JP3386346B2 - Water jet thruster bearing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device for a water jet propulsion device used in a watercraft, and more particularly to a bearing device for easily attaching and detaching a main shaft of an impeller. 2. Description of the Related Art Conventionally, a main shaft is inserted into a suction casing from an engine side, and the main shaft is supported on the suction casing by a bearing box in which a bearing and a seal component are assembled.
A method of assembling a discharge casing in the order and attaching a water jet propulsion device to a ship is known, for example, as shown in FIG. 1 of JP-A-4-325393. [0003] However, in the above-mentioned conventional water jet propulsion device, when replacing a bearing or a seal component incorporated in a bearing box, the main shaft of the impeller is moved to the engine side. In order to pull out the main shaft, space was required and the intermediate shaft coupling had to be lengthened or the engine had to be removed. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has a structure in which an impeller is provided on a horizontally arranged pump casing, and the impeller is stopped. The output shaft of the drive is connected to the main shaft, and the impeller is rotated, water is sucked from the suction casing provided with a suction port at the bottom of the ship, and water pressurized by the impeller is discharged from the casing to the rear of the stern. In the water jet propulsion device, an outer bearing box is connected to a bearing portion of the main shaft of the suction casing, and an inner bearing box is rotatably fitted to the main shaft. It is inserted and supported in a box. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is constructed as described above, and an external bearing in which a main shaft having an inner bearing housing rotatably fitted therein is inserted into a pump casing from the stern side and connected to a suction casing. The water jet propulsion device can be assembled by inserting and supporting the inner bearing box in the box, inserting the impeller into the main shaft from the stern side, and attaching the discharge casing. Then, at the time of inspection of the bearing portion or replacement of the bearing, if the main shaft is pulled out from the stern side, the inner bearing box can be taken out from the outer bearing box. Thereby, inspection and repair of bearings and the like can be performed without providing a long intermediate shaft or moving the driving device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to an embodiment. First, in FIG. 1, reference numeral 1 denotes a horizontally arranged pump casing, and the pump casing 1 is provided with an impeller 2. An output shaft 5 of a drive unit 4 shown in FIG. 4 is connected to a main shaft 3 to which the impeller 2 is fixed via a coupling 6. Reference numeral 7 denotes a suction casing provided with a suction port 8 at the bottom of the ship, and transfers water sucked from the suction port 8 to a pump casing 1 connected to the suction casing 7. Reference numeral 9 denotes a discharge casing provided at the subsequent stage of the pump casing 1, which discharges water pressurized by the impeller 2 and injects the water to the rear of the stern from a discharge port 10 having a reduced opening of the casing 9. Reference numeral 11 denotes a guide blade provided integrally with the discharge casing 9 so as to convert a water flow which is pressurized by the rotation of the impeller 2 and is turning into a linear flow. A stern-side tip of the main shaft 3 is supported by a bearing case 12 provided on the inner peripheral surface of the guide blade 11. Reference numeral 13 denotes a cylindrical outer bearing box. As shown in FIG. 2, a flange portion 13a of the outer bearing box 13 is horizontally connected to a bearing portion 7a of the main shaft 3 of the suction casing 7. I have. A cover 13b is provided on the drive unit 4 side of the external bearing box 13, and an opening for inserting the main shaft 3 is provided at the center of the cover 13b. Reference numeral 14 denotes a cylindrical internal bearing box into which the main shaft 3 is fitted, and a bearing 15 is inserted around the inner bearing box 14 so that the main shaft 3 is rotatably supported by the bearing 15. is there. Oil seals 16 are provided at both ends of the inner bearing housing 14 so as to seal the lubricating oil supplied to the bearings 15 of the inner bearing housing 14. Reference numeral 17 denotes the main shaft 3 on the suction casing 7 side.
