JPH0331095A - Driving gear of marine propeller - Google Patents

Abstract

PURPOSE:To improve propulsive efficiency through a propeller by arranging it in a side before a gear case so that no influence of cavitation, generated in a side surface of the gear case, is received by the propeller. CONSTITUTION:A gear case shell part 22, by which a propeller shaft 27 is rotatably supported, is formed in a gear case 21 secured to the lower part of an outboard engine, and a propeller 23 is mounted to a location in a side before the gear case 21 of the propeller shaft 27. In the gear case 21, in almost the central part in the lengthwise direction of the propeller shaft 27, a forward gear 31 and a reverse gear 32 are arranged and always meshed with a drive pinion gear 36 in the lower end of a drive shaft 35 for transmitting drive power from an engine. Thrust force, applied to the propeller shaft 27, is received by a thrust bearing 48, provided in a flange part 47 in the front part, and by a thrust bearing 51 in a propeller shaft housing 50 provided in the rear part of the gear case 21.

Description

Detailed Description of the Invention (Objective of the Invention) (Industrial Application Field) The present invention relates to a propeller drive device for a marine propulsion device such as an outboard motor or an outboard motor, and particularly for a front propeller type outboard motor. Two units of the present invention are installed in the hull of the ship, and the propeller drive system of a suitable marine propulsion machine is applied to an outboard motor equipped with a reverse rotation propeller.

(Prior Art) Among marine propulsion machines, particularly an outboard motor that is mounted on the outside of a ship's hull to propel the ship, as shown in FIG. 4, an engine 2 is mounted on the upper part of a drive shaft housing 1.
This engine 2 is covered by an engine cover 3.

A gear case 4 is engaged with the lower part of the drive shaft housing 1, and a propeller shaft 5 is disposed within the gear case 4.
is pivoted. The rotational driving force from the engine 2 is transmitted to the propeller shaft 5 via the rotation transmission mechanism (drive shaft 6, etc.) in the drive shaft housing 1 and gear case 4, so as to avoid rotating the propeller 7 and propel the hull. It has become. A clamp bracket h8 is installed separately on this outboard.
The outboard motor is mounted on the transom of the boat.

In the above-mentioned outboard motor, the propeller 6 is generally arranged at the rear of the gear case 4. Further, the horizontal cross-sectional shape of the gear case 4 is a symmetrical wing strut shape, and even if the gear case 4 is located in front of the propeller 7, consideration is given to preventing cavitation from occurring on the side surface of the gear case 4 underwater as much as possible.

By the way, the propeller drive device of the conventional marine propulsion machine is
As shown in FIG. 5, by reciprocating the shift yoke 9 up and down, the shift yoke 11 pivotally supported on the pivot shaft (-10) is rotated, and the slider 12 engaged with the shift yoke 11 is moved in the left-right direction. The left-right movement of the slider 12 is transmitted to the shifter dog 15 via the connector pin 13 and the dock pin 14, and the shifter dog 15 is selected as the forward gear 17 or reverse gear 18 that is always engaged with the toy love union 16 of the drive shaft 6. The shifter dog 15 is spline-coupled to the propeller shaft 5, and the forward gear 17 and reverse gear 18 are loosely fitted to the propeller shaft 5.

The engagement between the shifter dog 15 and the forward gear 17 or reverse gear 18 switches the propeller 7 between forward and reverse rotation.

Shifter dog 15 to forward gear 17 dog 17A
When you bite into it, it will turn out [! The propeller thrust horn during forward movement as shown by arrow A acts on the foot 5. This propeller thrust force during forward movement is transmitted to the forward thrust washer 19 interposed between the propeller shaft 5 and the forward gear 17, and further transmitted to the gear case 4 via the forward gear 17, thereby moving the hull forward. In this case, the propeller shaft 5 and the forward gear 17 rotate together, so the forward thrust washer 1
9 and other parts (forward gear 17 and propeller shaft 5), no relative rotation occurs at all.

Also, shift the shifter dog 15 to the dog 1 of the reverse gear 18.
8A, a propeller thrust force is applied to the propeller shaft 5 during backward movement as indicated by arrow B. This propeller shaft force during backward movement is transmitted to the reverse thrust washer 20 interposed between the propeller shaft 5 and the reverse gear 18, and further transmitted to the gear case 4 via the reverse gear 18, causing the ship to move backward. Also at this time, since reverse gear 18 and propeller shaft 5 rotate integrally, no relative rotation occurs between reverse thrust washer 20 and other members (propeller shaft 5 and reverse gear 18).

