JPH0334558Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention forms a pump section by fitting a coil spring to a transmission shaft disposed vertically, and the lubricating oil reservoir provided below the transmission shaft. The present invention relates to an oil lift pump that supplies lubricating oil to a bearing or the like disposed on the upper side of a transmission shaft.

BACKGROUND ART A conventional oil lift pump of this type is disclosed in, for example, Japanese Utility Model Application Laid-Open No. 61-47798. As shown in Fig. 3, a transmission shaft 3 is disposed vertically to a drive unit case 2 attached to the bottom of the main body 1 of the ship.
The coil spring 4 provided around the transmission shaft 3 is rotated integrally to draw lubricating oil from the lubricating oil reservoir 6 provided on the lower side of the transmission shaft 3 to the upper side of the transmission shaft 3 and to the bearing 5 etc. on the upper side. I try to supply lubricating oil. The lower end of the coil spring 4 is positioned and fixed by a retaining ring 7 fitted to the transmission shaft 3, and is prevented from coming off downward.

Problems to be Solved by the Invention However, in this conventional oil lift pump, as described above, the coil spring 4 is positioned and fixed by the retaining ring 7 fitted to the transmission shaft 3 to prevent it from coming off downward. Therefore, there is a risk that the retaining ring 7 will come off the transmission shaft 3 and fall downward. There was a danger of getting caught in it.

In addition, as a method that does not use such a retaining ring, the end of the coil spring is bent inward in the radial direction.
It is conceivable to insert it into a hole formed in the shaft, but it is not desirable to perform such a hole machining, which causes stress concentration on the shaft that transmits power.

The present invention has been developed in view of the above-mentioned problems, and is capable of fixing a coil spring fitted to a transmission shaft without using a fixing device such as a retaining ring.
Moreover, an air vent part can be formed in the middle of the transmission shaft, and the air in the lubricating oil, which is pumped up from the lubricating oil reservoir on the lower side of the transmission shaft to the upper side of the transmission shaft by this coil spring, is directed upward at the air vent part. It is an object of the present invention to provide an oil lift pump that can be smoothly extracted and can efficiently supply lubricating oil to the upper side of a transmission shaft.

Means for Solving the Problems In order to achieve the above object, the present invention forms a vertically intermediate portion of a vertically disposed transmission shaft with a slightly smaller diameter, and a longitudinal center that is fitted into this small diameter portion. A coil spring having a small diameter portion was fitted and fixed onto the transmission shaft.

Function: With the above structure, the coil spring is fixed with its small diameter part at the center in the longitudinal direction fitted into the small diameter part at the middle part in the vertical direction of the transmission shaft, and prevented from coming off downward. This prevents the coil spring from falling out.

In addition, since a gap is formed between the small diameter part of the coil spring and the inner circumferential surface of the case shaft hole where the transmission part is installed, the coil spring allows transmission to be carried out from the lubricating oil reservoir on the lower side of the transmission shaft. The air contained in the lubricating oil pumped up to the upper side of the shaft moves upward in this gap, allowing the air to bleed smoothly. This allows the lubricating oil to be well pumped up toward the upper side of the transmission shaft.

Embodiment Although the present invention is not limited to inboard/outboard motors, an embodiment applied to an inboard/outboard motor will be described in detail in order to facilitate comparison with the prior art.

In FIG. 1, an engine 14 covered by a cowling 13 is mounted on the upper part of a drive unit case 10 made up of an upper case 11 and a lower case 12. and,
The power from the engine 14 is transmitted to a transmission shaft 15 disposed vertically in the drive unit case 10.
The power is transmitted to an output shaft 16 horizontally disposed below the lower case 12, and the rotation of the output shaft 16 causes the propulsion propeller 17 to rotate.

The lower end side of the transmission shaft 15 is connected to the lower case 12.
It passes through a shaft hole 18 provided in the lower case 12 and projects into a cavity 19 in the lower part of the lower case 12. The transmission shaft 15 is supported via a bearing 20 provided on the upper side of the shaft hole 18.

On the other hand, a pair of forward and reverse driven bevel gears 22 and 23 of the clutch mechanism 21 attached to the output shaft 15
is meshed with the drive gear 24 at the lower end of the transmission shaft 15, and by vertical movement of the cam body 26 at the lower end of the shift rod 25 disposed on the side of the transmission shaft 15,
By sliding a clutch body 27 provided to slide in the horizontal direction, the forward and reverse driven bevel gears 22 and 23 of the clutch mechanism 21 are selected to perform forward and rearward switching. .
In addition, 30 in the figure is a lubricating oil reservoir provided on the lower side of the transmission shaft 15.

