IL45413A - Mechanical power transmission - Google Patents

Abstract

1431160 Change-speed gear CLARK EQUIPMENT CO 27 Aug 1974 [27 Aug 1973] 37416/74 Heading F2D A transmission providing three or four forward ratios and a corresponding number of reverse ratios comprises a system of constant mesh gears and clutches arranged on several shafts all lying in a common plane. In the arrangement shown in Fig. 2 the first forward ratio is established by engagement of fluidactuated multi-plate clutches 38, 64 so that drive is transmitted from the input shaft 14 to the output shaft 16 through gears 52, 54, 68, 70, 62, 66, 74, 76. Engagement of clutch 58, instead of 64, establishes second ratio through gears 52, 54, 66, 74, 76, and clutch 72 establishes third ratio, with clutches 64, 58 released, through gears 52, 54, 68, 74, 76. On release of the clutch 38 and engagement of the clutch 50 the three reverse ratios are similarly established by selective engagement of the clutches 64, 58, 72. The shaft 16 and gear 76 may be omitted, in which case the output is taken from the shaft 22. In a modification (Fig. 3, not shown) the clutch 72 is omitted, and a shaft (83) coaxial with the shaft 20 carries a gear in mesh with the gear 66, and two further gears in mesh with gears freely rotatable on the output shaft and clutchable thereto by a dog clutch. This arrangement provides four forward and reverse ratios. In a further three-ratio arrangement (Fig. 5, not shown) the gear 68 is omitted, and a gear in mesh with the gear 62 is fixed on the shaft 18. Again, the output may be taken from the shaft 22. In a modification with coaxial input and output shafts 14, 132, Fig. 8, three forward ratios are established by clutches 64, 58, 136 and forward or reverse by clutches 38, 50. Fig. 9 illustrates a modification of this arrangement in which the input and output shafts are not coaxial. As indicated in Fig. 2 the shaft 16 may provide two outputs, and one of these may be disconnectible by a sliding-tooth clutch. Also, in any of the embodiments the final drive wheel may be disconnectible from its output shaft, and a power take-off shaft may be provided, e.g. connected to the input shaft. [GB1431160A]

Description

Mechanical Power Transmissions ABSTRACT OF THE DISCLOSURE A family of multispeed constant-mesh-gear reversible mechanical power transmission has a basic structure that includes at least five drivingly-connected shafts, with all of these shafts lying in a common plane. A plurality of gear trains selectively drives the output shaft at various speed ratios, and pluralities of clutches are used for connecting several of the shafts and for connecting various ones of the gears to various shafts for conjoint rotation therewith. Numerous embodiments of connecting means are used for connecting the output shaft with at least one of the several gears.

This invention relates to mechanical power transmissions.

In multiple -speed gear transmissions, it is desirable to arrange the transmissions' major components, or basic structure, in such a way that a variety of additional components or modifica-tions may easily be added to this basic mechanism or structure. Transmissions of this general type are mainly utilised in off-highway heavy duty vehicles and construction equipment which often are manufactured for specific requirements in limited numbers. Thus, having a basic transmission structure which can readily be adapted to meet unique criteria is of paramount importance. Not only is cost reduced but dependability is improved.

According to the present invention there is provided a mechanical power transmission comprising an input shaft, a first gear fixed to said input shaft; a first shaft lying in a common plane with said input shaft; a second gear mounted for rotation on said first shaft and drivingly connected with said first gear; a second shaft axially aligned with said input shaft; a first clutch for connecting said input shaft with said second shaft; a second clutch for connecting said second gear to said first shaft for conjoint rotation therewith; a third gear fixed to said second shaft; a fourth gear fixed to said first shaft and in mesh with said third gear; a third shaft axially aligned with one of said first and second shafts; a third clutch for connecting said third shaft with one of said first and second shafts; a fifth gear mounted for rotation on said third shaft; a fourth clutch for connecting said fifth gear to said third shaft; a sixth gear fixed 'to said third shaft; and output shaft lying in said common plane; and means for drivingly connecting said output shaft with said third shaft each of said first, second third and fourth clutches being bidirect ionally engageable.

Different embodiments of the invention utilise different forms of connecting means for driving the output shaft. The family of transmissions of this invention has one common denominator in the fact that regardless of the number of shafts utilised, they always lie in a common plane, preferably vertical. This allows the production of a family of constant-width transmissions, which not only greatly facilitates installation procedures but also permits the use of large numbers of common parts. These transmissions include embodiments wherein the input shaft is axially aligned with the output shaft, i.e. an in-line transmission, and a series of transmissions wherein the output shaft is parallel but vertically displaced from the input shaft.

