JP2004314897A - Propeller shaft supporting structure of shipping propelling machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To hold good appearance commodity property by effectively hiding the head of a fastening bolt while keeping running resistance low with a small number of components. <P>SOLUTION: In a supporting structure of a propeller shaft, an insertion hole 15c of which rear part opens and directs forward is punched in a gear case 15 under an outboard motor or the like having a gear chamber 15a for storing a bevel gear mechanism 22 for transmitting the power to the propeller shaft 24. A propeller shaft holder 50 rotatably pivoting the propeller shaft 24 is inserted into the insertion hole 15c, and a rear end flange 55 of the propeller shaft holder 50 abuts on an opening end surface of the insertion hole 15c of the gear case 15 and is fastened by screwing of the fastening bolt 71. The rear end flange 55 extends partially and radially to form a mounting boss section 56, and a peripheral wall 56b formed on the propeller shaft holder circumferentially covers the head of the screwed fastening bolt 71. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a marine propulsion device such as an outboard motor in which an internal combustion engine is outboard and an inboard / outboard motor inboard, and more particularly to a propeller shaft support structure having a bevel gear mechanism in a submerged portion.
[0002]
[Prior art]
Various proposals have been made for a propeller shaft support structure of a conventional marine propulsion machine, and among them, a structure in which a propeller shaft holder rotatably supporting a propeller shaft is inserted into a gear case at a lower portion of the outboard motor. (For example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-1-262286
[0004]
The structure disclosed in Patent Document 1 has a structure in which a head portion of a fastening bolt screwed from behind to fasten a propeller shaft holder to a gear case is partially covered around its periphery. .
[0005]
Therefore, since the head of the fastening bolt and the dirt attached to it are visible from the outside and impair the appearance and product appeal, the structure of hiding the head of the fastening bolt with a separate cover and the diameter of the cylindrical base end of the propeller are increased to increase the diameter of the fastening bolt. A structure for hiding the head is disclosed.
[0006]
[Problems to be solved by the invention]
However, in the case of the former structure, a cover and a fastening bolt for attaching the cover are required, so that the number of parts is large and the cost is high.
In the case of the latter structure, there is a disadvantage that the running resistance is increased due to an increase in the diameter of the cylindrical base end of the propeller.
[0007]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to effectively hide a head portion of a fastening bolt while maintaining a low running resistance with a small number of parts, thereby maintaining a good appearance and productability. Another aspect of the present invention is to provide a propeller shaft support structure for a marine propulsion device.
[0008]
Means for Solving the Problems and Functions and Effects
In order to achieve the above object, the invention according to claim 1 is characterized in that a rearward opening is formed in a lower gear case of a marine propulsion device having a gear chamber in which a bevel gear mechanism for transmitting power to a propeller shaft is housed, and a forward opening is provided. A propeller shaft holder rotatably supporting a propeller shaft is inserted into the insertion hole, and a rear end flange of the propeller shaft holder is an opening end face of the insertion hole of the gear case. In the propeller shaft support structure which is brought into contact with and fastened by screwing of the fastening bolt, the rear end flange is a mounting boss part which partially extends in the radial direction, and a head of the screwed fastening bolt is provided. A propeller shaft support structure of a marine propulsion device is provided that is covered by a peripheral wall formed on the propeller shaft holder in the circumferential direction.
[0009]
Since the peripheral wall formed on the propeller shaft holder covers the head of the fastening bolt in the circumferential direction, the head of the fastening bolt is effectively hidden with a small number of parts without requiring a separate member for hiding the head of the fastening bolt. Thus, good appearance and productability can be maintained.
[0010]
The part to be fastened by the fastening bolt is a mounting boss part whose rear end flange is partially extended in the radial direction, and since the head of the fastening bolt is hidden by the peripheral wall, a propeller provided at the rear of the propeller shaft is provided. It is not necessary to cover the head of the fastening bolt by extending the diameter of the cylindrical base end portion of the cylinder to the mounting boss portion in the radial direction, and to reduce the running resistance by making the cylindrical base end portion of the propeller small.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment according to the present invention will be described below with reference to FIGS.
FIG. 1 is an overall side view of an outboard motor 10 according to the present embodiment.
[0012]
The outboard motor 10 is attached to the stern 1 via the attachment device 2.
The mounting device 2 includes a swivel pivotally attached to a stern 1 via a bolt 3 via a tilt bracket 4 fixedly mounted on a stern 1 via a bolt and a tilt shaft 4 mounted on a front end of the bracket 3. The swivel case 5 includes a case 5, and the swivel shaft 6 is rotatably supported in the swivel case 5 so as to be directed substantially vertically.
[0013]
The outboard motor 10 includes an outboard motor main body 10a connected to the swivel shaft 6 via upper and lower connecting members 7, 8.
Therefore, the outboard motor 10 can swing up and down around the tilt shaft 4 and swing left and right around the axis of the swivel shaft 6.
[0014]
The outboard motor main body 10a has an extension case 14 connected to at least one of the connecting members 7, 8, and a mount case 12 connected to the other of the connecting members 7, 8.
[0015]
The mount case 12 is directly or indirectly integrated with the extension case 14.
The internal combustion engine 11 is fixed on the mount case 12.
The mount case 12 and the extension case 14 integrally support the internal combustion engine 11 and the drive unit, and may include another oil case or the like.
[0016]
The internal combustion engine 11 has at least an upper half covered by an engine cover 13a.
The outboard motor main body 10a also has an under cover 13b to cover the lower half of the internal combustion engine 11, and constitutes the overall appearance of the outboard motor.
