GB2067684A - Reduction gear for marine propulsion systems - Google Patents
Reduction gear for marine propulsion systems Download PDFInfo
- Publication number
- GB2067684A GB2067684A GB7939117A GB7939117A GB2067684A GB 2067684 A GB2067684 A GB 2067684A GB 7939117 A GB7939117 A GB 7939117A GB 7939117 A GB7939117 A GB 7939117A GB 2067684 A GB2067684 A GB 2067684A
- Authority
- GB
- United Kingdom
- Prior art keywords
- gear
- clutch
- input shaft
- output shaft
- reduction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000002093 peripheral effect Effects 0.000 description 8
- 238000009434 installation Methods 0.000 description 3
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H23/00—Transmitting power from propulsion power plant to propulsive elements
- B63H23/02—Transmitting power from propulsion power plant to propulsive elements with mechanical gearing
- B63H23/06—Transmitting power from propulsion power plant to propulsive elements with mechanical gearing for transmitting drive from a single propulsion power unit
-
- 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
- F16H3/44—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion using gears having orbital motion
- F16H3/46—Gearings having only two central gears, connected by orbital gears
- F16H3/60—Gearings for reversal only
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H23/00—Transmitting power from propulsion power plant to propulsive elements
- B63H23/02—Transmitting power from propulsion power plant to propulsive elements with mechanical gearing
- B63H2023/0283—Transmitting power from propulsion power plant to propulsive elements with mechanical gearing using gears having orbital motion
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H1/00—Toothed gearings for conveying rotary motion
- F16H1/02—Toothed gearings for conveying rotary motion without gears having orbital motion
- F16H1/04—Toothed gearings for conveying rotary motion without gears having orbital motion involving only two intermeshing members
- F16H1/06—Toothed gearings for conveying rotary motion without gears having orbital motion involving only two intermeshing members with parallel axes
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Ocean & Marine Engineering (AREA)
- Structure Of Transmissions (AREA)
Abstract
An input shaft 16 is mounted in an upper part of a clutch case 10, 12, a parallel output shaft 19 is mounted in a lower part of the clutch case, and a small gear 26 rotatably carried by the input shaft and adapted to be connected to and disconnected from the latter by a multiple disc clutch 31, 32 meshes with a large gear 35 carried by the output shaft. A planetary type reduction gear 36 is disposed in the space around the output shaft below the clutch to make an efficient use of that space, thereby to provide an additional reduction stage between the large gear and the output shaft. The additional reduction stage provided by the planetary type reduction gear makes it possible to obtain a large variety of alternative reduction ratios up to 8 using the same clutch case. Teeth 34 on the clutch drive a second clutch (not shown) associated with a second small gear engaging the large gear 35 for reverse. <IMAGE>
Description
SPECIFICATION
Reduction gear for marine propulsion systems
The present invention broadly relates to marine propulsion systems and, more particularly, to a reduction gear for propulsion systems which makes it possible to use a clutch case for a small reduction ratio of conventional reduction gear to obtain a large variety of reduction ratios ranging between about 2.0 and about 8.0.
Hitherto, various measures have been taken to obtain a large variety of reduction ratios, the typical examples of which are: (a) to use the clutch case for the large reduction ratio also as the clutch case for the small reduction ratio and (b) to use different clutch cases for various reduction ratios, the clutch cases having different distances between the input and the output shafts.
The first measure (a), however, poses various problems such as high cost and increased weight, although this measure eliminates the necessity of different clutch cases. In addition, this measure makes it difficult to install the reduction and reversing gear on the hull. Thus, since the clutch case has a large vertical dimensions, the lower part inconveniently abuts the bottom of the hull, if the reduction and reversing gear is installed at the stern of the hull. To avoid this, it is necessary to shift the position of the clutch case towards the bow of the hull. Obviously this requires a large engine room.
In the method (b) above, the mounting of the engine, as well as the reduction and reversing gear on the hull, is made difficult because the different clutch cases provide different distances between the input and the output shafts. Thus, considerable work is required to modify the hull and the engine bed or the bed for the gear, to meet the various distances between the input and output shafts of the gear.
Generally, the reduction and reversing gear for marine propulsion systems has an input shaft disposed at an upper portion of a clutch case and an output shaft disposed at a lower portion of the clutch case in parallel with the input shaft. The input shaft carries a multiple disc clutch, while the output shaft carries a large gear. The large gear engages a small gear which in turn is adapted to be connected to the input shaft through the medium of the clutch.