Transmissions of this type are generally designated "drop" transmissions and may include short-drop, intermediate-drop and long-drop versions, wherein the output shaft is progressively further vertically displaced from the input shaft. In addition, several of the transmissions may be equipped with power takeoff shafts as well as front and rear-directed output shafts.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:- Fig. 1 is a longitudinal view, partially in section, of a three speed long-drop embodiment of the present invention ; Fig. 2 is a simplified schematic representation of the transmission shown in Fig. 1; Fig. 3 is a schematic representation of a two speed with mechanical range embodiment of the present invention; Fig. 4 is a schematic representation of a three speed intermediate-drop embodiment of the present inventio ; Fig. 5 is a schematic representation of another embodiment of a three speed long-drop transmission according to the present invention ; Fig. 6 is a schematic representation of a three speed intermediate-drop transmission according to the present invention; Fig. 7 is a longitudinal sectional view of an in-line three speed transmission according to the present invention; Fig. 8 is a simplified schematic representation of the transmission shown in Fig. 7; and Fig. 9 is a schematic representation of a three speed short-drop transmission according to the present invention.

Referring now to Figs. 1 and 2, the reference numeral 10 generally denotes a transmission of the constant -mesh-gear type, having a housing 12 in which an input shaft 14, an output shaft 16 and shafts 18, 20, 22, 24 and 26 are journalled for rotation.

The input shaft 14 is driven by means of a hydrodynamic torque converter 28 of known construction to which the shaft 14 is connected, with the torque converter 28 being in turn connected to any suitable source of power, such as an internal combustion engine (not shown). In addition, the torque converter 28 drives one or more pumps (not shown) on the housing 12, at engine speed, through at least one pair of meshing gears 30 and 32 which are connected respectively to the torque converter impellor and the drive shaft of a pump. One of the pumps, serves to provide pressurised fluid to operate various fluid-actuated clutches as well as to lubricate the gears and bearings associated with the transmission 10.

Connected to the input shaft 14 is an input gear 34 which is drivingly connected by means of an idler gear (not shown) with a gear 36 which is mounted for rotation on a shaft 24. The input shaft 14 can be connected to the shaft 18 for conjoint rotation therewith by means of a clutch 38 which is a multiple plate, fluid-actuated-type clutch. of well known construction, including a hub 40 connected to the gear 34 by any suitable means, such as welding; a drum 42 which has a web 44 integral there with, with the web 44 being fixed to the shaft 18 by any suitable means, such as welding; and a plurality of interleaved friction plates 46 splined alternately to the hub 40 and to the drum 42. The clutch 38 is engaged by supplying pressurised fluid behind a piston 48 which serves to press the plates 46 together so that the hub 40 is fractionally connected to the drum 42 through the plates 46.

The gear 36 can be connected to the shaft 24 for conjoint rotation therewith by means of a fluid-actuated multiple-plate clutch 50 which is substantially similar to the clutch 38, and so will not be described further.

At this time, it will be noted that a gear 52 is integral with the drum 42 of the clutch 38 and meshes with another gear 54 which is integral with the drum 56 of the clutch 50. It should be clear at this time that the shaft 18 is axially aligned with the input shaft 14 and that the shaft 24 is vertically aligned or in the same vertical plane as the input shaft 14.

The shaft 18 and the shaft 24 are interconnected by means of the meshing gears 52 and 54 so that for any given direction of rotation of one of these shafts, the other shaft will rotate in the opposite direction. In addition, since the gear 34 is drivingly connected, via an idler gear, with the gear 36, they therefore rotate in the same direction. Thus, engagement of the clutch 38 conditions the transmission 10 for what may be arbitrarily designated "forward drive" and engagement of the clutch 50 conditions the transmission for what may again be arbitrarily termed "reverse drive", depending, of course, on the direction of rotation of the input shaft 14.

The shaft 26, which is axially aligned with the shaft 24, can be connected to the shaft 24 for conjoint rotation therewith by engagement of another multiple-plate fluid-actuated-type clutch 58, with the clutch 58 being allochiral to the clutch 50 and sharing a common web 60 therewith. A gear 62 is mounted for rotation on the shaft 26 and can be connected thereto for conjoint rotation therewith by means of a clutch 64 which again is substantially similar to the previously-described clutch 38. In addition, a gear 66 is fixed to the shaft 26 for conjoint - rotation therewith.