Further, the outboard motor main body 10 a has a gear case 15 connected to a lower portion of the extension case 14.
[0017]
Normally, in a stopped state or a low speed navigation state, a lower part from the vicinity of the lower connecting member 8 corresponds to a submerged part immersed in water, and in a high speed navigation state, a lower part than an anti-cavitation plate 17b described later corresponds to a submerged part. I do.
[0018]
The crankshaft 20 of the internal combustion engine 11 is directed substantially vertically, and a drive shaft 21 connected to the crankshaft 20 extends downward inside the extension case 14 and reaches inside the gear case 15.
[0019]
A bevel gear mechanism 22 and a forward / reverse switching clutch mechanism 23 are built in the gear case 15, and the rotation of the drive shaft 21, which is directed substantially vertically, is transmitted to the propeller shaft 24, which is directed substantially horizontally, by the bevel gear mechanism 22. The propeller 25 provided on the propeller shaft 24 rotates.
[0020]
An upper shift rod 26 for operating the forward / reverse switching clutch mechanism 23 rotatably penetrates the swivel shaft 6 from the mount case 12 to the gear case 15 so as to rotate in front of the drive shaft 21 in parallel. A lower shift rod 27 connected coaxially to 26 is inserted into the gear case 15.
[0021]
The lowermost gear case 15 of the outboard motor 10 is a cast product of an aluminum alloy, and a cylindrical portion 18 around a gear chamber 15a, which will be described later, has a shell shape. are doing.
The gear case 15 has a rear lower portion cut out for a propeller 25 in a side view, and a lower end portion forming a skeg 16 having a triangular shape.
A splash guard 17a and an anti-cavitation plate 17b are formed on both upper and lower sides of the gear case 15 so as to protrude laterally.
[0022]
At the upper part of the skeg 16, a bullet-shaped cylindrical portion 18 oriented in the front-rear horizontal direction is formed so as to bulge left and right. The front end of the cylindrical portion 18 is reduced in diameter and closed, and the rear end is open.
[0023]
A gear chamber 15a is formed at the front of the internal space of the cylindrical portion 18, a drive shaft insertion hole 15b is formed upward from the gear chamber 15a, and the internal space from the gear chamber 15a of the cylindrical portion 18 to the rear opening is formed by a propeller. The shaft insertion hole 15c is provided.
[0024]
Therefore, the gear case 15 has a propeller shaft insertion hole 15c which is bent rearward in the gear chamber 15a at the lower end of the drive shaft insertion hole 15b oriented substantially vertically and formed substantially in the front-rear direction. It is drilled in the shape of a letter.
[0025]
Further, a shift rod insertion hole 15d is formed slightly in front of the drive shaft insertion hole 15b in parallel with the drive shaft insertion hole 15b, and the shift rod insertion hole 15d reaches a small diameter recess 15e further forward of the gear chamber 15a. ing.
[0026]
A small hole 15f for speed detection is formed further in front of the shift rod insertion hole 15d in parallel with the shift rod insertion hole 15d, and the lower end of the small hole 15f is bent forward to open outside the gear case 15. ing.
[0027]
On the other hand, a suction passage 15g for pumping water is formed at the rear along the drive shaft insertion hole 15b, and a lower portion of the suction passage 15g is laterally provided with a suction port 15g. ₁ (See FIG. 3), and its inlet 15g ₁ Is provided with a filter 30 (see FIG. 2).
Behind the suction passage 15g, an exhaust passage 15h having a long flat upper end opening in the front and rear direction is formed with a lower end penetrating the upper wall of the cylindrical portion 18.
[0028]
As shown in FIG. 4, a drive shaft insertion hole 15b has an opening and a shift rod insertion hole in front of the mating surface 19 (a portion indicated by a dotted pattern in FIG. 4) which is the upper end surface of the gear case 15 with the extension case 14. An opening of the suction passage 15g and an opening of the exhaust passage 15h are formed behind the opening 15d, the small hole 15f, and the drive shaft insertion hole 15b.
The opening end face of the drive shaft insertion hole 15b is slightly lower than the mating surface 19.
The cylindrical portion 18 of the gear case 15 is open rearward.
[0029]
Referring to FIG. 3, drive shaft insertion hole 15b into which drive shaft 21 is inserted has a maximum inner diameter portion 15b at its uppermost portion. ₁ Is formed, and the diameter of the valley is below the maximum inner diameter portion 15b. ₁ Female screw part 15b of approximately the same diameter as ₂ Is formed, and further below the internal thread portion 15b ₂ Bearing portion 15b having an inner diameter substantially equal to the inner diameter of ₃ Is formed.
[0030]
Bearing part 15b ₃ Under the step 15b ₄ Is formed, and the medium diameter portion 15b thereunder is formed. ₅ Oil pumping part 15b which has been further reduced in diameter ₆ Is formed, and the reduced diameter portion 15b thereunder is formed. ₇ The bearing part 15b with a slightly enlarged diameter at the bottom ₈ Are formed and open to the gear chamber 15a.
[0031]
Maximum inner diameter portion 15b formed at the top ₁ A communication hole 15i, which is formed obliquely downward from the front lower portion of the inner peripheral surface, penetrates the shift rod insertion hole 15d, and connects the drive shaft insertion hole 15b and the shift rod insertion hole 15d upward.
[0032]
Also, an oil pumping section 15b formed in the middle section ₅ An oil-absorbing passage 15j formed obliquely downward from the lower front part of the inner peripheral surface penetrates through the gear chamber 15a, and communicates the drive shaft insertion hole 15b and the gear chamber 15a below.