(Problem to be solved by the invention) By the way, as the speed of the ship increases, when the cavitation coefficient falls below a certain value, the gear case 4
Cavitation occurs on the sides etc. Then, a cavity is created in the water, and this cavity is caught up in the propeller 7.

When this cavity is formed, the compressibility of water is reduced, and the propulsion efficiency by the propeller 7 is significantly reduced.

Additionally, in order to improve the propulsive force of the hull, two outboard motors are generally attached to the hull. In this case, rotate the propellers of the left and right outboard motors in opposite directions.
Among the forces generated by the rotation of the propeller, forces other than the propulsion force are offset to ensure stability of operation.

When two outboard motors are used and one of the outboard motors is equipped with a propeller for reverse rotation, the reverse gear 18 becomes a forward gear, and the forward gear 17 becomes a reverse gear. In this case, for example, in the case of forward movement, the propeller thrust force during forward movement is transmitted to the gear case via the forward thrust washer 19, but at this time, the gear 17 and propeller shaft 5 are rotated at a rotation speed twice as high as the propeller rotation speed. Because of the relative rotation at There is a risk of being exposed. Further, even when a thrust force is applied during reverse movement, there is a risk that scratches such as seizure may occur between the reverse thrust washer 20 and the gear 18, etc.

Furthermore, even if it is desired to use rolling bearings instead of both thrust washers 19 and 20, the space for installing these thrust washers 19 and 20 is small.
It is not possible to install a rolling bearing with sufficient capacity to withstand the thrust force of both propellers.

This invention was made in consideration of the above circumstances,
Propeller propulsion efficiency can be improved, and
To provide a 10-peller drive device for a marine propulsion device that does not cause problems such as seizure even when a reverse rotation propeller is attached.

[Structure of the invention]

(Means for Solving the Problems) In the present invention, a propeller shaft is rotatably supported in a gear case, a propeller is attached to the front side of the gear case of the blower brush V71, and a drive shaft is attached to the propeller shaft. A forward gear and a reverse gear that are always engaged with the pinion gear are rotatably disposed, and a shifter dog that is slidably coupled to the propeller shaft and operated by a shift device selectively engages the dog of the forward gear and reverse gear. By being engaged, the propeller shaft is rotated in the forward direction or in the reverse direction, and a 7-flange portion is formed in the front portion of the gear case of the propeller shaft, and a forward thrust bearing is interposed between the flange portion and the gear case. and reverse thrust bearings are installed in the propeller, the rear end of the shaft, and the gear case, and these thrust bearings transmit propeller thrust force from the propeller shaft to the gear case. It is.

(Function) Therefore, according to the propeller drive device for a marine propulsion device according to the present invention, since the propeller is disposed on the front side of the gear case, the propeller is not subject to cavitation III that occurs on the side surface of the gear case. do not have. Therefore, the propulsion efficiency by the propeller can be improved.

In addition, the propeller thrust force is transmitted from the propeller shaft to the gear case via the forward thrust bearing or the reverse thrust bearing, so there is no sliding contact in this transmission path, and the propeller thrust force is transmitted by rolling contact. communicated. For this reason, especially when a propeller for reverse rotation is installed in one shaft of the propeller and the propeller is rotated in the opposite direction to move forward, the propeller thrust i
・Problems such as seizure will not occur when transmitting force.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is an enlarged partially cutaway view of the gear case of an outboard motor to which an embodiment of the propeller drive device for a marine propulsion device according to the present invention is applied, and FIG. 2 is an enlarged view showing the outboard motor shown in FIG. FIG. 2 is an overall side view of the machine. In this embodiment, the same parts as those in the conventional example are designated by the same reference numerals and the explanation thereof will be omitted.

As shown in FIG. 2, a gear case shell portion 22 that pivotally supports a propeller shaft 27 is formed in a gear case 21 fixed to the lower part of the drive shaft 1, and a propeller 23 is attached to the propeller thrusts 1 to 27. . The propeller 23 is a reverse rotation propeller and is disposed on the front side of the gear case 21.

An upper portion of the gear case shell section 22 in the gear case 21 is a gear case support column section 24 that supports the propeller shaft 27. Further, a scalar lugs 25 are attached to the lower part of the gear case shell portion 22 of the gear case 21, and the scalar lugs 25 and the gear case support portions 24 rectify the torsion of the water flow generated by the propeller 23.

Note that the reference numeral 26 in FIG. 2 indicates a cavitation plate.