The shaft 20, which is rotatably journalled below the shaft 24 and is consequently also vertically aligned or in the same vertical plane as the input shaft 14, has fixedly secured thereto a gear 68 and a gear 70 for conjoint rotation therewith, with the gear 68 meshing with the gear 54 and the gear 70 meshing with the gear 62. The shaft 22 can be connected to the shaft 20 for conjoint rotation therewith by engagement of a clutch 72, with the clutch 72 again being substantially similar to the previously- described clutch 38. A gear 74 is fixed to the shaft 22 and is in constant mesh with the gear 66.

The output shaft 16, which is also vertically aligned or in the same vertical plane as the input shaft 14, has a gear 76 fixed thereto for conjoint rotation therewith, with the gear 76 being in constant mesh with the gear 74.

While the output shaft 16 is shown in Fig. 1 as extending from both the rear and the front of the transmission housing 12, it should be understood that, if desired, it could extend on only one side of the housing, and that its opposite end could be provided with a coaxial auxiliary output shaft (not shown) that could be selectively engageable with the output shaft 16 by means of a conventional sliding tooth clutch (not shown). In addition, a power takeoff shaft 78 (Fig. 1 only) that is driven at torque converter output speed can be utilised in combination with a concentric, hollow shaft 18a (Fig. 1 only) instead of shaft 18, with the shaft 78 being coaxial with and splined to the input shaft 14. Furthermore, if desired, the output shaft gear 76 could be rotatably mounted on the output shaft 16 so that it could be selectively engageable therewith by means of, for example, a conventional sliding tooth clutch (not shown).

Disconnecting the gear 76 from the shaft 16 permits towing of a vehicle equipped with the transmission 10 without rotating any other transmission components besides the output shaft 16.

In view of the foregoing description, it will be apparent, since all of the gears are in constant mesh, that a first forward speed ratio is provided by the engagement of the clutches 38 and 64 so that the output shaft 16 is driven through the gear train comprising the gears 52, 54, 68, 70, 62, 66, 74 and 76. A second higher speed ratio is provided by continued engagement of clutch 38 and the engagement of the clutch 58 (instead of the clutch 64) so that the output shaft 16 is driven through a gear train comprising the gears 52, 54, 66, 74 and 76. A third, or high speed, ratio is provided by the continued engagement of the clutch 38 and the engagement of the clutch 72 (instead of the clutch 58) so that the output shaft 16 is driven through a gear train comprising the gears 52, 54, 68, 74 and 76. By engaging the clutch 50 and the clutch 64, a low reverse speed ratio is provided through the gears 34, 36, 54, 68, 70, 62, 66, 74 and 76. By releasing the clutch 64 and engaging the clutch 58, a second or intermediate reverse speed ratio is provided through the gears 34, 36, 66, 74 and 76. A third, or high, reverse speed ratio is provided through the gears 34, 36, 54, 68, 74 and 76 by engaging the clutches 50 and 72.

It should be noted that in this transmission , the input shaft 14 and the output shaft 16 are parallel and lie in a common vertical plane, with all of the other shafts also lying in the same vertical plane. In addition, the input shaft 14 and the shaft 18 are axially aligned, shafts 24 and 26 are axially aligned and shafts 20 and 22 are axially aligned. The utilisation of this arrangement allows the production of a compact, space-saving transmission that is also easy to manufacture .

Referring now to Fig. 3, there is shown an embodiment of this invention which provides two speed ratios in both the forward and reverse direction, in both a high and a low range. Thus, the transmission 80 is capable of providing four forward and reverse speeds, but a shift is required between the first and second ranges. To the extent that this embodiment is the same as the previously-described transmission 10 in Figs. 1 and 2, reference is made here to this preceding description, with like reference numerals being applied to like parts. A comparison of Figs. 2 and 3 will show that in transmission 80 (Fig. 3) clutch 72 is not utilised for selectively connecting the shaft 20 to a shaft 83 that is axially aligned therewith. In addition, a gear 81 is not affixed to, but is mounted for rotation on, the output shaft 16. A gear 82 is fixed to the shaft 83 and is in constant mesh with the gear 81. Another gear 84 is also mounted for rotation on the output shaft 16 and is in constant mesh with a further gear 86 that in turn is fixed to the shaft 83. The output shaft 16 also has secured thereto connecting means 88 for alternately connecting the gears 81 and 84 to the output shaft 16 for conjoint rotation therewith. The connecting means 88 may, for example, be a conventional sliding tooth clutch which can be shifted in any desired manner to axially couple either the gear 81 or the gear 84 to the output shaft.

By engaging the clutch 38, the transmission is conditioned for forward drive, but by disengaging the clutch 38, and by engaging the clutch 50, the transmission is conditioned for reverse drive. At this point it will be seen, since all of the gears are in constant mesh, that a first speed ratio is provided, in both forward and reverse, by engaging the clutch 64 so that the shaft 83 is driven through the gear trains comprising either the gears 52, 54, 68, 70, 62, 66 and 74 or the gears 34, 36, 54, 68, 70, 62, 66 and 74. A second speed ratio is provided, in both forward and reverse, by engaging the clutch 58 so that the shaft 83 is driven through the gear trains comprising either the gears 52, 54, 66 and 74 or the gears 34, 36, 66 and 74. It will also be seen that the shaft 83 drives the output shaft 16 either through the gear train comprising the gears 82 and 81 when the connecting means 88 is axially shifted to connect the gear 81 to the output shaft 16 for conjoint rotation therewith, or through the gear train comprising the gears 86 and 84 when the connecting means 88 is shifted to connect the gear 84 for conjoint rotation with the output shaft 16. The connection of the gear 81 with the output shaft 16 provides first, or low, range drive, whereas connection of the gear 84 with the output shaft 16 provides for a second, or high, range drive. It should be clear that both first and second speed ratios, via the clutches 64 and 58, respectively, can be provided in both the high and low range previously described. Thus, the operator has two speeds forward or reverse in each of the two drive ranges, with a shift of the connecting means 88 being required to select either of the two ranges .

It should be clear that the connecting means 88 can be shifted to a neutral position, i.e. in which neither of the gears 81 and 84 is coupled to the output shaft 16. This neutral position permits towing of a vehicle equipped with the transmission 80 without rotating any other transmission components besides the output shaft 16.

Referring now to Fig. 4, there is shown a schematic representation of a three speed intermediate-drop transmission 90 having three speed ratios in both the forward and reverse direction. To the extent that this embodiment is the same as the previously described transmission 10 (Figs. 1 and 2), reference is made here to this preceding description, with like numerals being applied to like parts. In the transmission 90 in Fig. 4, the separate fourth vertical level output shaft 16 and affixed gear 76 of Figs. 1 and 2 have been deleted; thus the shaft 22 (Figs. 1 and 2) becomes the output shaft 92 in Fig. 4. Another gear 94 is fixed to the output shaft 92 and is in constant mesh with the gear 66.

In order to maintain the same arbitrarily designated "forward" and "reverse" rotation of the output shaft 92, the clutch 38 is now designated as "reverse" and the clutch 50 is now designated as "forward" .

It will be seen at this point that a first speed ratio is provided, in both forward and reverse, by engaging the clutch 64 so that the output shaft 92 is driven through the gear trains comprising either the gears 34, 36, 54, 68, 70, 62, 66 and 94 or the gears 52, 54, 68, 70, 62, 66 and 94. A second speed ratio is provided, in both forward and reverse, by engaging the clutch 58 so that the output shaft 92 is driven through the gear trains comprising either the gears 34, 36, 66, and 94 or the gears 52, 54, 66 and 94. A third speed ratio is provided, in both forward and reverse, by engaging the clutch 72 so that the output shaft 92 is driven through the gear trains comprising either the gears 34, 36, 54 and 68 or the gears 52, 54 and 68.

Referring now to Fig. 5 there is shown a schematic representation of another embodiment of three speed long-drop transmission 100. To the extent that this embodiment is the same as the previously described transmission 10 (Figs. 1 and 2), reference is made here to this preceding description, with like numerals being applied to like parts.

In the transmission 100 in Fig. 5, the separate shaft 20 and affixed gear 68 of Figs. 1 and 2 have been deleted; thus, the shaft 22 (Figs. 1 and 2) becomes the shaft 102 in Fig. 5.

In the transmission 100, a gear 104 is fixedly mounted on the shaft 18, with the gear 104 meshing with the gear 62. The shaft 102, which is rotatably journalled below the shaft 26 and is also vertically aligned or in the same vertical plane as the input shaft 14, has another gear 106 mounted for rotation on the shaft 102 and can be connected thereto for conjoint rotation therewith by means of a clutch 110 which is again substantially similar to the previously-described clutch 38. In addition, a gear 108 is fixed to the shaft 102 for conjoint rotation therewith, with the gear 108 meshing with the gear 66 and the gear 112 affixed to the output shaft 116.

By engaging the clutch 38, the transmission is conditioned for forward drive; by disengaging the clutch 38, and by engaging the clutch 50, the transmission is conditioned for reverse drive.