[0033]
Before the drive shaft 21 is inserted into the drive shaft insertion hole 15b from above, a forward driven gear 32, which is a bevel gear, is fitted into a reduced diameter portion at the front of the gear chamber 15a via a tapered roller bearing 31. Keep it.
[0034]
When the drive shaft 21 is inserted into the drive shaft insertion hole 15b from above, the lowermost bearing portion 15b ₈ The needle bearing 33 is fitted from below.
The drive shaft 21 inserted from above into the drive shaft insertion hole 15b penetrates the needle bearing 33 and protrudes a lower end portion into the gear chamber 15a. A drive gear 34, which is a bevel gear, is provided at the protruded lower end portion with the forward driven gear 32. And the drive gear 34 is fastened by screwing the nut 35.
[0035]
An oil pumping cylindrical member 36 having an external thread formed on an outer peripheral surface thereof is fitted to an intermediate portion of the drive shaft 21, and the oil pumping portion 15 b of the drive shaft insertion hole 15 b is provided. ₆ Is inserted into
Referring to FIG. 11, bearing portion 15b ₃ A double tapered roller bearing 37 is fitted between the drive shaft 21 and the female screw portion 15b thereon. ₂ The ring-shaped male screw fixing member 38 is screwed into the tapered roller bearing 37 to fix the tapered roller bearing 37.
[0036]
As shown in FIGS. 6 and 7, the male screw fixing member 38 has a star polygonal shape so that the male screw 38a is formed on the outer peripheral surface and the inner peripheral surface 38b is easily screwed by a tool, and the outer peripheral portion extends slightly downward. An extended portion 38c is formed.
[0037]
Internal thread 15b of drive shaft insertion hole 15b ₂ When the male screw fixing member 38 is screwed into the bearing, the outer peripheral extension 38c ₃ Abuts on the outer race of the tapered roller bearing 37 inserted into the outer race, and fits the outer race to the reduced-diameter step portion 15b. ₄ To securely fix the tapered roller bearing 37 to the inner periphery of the drive shaft insertion hole 15b.
[0038]
Accordingly, the drive shaft 21 inserted into the drive shaft insertion hole 15b is rotatably supported on the gear case 15 by the needle bearing 33 and the tapered roller bearing 37, and the vertical movement is also restricted by the fixed tapered roller bearing 37. .
[0039]
Then, the maximum inner diameter portion 15b at the top of the drive shaft insertion hole 15b ₁ The cover member 40 is fitted to the opening, and the upper end opening of the drive shaft insertion hole 15b is closed.
As shown in FIGS. 8 to 10, the lid member 40 has a coaxial inner cylindrical portion 40 b and an outer cylindrical portion 40 c which are doubly extended below a circular plate portion 40 a having a circular hole in the center. An inner peripheral edge of 40a extends upward to form an upper cylindrical portion 40d.
[0040]
The outer diameter of the disk portion 40a is slightly larger than the outer diameter of the outer cylindrical portion 40c. ₁ Is overhanging.
The lower inner cylindrical portion 40b has a larger diameter than the upper cylindrical portion 40d.
Symmetrical portions of the outer peripheral edge of the disk portion 40a protrude outward to form mounting bosses 40e, 40e. The mounting bosses 40e, 40e have bolt insertion holes 40e. ₁ , 40e ₁ Are drilled.
[0041]
Grooves 40c are formed on the outer peripheral surface of the outer cylindrical portion 40c in the circumferential direction. ₁ Is formed, and an oil passage groove 40c is formed in a part of the lower end edge of the outer cylindrical portion 40c. ₂ Are formed at predetermined positions.
A part of the lower end of the upper cylindrical portion 40d, which is located on the front side of the outboard motor, has a drain hole 40d. ₁ Are perforated.
[0042]
The sealing member 41 is fitted inside the inner cylindrical portion 40b of the lid member 40, and the groove 40c on the outer peripheral surface of the outer cylindrical portion 40c is provided. ₁ The O-ring 42 is fitted in the drive shaft insertion hole 15b, and the lid member 40 is inserted into the drive shaft insertion hole 15b. ₁ To close the upper end opening of the drive shaft insertion hole 15b (see FIG. 11).
[0043]
At this time, the outer cylindrical portion 40c of the lid member 40 is ₁ And the O-ring 42 seals the space between the drive shaft insertion hole 15b and the inner peripheral surface thereof. The drive shaft 21 passes through the center of the lid member 40, and the space between the drive shaft 21 and the seal member 41 is sealed. (See FIG. 11).
The water that has entered the upper cylindrical portion 40d along the drive shaft 21 is blocked by the seal member 41, and the water drain hole 40d that has been drilled forward is formed. ₁ Is discharged from the front.
[0044]
Flange portion 40a of lid member 40 ₁ Is fitted to the opening end surface of the drive shaft insertion hole 15b, and the mounting bosses 40e, 40e are fitted to the bulged screw hole bosses 15k, 15k (see FIG. 4) on the opening end surface of the drive shaft insertion hole 15b. ₁ , 40e ₁ The cover member 40 is fixed to the opening of the drive shaft insertion hole 15b by two bolts 43, 43 inserted into the screw hole and screwed into the screw holes.
[0045]
As shown in FIG. 11, there is a gap between the cover member 40 attached to the opening of the drive shaft insertion hole 15b and the male screw fixing member 38 thereunder, and the communication hole 15i is formed in a gap between them. Even if the position of the lid member 40 is lowered as much as possible to lower the upper wall 14a which is open and protrudes forward from the lower part of the extension case 14 and is lower than the swivel shaft 6, the communication hole 15i is formed. Oil passage groove 40c so as not to partially block the opening of ₂ Is located.
[0046]
As described above, the upper end opening of the drive shaft insertion hole 15 b is closed by the lid member 40, and the tapered roller bearing 37 that rotatably supports the drive shaft 21 is formed by the male screw fixing member 38 separate from the lid member 40. Fixed.
[0047]
Therefore, since it is not necessary to fix the tapered roller bearing 37 to the lid member 40, it is sufficient to fix the taper roller bearing 37 with the two bolts 43, 43 in terms of strength, and the screw hole boss portions 15k, 15k around the drive shaft insertion hole 15b are sufficient. Of the gear case 15 can be avoided by minimizing the swelling volume of the gear case 15.
[0048]
In particular, the increase in the width of the gear case 15 in the width direction causes running resistance, and therefore it is required to reduce the size as much as possible.
At the same time, the tapered roller bearing 37 is firmly fixed by the male screw fixing member 38, so that the fluctuation of the drive shaft 21 in both the up and down directions can be reliably prevented.
[0049]
An under panel 46 penetrates the drive shaft 21 so as to cover the closed mating surface 19 around the drive shaft insertion hole 15b and the suction passage 15g, and a water pump 45 is provided thereon.
[0050]
As shown in FIG. 11, the water pump 45 is a positive displacement water pump having the drive shaft 21 as a drive shaft. The pump case 47 is positioned by the knock pin 48 and a substantially rectangular under pump is provided between the pump case 47 and the mating surface 19 of the gear case 15. A plurality of impellers 45b extend in the radial direction from the drive shaft 21 which is fixed with the panel 46 interposed therebetween and is eccentric from the center of the pump chamber 45a.
[0051]
The pump case 47 is formed with a discharge pipe 47b protruding upward adjacent to a cylindrical part 47a forming a pump chamber 45a. As shown in FIG. 12, an under panel 46 is formed around the cylindrical part 47a and the discharge pipe 47b. A rectangular flange portion 47c corresponding to the flange portion 47c protrudes, and four corners of the flange portion 47c are fixed to the mating surface 19 of the gear case 15 by a bolt 49 via a large diameter washer 49a.
[0052]
A water passage (not shown) communicates the suction passage 15g on the gear case 15 side with the pump chamber 45a, and a discharge port formed at a lower end of a wall adjacent to the pump chamber 45a and separating the discharge pipe 47b and the pump chamber 45a. 45c communicates between the pump chamber 45a and the inside of the discharge pipe 47b.
[0053]
Therefore, when the water pump 45 is driven by the rotation of the drive shaft 21, the water is sucked into the suction passage 15g, which is opened by fitting the filter 30 to the side surface of the gear case 15, and is sucked into the pump chamber 45a via the water passage.
[0054]
The water discharged from the discharge port 45c of the pump chamber 45a to the discharge pipe 47b is sent to the upper internal combustion engine 11 by a water tube connected to the discharge pipe 47b, and is used for cooling the internal combustion engine 11.
[0055]
Next, the propeller shaft 24 is inserted into the propeller shaft insertion hole 15c. The propeller shaft 24 is supported by a propeller shaft holder 50 that rotatably supports the propeller shaft 24, and a part of the bevel gear mechanism 22 and forward and backward movement. It is inserted into the propeller shaft insertion hole 15c with the switching clutch mechanism 23 incorporated.
[0056]
The propeller shaft 24 has a propulsion transmitting flange 24a formed somewhat forward from the center, and a cylindrical portion 24b formed by drilling a circular hole rearward from the front end face of the propeller shaft 24 to near the flange 24a. At the same time, a long hole 24c is formed in the center of the cylindrical portion 24b in the axial direction penetrating in a direction perpendicular to the axis.
[0057]
The propeller shaft holder 50 that rotatably supports the central portion of the propeller shaft 24 has a tapered portion between the front large-diameter portion and the rear large-diameter portion as shown in FIGS. A small-diameter cylindrical portion constricted through is formed.
[0058]
Referring to FIG. 14, the rear large-diameter portion 54 is configured such that an inner cylinder 54a and an outer cylinder 54b are coaxial, and four connecting branches 54c are radially extended and connected between the inner cylinder 54a and the outer cylinder 54b.
The space between the four connecting branches 54c constitutes an exhaust port 54d.
[0059]
A rear end flange 55 protrudes from the outer periphery of the outer cylinder 54b, and symmetrical portions of the rear end flange 55 bulge outward to form mounting bosses 56,56.
A bolt insertion hole 56a is drilled in the mounting boss portion 56, and a rear opening of the bolt insertion hole 56a forms a circular hole 56b whose diameter is enlarged.
[0060]
The depth of the circular hole 56b is slightly deeper than the thickness of the head of the fastening bolt 71.
Therefore, when the fastening bolt 71 is inserted into the bolt insertion hole 56a of the mounting boss portion 56 from behind, the head of the fastening bolt 71 is immersed in the circular hole 56b and covered with the circular hole 56b surrounding the entire circumference of the bolt head. become.
[0061]
The propeller shaft 24 penetrates the propeller shaft holder 50 having the above structure from the front, the thrust bearing 60 is sandwiched by the flange 24a of the propeller shaft 24, and the needle bearing 61 and the seal member 62 are interposed as shown in FIG. You.