The inside of the gear case 21 will be explained in detail using FIG.

A propeller shaft 27 is disposed within the gear case shell portion 22 of the gear case 21, and a propeller shaft bearing 28 is disposed within the gear case shell portion 22.
It is rotatably supported by A and 28B. The propeller 23 is spline-coupled to the front portion of the propeller shaft 27. The propeller 23 is positioned by a propeller stopper 29 and fixed to the propeller shaft 27 by a propeller nut 3o screwed onto the front end of the propeller shaft 27. Boss part 2 of propeller 23
3A and propeller nut 3o are formed into a continuous streamlined shape.

A forward gear 31 and a reverse gear 32 are inserted into a substantially central portion of the propeller shaft 27 in the longitudinal direction so as to be rotatable with respect to the propeller shaft 27 .

These forward gear 31 and reverse gear 32 are supported by gear case 21 by forward gear bearing 33 and reverse gear bearing 34, respectively. Forward gear 31 and reverse gear 32 are connected to drive shaft 3 that transmits driving force from engine 21.
It is always engaged with the drive pinion gear 36 of No. 5.

Further, a shift housing 37 is attached to the gear case 21 with a nut 37Δ, and a shift rod 38 and a pivot shaft 39 are attached to the shift housing 37.
are installed in parallel.

Shift yoke 4 at the tip of the shaft 39
0 is rotatably supported.

This shift yoke 40 has a single-shape shape, and one end thereof is fitted into the hole 38A of the shift rod 38.

The other end of the shift yoke 40 is fitted into a circumferential groove 41A of a slider 41 that is slidably mounted on the pivot shaft 39. Therefore, by moving the shift rod 38 up and down, the shift yoke 40 rotates, and the slider 41
is provided to slide back and forth in the longitudinal direction of the propeller shaft 27.

A connect rod 42 is housed inside the propeller shaft 27, and a slide bin 43 is diametrically attached to the front end of the connect rod 42.

A slider 41 is integrally attached to this slide pin 43. Further, a dog pin 44 is attached to the rear end of the connecting rod 42 in the diametrical direction. A shifter dog 45 is attached to this dog bin 44. The shifter dog 45 is spline-coupled to the propeller shaft 27, and is inserted through the propeller shaft 27 so as to be slidable back and forth in the longitudinal direction of the shaft. This allows shifter dog 45
are provided to selectively mesh with each dog 46A, 46B of forward gear 31 and reverse gear 32.

Also, Propeushi 1? A seven flange portion 47 is formed on the foot 27 on the front side of the slider 41, and this flange portion 47
A forward thrust bearing 48 is installed in the forward thrust bearing 48. A thrust washer 49 is fixed to the gear case 21 facing the forward thrust bearing 48. The propeller shaft thrust force from the propeller shaft 27 during forward movement is transmitted to the gear case 21 via the forward thrust bearing 48 .

Furthermore, at the rear of the gear case 21, there is a blower shaft]
A propeller shaft housing 50 is disposed so as to surround the rear part of the propeller shaft 27, and the aforementioned propeller shaft 11 foot bearing 28A is interposed between the propeller shaft housing 50 and the propeller shaft 27. A reverse thrust bearing 51 and a thrust washer 52 are provided between the rear end of the propeller shaft 27 and the propeller shaft housing 5o, and the thrust washer 52
is fixed to the professional spatula shaft housing 50. Via the reverse thrust bearing 51, the thrust force of the blower shaft during reverse movement is transmitted to the gear case 21 via the thrust washer 52.

In addition, the reference numeral 53G in FIG. 1 indicates the cooling water inlet.
Reference numeral 54 indicates an exhaust passage. Further, reference numeral 55 is an oil seal.

According to the above embodiment, since the propeller 23 is disposed on the front side of the gear case 21, the propeller 23 can generate propulsive force in a -like water flow without being influenced by the gear case 21.

In other words, cavitation occurs when the speed of the ship increases to a certain flow velocity or higher. As the speed of the hull increases further, as shown in FIG.
6, supercavitation begins to occur stably. However, since the propeller 23 is located on the front side of the gear case support 24, the propeller 23 is not caught in the super cavitation generated in the gear case support 24, and the propulsion efficiency of the propeller 23 is improved. In this case, most of the gear case 21 is accommodated within the cavity 57 created by this super cavitation, so the fluid a! The friction resistance is reduced, and the effectiveness of the gear case support column 24 is significantly reduced. Improving the propulsion efficiency of these propellers 23 and gear case 21
The overall propeller propulsion efficiency can be improved by reducing the effectiveness of the propeller.