At this point it will be seen, since all of the gears are in constant mesh, that a first speed ratio is provided, in both forward and reverse, by engaging the clutch 64 so that the output shaft 116 is driven through the gear trains comprising either the gears 104, 62, 66, 108 and 112 or the gears 34, 36, 54, 52, 104, 62, 66, 108 and 112. A second speed ratio is provided, in both forward and reverse, by engaging the clutch 58 so that the output shaft 116 is driven through the gear trains comprising either the gears 52, 54, 66, 108 and 112 or the gears 34, 36, 66, 108 and 112. A third speed ratio is provided, in both forward and reverse, by engaging the clutch 110 so that the output shaft 116 is driven through gear trains comprising either the gears 104, 62, 106, 108 and 112 or the gears 34, 36, 54, 52, 104, 62, 106, 108 and 112.

' It will now be apparent that a first forward speed ratio is provided by the engagement of the clutches 38 and 64, a second higher speed ratio is provided by continued engagement of the clutch 38 and the engagement of the clutch 58 instead of the clutch 64, and a third speed ratio is provided by the continued engagement of the clutch 38 and the engagement of the clutch 110 instead of the clutch 38. By engaging the clutches 50 and 64, a low reverse speed ratio is provided, and by releasing the clutch 64 and engaging the clutch 58, a second reverse speed ratio is provided, with a third reverse speed ratio being provided by the engagement of the clutches 50 and 110.

It should be noted that in the transmission 100, as in the previously described transmissions, the input and output shafts are parallel and lie in a common vertical plane, with all of the shafts also lying in the same vertical plane. In addition, the transmission 100, by mounting the gear 104 on the shaft 18, utilises one less shaft than does the transmission 10 shown in Figs. 1 and 2.

Referring now to Fig. 6, there is shown a schematic representation of a three speed intermediate-drop transmission 120 having three ratios in both the forward and reverse direction. To the extent that this embodiment is the same as the previously described transmission 10 ( Figs. 1 and 2) and the transmission 100 (Fig. 5), reference is made here to these preceding descriptions with like numerals again being applied to like parts. In the transmission 120 in Fig. 6, the separate fourth vertical level output shaft 116 and affixed gear 112 of Fig. 5 have been deleted; thus, the shaft 102 (Fig. 5) becomes the output shaft 122 in Fig. 6. A gear 124 is affixed to the output shaft 122 and is in constant mesh with the gear 66.

In order to maintain the same arbitrarily designated "forward" and "reverse" rotation of the output shaft 122, the clutch 38 is now designated as "reverse" and the clutch 50 is now designated as "forward".

It will be seen at this point that a first speed ratio is provided, in both forward and reverse, by engaging the clutch 64 so that the output shaft 122 is driven through the gear trains comprising either the gears 34,36,54,52,104,62,66 and 124 or the gears 104,62,66 and 124. A second speed ratio is provided in both forward and reverse, by engaging the clutch 58 so that the output shaft 122 is driven through the gear trains comprising either the gears 34,36,66 and 124 or the gears 52,54,66 and 124. A third speed ratio is provided, in both forward and reverse, by engaging the clutch 110 so that the output shaft 122 is driven by gear train comprising either the gears 34,36,54,52,104,62 and 106 or the gears 104,62 and 106.

Referring now to Figs. 7 and 8, there is shown another embodi ment of this invention, with the reference numeral 130 generally denoting a transmission of the constant-gear-mesh type. Fig. 7 is a longitudinal sectional view of an in-line three speed embodiment of the transmissions of this invention. From Fig. 8, which is a simplified schematic representation of the transmission 130 shown i Fig. 7, it may readily be ascertained that the input and output shafts are axially aligned. To the extent that the transmission 130 is the same as the previously described transmission 10 in Figs. 1 and 2, reference ismade here to this preceding description, with like reference numerals being applied to like parts.

Similar to the transmission 10, the transmission 130 has a housing 12 in which an input shaft 14, an output shaft 132, as well as shafts 24, 26 and 134, are journalled for rotation.

The input shaft 14 is driven by means of a hydrodynamic torque converter (not shown) of known construction to which the input shaft 14 is connected, with the torque converter in turn being connected to any suitable source of power, such as an internal combustion engine (not shown) . The torque converter impellor again drives one or more hydraulic pumps (not shown) of well known construction, at least one of which serves to provide pressurised fluid to operate the fluid-actuated clutches, as well as to lubricate the gears and bearings associated with the transmission 130.

Connected to the input shaft 14 is a gear 34 which is drivingly connected by means of an idler gear (not shown) with a gear 36, which is mounted for rotation on the shaft 24. The shaft 134, which is axially aligned with the input shaft 14, can be connected thereto for conjoint rotation therewith by means of a clutch 38 (previously described with reference" to Figs. 1 and 2) .