[0062]
A ball bearing 63 is interposed in the large-diameter portion on the front side of the propeller shaft holder 50, and the base cylindrical portion of the retreating driven gear 64, which is a bevel gear, is fitted into the inner race.
[0063]
There is an air gap between the retreating driven gear 64 and the propeller shaft 24, and therefore the propeller shaft 24 and the retreating driven gear 64 rotate independently of each other while being supported by the propeller shaft holder 50.
[0064]
Further, on the front cylindrical portion 24b of the propeller shaft 24, a rear shift slider 66 composed of a front shift slider 65 and a rear shift slider 66 which are coaxially connected and slide integrally, are slidable in the cylinder. And a cylindrical dog clutch 67 is slidably fitted around the outer periphery of the cylinder.
[0065]
A pair of front and rear flanges 65a, 65b are integrally formed on the front shift slider 65 rearward from the center. The rear shift slider 66 is formed by forming a circular hole from the front end surface to the vicinity of the rear end portion. No, the rear end small diameter portion of the front shift slider 65 fits into the front end opening, and a pin penetrates the fitting portion at a right angle to connect the two and prevent them from coming off. The configuration and cost can be reduced.
[0066]
Note that the rear shift slider 66 has a circular tubular portion that is open at the front, thereby facilitating assembly of a detent mechanism using a compression spring therein.
A clutch shifter pin 68, which is supported so as to be orthogonal to the rear end of the rear shift slider 66, passes through the elongated hole 24c of the cylindrical portion 24b of the propeller shaft 24 and fits into the circular hole of the dog clutch 67.
[0067]
Therefore, when the front shift slider 65 is slid in the axial direction together with the rear shift slider 66, the dog clutch 67 moves back and forth through the clutch shifter pin 68 within the range of the front and rear widths of the long hole 24c.
[0068]
As described above, the propeller shaft 24 is rotatably supported by the propeller shaft holder 50, and the propeller shaft insertion hole 15c with the partially driven gear 64 and the forward / reverse switching clutch mechanism 23 of the bevel gear mechanism 22 incorporated therein. Is inserted into
[0069]
The outer diameters of the front large-diameter portion 51 and the rear large-diameter portion 54 of the propeller shaft holder 50 are substantially equal to the inner diameter of the propeller shaft insertion hole 15c, and the O-ring 69 is fitted on the outer peripheral surface of the front large-diameter portion 51 so that the propeller The shaft holder 50 is fitted into the propeller shaft insertion hole 15c.
[0070]
The front portion of the cylindrical portion 24b of the propeller shaft 24 is fitted into a needle bearing 70 previously fitted inside the proximal cylindrical portion of the forward driven gear 32, which is already fitted deep inside the gear chamber 15a. The front shift slider 65 protruding forward from the portion 24a is provided with a cylindrical portion 15e formed on the front surface of the small-diameter concave portion 15e. ₁ The front end is slidably inserted back and forth and is rotatably supported.
[0071]
Therefore, the shift slider including the front shift slider 65 and the rear shift slider 66 is slidably moved forward and backward and rotatably supported, so that the shift operation is reliably performed.
[0072]
In the gear chamber 15a, the retreat-side driven gear 64 meshes with the drive gear 34 fitted to the lower end of the drive shaft 21 to form the bevel gear mechanism 22.
The rotation of the drive shaft 21 causes the forward driven gear 32 meshing on the front side with the drive gear 34 rotating integrally with the drive shaft 21 to rotate forward, and the retreating driven gear 64 meshing on the rear side with the drive gear 34 rotates in the reverse direction.
[0073]
A dog clutch 67 is interposed between the front and rear forward driven gears 32 and the reverse driven gear 64 so as to be movable back and forth, and the forward / reverse switching clutch mechanism 23 is configured.
The dog clutch 67 has clutch teeth formed on both front and rear end surfaces of the cylinder, and clutch teeth corresponding to the forward driven gear 32 and the reverse driven gear 64 facing each other are formed so as to be disengageable.
[0074]
When the dog clutch 67 is at an intermediate position between the forward driven gear 32 and the backward driven gear 64 and is not engaged with any of them, the dog clutch 67 is in a neutral state.
When the dog clutch 67 moves forward, it engages with the forward driven gear 32, and forward rotation of the forward driven gear 32 is transmitted as forward rotation to the propeller shaft 24 via the dog clutch 67 and the clutch shifter pin 68 to travel forward. it can.
[0075]
Conversely, when the dog clutch 67 moves rearward, the dog clutch 67 engages with the driven gear 64 on the reverse side, and the reverse rotation of the driven gear 64 on the reverse side is transmitted to the propeller shaft 24 via the dog clutch 67 and the clutch shifter pin 68 as reverse rotation, and the vehicle is driven backward. I do.
[0076]
When the propeller shaft holder 50 supporting the propeller shaft 24 is fitted into the propeller shaft insertion hole 15c in this manner, the rear end flange 55 of the rear large-diameter portion 54 of the propeller shaft holder 50 inserts the propeller shaft into the gear case 15. It comes into contact with the opening end surface 18a of the hole 15c (dotted portion in FIG. 5).
[0077]
At this time, the mounting bosses 56, 56 protruding from the rear end flange 55 have the mounting surface 18b of the boss portion having the bolt holes 18c protruding above and below the opening end surface 18a of the propeller shaft insertion hole 15c (see FIGS. 3 and 5). ), And tightening bolts 71, 71 are inserted into the bolt insertion holes 56a, 56a of the mounting bosses 56, 56 of the propeller shaft holder 50, and screwed into the bolt holes 18c, 18c on the gear case 15 side to be tightened. You.
