GB2490756A - A gear train with direct drive between input and output - Google Patents

A gear train with direct drive between input and output Download PDF

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Publication number
GB2490756A
GB2490756A GB201120920A GB201120920A GB2490756A GB 2490756 A GB2490756 A GB 2490756A GB 201120920 A GB201120920 A GB 201120920A GB 201120920 A GB201120920 A GB 201120920A GB 2490756 A GB2490756 A GB 2490756A
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GB
United Kingdom
Prior art keywords
shaft
gear
lay
main
input
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Pending
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GB201120920A
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GB201120920D0 (en
Inventor
Michael Quaife
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R T QUAIFE ENGINEERING Ltd
Original Assignee
R T QUAIFE ENGINEERING 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 R T QUAIFE ENGINEERING Ltd filed Critical R T QUAIFE ENGINEERING Ltd
Priority to GB201120920A priority Critical patent/GB2490756A/en
Publication of GB201120920D0 publication Critical patent/GB201120920D0/en
Publication of GB2490756A publication Critical patent/GB2490756A/en
Priority to GB201221790A priority patent/GB2497416B/en
Pending legal-status Critical Current

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Classifications

    • 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

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 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 arrangement to the driven wheels of the 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 the common axis of the input and output shafts.
The gear train of the gearbox typically includes an input gear pair arranged to transmit torque 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 the 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 substantially parallel to one another, the main shaft comprising an input shaft portion and an output shaft portion, the input and output shaft portions being arranged coaxially on the main shaft axis and selectively rotatable relative to one another, 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 the main shaft gear, 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 a first set of gear pairs where the main shaft gear is fixed for rotation with the main shaft and the lay shaft gear is selectively coupleable to the lay shaft and a second set of gear pairs where the lay shaft gear is fixed for rotation with the lay shaft and the main shaft gear is selectively coupleable to the main shaft and wherein further one of main shaft gears 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 therebetween.
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 the lay shaft, and third and fourth gear pairs where the main shaft gears are selectively coupleable to the output shaft and the lay shaft gears are fixed for rotation with the lay shaft. In such an embodiment the main shaft gear of the third 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 therebetween.
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 arc 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 coupleable to the input shaft and the lay shaft gear is fixed for rotation with the lay shaft, and fourth and fifth gear pairs where the main shaft gears are selectively coupleable to the output shaft and the lay shaft gears are fixed for rotation with the lay shaft. In such an embodiment the main shaft gear of the fourth gear pair is selectively coupleablc 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 therebetween.
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 gearbox according to the present invention; Figure 2 shows a cross-sectional view of the 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; and Figure 9 shows a plan view of an eight forward ratio gear train of a gearbox according to the present invention.
Referring firstly to figures 1 and 2 there is shown a gear train 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 posit ion 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 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 main shaft 12 being engaged with correspondingly splined formations provided around inner periphery of the main shaft gears 42a,44a. 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 gears 42b,44b when not coupled for rotation.
In the third and fourth gear pairs 46,4 8 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 are mounted on needle roller bearing arrangements 56.
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 gear 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 may be 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 58a 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 engageable 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 86,8 8 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 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 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 three 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 1 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,58c 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 112a 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 further 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 gear 46a 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 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.
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 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 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 1 12a in order to couple said gear 112a 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 18 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 further 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.
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 (9)

  1. 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 substantially parallel to one another, the main shaft comprising an input shaft portion and an output shaft portion, the input and output shaft portions being arranged coaxially on the main shaft axis and selectively rotatable relative to one another, 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 a first set of gear pairs where the main shaft gear is fixed for rotation with the main shaft and the lay shaft gear is selectively coupleable to the lay shaft and a second set of gear pairs where the lay shaft gear is fixed for rotation with the lay shaft and the main shaft gear is selectively coupleable to the main shaft and wherein further one of main shaft gears 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 therebetween.
  2. 2. A gear train as claimed in claim 1 wherein the gear train includes four gear pairs and three dog rings interspersed between the gear pairs.
  3. 3. A gear train as claimed in claim 2 wherein 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, and third and fourth gear pairs where the main shaft gears are selectively coupleable to the output shaft and the lay shaft gears are fixed for rotation with the lay shaft.
  4. 4. A gear train as claimed in claim 3 wherein the main shaft gear of the third 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 therebetween.
  5. 5. A gear train as claimed in claim 1 wherein the gear train includes five gear S pairs and three dog rings interspersed between the gear pairs.
  6. 6. A gear train as claimed in claim 5 wherein 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 coupleable to the input shaft and the lay shaft gear is fixed for rotation with the lay shaft, and fourth and fifth gear pairs where the main shaft gears are selectively coupleable to the output shaft and the lay shaft gears are fixed for rotation with the lay shaft.
  7. 7. A gear train as claimed in claim 6 wherein 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 therebetween.AMENDMENTS TO THE CLAIMS FILED AS FOLLOWS:-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 substantially parallel to one another, the main shaft comprising an input shaft portion and an output shaft portion, the input and output shaft portions being arranged coaxially on the main shaft axis and selectively rotatable relative to one another, 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 a first plurality of gear pairs where the main shaft gear of each of said first plurality of gear pairs is fixed for (\J 15 rotation with the main shaft and the lay shaft gear, of each of said first plurality of gear pair is selectively coupleable to the lay shaft and a second plurality of gear pairs C) where the lay shaft gear of each of said second plurality of gear pairs is fixed for 0 rotation with the lay shaft and the main shaft gear of each of said second plurality of (0 gear pair is selectively coupleable to the main shaft and wherein further one of the main shaft gears 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 therebetween.2. A gear train as claimed in claim 1 wherein the gear train includes four gear pairs and three dog rings interspersed between the gear pairs.3. A gear train as claimed in claim 2 wherein 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, and third and fourth gear pairs where the main shaft gears are selectively coupleable to the output shaft and the lay shaft gears are fixed for rotation with the lay shaft.4. A gear train as claimed in claim 3 wherein the main shaft gear of the third 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 therebetween.5. A gear train as claimed in claim 1 wherein the gear train includes five gear pairs and three dog rings interspersed between the gear pairs.6. A gear train as claimed in claim 5 wherein 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 arc selectively couplcablc for rotation with the lay shaft, a third gear pair where the main shaft gear is selectively coupleable to the input shaft and the lay shaft gear is fixed for rotation with the lay shaft, and fourth and fifth gear pairs C\i 15 where the main shaft gears are selectively coupleable to the output shaft and the lay shaft gears are fixed for rotation with the lay shaft. C)7. A gear train as claimed in claim 6 wherein 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 therebetween.
  8. 8. A gear train substantially as hereinbefore described with reference to Figures 1 to 8 or Figure
  9. 9.
GB201120920A 2011-12-06 2011-12-06 A gear train with direct drive between input and output Pending GB2490756A (en)

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GB201120920A GB2490756A (en) 2011-12-06 2011-12-06 A gear train with direct drive between input and output
GB201221790A GB2497416B (en) 2011-12-06 2012-12-04 A gear train with direct drive between input and output

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GB201120920A GB2490756A (en) 2011-12-06 2011-12-06 A gear train with direct drive between input and output

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GB201120920D0 GB201120920D0 (en) 2012-01-18
GB2490756A true GB2490756A (en) 2012-11-14

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GB2514995A (en) * 2013-04-08 2014-12-17 Paratus Developments Ltd A Gear Box

Citations (4)

* Cited by examiner, † Cited by third party
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

Patent Citations (4)

* Cited by examiner, † Cited by third party
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

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GB201120920D0 (en) 2012-01-18
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