The gear 36 can be connected to the shaft 24 for conjoint rotation therewith by means of the clutch 50, with the shaft 26, which is axially aligned with .the shaft 24, being connectible to the shaft 24 for conjoint rotation therewith by engagement of a clutch 58. The clutches 50 and 58 are the two halves of the double clutch and are joined by a common web 60 which is affixed to the shaft 24 by any suitable means, such as welding.

At this time, it will be noted that a gear 52 is integral with the drum 42 of the clutch 38 and meshes with another gear 54 which is integral with the common drum of the clutches 50 and 58. It should also be clear at this time that the shafts 24 and 26 are vertically aligned or in the same vertical plane as the input shaft 14 and the shaft 134. The shaft 134 and the shaft 24 are interconnected by means of meshing gears 52 and 54 so that for any given direction of rotation of one of these shafts, the other shaft will rotate in the opposite direction. In addition, since the gear 34 is drivingly connected, via an idler gear, with the gear 36, they, therefore, rotate in the same direction. Thus, engagement of the clutch 38 conditions the transmission 130 for what may be arbitrarily designated "forward drive", and engagement of the clutch 50 conditions the transmission for what may again arbitrarily be termed "reverse drive" depending, of course, on the direction of rotation of the input shaft 14.

A gear 140 is fixed to the shaft 134 and can be connected to the output shaft 132, which is axially aligned with the shaft 134, by means of a clutch 136 which is substantially similar to the clutch 38, and so will not, be described further.

A gear 62 is mounted for rotation on the shaft 26 and can be connected thereto for conjoint rotation therewith by means of a clutch 64, with the gear 62 being in constant mesh with the gear 140. In addition, a gear 66 is fixed to the shaft 26 for conjoint rotation therewith, with the gear 66 being in constant mesh with a gear 138 affixed to the output shaft 132.

At this point, it will be seen, since all of the gears are in constant mesh, that a first speed ratio is provided, in both forward and reverse, by engaging the clutch 64 so that the output shaft 132 is driven through the gear trains comprising either the gears 140, 62, 66 and 138 or the gears 34, 36, 54 52, 140, 62, 66 and 138. A second speed ratio is provided, in both forward and reverse, by engaging the clutch 58 so that the output shaft 132 is driven through the gear trains comprising either the gears 52, 54, 66 and 138 or the gears 34, 36, 66 and 138. A third speed ratio is provided by engaging the clutch 136 so that the output shaft 132 is directly driven in the forward direction, via the clutch 38, with no load on any gears, and in the reverse direction through the gear train comprising the gears 34, 36, 54 and 52.

In view of the foregoing description, it will be apparent that a first forward speed ratio is provided by the engagement of the clutch 38 and the clutch 64, a second higher speed ratio is provided by continued engagement of the clutch 38 and the engagement of the clutch 58 instead of the clutch 64, and a third speed ratio is provided by the continued engagement of the clutch 38 and the engagement of the clutch 136 instead of the clutch 58. By engaging the clutches 50 and 64, a low reverse speed ratio is provided, and by releasing the clutch 64 and engaging the clutch 58, a second . reverse speed ratio is provided. A third, or high, reverse speed ratio is provided by engaging the clutches 50 and 136.

It should be noted that in the transmission 130, the input shaft 14, the shaft 134 and the output shaft 132 are all axially aligned, as are the shafts 24 and 26. In addition, all of these shafts lie in a common vertical plane, with this arrangement giving a compact three speed in-line constant-mesh-gear transmission.

Referring now to Fig. 9, there is shown a schematic representation of a three speed short-drop transmission 150 having three speed ratios in both the forward and reverse direction. To the extent that the transmission 150 is the same as the previously-described transmission 130 in Figs. 7 and 8, reference is made here to this preceding description, with like reference numerals being applied to like parts .

The transmission 150 incorporates an input shaft 14, an output shaft 132, as well as shafts 134, 152 and 154 all of which are journalled for rotation.

Connected to the input shaft 14 is a gear 34 which is drivingly connected by means of an idler gear (not shown) with a gear 36 which is mounted for rotation on a shaft 154. The gear 34 can. be connected to the shaft 134 for conjoint rotation therewith by means of a clutch 38, with the shaft 152, which is axially aligned with the shaft 134, being connectible to the shaft 134 for conjoint rotation therewith by engagement of a clutch 58. The gear 36 can be connected to the shaft 154 for conjoint rotation therewith by means of a clutch 50.

At this time, it will be noted that a gear 52 is integral with the double drum of the clutches 38 and 58, and meshes with a gear 54 which is integral with the drum of the clutch 50. It should also be clear at this time that the input shaft 14, the shaft 134 and the shaft 152 are in axial alignment and are also vertically aligned with, and in the same vertical plane with, the shaft 154 and output shaft 132, with the shaft 154 and the output shaft 132 also being axially aligned. The shaft 134 and the shaft 154 are interconnected by means of meshing gears 52 and 54, so that for any given direction of rotation of one of these shafts, the other shaft will rotate in the opposite direction. In addition, since the gear 34 is drivingly connected, via an idler gear, with the gear 36, they, therefore, rotate in the same direction. Thus, engagement of the clutch 38 conditions the transmission 150 for what may arbitrarily be designated "reverse drive", and engagement of the clutch 50 conditions the transmission for what may again be arbitrarily termed "forward drive" depending,, of course, on the direction of rotation of the input shaft 14.

A gear 62 is mounted for rotation on the shaft 152 and can be connected thereto for conjoint rotation therewith by means of a clutch 64. In addition, another gear 66 is fixed to the shaft 152 for conjoint rotation therewith, and is in constant mesh with a gear 138 affixed to the output shaft 132. A further gear 140 is fixed to the shaft 154 and can be connected to the output shaft 132, which is axially aligned with the shaft 154, by means of a clutch 136.

At this point, it will be seen, since all of the gears are in constant mesh, that a first speed ratio is provided, in both forward and reverse, by engaging the clutch 64 so that the output shaft 132 is driven through the gear trains comprising either the gears 34, 36, 140, 62, 66 and 138 or the gears 52, 54, 140, 62, 66 and 138. A second speed ratio is provided, in both forward and reverse, by engaging the clutch 58 so that the output shaft 132 is driven through the gear trains comprising either the gears 34, 36, 54, 52, 66 and 138 or the gears 66 and 138. A third speed ratio is provided, in both forward and reverse, by engaging the clutch 136, thereby driving the output shaft 132 through gear trains comprising either the gears 34 and 36 or the gears 52 and 54.

In view of the foregoing description, it will be apparent that a first, or low, forward speed ratio is provided by the engagement of the clutches 50 and 64; a second, or intermediate, speed ratio is provided by the continued engagement of the clutch 50 and the engagement of the clutch 58 instead of the clutch 54; and a third, or high, speed ratio is provided by the continued engagement of the clutch 50 and the engagement of the clutch 136 instead of the clutch 58. By engaging the clutches 38 and 64, a low reverse speed ratio is provided, and by releasing the clutch 64 and engaging the clutch 58, a second, or intermediate, reverse speed ratio is provided.

A third, or high, reverse speed ratio is provided by engaging the clutches 38 and 136.

It should again be noted that in the transmission 150, all shafts lie in a common vertical plane, with this arrange-ment giving a compact three speed short-drop constant -mesh-gear transmission.

From the foregoing, it is believed that those familiar with the art will readily recognise and appreciate the novel concepts and features of the present invention. Obviously, while the invention has been described in relation to only a limited number of embodiments, numerous variations, changes and substitutions of equivalents will present themselves to persons skilled in the art. For example, while the addition of a power takeoff shaft 78, driven at torque converter output speed, is discussed with reference to the transmission 10 in Fig. 1, it should be understood that such a power takeoff shaft can also readily be utilised with, the transmissions 80,90, 100 and 120 shown in Figs. 2, 3, 4, 5 and 6, respectively. In addition, while reference is made that the output shaft gear 76 could be mounted so as to be selectively engageable and dis-engageable with the output shaft 16, so as to readily permit towing without rotating any other transmission components besides the output shaft, it should be understood that this feature may be incorporated in all of the embodiments of this invention. Furthermore, front power takeoff shafts and/or coaxial auxiliary output shafts, as described with reference to the transmission 10 in Figs. 1 and 2, may also readily be used in the transmissions 80 and 100 shown in Figs. 3 and 5, respectively.

Claims (11)

4 A I 3 2 What we claim is: '

1. A mechanical power transmission comprising an input shaft; a first gear fixed to said input shaft; a first shaft lying in a common plane with said input shaft ; a second gear mounted for rotation on said first shaft and drivingly connected with said first gear; a second shaft axially aligned with said input shaft; a first clutch for connecting said input shaft with said second shaft ; a second clutch for connecting said second gear to said first shaft for conjoint . rotation therewith; a third gear fixed to said second shaft; a fourth gear fixed to said first shaft and in mesh with said third gear; a third shaft axially aligned with one or said first and second shafts; a third clutch for connecting said third shaft with said one of said first and second shafts; a fifth gear mounted for rotation on said third shaft; a fourth clutch for connecting said fifth gear to said third shaft; a sixth gear fixed to said third shaft; and output shaft lying in said common plane, and means for drivingly connecting said output shaft with said third shaft each of said first second third and fourth clutches being bidirectionally engageable.

2. A transmission as claimed in claim 1, wherein said connecting means includes a fourth shaft lying in said common plane; a seventh gear fixed to said fourth shaft and in mesh with said fourth gear; an eighth gear fixed to said fourth 454/3 2 shaft and in mesh with said fifth gear; a fifth shaft axially aligned with said fourth shaft; a fifth clutch for connecting said fourth shaft to said fifth shaft for conjoint rotation therewith; a ninth gear fixed to said fifth shaft and in mesh with said sixth gear and a tenth gear fixed to said output shaft and in mesh with said ninth gear, with said output shaft being vertically aligned with said input shaft said fifth clutch being bidirectionally engageable.

3. A transmission as claimed in claim 1, wherein said connecting means includes a fourth shaft lying in said common plane, a seventh gear fixed to said fourth shaft and in mesh with said fourth gear; an eighth gear fixed to said fourth shaft and in mesh with said fifth gear; a fifth shaft axially aligned with said fourth shaft; a ninth gear fixed to said fifth shaft and in mesh with said sixth gear; a tenth gear mounted for rotation on said output shaft; an eleventh gear fixed to said fifth shaft and in mesh with said tenth gear; a twelfth gear mounted for rotation on said output shaft; a thirteenth gear fixed to said fifth shaft and in mesh with said twelfth gear; and means for alternately connecting said tenth and twelfth gears to said output shaft for conjoint rotation therewith, with said output shaft being vertically aligned with said input shaft.

4. A transmisson as claimed in claim 1 wherein said connecting means includes a fourth shaft lying in said common plane, a seventh gear fixed to said fourth shaft and in mesh ¾ 54 13 with said fourth gear; an eighth gear fixed to said fourth / shaft and in mesh with said fifth gear; a fifth clutch for connecting said fourth shaft to said output shaft for conjoint rotation therewith; and a ninth gear fixed to said output shaft and in mesh with said sixth gear, with said output shaft being vertically aligned with said input shaft said fifth clutch being bidirectionally engageable.

5. A transmission as claimed in claim 1, including a seventh gear fixed to said second shaft and in mesh with said fifth gear, and wherein said connecting means includes a fourth shaft vertically aligned with said input shaft; an eighth gear mounted for rotation on said fourth shaft and in mesh with said fifth gear; a fifth clutch for connecting said eighth gear to said fourth shaft for conjoint rotation therewith; a ninth gear fixed to said fourth shaft and in mesh with said sixth gear; and a tenth gear fixed to said output shaft and in mesh with said ninth gear, with said output shaft being vertically aligned with said input shaft said fifth clutch being bidirectionally engageable.

6. A transmission as claimed in claim 1, including a seventh gear fixed to said second shaft and in mesh with said fifth gear and wherein said connecting means includes an eighth gear mounted for rotation on said output shaft and in mesh with said fifth gear; a fifth clutch for connecting said eighth gear to said output shaft for conjoint rotation therewith; and a 4 54 13 2- ninth gear fixed to said output shaft and in mesh with said ' sixth gear, with said output shaft being vertically aligned with said input shaft said fifth clutch being bidirect ionally engageable .

7. A transmission as claimed in claim 1 wherein said connecting means includes a seventh gear fixed to said output shaft and in mesh with said sixth gear; an eighth gear fixed to said second shaft and in mesh with said fifth gear; and a fifth clutch for connecting said second shaft to said output shaft for conjoint rotation therewith, with said output shaft being axially aligned with said input shaft said fifth clutch being bidirectionally engageable.

8. A transmission as claimed in claim 1 wherein said connecting means includes a seventh gear fixed to said butput shaft and in mesh with said sixth gear; an eighth gear fixed to said first shaft and in mesh with said fifth gear; and a fifth clutch for connecting said first shaft to said output shaft for conjoint rotation therewith, with said output shaft being vertically aligned with said input shaft said fifth clutch being bidirectionally engageable.

9. A transmission as claimed in claim 1 including a power takeoff shaft concentric with said second shaft and connected to said input shaft for conjoint rotation therewith.

10. A transmission as claimed in claim 1, wherein said connecting means includes at least one gear mounted for rotation on said output shaft, and said transmission further includes means for selectively connecting and disconnecting said at . least one gear with respect to said output shaft.

11. A mechanical power transmission substantially as hereinbefore, described with reference to Figs. 1 and 2, or Fig. 3, or Fig. 4, or Fig. 5, or Fig. 6, or Figs. 7 and 8, or Fig. 9 of the accompanying drawings. COSHEN ZEDEK & SPISBACH p Box 33116, Tel-Aviv Attorneys for Applicant