[0078]
When the propeller shaft holder 50 is inserted and fixed in the propeller shaft insertion hole 15c, the exhaust passage 15h of the gear case 15 communicates with the outer peripheral space of the constricted small-diameter cylindrical portion 53 at the center of the propeller shaft holder 50, and the outer peripheral space becomes Since it communicates with the exhaust port 54d of the rear large diameter portion 54, the exhaust passage 15h communicates with the exhaust port 54d.
[0079]
A propeller 25 is attached to a portion of the propeller shaft 24 protruding rearward from the propeller shaft holder 50.
As shown in FIG. 2, the propeller 25 has a propeller blade 25b protruding from a cylindrical base end 25a, and the cylindrical base end 25a is attached to a rear part of the propeller shaft 24 via an internal rubber bush 25c.
[0080]
The fastening bolt 71 for fixing the propeller shaft holder 50 to the gear case 15 has the head of the fastening bolt 71 immersed in the circular hole 56b of the mounting boss portion 56 as described above, and the entire periphery of the bolt head is covered with the peripheral wall. Will be.
Therefore, a member for hiding the head of the fastening bolt 71 is not required separately, and the head of the fastening bolt can be effectively hidden with a small number of parts, so that good appearance and product quality can be maintained.
[0081]
The portion to be fastened by the fastening bolt 71 is the mounting boss portion 56 in which the rear end flange 55 partially bulges in the radial direction, and is buried in the circular hole 56b so that the head of the fastening bolt 71 is hidden. 2, the diameter of the cylindrical base end portion 25a of the propeller 25 provided at the rear portion of the propeller shaft 24 does not need to be extended to the mounting boss portion 56 in the radial direction to increase the diameter, and there is no need to hide the head of the fastening bolt 71. As shown, the traveling resistance can be reduced by making the cylindrical base end portion 25a of the propeller 25 a small diameter.
[0082]
Next, the lower shift rod 27 is inserted into a shift rod insertion hole 15d drilled in parallel (substantially up and down) in front of the drive shaft insertion hole 15b.
As shown in FIG. 3, the shift rod insertion hole 15d has a maximum diameter portion 15d at the uppermost portion opened to the mating surface 19. ₁ Is formed, and a small-diameter portion 15d penetrates the small-diameter concave portion 15e at the lowermost portion. ₂ Is formed.
[0083]
On the other hand, in the lower shift rod 27, a bearing holder 29 is provided in the vicinity of the lower part so as to be able to rotatably support the lower shift rod 27, and a lower end of the lower shift rod 27 protruding downward from the bearing holder 29 is provided. A shift fork 28 eccentrically protruding downward from the shaft center is provided.
[0084]
When the lower shift rod 27 is inserted into the shift rod insertion hole 15d from above, the bearing holder 29 is moved to the small diameter portion 15d at the bottom of the shift rod insertion hole 15d. ₂ Abuts on the upper opening end face of the small diameter portion 15d. ₂ The shift fork 28, which is eccentric through the lower portion of the lower shift rod 27, is engaged between the pair of flanges 65a, 65b of the front shift slider 65.
[0085]
The upper portion of the lower shift rod 27 is rotatably supported by the closing member 80 through a closing member 80 that closes the shift rod insertion hole 15d.
As shown in FIGS. 16 to 18, the closing member 80 is connected to a rib 80c radially extending between the inner cylindrical portion 80a and the flat outer cylindrical portion 80b, and has an annular shape between the inner cylindrical portion 80a and the outer cylindrical portion 80b. The upper part of the space is closed by an upper wall 80d.
[0086]
The left and right portions of the upper wall 80d swell upward to form left and right swelling walls 81L and 81R, and air compensation chambers 82L and 82R are formed inside the left and right swelling portions 81L and 81R, respectively.
[0087]
A groove passage 83 is formed between the left and right bulging walls 81L and 81R in the front and rear directions, and an inner hole of the inner cylindrical portion 80a penetrates downward in the center of the groove passage 83.
The outer peripheral surfaces of the left and right swelling walls 81L and 81R have the same circumferential surface, and have a shape cut to the left and right by a groove passage 83.
[0088]
The circular hole inside the inner cylindrical portion 80a has an enlarged diameter portion 80a at the top. ₁ Is formed, and the enlarged diameter portion 80a is formed. ₁ (See FIG. 11), the outer cylindrical portion 80b is located at a position protruding outside the outer peripheral surfaces of the left and right bulging walls 81L and 81R, and a groove 80b is formed on the outer periphery thereof. ₁ Is formed, and the O-ring 86 is fitted.
[0089]
The closing member 80 as described above fits into and closes the upper end opening of the shift rod insertion hole 15d.
At this time, as shown in FIG. 11, the outer cylindrical portion 80b of the closing member 80 is the largest diameter portion 15d at the top of the shift rod insertion hole 15d. ₁ And is sealed by an O-ring 86, and the space between the closing member 80 and the lower shift rod 27 penetrating through the inner cylindrical portion 80 a is sealed by a sealing member 85.
[0090]
Note that a spring 88 is interposed between the retaining ring 87 fitted in the middle of the lower shift rod 27 and the lower end of the inner cylindrical portion 80a of the closing member 80, and the spring 88 attaches the lower shift rod 27 downward. I'm trying to prevent rattling.
[0091]
The outer cylindrical portion 80b protruding outside the outer peripheral surfaces of the left and right bulging walls 81L and 81R of the closing member 80 is a maximum diameter portion 15d of the shift rod insertion hole 15d. ₁ And the rear end of the upper end surface of the outer cylindrical portion 80b is pressed from above by the under panel 46 of the water pump 45 and the end of the pump case 47, and has a floating prevention structure (see FIGS. 11 and 12). .
[0092]
12, a large diameter washer 89 is provided at the front end of the upper end surface of the outer cylindrical portion 80b of the closing member 80 in a bolt hole 15p (see FIG. 4) formed in the mating surface 19 of the gear case 15 as shown in FIG. The large diameter washer 89 presses the front end of the upper end surface of the outer cylindrical portion 80b of the closing member 80 from above by tightening the bolt 90 which is mounted and screwed.
[0093]
As described above, the closing member 80 is connected to the maximum diameter portion 15d of the shift rod insertion hole 15d. ₁ The pump case 47 and the large diameter washer 89 hold down the front and back of the upper end surface of the outer cylindrical portion 80b to be inserted into the outer cylindrical portion 80b, and can sufficiently withstand the rise in the internal pressure of the shift rod insertion hole 15d. Since no bolts and bolt mounting portions are required for directly fixing the gear case 15, the number of parts can be reduced, the surroundings of the closing member 80 can be designed compact, and the gear case 15 can be prevented from being enlarged.
[0094]
A connection end 27a of the upper end of the lower shift rod 27 with the upper shift rod 26 protrudes above the inner cylindrical portion 80a of the closing member 80 into the groove passage 83 between the left and right swelling walls 81L and 81R.
[0095]
The base of the connection end 27a protruding upward from the inner cylindrical portion 80a of the closing member 80 is sealed by a sealing member 85, and the exposed upper end surface of the sealing member 85 becomes the bottom surface of the groove passage 83 of the closing member 80. Since the water is transmitted from the upper shift rod 26 by the seal member 85, the water transmitted from the upper shift rod 26 is not easily discharged and accumulated by the groove passages 83 formed at the front and rear, since the water is transmitted from the upper shift rod 26.
[0096]
When the lower shift rod 27 rotates integrally with the upper shift rod 26, the lower shift fork 28 turns and slides the front shift slider 65 engaged and engaged with the rear shift slider 66 back and forth, and The forward switching clutch mechanism 23 can be driven to switch among three states, forward, reverse, and neutral.
[0097]
The drive shaft insertion hole 15b and the shift rod insertion hole 15d, which communicate with each other through the communication hole 15i, form a common space together with the gear chamber 15a.
A screw hole 15d is formed at the opening height of the communication hole 15i in the shift rod insertion hole 15d so that a predetermined amount of lubricating oil is injected into the gear chamber 15a. ₂ (See FIG. 11), and the lubricating oil is filled up to the height of the tapered roller bearing 37.
[0098]
The drive shaft insertion hole 15b and the shift rod insertion hole 15d are communicated with each other by a communication hole 15i at the upper side. When the internal combustion engine 11 is driven and the drive shaft 21 rotates, the lubricating oil is rotated by the oil pumping cylindrical member 36 that rotates together. Is pumped upward.
[0099]
At this time, the lubricating oil in the lower gear chamber 15a is pumped up by the oil suction passage 15j communicating the drive shaft insertion hole 15b and the gear chamber 15a.
The pumped lubricating oil lubricates the tapered roller bearing 37, passes through the central cavity of the male screw fixing member 38, reaches the space between the lid member 40, and is supplied from the front communication hole 15i to the shift rod insertion hole 15d. Lubricate the lower shift rod 27.
[0100]
The upper end opening of the drive shaft insertion hole 15b is closed by a lid member 40, and the upper end opening of the shift rod insertion hole 15d is closed by a closing member 80 so that the stored lubricating oil does not leak out and water does not enter from the outside. And the common space such as the gear chamber 15 is liquid-tightly sealed.
[0101]
The volume of the common space such as the gear chamber 15 and the like is designed to be as small as possible in order to reduce the weight and running resistance of the marine propulsion unit. The drive shaft insertion hole 15b and the shift rod insertion hole communicated by the communication hole 15i. The volume of the upper air chamber of 15d is also limited.
[0102]
Therefore, when heat is generated due to meshing of the gears of the bevel gear mechanism 22 and the lubricating oil expands, the air in the upper space other than the lubricating oil in the common space such as the gear chamber 15 is compressed to absorb the volume change, but the volume is limited. In this state, the air compensating chambers 82L and 82R swelled above the closing member 80 can secure sufficient air chamber capacity to absorb a volume change due to thermal expansion in the closed state, and the internal pressure applied to each part can be increased. It can be kept within the allowable range.
[0103]
Air compensation chambers 82L and 82R are formed in the closing member 80 through which the lower shift rod 27 penetrates by closing the upper end opening of the shift rod insertion hole 15d and using the space above the lower shift rod 27. By making the closing member 80 also function as an air compensating function, it is possible to reduce the number of parts and the number of working steps, thereby reducing costs.
[0104]
Also, there is no need to form a dedicated hole or the like that communicates with the gear chamber 15a, and the cost can be further reduced.
The closing member 80 also has a function of pivotally supporting the penetrating lower shift rod 27, so that one member has three functions in accordance with the closing function of the gear chamber and the air compensating function.
[0105]
The closing member 80 is a compact body having an inner cylindrical portion 80a, which is a holding portion of the lower shift rod 27, extending below the mating surface 19 of the gear case 15 and having air compensation chambers 82L, 82R above the mating surface 19. Has a structure.
The lower shift rod 27 is securely held by the inner cylindrical portion 80a extending downward.
[0106]
The height of the space above the closing member 80 is regulated by an upper wall 14a projecting forward at the lower part of the extension case 14 (see FIG. 11).
A predetermined space is provided between the central portion 8a of the lower connecting member 8 and the upper wall 14a of the extension case 14, thereby facilitating the connection work between the upper shift rod 26 and the lower shift rod 27.
[0107]
By keeping the height of the upper wall 14a of the extension case 14 low, the lower connecting member 8, which is a part of the anti-vibration support structure of the outboard motor, is set at a low position to obtain the desired anti-vibration function. It is possible.
[0108]
In the space below the upper wall 14a of the extension case 14 at the height position thus limited, the bulging walls 81L and 81R are connected to the extension case 14 in order to secure the maximum volume of the air compensating chambers 82L and 82R. The upper side has a shape inclined forward and downward in a side view along the shape of the upper wall 14a.
[0109]
Since the shift rod is divided into upper and lower parts and the lower shift rod 27 penetrates the closing member 80 to project the upper connection end 27a upward, the gear case 15 is unitized to facilitate assembly. Can be.
In the case of the present embodiment, since the lower shift rod 27 rotates about the axis, the lower shift rod 27 does not protrude and retract from the closing member 80, and the sealing can be easily performed completely.
[Brief description of the drawings]
FIG. 1 is an overall side view of an outboard motor according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a structure inside a gear case.
FIG. 3 is a sectional view of a gear case.
FIG. 4 is a top view of the same.
FIG. 5 is a rear view of the same.
FIG. 6 is a top view of the male screw fixing member.
FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6;
FIG. 8 is a top view of the lid member.
FIG. 9 is a bottom view of the same.
FIG. 10 is a sectional view taken along line XX in FIG. 9;
FIG. 11 is a cross-sectional view showing a structure of an upper main part of the gear case.
FIG. 12 is a top view of the same.
FIG. 13 is a rear view of the propeller shaft holder.
14 is a sectional view taken along the line XIV-XIV in FIG.
FIG. 15 is a rear view showing a state where a propeller shaft holder is attached to a gear case.
FIG. 16 is a top view of the closing member.
FIG. 17 is a bottom view of the same.
18 is a sectional view taken along the line XVIII-XVIII in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Stern, 2 ... Mounting device, 3 ... Hanging bracket, 4 ... Tilt shaft, 5 ... Swivel case, 6 ... Swivel shaft, 7, 8 ... Connection member,
DESCRIPTION OF SYMBOLS 10 ... Outboard motor, 11 ... Internal combustion engine, 12 ... Mount case, 13a ... Engine cover, 13b ... Under cover, 14 ... Extension case, 15 ... Gear case, 15a ... Gear room,
15b: Drive shaft insertion hole, 15c: Propeller shaft insertion hole, 15d: Shift rod insertion hole, 15e: Small diameter recess, 15f: Small hole, 15g: Suction passage, 15h: Exhaust passage, 15i: Communication hole, 15j: Oil absorption passage , 15k: screw hole boss portion, 16: skeg, 17a: splash guard, 17b: anti-cavitation plate, 18: cylindrical portion, 19: mating surface,
Reference numeral 20: crankshaft, 21: drive shaft, 22: bevel gear mechanism, 23: forward / reverse switching clutch mechanism, 24: propeller shaft, 25: propeller, 26: upper shift rod, 27: lower shift rod, 28: shift fork, 29 ... Bearing holder,
Reference numeral 30: filter, 31: tapered roller bearing, 32: forward driven gear, 33: needle bearing, 34: drive gear, 35: nut, 36: oil pumping cylindrical member, 37: tapered roller bearing, 38: male screw fixing member , 40 ... lid member, 41 ... seal member,
42 ... O-ring, 43 ... bolt, 45 ... water pump, 46 ... under panel, 47 ... pump case, 48 ... knock pin, 49 ... bolt,
Reference numeral 50: propeller shaft holder, 54: rear large diameter portion, 55: rear end flange, 56: mounting boss portion,
Reference numeral 60 denotes a thrust bearing, 61 denotes a needle bearing, 62 denotes a sealing member, 63 denotes a ball bearing, 64 denotes a reversing driven gear, 65 denotes a front shift slider, 66 denotes a rear shift slider, 67 denotes a dog clutch, and 68 denotes a clutch shifter pin. 69 ... O-ring, 70 ... Needle bearing, 71 ... Tightening bolt,
80: closing member, 81L, 81R: bulging wall, 82L, 82R: air compensation chamber, 83: groove passage,
85: seal member, 86: O-ring, 87: retaining ring, 88: spring, 89: large diameter washer, 90: bolt.

Claims (1)

A fitting hole is opened in the lower gear case of the marine propulsion device including a gear chamber in which a bevel gear mechanism that transmits power to the propeller shaft is housed, and a rearward opening is made toward the gear chamber in the front,
A propeller shaft holder rotatably supporting a propeller shaft is fitted into the fitting hole,
In a propeller shaft support structure in which a rear end flange of the propeller shaft holder abuts on an opening end surface of the fitting hole of the gear case and is fastened by screwing a fastening bolt,
The rear end flange is a mounting boss part partially extending in a radial direction, and a peripheral wall formed on a propeller shaft holder covers a head portion of the screwed fastening bolt in a circumferential direction. Propeller shaft support structure for ship propulsion machines.

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