On the other hand, when the connect rod 42 shown in FIG. 1 is operated downward to engage the shifter dog 45 with the dog 46A of the forward gear 31 via the slider 41 and the connect rod 42, the driving force of the drive pinion gear 36 is transferred forward. It is transmitted to the propeller shaft 27 via the gear 31 and the shifter dog 45, and this propeller shaft 2
7 and propeller 23 are reversed. The forward propeller shaft thrust force generated by the reverse rotation of the propeller 23 is transmitted from the propeller shaft 27 through its flange 47 to the forward thrust bearing 48, and through the thrust washer 49 to the gear case 21, causing the hull to move forward. .

At this time, the thrust force of the propeller shaft during forward movement is transmitted through rolling contact by the forward thrust bearing 48 and not through sliding contact, so that problems such as seizure will not occur. Furthermore, at this time, the forward thrust bearing 48 is disposed at a position with a large space, so that it can be a thrust bearing with a large capacity.

Also, operate the connect rod 42 upward to engage the shifter dog 45 with the dog 46B of the reverse gear 32,
When the propeller shaft 27 rotates forward, the propeller thrust force generated by the propeller 23 during backward movement is transferred from the propeller shaft 27 to the reverse thrust bearing 51.
The signal is transmitted to the propeller shaft housing 50, and then to the propeller shaft 27, thereby moving the ship backward. Also at this time, since the thrust force of the propeller shaft during backward movement is transmitted through rolling contact, problems such as seizure do not occur, and the capacity of the reverse thrust bearing 51 can be increased.

In addition, in the propeller drive device of an outboard motor equipped with this reverse rotation propeller 23, a reverse thrust bearing is mounted between the propeller shaft 27 and the propeller shaft housing 50, compared to an outboard motor equipped with a forward rotation propeller. 51 and attach the flange portion 4 to the propeller shaft 27.
Since 7 is only EIG, the structure is not complicated.

Therefore, assembly is easy and costs do not increase.

As mentioned above, the propeller shaft is attached to the front side of the gear case, and the outboard motor with the forward-rotating propeller and the outboard motor with the reverse-rotating propeller are attached to the transom of the hull. Due to the numbered design, problems such as seizure will not occur even if the propeller rotation directions of both outboard motors are reversed. For this reason, compared to the case where the rotation directions of the propeller shafts of both outboard motors are not reversed, the gear case support 24
The propeller 23 does not suffer from the effects of cavitation, and the propeller efficiency is improved, and the propulsion performance of the ship can be improved, as well as the stability and steering stability of the ship.

[Efficacy of invention]

As described above, according to the propeller drive device for a marine propulsion device according to the present invention, since the propeller is disposed in front of the first case, the propeller ttt advancement efficiency can be improved, and the propeller shaft thrust Since power can be transmitted from the propeller shaft to the gear case via a large-capacity thrust bearing, there is no sliding contact in the transmission path of the propeller shaft thrust force, and as a result, even if a reverse rotation propeller is installed, seizures and other problems will not occur. No problems will occur.

Housing, 51... reverse thrust bearing,
57...Hollow.

[Brief explanation of drawings]

FIG. 1 is an enlarged view showing a partially broken gear case of an outboard motor to which an embodiment of the propeller drive device for a marine propulsion device according to the present invention is applied, and FIG. 2 is an enlarged view of the boat shown in FIG. 1. Figure 3 is a sectional view taken along the line ■-■ in Figure 2, Figure 4 is an overall side view showing a conventional outboard motor, and Figure 5 is the outboard motor in Figure 4. It is a sectional view showing a propeller drive device in .

Claims (1)

[Claims] A propeller shaft is rotatably supported within the gear case, a propeller is attached to the front side of the gear case of the propeller shaft, and a forward gear and a reverse gear that are constantly meshed with a drive pinion gear rotate on the propeller shaft. A shifter dog freely disposed, slidably coupled to the propeller shaft and operated by a shift device is selectively engaged with the dogs of the forward gear and reverse gear, thereby causing the propeller shaft to rotate forward or reverse. and furthermore,
A flange portion is formed at the front portion of the gear case of the propeller shaft, and a forward thrust bearing is interposed between the flange portion and the gear case, and a reverse thrust bearing is provided at the rear end portion of the propeller shaft and the gear case. A propeller drive device for a marine propulsion device, characterized in that a propeller thrust force is transmitted from the propeller shaft to the gear case by these thrust bearings.