In the inboard/outboard motor configured as described above, as clearly shown in FIG. A coil spring 28 having a small diameter portion is fitted onto the transmission shaft 15, and the small diameter portion 28a and the small diameter portion 1 of the transmission shaft 15 are connected to each other.
It is fixed by fitting with 5a. This coil spring 28 has its upper end abutted against the lower surface of the flange-shaped portion 15b provided on the upper side of the transmission shaft 15, and its lower end abutted against the upper surface of the cylindrical base 24a of the drive gear 24 at the lower end of the transmission shaft 15. It is in contact.
Then, the small diameter portion 28a of the coil spring 28 and the shaft hole 1
A gap 18b is formed between the peripheral wall inner surface 18a of No.8. The coil spring 28 is fitted to the transmission shaft 15 so as to rotate together with the transmission shaft 15 as the transmission shaft 15 rotates. and,
By the rotation of the coil spring 28 accompanying the rotation of the transmission shaft 15, the lubricating oil reservoir 30 on the lower side of the transmission shaft 15 is drawn up and supplied to the bearing 20, etc. on the side of the transmission shaft 15. There is.

With the above configuration, the coil spring 28 is fixed with its longitudinally central small diameter portion 28a fitted into the vertically intermediate small diameter portion 15a of the transmission shaft 15 and prevented from coming off downward. , the coil spring 28 can be fixed without using a fixing device such as a retaining ring as in the conventional example described above, and the coil spring 2
8 can be prevented from falling off downward.

The coil spring 28 is divided into a lower pump part 28b and an upper pump part 28c by the small diameter part 28a, with the lower pump part 28b mainly performing a pushing up action and the upper pump part 28c performing a suction action. Since a gap 18b is formed between the small diameter portion of the coil spring 28 and the inner circumferential surface of the peripheral wall of the shaft hole 18, the coil spring 28 allows the lubricating oil reservoir 30 on the lower side of the transmission shaft 15 to be supplied to the transmission shaft 15. The air contained in the lubricating oil that is pumped up to the upper side moves smoothly upward in this gap 18b, and the air removal effect is performed well. It is pumped well towards the upper side.

Furthermore, since the coil spring 28 can be fixed to the power transmission shaft 15 without using a retaining ring or other fixing device, the number of parts can be reduced and costs can be reduced.

Effects of the invention As described above, in the present invention, the vertically intermediate portion of the vertically disposed transmission shaft is formed to have a slightly small diameter, and the longitudinally central portion that fits into this small diameter portion is formed to be small in diameter. By fitting and fixing the coil spring to the transmission shaft, the coil spring is prevented from coming off downward because its small diameter part at the center in the longitudinal direction is fitted into the small diameter part at the vertical middle part of the transmission shaft. Therefore, the coil spring can be fixed without using a retainer such as a retaining ring as in the conventional example described above, and the coil spring can be prevented from coming off downward. In addition, since a gap is formed between the small diameter part of the coil spring and the inner peripheral surface of the peripheral wall of the shaft hole, the lubricating oil air pumped upward by this coil spring is smoothly directed upward in this gap. The lubricating oil is smoothly pumped up around the transmission shaft toward the upper side. Furthermore, since the coil spring can be fixed to the transmission shaft without using a retaining ring or other fixing device, the number of parts can be reduced, costs can be reduced, and there is no need to drill holes, etc., which can cause stress concentration.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the overall structure of an inboard/outboard motor equipped with an oil lift pump according to an embodiment of the present invention, Fig. 2 is an explanatory view showing a state in which a coil spring is fitted to the transmission shaft, and Fig. 3 1 is a sectional view of a portion of an inboard/outboard motor equipped with a conventional oil lift pump. 15...Transmission shaft, 15a...Small diameter part, 28...
Coil spring, 28a...small diameter part.

Claims (1)

[Scope of utility model registration request] A vertically intermediate portion of a vertically disposed power transmission shaft is formed to have a slightly small diameter, and a coil spring that is fitted into the small diameter portion and whose longitudinal center portion is formed to have a small diameter is fitted and fixed to the power transmission shaft. An oil lift pump characterized by: