, 44b,4 6b, 48b meshed with the main and output shaft gears 42a, 44a, 46a, 48a. A plurality of dog rings 58a, 58b, 58c between the gear pairs couples a gear for rotation with a shaft. One of main shaft gears 46a is selectively coupleable to the input shaft 16 via dog ring 58b to transmit torque from the input shaft 16 to the lay shaft 14 to the output shaft 18, or by engaging both dog rings 58b, 58c with gear 46a direct drive is effected between the input shaft 16 and the output shaft 18.
Description
IMPROVED GEAR TRAIN
The present invention relates to an improved gear train and in particular, though not exclusively, to an improved gear train for a manually operated single lay shaft automotive gear box.
A manually operated automotive gearbox typically includes an input shaft which is connectable to an engine, an output shaft that is connected via a differential gear 0 arrangement to thc driven wheels of thc vehicle and a lay shaft. The input and output shafts are typically aligned along a common axis. The lay shaft is typically aligned on an axis that is substantially parallel to thc common axis of the input and output shafts.
The gear train of the gearbox typically includes an input gear pair arranged to transmit torquc to the lay shaft and a plurality of output gear pairs arranged to transmit torque to the output shaft. Typically the number of gear pairs equals thc number of forward gear ratios of the gearbox.
According to the present invention there is provided a gear train for a single lay shaft automotive gearbox, the gear train having a main shaft having a main shaft axis and a lay shaft having a lay shaft axis, the axes of the main and lay shafts being arranged parallel to one another, the main shaft comprising an input shaft and an output shaft, the input and output shafts being arranged coax ially on the main shaft axis and selectively rotatable relative to one another on said main shaft axis, the gear train further including a plurality of gear pairs spaced axially along the main and lay shafts, each gear pair comprising a main shaft gear and a lay shaft gear in meshed engagcmcnt with one another, and plurality of dog rings axially interspersed bctween the gear pairs for coupling a gear for rotation with a shaft, whcrcin thc plurality of gear pairs comprises two input shaft gear pairs whcre the main shaft gear of each of said input shaft gear pairs is fixed for rotation with the input shaft, and the lay shaft gear of each of said two input shaft gear pairs is selectively coupleable to the lay shaft, an output gear pair where the lay shaft gear is fixed for rotation with the lay shaft and the main shaft gear is selectively eoupleable to the output shaft, and a further gear pair wherein the lay shaft gear is fixed for rotation with the lay shaft and the main shaft gear is mounted to thc output shaft and further is selectively coupleable to either the input shaft to transmit torque from the input shaft to the lay shaft or to the output shaft to transmit torque from the lay shaft to the output shaft, or is utilisable to couple the input shaft to the output shaft to effect direct drive therebetwccn.
In such an embodiment, the main shaft gear of the further gear pair is preferably located at the interface of the input and output shafts.
By providing two input shaft gears meshed with lay shaft gears that are selectively coupleable to the lay shaft, and an output shaft gear that is coupleablc to either the input shaft or the output shaft, or manipulable to connect the input shaft to the output shaft, it is possible to provide a number of gear ratios that exceeds the number of gear pairs. It will be appreciated that torque may thus be transmifted to the lay shaft via either of the input shaft gears or the output shaft gear that can be coupled to the input shaft.
The main shaft gear of each input shaft gear pair may be formed integrally with the input shaft. Alternatively, the main shaft gear of each input shaft gear pair may be removable from the input shaft. In yet a further alternative embodiment one of the main shaft gears of an input gear pair may be formed integrally with the input shaft and the main shaft gear of the other of the input gear pairs may be removable from the input shaft.
The input shaft may be connected to a quill shaft extending through the lay shaft. In such an embodiment the quill shaft may connected to the input shaft through a transfer gear pair comprising a gear mounted to the input shaft meshed with a gear mounted to the quill shaft. The transfer gears may be releasably mounted to the input and quill shafts, for example the transfer gears may mounted to the input and quill shafts by splined arrangements.
The gear train may include an additional gear pair comprising a lay shaft gear fixed for rotation with the lay shaft and a main shaft gear that is selectively coupleable to the input shaft.
The gear train of the present invention may be incorporated into a gear box or a transaxle. The gear box or transaxle may in turn be incorporated into a vehicle, and particularly a road vehicle.
In a first embodiment of the present invention the gear train includes four gear pairs and three dog rings interspersed between the gear pairs. In such an embodiment the gear train includes first and second gear pairs where the main shaft gears are fixed for rotation with the input shaft and the lay shaft gears are selectively coupleable for rotation with thc lay shaft, a third gear pair whcre the lay shaft gear is fixed for rotation with the lay shaft and the main shaft gear is mounted to the output shaft and further is selectively eoupLeable to either the input shaft to transmit torque from the input shaft to the lay shaft or to the output shaft to transmit torque from the lay shaft to the output shaft, or is utilisable to couple the input shaft to the output shaft to effect direct drive therebetween. and a fourth gear pair where the main shaft gear is selectively coupleable to the output shaft and the lay shaft gear is fixed for rotation with the lay shaft.
In such an embodiment the main shaft gear of the third gear pair is selectively eoupleable to the input shaft to transmit torque from the input shaft to the lay shaft, to the output shaft to transmit torque from the lay shaft to the output shaft, or may be utilised to couple the input shaft to the output shaft to effect direct drive therebetween.
The gear train of this first embodiment is able to provide six gear ratios from four gear pairs.
In a further embodiment of the present invention the gear train includes five gear pairs and three dog rings interspersed between the gear pairs. In such an embodiment the gear train includes first and second gear pairs where the main shaft gears are fixed for rotation with the input shaft and the lay shaft gears are selectively coupleable for rotation with the lay shaft, a third gear pair where the main shaft gear is selectively eoupleable to the input shaft and the lay shaft gear is fixed for rotation with the lay shaft, a fourth gear pair where the lay shaft gear is fixed for rotation with the lay shaft and the main shaft gear is mounted to the output shaft and further is selectively coupleable to either the input shaft to transmit torque from the input shaft to the lay shaft or to the output shaft to transmit torque from the lay shaft to the output shaft, or is utilisable to couple the input shaft to the output shaft to effect direct drive therebetween, and a fifth gear pair where the main shaft gear is selectively coupleable to the output shaft and the lay shaft gear is fixed for rotation with the lay shaft.
In such an embodiment the main shaft gear of the fourth gear pair is selectively coupleable to the input shaft to transmit torque from the input shaft to the lay shaft, to the output shaft to transmit torque from the lay shaft to the output shaft, or to couple the input shaft to the output shaft to effect direct drive therebetwccn. The gear train of this embodiment is able to provide eight gear ratios from five gear pairs.
Embodiments of the present invention will now be described with reference to the accompanying drawings in which; Figure 1 shows a plan view of a six forward ratio gear train of a longitudinal gearbox according to the present invention; Figure 2 shows a cross-sectional view ofthe gear train of figure 1; Figure 3 shows the gear train configured to provide first gear; Figure 4 shows the gear train configured to provide second gear; Figure 5 shows the gear train configured to provide third gear; Figure 6 shows the gear train configured to provide fourth gear; Figure 7 shows the gear train configured to provide fifth gear; Figure 8 shows the gear train configured to provide sixth gear; Figure 9 shows a plan view of an eight forward ratio gear train of a gearbox according to the present invention; Figure 10 shows a cross-sectional view of a six forward ratio gear train of a transverse gearbox according to the present invention; and Figure 11 shows a cross-sectional view of a six forward ratio gear train of a transaxle according to the present invention.
Referring firstly to figures 1 and 2 there is shown a gear train suitable for a longitudinal gearbox generally designated 10. The gear train 10 includes a main shaft generally designated 12 and a lay shaft 14. As can be seen from figure 2, the main shaft 12 is comprised of an input shaft 16 and an output shaft 18. The input shaft 16 is provided with a splined portion 20 adjacent a first end 22 of the input shaft 16 which is distal to the output shaft 18. It will be appreciated that the splined portion 20 enables the input shaft 16 to be connected to a torque source, such as an engine, through an appropriately configured clutch mechanism (not shown).
The input and output shafts 16,18 are commonly aligned along a main shaft longitudinal centreline axis generally designated 24. The second end 26 of the input shaft 16 is received in a blind recess 28 of the output shaft 18. A bearing 30 is provided between said second end 26 and the blind recess 30 SO as to enable the input and output shafts 16,18 to rotate relative to one another about the centreline axis 24.
The main shaft 12 is supported for rotation by a pair of bearings 32,34 which, in use, are themselves supported by a gearbox casing (not shown).
The lay shaft 14 is rotatable about a lay shaft longitudinal centreline axis generally designated 36. The lay shaft axis 36 is substantially parallel to the main shaft axis 24.
The lay shaft 14 is of unitary construction and is supported at opposing ends by bearings 38,40. As with the main shaft 12, the lay shaft bearings, in use, are supported by a gearbox casing.
The gear train 10 further includes a plurality of gear pairs generally designated 42,44,46 and 48. For the purpose of describing the invention, the gear pairs are identified as a first gear pair 42, a second gear pair 44, a third gear pair 46 and a fourth gear pair 48. As will be described in greater detail below, reference to "first", "second", "third" and "fourth" in relation to the gear pairs is not intended to refer to gear ratios. Instead, the terms are intended to refer to the position of the pairs on the shafts 12,14, with the first gear pair being located axially closest to the first end 22 of the input shaft 14 and the fourth gear pair being located axially furthest away from the first end 22 of the input shaft 14.
Each gear pair 42,44,46,48 comprises a main shaft gear 42a,44a,46a,48a and a lay shaft gear 42b,44b,46b,48b. The gears of each pair are constantly meshed. A reverse gear pair 49 is provided between the second and third gear pairs 44,46.
In the first and second gear pairs 42,44, the main shaft gears 42a,44a, alternatively termed input shaft gears, are fixed for rotation with the main shaft 12. This is achieved in a conventional manner by the provision of a splined region 50 of the input shaft 14 being engaged with correspondingly splined formations provided around inner periphery of the main shaft gears 42a,44a. In an alternative embodiment the main shaft gears 42a,42b may be formed integrally with thc input shaft 14. In yet a further embodiment one of the main shaft gears may be formcd integrally with the input shaft 14 and the other may be connected to the input shaft 14 with a splined connection. The lay shaft gears 42b,44b of the first and second gear pairs 42,44 are selectively coupleable for rotation with the lay shaft 14 as will be described in greater detail below. The lay shaft gears 42b,44b are mounted on needle roller bearing arrangements 54 so that the lay shaft 14 is able to rotate relative to the gcars 42b,44b when not coupled for rotation.
In the third and fourth gear pairs 46,48 the arrangement is reversed, with the lay shaft gears 46b,48b being fixed for rotation with lay shaft 14 by a splined connection 52, and the main shaft gears 46a,48a, ahernatively termed the output shaft gears, are mounted on needle roller bearing arrangements 56. The third main shaft gear 46a is positioned at the interface of the input and output shafts 16,18. As will be described in greater detail below, the third main shaft gear 46a may be connected to either the input shaft 16 or the output shaft 18, or be used to rotationally connect the input shaft 16 to the output shaft 18.
While needle roller bearing arrangements 54,56 are shown in the described embodiment, it will be appreciated that other bearing arrangements may be used depending upon the application for which the gear train 10 is used. For example, the shafts 12,14 may be mounted for rotation in plain bearings or bushes.
In order to couple the coupleable gears 42b, 44b, 46a, 48a to their respective shafts, there are provided first, second and third dog rings 58a, 58b, 58c. As before, the terms "first", "second" and "third" used in relation to the dog rings 58a, 58b, 58c are not intended to refer to gear ratios, but instead to the axial position of each dog ring 58a, 58b, 58c in the gcar train 10, with the first dog ring 58a being located axially closest to the first end 22 of the input shaft 12, and the third dog ring 58c being located axially furthest away from said first end 22.
The first dog ring 58a is provided on the lay shaft 14 between the first and second lay shaft gears 42b,44b. The first dog ring 58a is fixed for rotation with the lay shaft 14.
The first dog ring 58a is rotationally fixed to a sleeve 60 which in turn is rotationally fixed to the lay shaft 14. This rotational fixing is achieved by splined connections 62,64 between the first dog ring 58a and the sleeve 60, and the sleeve 60 and the lay shaft 14 respectively. The splined connection 62 between the first dog ring 58a and the sleeve 60 is configured such that the dog ring 58a maybe moved axially relative to the lay shaft 14. The first and second lay shaft gears 42b,44b are provided with a plurality of dog teeth 66,68 which face the first dog ring 58a. The first dog ring 58a is further provided on opposing sides with corresponding dog teeth 70 which can be brought into engagement with either the dog teeth 60 of the first lay shaft gear 42b or the dog teeth 62 of the second lay shaft gear 44b depending upon the axial direction in which the first dog ring SSa is moved. In order to effect axial movement of the first dog ring 58a, the first dog ring 58a is surmounted by a selector fork 72.
The second dog ring 58b is provided on the input shaft 16 between the second and third main shaft gears 44a.46a. The second dog ring 58b is rotationally fixed to the input shaft 16 by a splined connection 74 and is movable axially relative to the main shaft 16 by a selector fork 76. The second dog ring 58a is provided with a plurality of dog teeth 78 which are eagageable with a corresponding plurality of dog teeth 80 provided on the facing side of the third main shaft gear 46a to rotationally couple the third main shaft gear 46a to the input shaft 16.
The third dog ring 58c is provided on the output shaft 18 between the third and fourth main shaft gears 46a,48a. The third dog ring 58c is rotationally fixed to the output shaft 18 by a splined connection 82 and is movable axially relative to the main shaft 16 by a selector fork 84. The third and fourth main shaft gears 46a,48a are provided with a plurality of dog teeth 86,88 which face the third dog ring 58c. The third dog ring 58c is further provided on opposing sides with corresponding dog teeth 90 which can be brought into engagement with either the dog teeth 86 of the third main shaft gear 46a or the dog teeth 88 of the fourth main shaft gear 48a, depending upon the axial direction in which the third dog ring 58c is moved, in order to rotationally couple either the third main shaft gear 46a or the fourth main shaft gear 48a to the output shaft 18.
Operation of the gear train 10 in order to select defined gear ratios will now be described.
Figures 1 and 2 show the gear train 10 in a neutral configuration wherein none of the dog rings 58a,58b,58c are engaged with a gear. It will thus be appreciated that rotation of the input shaft 16 results in rotation of the first and second main shaft gears 42a,44a. This in turn results in rotation of the first and second lay shaft gears 42b,44b, however the lay shaft 14 does not rotate as the lay shaft gears 42b,42c are not coupled thereto by the first dog ring 58a.
Figure 3 shows the manner in which first gear is selected. The first dog ring 58a is moved in the direction of the first lay shaft gear 42b as indicated by arrow 92 in order to couple said gear 42b to the lay shaft 14. The third dog ring 58c is moved in the direction of the fourth main shaft gear 48a as indicated by arrow 94 in order to couple said gear 48a to the output shaft 18. Torque applied to the input shaft 16 is thus transferred to the lay shaft 14 by the first gear pair 42 and from the lay shaft 14 to the output shaft 18 by the fourth gear pair 48.
Figure 4 shows the manner in which second gear is selected. The first dog ring 58a is moved in the direction of the second lay shaft gear 44b as indicated by arrow 96 in order to couple said gear 44b to the lay shaft 14. The third dog ring 58c remains in contact with the fourth main shaft gear 48a as indicated by arrow 94 in order to couple said gear 48a to the output shaft 18. Torque applied to the input shaft 16 is thus transferred to the lay shaft 14 by the second gear pair 44 and from the lay shaft 14 to the output shaft 18 by the fourth gear pair 48.
Figure 5 shows the manner in which third gear is selected. The second dog ring 58b is moved in the direction of the third main shaft gear 46a as indicated by arrow 98 in order to couple said gear 46a to the input shaft 16. The third dog ring 58c remains in contact with the fourth main shaft gear 48a as indicated by arrow 94 in order to couple said gear 48a to the output shaft 18. Torque applied to the input shaft 16 is thus transferred to the lay shaft 14 by the third gear pair 46 and from the lay shaft 14 to the output shaft 18 by the fourth gear pair 48.
Figure 6 shows the manner in which fourth gear is selected. The first dog ring 58a is moved in the direction of the first lay shaft gear 42b as indicated by arrow 92 in order to couple said gear 42b to the lay shaft 14. The third dog ring 58c is moved in the direction of the third main shaft gear 46a as indicated by arrow 100 in order to couple said gear 46a to the output shaft 18. Torque applied to the input shaft 16 is thus transferred to the lay shaft 14 by the first gear pair 42 and from the lay shaft 14 to the output shaft 18 by the third gear pair 46.
Figure 7 shows the manner in which fifth gear is selected. The first dog ring 58a is moved in the direction of the second lay shaft gear 44b as indicated by arrow 96 in order to couple said gear 44b to the lay shaft 14. The third dog ring 58c remains in contact with the third main shaft gear 46a as indicated by arrow 100 in order to couple said gear 46a to the output shaft 18. Torque applied to the input shaft 16 is thus transferred to the lay shaft 14 by the second gear pair 44 and from the lay shaft 14 to the output shaft 18 by the third gear pair 46.
Figure 8 shows the manner in which sixth or top gear is selected. The second dog ring SSb is moved in the direction of the third main shaft gear 46a as indicated by arrow 98 in order to couple said gear 46a to the input shaft 16. The third dog ring 58c remains in contact with the third main shaft gear 46a as indicated by arrow 100 in order to couple said gear 46a to the output shaft 18. The input shaft 16 is thus coupled to the output shaft 18 through the third main shaft gear 46a.
It will thus be appreciated that the gear train 10 of the present invention described with reference to figures 1 to 8 provides six rear ratios from four gear pairs 42,44,46,48 and thrcc dog rings 58a,58b,58c. The first and second gear pairs 42, 44 can be manipulated to selectively transmit torque to the lay shaft 14 from the input shaft 16. The third gear pair 46 can be manipulated to either transmit torque to the lay shaft 14 from the input shaft 16, transmit torque from lay shaft 14 to the output shaft 18, or couple the input shaft 16 to the output shaft 18. The fourth gear pair 48 can be manipulated to transmit torque from the lay shaft to the output shaft 18.
Figure 9 shows a further embodiment of a gear train according to the present invention and generally designated 110. Features common to the embodiment of figures 1 to 8 are identified with like reference numerals. The gear train 110 differs in that it is provided with a further gear pair 112 located between the second and third gear pairs 44,46. The further gear pair 112 comprises a main shaft gear 1 12a and a lay shaft gear 1 12b. The further gear pair lay shaft gear I 12b is fixed for rotation with the lay shaft 14. The further gear pair main shaft gear 1 12a is mounted for rotation relative to the input shaft 16 and may be selectively coupled for rotation with the input shaft 16 by the second dog ring 58b.
Figure 9 shows the gear train 110 in a neutral configuration where none of the dog rings 58a,58b,58e are engaged with a gear.
In order to select first gear the first dog ring 58a is moved in the direction of the first lay shaft gear 42b in order to couple said gear 42b to the lay shaft 14. The third dog ring 58c is moved in the direction of the fourth main shaft gear 48a in order to couple said gear 48a to the output shaft 18. Torque applied to the input shaft 16 is thus transferred to the lay shaft 14 by the first gear pair 42 and from the lay shaft 14 to the output shaft 18 by the fourth gear pair 48.
In order to select second gear the first dog ring 58a is moved in the direction of the second lay shaft gear 44b in order to couple said gear 44b to the lay shaft 14. The third dog ring 58c remains in contact with the fourth main shaft gear 48a in order to couple said gear 48a to the output shaft 18. Torque applied to the input shaft 16 is thus transferred to the lay shaft 14 by the second gear pair 44 and from the lay shaft 14 to the output shaft 18 by the fourth gear pair 48.
In order to select third gear the second dog ring 58b is moved in the direction of the further main shaft gear 1 12a in order to couple said gear II 2a to the input shaft 16.
The third dog ring 58c remains in contact with the fourth main shaft gear 48a in order to couple said gear 48a to the output shaft 18. Torque applied to the input shaft 16 is thus transferred to the lay shaft 14 by the frirther gear pair 112 and from the lay shaft 14 to the output shaft 18 by the fourth gear pair 48.
In order to select fourth gear the second dog ring 58b is moved in the direction of the third main shaft gcar 46a in order to couple said gear 46a to thc input shaft 16. The third dog ring 58c remains in contact with the fourth main shaft gear 48a in order to couple said gear 48a to the output shaft 18. Torque applied to the input shaft 16 is thus transferred to thc lay shaft 14 by thc third gcar pair 46 and from thc lay shaft 14 to the output shaft 18 by the fourth gear pair 48.
In order to select fifth gear the first dog ring 58a is moved in the direction of the first lay shaft gear 42b in order to couple said gear 42b to the lay shaft 14. The third dog ring 58c is moved in the direction of the third main shaft gear 46a in order to couple said gear 46a to the output shaft 18. Torque applied to the input shaft 16 is thus transferred to the lay shaft 14 by the first gear pair 42 and from the lay shaft 14 to the output shaft 18 by the third gear pair 46.
In order to select sixth gear the first dog ring 58a is moved in the direction of the second lay shaft gear 44b in order to couple said gear 44b to the lay shaft 14. The third dog ring 58c remains in contact with thc third main shaft gear 46a in order to couple said gear 46a to the output shaft 18. Torque applied to the input shaft 16 is thus transferred to the lay shaft 14 by the second gear pair 44 and from the lay shaft 14 to the output shaft 18 by the third gear pair 46.
In order to select seventh gear the second dog ring 58b is moved in the direction of the further main shaft gear 112a in order to couple said gear 1 12a to the input shaft 16.
The third dog ring 58c remains in contact with the third main shaft gear 46a in order to couple said gear 46a to the output shaft 18. Torque applied to the input shaft 16 is thus transferred to the lay shaft 14 by the further gear pair 112 and from the lay shaft 14 to the output shaft 18 by the third gear pair 46.
In order to select eighth or top gear the second dog ring 58b is moved in the direction of the third main shaft gear 46a in order to couple said gear 46a to the input shaft 16.
The third dog ring 58c remains in contact with the third main shaft gear 46a in order to couple said gear 46a to the output shaft 18. The input shaft 16 is thus coupled to the output shaft 1 8 through the third main shaft gear 46a.
It will thus be appreciated that the gear train 110 of the present invention described with reference to figure 9 provides eight rear ratios from five gear pairs 42,44,46,48,112 and three dog rings 58a,58b,58c. The first, second and flirthcr gear pairs 42, 44, 112 can be manipulated to selectively transmit torque to the lay shaft 14 from the input shaft 16. The third gear pair 46 can be manipulated to either transmit torque to the lay shaft 14 from the input shaft 16, transmit torque from lay shaft 14 to the output shaft 18, or couple the input shaft 16 to the output shaft 18. The fourth gear pair 48 can be manipulated to transmit torque from the lay shaft to the output shaft 18.
The gear arrangements described above are suitable for use with a longitudinal gear box configuration. It will be appreciated that the gear arrangements may be utilised in alternative gear box configurations. Figures 10 and 11 show, respectively, a front wheel drive gear box gear arrangement, generally designated 150, and a transaxie gear arrangement, generally designated 250. Features eoninion to the embodiments of figures ito 9 are identified with like reference numerals.
Looking firstly at figure 10, the gear arrangement 150 differs in that the lay shaft 14 is hollow and has a through bore 152. A quill shaft 154 extends through the bore 152.
The input shaft 16 is also hollow and has a through bore 156. The output shaft 18 extends into the bore 156 of the input shaft 16. The gear arrangement further includes a pair of meshed transfer gears 158a, lSSb which connect the quill shaft 154 to the input shaft 16. The quill shaft gear 1 58a is fixed for rotation with the quill shaft 154 by virtue of a splined connection therebetween. The quill shaft gear 158a is retained axially on the quill shaft 154 by a circlip 160 of thc quill shaft 154 and a plain bearing 162 located between the quill shaft gear 158a and the end of the lay shaft 14.
The input shaft gear 158b is fixed for rotation with the input shaft 16 by virtue of a splined connection therebetween. The input shaft gear 1 58b is retained axially on the input shaft 16 by a circlip 164 of the input shaft 16 and the input shaft bearing 32 located between the input shaft gear I 55b and the input shaft 16.
The axial retention of the meshed transfer gears 15 8a, 15 Sb on the splines of the quill and input shafts 154,16 means that thc transfer gears 158a, 158b can be easily be removed and replaced. As both gears 158a, lSSb are located at the same end of the gear arrangement 150, then it will be appreciated that the easing within which the gear arrangement 150 is located, in use, may be configured such that the gears iSSa, 155b are replaceable in situ. For example, the casing may be provided with a removable panel which permits access to the transfer gears 158a, 158b. It will be understood that the transfer gears iSSa, 158b may be replaced so as to vary the gearing between the quill shaft 154 and the input shaft 16, and thus alter the gearing of the gear arrangement in its entirety. In the embodiment shown, the input shaft gears 42a, 42b are formed integrally with the input shaft 16.
The transaxle gear arrangement 250 of figure 11 has essentially the same configuration as the gear arrangement 150 of figure 10. As before, input torque is transmitted to the input shaft 16 via a quill shaft 154 extending through the lay shaft 14 and replaceable transfer gears 158a, lSSb.
By providing a plurality of different paths by which input torque can be routed to the lay shaft, and a plurality of different paths by which torque can be routed from the lay shaft to the output shaft, a greater number of gear ratios than gear pairs can be realised.
Claims (1)
- <claim-text>Claims 1. A gear train for a single lay shaft automotive gearbox, the gear train having a main shaft having a main shaft axis and a lay shaft having a lay shaft axis, the axes of the main and lay shafts being arranged parallel to one another, the main shaft comprising an input shaft and an output shaft, the input and output shafts bcing arranged coaxially on the main shaft axis and selectively rotatable relative to one another on said main shaft axis, the gear train further including a plurality of gear pairs spaced axially along the main and lay shafts, each gear pair comprising a main shaft gear and a lay shaft gear in meshed engagement with one another, and plurality of dog rings axially interspersed between the gear pairs for coupling a gear for rotation with a shaft, wherein the plurality of gear pairs comprises two input shaft gear pairs where the main shaft gear of each of said input shaft gear pairs is fixed for rotation with the input shaft, and the lay shaft gear of each of said two input shaft gear pairs is selectively coupleable to the lay shaft, an output gear pair where the lay shaft gear is fixed for rotation with the lay shaft and the main shaft gear is selectively coupleable to the output shaft, and a further gear pair wherein the lay shaft gear is fixed for rotation with the lay shaft and the main shaft gear is mounted to the output shaft and thither is selectively coupleable to either the input shaft to transmit torque from the input shaft to the lay shaft or to the output shaft to transmit torque from the lay shaft to the output shaft, or is utilisable to couple the input shaft to the output shaft to effect direct drive thcrebctwccn.</claim-text> <claim-text>2. A gear train as claimed in claim I where the main shaft gear of the further gear pair is located at the interface of the input and output shafts.</claim-text> <claim-text>3. A gear train as claimed in claim 1 or claim 2 wherein the main shaft gear of each input shaft gear pair is fomued integrally with the input shaft.</claim-text> <claim-text>4. A gear train as claimed in claim I or claim 2 whcrcin the main shaft gear of each input shaft gear pair is removable from the input shaft.</claim-text> <claim-text>5. A gear train as claimed in claim 1 or claim 2 wherein one of the main shaft gears of an input gear pair is formed integrafly with the input shaft and the main shaft gear of the other of the input gear pairs is removable from the input shaft.</claim-text> <claim-text>6. A gear train as claimed in any preceding claim wherein the input shaft is connected to a quill shaft extending through the lay shaft.</claim-text> <claim-text>7. A gear train as claimed in claim 6 where the quill shaft is connected to the input shaft through a transfer gear pair comprising a gear mounted to the input shaft meshed with a gear mounted to the quill shaft.</claim-text> <claim-text>8. A gear train as claimed in claim 7 wherein the transfer gears are rclcasably mounted to the input and quill shafts.</claim-text> <claim-text>9. A gear train as claimed in claim 8 wherein the transfer gears are mounted to the input and quill shafts by splined arrangements.</claim-text> <claim-text>10. A gear train as claimed in any preceding claim, wherein the gear train includes an additional gear pair comprising a lay shaft gear fixed for rotation with the lay shaft and a main shaft gear that is selectively coupleable to the input shaft.</claim-text> <claim-text>11. A gear box including a gear train as claimed in any preceding claim.</claim-text> <claim-text>12. A transaxle including a gear train as claimed in any of claims I to 10.</claim-text> <claim-text>13. A vehicle including a gear box as claimed in claim 11 or a transaxle as claimed in claim 12.</claim-text> <claim-text>14 A gear train substantially as hereinbefore described with reference to Figures 1 to 8, or Figure 9, or Figure 10, or Figure 11.</claim-text>
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1120920.2A GB2490756A (en) | 2011-12-06 | 2011-12-06 | A gear train with direct drive between input and output |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2497416A true GB2497416A (en) | 2013-06-12 |
| GB2497416B GB2497416B (en) | 2014-06-04 |
Family
ID=45541253
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1120920.2A Pending GB2490756A (en) | 2011-12-06 | 2011-12-06 | A gear train with direct drive between input and output |
| GB1221790.7A Expired - Fee Related GB2497416B (en) | 2011-12-06 | 2012-12-04 | A gear train with direct drive between input and output |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1120920.2A Pending GB2490756A (en) | 2011-12-06 | 2011-12-06 | A gear train with direct drive between input and output |
Country Status (1)
| Country | Link |
|---|---|
| GB (2) | GB2490756A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2514995A (en) * | 2013-04-08 | 2014-12-17 | Paratus Developments Ltd | A Gear Box |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5881600A (en) * | 1996-04-16 | 1999-03-16 | Ford Global Technologies, Inc. | Transmission for motor vehicles |
| EP1004795A1 (en) * | 1998-11-27 | 2000-05-31 | Ford Global Technologies, Inc., A subsidiary of Ford Motor Company | Change speed transmission with one countershaft, particularly for automotive vehicles. |
| FR2787855A1 (en) * | 1998-12-28 | 2000-06-30 | Michel Catimel | Gearbox for a motor vehicle using a series of gears and declutchable drive couplings |
| US20080053258A1 (en) * | 2005-05-11 | 2008-03-06 | Bayerische Motoren Werke | Motor Vehicle Gearbox with Six Forward Gears for Normal Driving, and with a Crawling Gear or Hill Gear and a Reverse Gear |
-
2011
- 2011-12-06 GB GB1120920.2A patent/GB2490756A/en active Pending
-
2012
- 2012-12-04 GB GB1221790.7A patent/GB2497416B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5881600A (en) * | 1996-04-16 | 1999-03-16 | Ford Global Technologies, Inc. | Transmission for motor vehicles |
| EP1004795A1 (en) * | 1998-11-27 | 2000-05-31 | Ford Global Technologies, Inc., A subsidiary of Ford Motor Company | Change speed transmission with one countershaft, particularly for automotive vehicles. |
| FR2787855A1 (en) * | 1998-12-28 | 2000-06-30 | Michel Catimel | Gearbox for a motor vehicle using a series of gears and declutchable drive couplings |
| US20080053258A1 (en) * | 2005-05-11 | 2008-03-06 | Bayerische Motoren Werke | Motor Vehicle Gearbox with Six Forward Gears for Normal Driving, and with a Crawling Gear or Hill Gear and a Reverse Gear |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2514995A (en) * | 2013-04-08 | 2014-12-17 | Paratus Developments Ltd | A Gear Box |
Also Published As
| Publication number | Publication date |
|---|---|
| GB201120920D0 (en) | 2012-01-18 |
| GB2497416B (en) | 2014-06-04 |
| GB2490756A (en) | 2012-11-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20161204 |