It is to be noted that this construction of the reduction and reversing gear provides a comparatively large vacant space beneath the clutch and around the output shaft.
Upon recognition of this point, the present invention proposes to make an efficient use of this vacant space, by mounting in this space a planetary gear type reduction gear so that an additional reduction may be achieved between the large gear and the output shaft.
Thus, according to the invention, a reduction gear for marine propulsion systems has a clutch case, an input shaft mounted in an upper portion of said clutch case, an output shaft mounted in a lower portion of said clutch case and extending parallel to said input shaft, an ahead unit including a clutch mounted on said input shaft and having a clutch member adapted to rotate with said input shaft, a small gear rotatably mounted adjacent to the clutch, said small gear being adapted to be connected to and disconnected from said input shaft in accordance with the state of said clutch, a large gear mounted for engagement with said small gear, a planetary gear type reduction gear disposed in the space below said clutch of said ahead unit, the planetary gear type reduction gear being connected on one side to said large gear and on its other side to said output shaft.
The invention may be carried into practice in various ways but several specific embodiments will now be described, by way of example, with reference to the accompanying drawings, in which: FIGURE 1 is an illustration of a conventional reduction and reversing gear in which the clutch case for a reduction gear of a large reduction ratio is used also for a reduction gear of a small reduction ratio;
FIGURE 2 is a sectional view of a first embodiment of the invention;
FIGURE 3 is a sectional view of a planetary gear type reduction gear taken along the line Ill-Ill of
Figure 2::
FIGURE 4 is a sectional view of a second embodiment of the invention;
FIGURE 5 is a sectional view of a planetary gear type reduction gear taken along the line V-V of
Figure 4;
FIGURE 6 is a sectional view of a third embodiment of the invention;
FIGURE 7 is a sectional.view of a planetary gear type reduction gear taken along the line VIl-VIl of Figure 6;
FIGURE 8 is a sectional view of a fourth embodiment of the invention, and
FIGURE 9 is a sectional view of a planetary gear type reduction gear taken along the line IX-IX of
Figure 8.
Before turning to the description of the preferred embodiment of the invention, a description will be given of a typical conventional reduction and reversing gear, in order to clarify the drawbacks of the prior art, and hence, the advantages of the present invention.
Figure 1 shows a typical conventional reduction and reversing gear in which a clutch case for a large reduction ratio is used also for a small reduction ratio. This conventional reduction and reversing gear involves various problems such as high cost and weight, although it eliminates the necessity for a different clutch case. In addition, this reduction and reversing gear is difficult to install on a hull, due to the large vertical dimensions of the clutch case. Thus, if this gear is installed on the stern portion of the hull 4, the bottom of the hull 4 is inconveniently contacted by the lower end 3 of a clutch case 2 which has large vertical dimensions. It is, therefore, necessary to shift the position of the clutch case 2 toward the bow of the hull, i.e., to the left as viewed in Figure 1, as shown by an arrow. Obviously this in turn requires a larger space in the engine room 5.
As stated before, it has been proposed to use different clutch cases for different reduction ratios, having different distances A between the input and the output shafts. This measure, however, gives rise to difficulties in installation of the engine, due to the variation of distance A between the input and the output shafts. As a result considerable modification of the hull and the engine bed or the bed for the reduction and reversing gear is required.
In Figure 1 the reference numerals 1,6,7 and 8 denote, respectively, an engine, a coupling, a propeller shaft and a propeller.
Figures 2 and 3 show a first embodiment of the invention. Referring first to Figure 2, a front section 10 of the clutch case is open at its rear end (to the right) and to which is attached a rear clutch case 12 by means of a plurality of bolts. The rear section 12 of the clutch case is adapted to play also the role of supporting bearings. The clutch case 10, 12 carries in an upper portion thereof, an input shaft 1 6 mounted in bearings 14 and 15. An output shaft 19 is mounted below and parallel to the input shaft 1 6 in bearings 17, 1 8.
A reference numeral 20 generally designates a commonly used ahead unit incorporating a wet type multiple disc clutch having a clutch housing 21 which is fitted to the input shaft 1 6 by hydraulic pressure.