And a mechanical seal provided between the internal bearing housing 14 and the internal bearing housing 14. The inner bearing box 14 fitted into the main shaft 3 is inserted into the outer bearing box 13, and as shown in FIGS. 2 and 3, the cover 13 b of the outer bearing box 13 and the side surface of the inner bearing box 14 are fixed by bolts 18. To prevent rotation of the internal bearing box 14 during rotation of the impeller 2 and to prevent slippage of the internal bearing box 14 toward the stern side due to reverse thrust generated when the boat stops. It is. Reference numeral 19 denotes a screw hole provided in the cover 13b of the external bearing box 13, and
When it is difficult to pull out the inner bearing box 14 fitted in the main shaft 3, a long bolt is screwed into the screw hole 19 and the side surface of the inner bearing box is pressed to push the inner bearing box 14 back to the stern side. I can do it. Note that reference numeral 13c,
Reference numeral 14a denotes an oil supply port, and reference numerals 13d and 14b denote oil discharge ports, which are provided so as to communicate with the outer bearing box 13 and the inner bearing box 14, respectively. Reference numeral 13e is a cooling water supply port provided in the external bearing box 13. A method of disassembling the water jet propulsion device when the inspection and repair of the inner bearing housing 14 and the like configured as described above is required will be described in detail with reference to FIGS. 4 (a) and 4 (b). After removing the discharge casing 9 from the pump casing 1 and disengaging the coupling 6 connecting the main shaft 3 and the output shaft 5 of the drive unit 4, a fixing bolt into which the outer bearing box 13 and the inner bearing box 14 are screwed. 18 and move the main shaft 3 to the stern side. When it is difficult to move the main shaft 3,
If the bolt is screwed into the screw hole 19 of the lid 13b of the outer bearing box 13, the inner bearing box 14 can be pushed back to the stern side, and if the coupling 6 on the drive unit 4 side is removed, the main shaft 3 can be removed.
Can be easily pulled out to the stern side. When assembling, the inner bearing box 14 fitted into the main shaft 3 is inserted into the outer bearing box 13, the discharge casing 9 is attached to the pump casing 1, and the shaft of the stern-side main shaft 3 is mounted on the bearing case 12 of the guide blade 11. By supporting the ends, the assembly of the water jet propulsion device can be easily performed. Reference numeral 20 denotes a deflector for changing the course, and reference numeral 21 denotes a reverser for moving backward. The present invention is configured as described above,
The main shaft can be taken out to the stern side by extracting the inner bearing box from the outer bearing box provided in the bearing portion of the suction casing. That is, in the conventional apparatus, a bearing box incorporating a bearing and a seal component is mounted from the engine side. In the present invention, an internal bearing box incorporating a bearing and a seal member is used as an impeller. This inner bearing box is inserted into and supported from the stern side by an outer bearing box provided in the bearing portion of the suction casing, so if the discharge casing is removed from the pump casing, as in the conventional device, There is no need for a space for pulling out the motor, and there is no need to provide a long intermediate shaft or remove the driving device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view of a water jet propulsion device according to the present invention. FIG. 2 is a side view of a main part bearing box of the water jet propulsion device according to the present invention. FIG. 3 is a front view of a main bearing box of the water jet propulsion device cut along the line AA in FIG. 2; FIG. 4 (a) is a longitudinal sectional side view showing a state where an inner bearing box according to the present invention is extracted from an outer bearing box. FIG. 4 (b) is a longitudinal sectional side view showing a state where the inner bearing box is extracted from the outer bearing box. FIG. 5 is a schematic longitudinal sectional side view of a boat equipped with a water jet propulsion device according to the present invention. [Description of Signs] 1 Pump casing 2 Impeller 3 Main shaft 4 Drive unit 5 Output shaft 7 Suction casing 8 Suction port 9 Discharge casing 13 External bearing box 14 Internal bearing box

Claims (1)

(57) [Claims 1] An impeller 2 is provided on a horizontally disposed pump casing 1, and an output shaft 5 of a driving machine 4 is connected to a main shaft 3 to which the impeller 2 is fixed. Then, the impeller 2 is rotated to suck water from a suction casing 7 provided with a suction port 8 at the bottom of the ship, and the water pressurized by the impeller 2 is discharged and jetted from the casing 9 to the rear of the stern. In the machine, an external bearing box 13 is connected to the bearing portion of the main shaft 3 of the suction casing 7, and an inner bearing box 14 is rotatably fitted to the main shaft 3. A bearing device for a water jet propulsion device, wherein the bearing device is inserted into and supported by a box 13.