KR20000039958A - Ship propeller system - Google Patents

Abstract

PURPOSE: A propeller system for a ship is provided to prevent a propeller and a steering gear from being damaged owing to contact with the ground in salvaging a ship. CONSTITUTION: A hydraulic pump(2) is mounted on an installing stand(3) and a plate(7) is fixed to a stern wall(6) by bolts. Two salvage cylinders(9) moves a salvage link(10) up and down so a stern propeller as to keep proper tilting angle to prevent the propeller from being collided with protrusions on the bottom of the sea in salvaging a ship. In normal running, the propeller is not directly contacted with the stern wall and supported by the cylinder to control the tilting angle of the stern propeller at a distance. Besides, the propeller is prevented from a collision owing to the protrusions and the ship is salvaged easily without manpower by using traveling inertia of the ship.

Description

Ship propulsion

The present invention relates to a ship propulsion apparatus, and is directed to a hydraulic motor direct drive type stern propulsion apparatus having a structure which is attached to a stern wall to remotely control forward and backward driving, steering, and lifting angle to propel a small ship.

Conventionally, the propulsion and the steering gear installed for turning left and right are connected to the propulsion shaft through the reduction gear, clutch, and reversing device by the power of the driving engine, and the steering device is installed on the bottom of the ship. There was a problem that the propeller and the steering gear collide with the surface or the underwater projections and are damaged.

The present invention has been developed to solve the above problems, the object of the present invention is to prevent damage to the propeller and steering device in contact with the ground when the vessel is raised and maintain the maintenance such as replacement of the propeller and sealing seals It is to provide a new type propulsion device that can lift the city propulsion device upwards of 90 degrees.

Furthermore, in comparison with the engine direct stern propulsion system and hydraulic motor upper-mounted stern propulsion system, which are recently developed and attempted to be localized, the flexible motor is connected between the driving engine and the propulsion device because the hydraulic motor is embedded in the main body of the propulsion system. By eliminating the CV joint, drive shaft, reversing clutch, reduction gear, vertical shaft, connecting gear, etc., it is possible to reduce the weight or size and to improve durability by eliminating the damage problem of these components. The stern wall can be inserted by inserting an intermediate body that increases the distance between the upper body and the lower body as the position of the propulsion device and the height of the propeller vary according to the size of the ship. It has the advantage of properly adjusting the distance between the fixing plate and the propeller attached to the.

The present invention to achieve the above object is an engine installed in a predetermined position inside the stern wall of the ship; A hydraulic pump installed at one side of the engine to generate hydraulic pressure; Top suspended from the stern wall, pivotable up and down, left and right, and separated from each other through lifting / steering means including lifting links, lifting cylinders, steering links and steering cylinders for forward and backward propulsion and left and right steering of the vessel. A main body including a middle and a lower main body; A hydraulic motor provided inside the main body and connected by the hydraulic pump and the hydraulic hose to rotate the propeller installed at the rear end of the propulsion main body using the hydraulic pressure generated from the hydraulic pump; A hydraulic system for moving the propulsion body back and forth using hydraulic pressure; A cooling system for cooling the engine and the hydraulic system; And a discharge means for discharging the exhaust gas generated from the engine to a passage such as sea water cooled inside the propulsion main body.

The propulsion main body portion is coupled to the lifting means, the lower body is coupled to the upper body, the upper body and the bolt and detachable central body and the propeller is mounted therein coupled to the propulsion shaft extending from the hydraulic motor therein; Include.

The propulsion shaft is equipped with a support bearing and a sealing seal.

The hydraulic system includes a hydraulic oil tank containing hydraulic oil, a hydraulic control valve for regulating the hydraulic pressure supplied from the hydraulic pump to the hydraulic motor, and a flow direction of the hydraulic oil for selectively adjusting the forward or reverse operation of the vessel. And a control lever and coaxial with the hydraulic pump, and suction the hydraulic oil from the hydraulic oil tank to circulate the hydraulic oil in one direction, replenish the leakage of the hydraulic oil and allow a part of the hydraulic oil to pass through the cooler and the filter. And a circulation pump for maintaining an appropriate temperature and for removing foreign matter contained in the hydraulic oil.

The cooling system is a coolant for cooling the hydraulic oil of the hydraulic system by heat exchange with the seawater pump driven through the drive pulley and the V-belt installed on the crank shaft of the engine, the seawater pump, the engine of the A fresh water pump driven by power, and a fresh water cooler for heat-exchanging fresh water circulated by the fresh water pump and sea water circulated by the sea water pump.

The conventional propulsion system that installs such steering gear and propeller separately on the bottom of the ship, or the hydraulic motor direct drive type stern propulsion system that combines the functions of the outboard machinery installed outside the stern wall by integrating the propulsion engine and the driving engine, the driving engine The main body of the propulsion device installed in the engine room of the ship and having the function of steering and steering is fixed to the stern wall. The body is equipped with a hydraulic motor and a sealing device to prevent the inflow of seawater from the propulsion shaft and the propulsion shaft directly connected to it. The thruster is installed on the propulsion shaft exposed. Since the main body of the propulsion system has a wide streamline cross-sectional area in the front-rear direction and a narrow streamline in the left-right direction, it has the function of steering when steering left and right, and the rotational direction and speed of the hydraulic motor according to the flow direction and flow rate of the hydraulic oil supplied from the hydraulic pump. To change the propeller directly forward and backward or shift, and to control the hydraulic cylinder which adjusts the height of the propeller according to the steering angle and the depth of the main body remotely. Can improve. Since the drive engine directly drives the hydraulic pump and does not separately install the reversing, reduction gear, or flexible coupling, the drive engine in the engine room and the installation position of the hydraulic pump attached to it can be selected arbitrarily. There is this.