A torsion damper 23 is fixed to the fly-wheel of the engine and is provided with a central spline hub 24 splined to the input shaft 16. The input shaft 1 6 rotatably carries a small gear 26 which has a drum 27 connected thereto. This drum 27 is disposed in the clutch housing 21 and is provided with splines on its outer peripheral surface.
An annular piston 28 is a sliding fit in the inner surface of the clutch housing 21 and is also a sliding fit on the surface of the input shaft 1 6. The piston is resiliently biased to the right by the force of a compression spring 29. A pressure disc 3O is fixed to the open left hand end of the clutch housing 21 by means of a snap ring 30'. A plurality of discs 31 and a plurality of friction discs 32 are disposed alternatingly between the piston 28 and the pressure disc 30. Each of the discs 31 is provided with peripheral teeth or projections which engage grooves formed in the inner peripheral surface of the clutch housing 21. Thus, the discs 31 are allowed to move relatively to the clutch housing 21 in the axial direction, but are prevented from rotating relatively to the latter.
Also, the friction discs 32 have inner peripheral splines which engage the splines of the drum 27 to freely move only in the axial direction.
Therefore, as the hydraulic pressure is introduced into the pressure chamber 33 behind the piston 28, the discs 31 are brought into pressure contact with the friction discs 32 so that the clutch becomes operative to connect the small gear 26 to the clutch housing 21. The described small gear and multiple disc clutch in combination constitute the ahead unit 20.
The periphery of the clutch housing 21 has gear teeth 34 thereon which engage a corresponding gear formed on the outer periphery of the clutch housing of an astern unit (not shown). The astern unit has a small gear corresponding to the small gear 26 of the ahead unit and meshing with a large gear 35 carried by the output shaft 19 together with the small gear 26.
The large gear 35 has an externally toothed sun gear 37 of a small diameter formed unitarily and coaxially therewith. This externally toothed sun gear 37 projects into the space 25 below the clutch housing 21 of the ahead unit 20.
The clutch case section 12 has secured to it, by bolts 39, an internal gear 38 of a large diameter and which is in alignment and coaxial with the externally toothed sun gear 37. An outwardly directed flange 40 is provided on the output shaft 19 and is disposed adjacent to the externally toothed gear 37. The flange 40 has three support shafts 41 which are extended in parallel with the output shaft 1 9 and equi-spaced in the circumferential direction to project into the space between the externally toothed sun gear 37 and the internally toothed gear 38. Each support shaft 41 supports a planet gear 42 which engages both of the externally toothed sun gear 37 and the internally toothed gear 38, thereby to constitute a planetary gear type reduction gear generally designated at a reference numeral 36. (See
Figure 3).
During the operation of the engine, the input shaft 1 6 rotates counter-clockwise (in the direction of arrow L) as viewed from the stern side (right side in the drawing). As the clutch of the ahead unit 20 is put into an operative condition, the small gear 26 rotates in the same direction as the input shaft 16, so that the large gear 35 rotates clockwise (in the direction of arrow R in
Figure 3) as viewed from the stern side. The externally toothed small sun gear 37 is also rotated clockwise (in the direction of arrow R) as shown in Figure 3, together with the large gear 35. Therefore, the planet gears 42 revolve clockwise around the internally toothed large gear 38 fixed to the clutch case 12, while making counter-clockwise rotation about their own axes.
The revolution of the planet gear 42 is transmitted to the output shaft 1 9 through the support shafts 41 (Figure 2) and then through the flange 40, so that the output shaft 1 9 is rotated in a clockwise direction at a reduced speed of rotation.
It is assumed here that three reduction ratios i,.
i2 and i3 are obtainable between the small gear 26 and the large gear 35, by changing the number of teeth of the meshing gears 26 and 35, but using the same clutch case 10, 12 as for the small reduction ratio shown in Figure 2. According to the invention, it is remarkable that, thanks to the provision of the planetary gear type reduction gear 36 having a reduction ration of i4, it is possible to obtain the six different reduction ratios i" i2, i3, i, i4, i2 i4 and i3 i4 with the same clutch case 10, 12.Namely, in addition to the three reduction ratios ir, i2 and i3 which are obtained in the conventional reduction gear in which the large gear 35 is merely fixed to the output shaft 1 9, three further reduction ratios i, i4, 2 i4 and i3 i4 become available thanks to the combination of the free rotation of the large gear 35 relative to the output shaft and the planetary gear type reduction gear 36. More practically, assuming here that the reduction ratios ii, 2 3 and i4 are 2.0, 2.5, 3.0 and 2.5, respectively, it is possible to obtain the reduction ratios of 2.0, 2.5, 3.0, 5.0, 6.25 and 7.5 with the same clutch case 10, 12.
The following advantages are offered by the reduction gear of the described embodiment. (1) It is possible to obtain a wide range of reduction ratio of, for example, between about 2.0 and about 8.0 with the same clutch case as is used for the small reduction ratio in the conventional reduction gear. In other words, it becomes possible to obtain a wide variety of reduction ratios ranging between small reduction ratio (3.0 or smaller) and large reduction ratio (3.5 to 8.0) making use of the same clutch case of small reduction ratio as that used in the conventional reduction gear. It is, therefore, possible to obtain a less-expensive, small-sized and compact reduction and reversing gear for marine propulsion systems, capable of providing a large reduction ratio.
(2) Since a large variety of reduction ratios can be attained making use of a common small clutch case, the aforementioned troublesome modification of the hull required in the installation of the engine is eliminated and the installation of the reduction and reversing gear on the stern portion of the hull is very much facilitated. In consequence, the length of the engine room is reduced and the effective area of the ship is increased correspondingly. This, if the required reduction ratio is small, the conventional reduction gear is used without the planetary gear type reduction gear. However, when a large reduction ratio is required, the planetary gear type reduction gear as shown in Figure 2 is attached to the conventional reduction gear.It will be apparent to those skiiled in the art that the same direction of rotation of the propellor is obtained irrespective of the reduction ratio i.e., irrespective of whether the planetary gear type reduction gear is used or not.
Figures 4 and 5 in combination show a second embodiment of the invention. The description of parts of this second embodiment other than the planetary gear type reduction gear is omitted because these parts are materially identical to those of the first embodiment.
Referring to Figure 4, a large gear 35 carried by the output shaft 1 9 has a cylindrical internally toothed gear 43 of a large diameter formed unitarily and coaxially thereiwht. This internally toothed gear 43 projects into the space 25 below the clutch housing 21 of the ahead unit 20. To the rear section 12 of the clutch case close to the opened end of the internally toothed gear 43, an externally toothed small sun gear 44 is attached in alignment and coaxially with the internally toothed gear 43, by means of a plurality of bolts 45. An outwardly directed flange 46 is attached to the output shaft 1 9 between the large gear 35 and the externally toothed gear 44. Three support shafts 47, which are equi-spaced in the circumferential direction and extended parallel to the output shaft
19 are provided on the flange 46.Each support shaft 47 carries a planet gear 48 which engages both the internally toothed gear 44 and the externally toothed gear 43 to constitute a planetary gear type reduction gear 49. (See
Figure 5).
In operation, the input shaft 1 6 rotates counterclockwise (direction of arrow L) as viewed from the stern of the hull (right side in the drawings). As the clutch of the ahead unit 20 is put into the operating condition, the small gear 26 rotates in the same direction as the input shaft 1 6 and the large gear 35 rotates clockwise (direction of arrow
R) as viewed from the stern of the hull. Since the internally toothed large gear 43 rotates also in the clockwise direction (direction of arrow R) together with the large gear 35, the planetary gears 48 revolve in the clockwise direction around the externally toothed gear 44 fixed to the clutch case 12, while making clockwise rotation around their own axes.
The revolution of the planet gears is transmitted to the output shaft 1 9 through the support shafts 47 (See Figure 4) and the flange 46, so that the output shaft 1 9 is rotated clockwise at a reduced speed of rotation.
Figures 6 and 7 show a third embodiment of the invention which makes use of a reduction and reversing gear of small reduction ratio having a construction different from that used in the first and the second embodiments shown in Figures 2 to 5. More specifically, in which third embodiment, the positional relationship between the multiple disc clutch and the small gear on the input shaft is reverse to that in the first and the second embodiments. Accordingly, the arrangement of the large gear and the planetary gear type reduction gear on the output shaft is also reverse to that in the first and the second embodiments.
This third embodiment is different from the first and the second embodiments in some other respects than that specifically mentioned above.
The clutch case 1 Oa of Figure 6 is open at its front and rear ends (left and right ends as viewed in the drawings). A front end cover 11 a and a rear end cover 1 2a are attached to the open ends of the clutch case 1 Oa by means of a plurality of bolts so as to play also the role of bearing supporting members. The clutch case 1 Oa carries at its upper portion an input shaft 1 6a through the medium of bearings 1 4a and 15a. Also, an output shaft 1 9a is mounted below the input shaft 1 6a in parallel with the latter, through the medium of the bearings 17a, 18a.
A reference numeral 20a generally designates a commonly used ahead unit incorporating a wet type multiple disc clutch having a clutch housing 21a which is fitted to the input shaft 1 6a making use of a taper of the latter, and is fixed by means of a nut 22a.
A reference numeral 23a denotes an input flange fixed at its central portion to the boss of the clutch housing 21 a by means of a plurality of bolts 24a. The input shaft 1 6a rotatably carries a small gear 26a which has a drum 27a connected thereto. This drum 27a is disposed in the clutch housing 21 a and is provided with a spline on its outer peripheral surface.
An annular piston 28a is in sliding fit with the inner surface of the clutch housing 21 a and is also in sliding fit with the surface of the input shaft 1 6a and is resiliently biased to the left by the force of a compression spring 29a. A reference numeral 30a denotes a pressure disc which is fixed to the open end of the clutch housing 21 a, for example, by means of a snap ring (not shown). A plurality of discs 31 a and a plurality of friction discs 32a are disposed alternatingly between the piston 28a and the pressure disc 30a. Each of the discs 31a is provided with peripheral teeth or projections which engage the grooves formed in the inner peripheral surface of the clutch housing 21 a. Thus, the discs 31 a are allowed to move relatively to the clutch housing 21 a in the axial direction, but are prevented from rotating relatively to the latter.
Also, the friction discs 32a have inner peripheral splines which engage the spline of the drum 27a to freely slide only in the axial direction.
Therefore, as hydraulic pressure is introduced into the pressure chamber 33a behind the piston 28a, the discs 31 a are brought into pressure contact with the friction discs 32a so that the clutch becomes operative to connect the small gear 26a to the housing 21 a. The described small gear and multiple disc clutch in combination constitute the ahead unit 20a.
A reference numeral 34a denotes a gear which is provided on the periphery of the housing 21 a
and meshing with a corresponding gear formed on the outer periphery of the clutch housing of an
astern unit (not shown) which is disposed in
parallel with the ahead unit 20a. The astern unit
has a small gear corresponding to the small gear
26a of the ahead unit and meshing with the large
gear 35a together with the small gear 26a.
The large gear 35a carried by the output shaft 1 9a has an externally toothed sun gear 37a of a small diameter formed unitarily and coaxially therewith. This externally toothed sun gear 37a lies in the space 25a below the clutch housing 21a of the ahead unit 20a.
To the clutch case 1 Oa close to the open end of the externally toothed gear 37a (left end as viewed in the drawing), and attached by means of a plurality of bolts 39a, is an internally toothed gear 38a of a large diameter which is in alignment and coaxial with the externally toothed gear 37a.
An outwardly directed flange 40a is provided on the output shaft 19a. The flange 40a has three support shafts 41 a which extend parallel to the output shaft 1 9a and are equi-spaced in the circumferential direction to project into the space between the externally toothed gear 37a and the internally toothed gear 38a. Each support shaft 41 a supports a planet gear 42a which engages both of the externally toothed sun gear 37a and the internally toothed gear 38a, thereby to constitute a planetary gear type reduction gear generally designated by a reference numeral 36a.
(See Figure 7).
During the operation of the engine, the input shaft 1 6a rotates counter-clockwise (in the direction of arrow L) as viewed from the stern side (right side in the drawing). As the clutch of the ahead unit 20a is put in operative condition, the small gear 26a rotates in the same direction as the input shaft, so that the large gear 35a rotates clockwise (in the direction of arrow R) as viewed from the stern side. The externally toothed small sun gear 37a is also rotated clockwise (in the direction of arrow R) as shown in Figure 7, together with the large gear 35a. Therefore, the planet gears 42a revolve clockwise around the internally toothed large gear 38a fixed to the clutch case 1 0a, while making counter-clockwise rotation around their own axes.The revolution of the planet gears 42a is transmitted to the output shaft 1 9a through the support shafts 41 a (Figure 6) and then through the flange 40a so that the output shaft 1 9a is rotated in the clockwise direction at a reduced speed of rotation.
Figures 8 and 9 show a fourth embodiment of the invention making use of the same reduction and reversing gear for a small reduction ratio as that used in the third embodiment. Other parts of this fourth embodiment than the planetary gear type reduction gear are not described here because these parts are materially identical to those of the third embodiment.
Referring to Figure 8, a large gear 35a carried by the output shaft 1 9a has an internally toothed large gear 43a formed coaxially and unitarily therewith. This internally threaded gear 43a extends into the space 25a below the clutch housing 21a of the ahead unit 20a. To the clutch case section 1 Oa closer to the open end (left side in the drawings) of the internally toothed gear 43a, and attached by means of bolts 45a is an externally toothed small sun gear 44a in alignment with and lying coaxially with respect to the internally toothed gear 43a. An outwardly directed flange 46a is attached to the output shaft 1 9a between the large gear 35a and an externally toothed gear 44a.Three support shafts 47a, which are equi-spaced in the circumferential direction and which extend parallel to the output shaft 19a, are attached to the flange 46a. Each support shaft 47a. Each support shaft 47a carries a planet gear 48a meshing with the internally toothed gear 43a and the externally toothed gear 44a thereby to constitute a planetary gear type reduction gear generally designated by a numeral 49a. (See Figure 9).
In operation, the input shaft 1 6a rotates counter-clockwise (direction of arrow L) as viewed from the stern (right side in the drawings). As the clutch of the ahead unit 20a is turned into operative condition, the small gear 26a starts to rotate in the same direction as the input shaft 16a, so that the large gear 35a rotates in the clockwise direction (direction of arrow R) as viewed from the stern. Also, the internally toothed large gear 43a is rotated in the clockwise direction (direction of arrow R) as shown in Figure 9, together with the large gear 35a. As a result, the planet gears 48a revolve in the clockwise direction around the externally toothed sun gear 44a fixed to the clutch case 1 0a, while making clockwise rotation around their own axes. The revolution of the planet gears 48a is transmitted through the support shafts 47a (Figure 8) and the flange 46a to the output shaft 1 9a to rotate the latter in the clockwise direction at a reduced speed of rotation.
It will be apparent to those skilled in the art that the advantages brought about by the first embodiment can equally be achieved by the second, third and the fourth embodiment of the invention.
In each embodiment, the astern unit may be dispensed with if the reduction gear is used in combination with a controllable pitch propeller.
Claims (9)
1. A reduction gear for marine propulsion systems, having: a clutch case, an input shaft mounted in an upper portion of said clutch case, an output shaft mounted in a lower portion of said clutch case and extending parallel to said input shaft, an ahead unit including a clutch mounted on said input shaft and having a clutch member adapted to rotate with said input shaft1 a small gear rotatably mounted adjacent ot the clutch, said small gear being adapted to be connected to and disconnected from said input shaft in accordance with the state of said clutch, a large gear mounted for engagement with said small gear, a planetary gear type reduction gear disposed in the space below said clutch of said ahead unit, the planetary gear type reduction gear being connected on one side to said large gear and on its other side to said output shaft.
2. A reduction gear for marine propulsion systems as claimed in Claim 1 , wherein said planetary gear type reduction gear includes: an externally toothed small sun gear coaxial with and connected to said large gear; an internally toothed large gear fixed to said clutch case and disposed in alignment and coaxially with said externallytoothed gear; a flange provided on said output shaft; a plurality of support shafts carried by said flange and extending into the space between said externally toothed sun gear and said internally toothed gear; and a plurality of planet gears supported one by each support shaft and engaging with said externally toothed gear and said internally toothed sun gear.
3. A reduction gear for marine propulsion systems as claimed in Claim 1, wherein said planetary gear type reduction gear includes: an internally toothed large gear coaxial with and mounted on said large gear; an externally toothed small sun gear fixed to said clutch case and disposed in alignment and coaxially with said internally toothed gear; a flange provided on said output shaft; a plurality of support shafts carried by said flange and extending into the space between said internally toothed gear and said externally toothed sun gear; and a plurality of planet gears supported one by each support shaft and engaging with said externally toothed gear and said internally toothed gear.
4. A reduction gear for marine propulsion systems as claimed in Claim 2 or Claim 3, wherein said small gear on said input shaft and said large gear on said output shaft are disposed at the input side of the space in said clutch case, while said multiple disc clutch on said input shaft and said planetary gear type reduction gear coaxial with said output shaft are disposed at the output side of the space in said clutch case.
5. A reduction gear for marine propulsion systems as claimed in Claim 2 or Claim 3, wherein said multiple disc clutch on said input shaft and said planetary gear type reduction gear coaxial with said output shaft are disposed at the input side of the space in said clutch case, while said small gear on said input shaft and said large gear on said output shaft are disposed at the output side of the space in said clutch case.
6. A reduction gear as claimed in any one of the preceding claims, in which the large gear is mounted for rotation on said output shaft.
7. A reduction gear as claimed in any one of the preceding claims in which said small gear is rotatably mounted on said input shaft.
8. A reduction and reversing gear for marine propulsion systems, the reduction and reversing gear having: a clutch case, an input shaft mounted on an upper portion of said clutch case, an output shaft mounted at a lower portion of said clutch case and extending parallel to said input shaft, an ahead unit including a multiple disc clutch mounted on said input shaft and having a clutch housing adapted to rotate with said input shaft, a small gear rotatably mounted on said input shaft and adjacent to said multiple disc clutch, said small gear being adapted to be connected to and disconnected from said input shaft in accordance with the state of said clutch, a large gear mounted on said output shaft for engagement with said small gear, and an astern unit disposed in parallel with said ahead unit including a clutch having a clutch housing operatively connected to said clutch housing of said ahead unit and a small gear for engagement with said large gear; a planetary gear type reduction gear disposed in the space below said multiple disc clutch of said ahead unit, the planatary gear type reduction gear being connected on one side to said large gear and on its other side to said output shaft.
9. A reduction gear for marine propulsion systems substantially as specifically described herein with reference to Figures 2 and 3; or
Figures 4 and 5; or Figures 6 and 7; or Figures 8 and 9 of the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7939117A GB2067684B (en) | 1979-11-12 | 1979-11-12 | Reduction gear for marine propulsion systems |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7939117A GB2067684B (en) | 1979-11-12 | 1979-11-12 | Reduction gear for marine propulsion systems |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2067684A true GB2067684A (en) | 1981-07-30 |
| GB2067684B GB2067684B (en) | 1983-06-08 |
Family
ID=10509140
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7939117A Expired GB2067684B (en) | 1979-11-12 | 1979-11-12 | Reduction gear for marine propulsion systems |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2067684B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998041447A1 (en) * | 1997-03-14 | 1998-09-24 | Westerbeke Corporation | Marine auxiliary power supply system |
| WO2000038981A1 (en) * | 1998-12-16 | 2000-07-06 | Ab Volvo Penta | Boat propeller transmission |
| EP2908030A1 (en) * | 2014-02-17 | 2015-08-19 | Hamilton Sundstrand Corporation | Electric generator oil pump drive gear |
| CN112823121A (en) * | 2019-06-11 | 2021-05-18 | 沃尔沃遍达公司 | Multi-plate clutch transmission and marine vehicle comprising a multi-plate clutch transmission |
-
1979
- 1979-11-12 GB GB7939117A patent/GB2067684B/en not_active Expired
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998041447A1 (en) * | 1997-03-14 | 1998-09-24 | Westerbeke Corporation | Marine auxiliary power supply system |
| WO2000038981A1 (en) * | 1998-12-16 | 2000-07-06 | Ab Volvo Penta | Boat propeller transmission |
| US6439937B1 (en) | 1998-12-16 | 2002-08-27 | Ab Volvo Penta | Boat propeller transmission |
| EP2908030A1 (en) * | 2014-02-17 | 2015-08-19 | Hamilton Sundstrand Corporation | Electric generator oil pump drive gear |
| US9502942B2 (en) | 2014-02-17 | 2016-11-22 | Hamilton Sundstrand Corporation | Electric generator oil pump drive gear |
| CN112823121A (en) * | 2019-06-11 | 2021-05-18 | 沃尔沃遍达公司 | Multi-plate clutch transmission and marine vehicle comprising a multi-plate clutch transmission |
| CN112823121B (en) * | 2019-06-11 | 2024-04-26 | 沃尔沃遍达公司 | Multi-plate clutch type transmission and marine vehicle including the same |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2067684B (en) | 1983-06-08 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19971112 |