1 is a block diagram of a hydraulic motor direct drive type propulsion device.

2 is a configuration of the exhaust and cooling system of the drive engine and the hydraulic system.

Figures 3a, 3b, 3c is a side view, back view and plan view of the propulsion device, respectively.

Figure 4 is a forward and backward, traveling speed remote control hydraulic system configuration.

Figures 5a, 5b is a steering angle and lifting angle remote control hydraulic system configuration.

* Explanation of symbols for main parts of the drawings

1. Drive Engine 2. Hydraulic Pump 3. Hydraulic Pump Mounting Table

4. Hydraulic motor 5. Exhaust gas pipe 6. Stern wall

7. Retaining Plate 8. Tilting Arm / Pin 9. Lifting Cylinder

10. Lifting link 11. Hydraulic hose 12. Steering yoke

13. Steering arm / pin 14. Upper body 15. Middle body

16. Lower Body 18. Support Bearing / Seal Seal

19. Propulsion Shaft Coupling 20. Propulsion Shaft 21. Propeller

22. Suction filter 24. Joon switch

25. Oil cooler 26. Hydraulic oil tank 27. Hydraulic control valve

28. Circulation flow control valve 29. Control lever 30. Circulation pump

31. Anticorrosive zinc plate 32. Seawater pump 33. Anticorrosive zinc plate

34. Fresh water cooler 35. Temperature control valve 36. Fresh water pump

38. Propulsion 39. Steering wheel

40. Steering Pump 41. Steering Check Valve 42. Steering Cylinder

43. Steering link 44. Lifting pump tank 45. Impact load relief valve

46. Lifting check valve 47. Lifting relief valve 48. DC motor

47. Lift Pump 48. Lift Pump Filter 49. Lift Pump Tank

Hereinafter, a ship propulsion device according to an embodiment will be described in detail with reference to FIGS. 1 to 5.

1 shows a hydraulic motor direct drive type stern propulsion device. The main functions of the propulsion device may include exhaust gas discharge and cooling of the driving engine, generation of hydraulic pressure, forward and backward conversion of the traveling speed, steering angle and lifting angle control, and thrust generation. Referring to FIG. 1, the stern propulsion device assembled with the hydraulic pump 2 to the hydraulic pump mounting stand 3 of the drive engine 1 installed in the closed engine room inside the ship and driven by the hydraulic motor 4 is a stern wall 6. The fixed plate (7) is fixed to the bolt with two lifting cylinders (9) installed on the fixed plate (7) to prevent damage to the ship's anchorage or repair during the anchoring or repair, or to be damaged by hitting the projection of the sea bottom of the propeller according to the depth The lifting link 10 is driven up and down so that the propulsion device connected to the tilting arm / pin 8 is maintained at an appropriate lifting angle. The lifting angle and steering angle are remotely controlled by a separately installed lifting and steering hydraulic system (shown in FIG. 5) and the tilting arm 8 is integrally cast on the stationary plate 7. Steering angle of the propulsion device (steering angle) is a steering body connected to the steering yoke (12) between the tilting arm / pin (8) and the steering arm / pin (13) attached to the upper body (14) the upper body ( One steering cylinder (see Fig. 5) installed in 14) is controlled by remote control. Changes in engine speed, forward and backward operation, lifting angle and steering angle control are carried out in a centralized control panel located on the deck of the ship. The main body of the propulsion unit 14 includes a lower main body 14 and a hydraulic motor 4, a propulsion shaft coupling 19, a propulsion shaft 20, a support bearing / sealing seal 18, and a propeller 21 installed outside. Separated by (16) and insert the intermediate body 15 to adjust the distance between the propeller 21 and the fixed plate (7) and they are assembled with bolts. The rotational force of the hydraulic motor 4 is transmitted to the propeller 21 via the propulsion shaft coupling 19 and the propulsion shaft 20, and the propulsion shaft 20 is supported by the support bearing / sealing seal 18 and is embedded in the main body. Leakage of one lubricant is prevented. The hydraulic hose 11 connected between the stern wall 6 and the hydraulic pump 2 in the ship and the hydraulic motor 4 outside the ship and the exhaust manifold of the driving engine and the exhaust gas pipe 5 connected to the driving device are driven. It is made of structure and material that maintains sufficient elasticity and wear resistance so as not to be damaged when it is operated by left and right strings (steering) or up and down (lifting). Exhaust gas of the drive engine is discharged to the water outside the ship through the exhaust gas pipe (5) to improve the exhaust effect as the discharge of the exhaust gas is promoted due to the vacuum generated at the outlet of the exhaust gas pipe under water due to the running speed, Referring to 2, the forced circulating cooling seawater is discharged through the lubricating oil cooler, the fresh water cooler, and the exhaust manifold to be discharged under the surface of the exhaust gas and the stern wall. Even during normal operation, the propulsion device is supported by the lifting cylinder 9 without being in direct contact with the stern wall 6, so that the lifting angle of the stern drive device can be finely adjusted remotely according to the water depth while driving, and the stern drive device by the subsea projections. It prevents collision accidents and uses the inertia of ships in nurturing, so it is easy to raise them to a sufficient position without using manpower, so the maintenance of ship and storage of the stern propulsion device are more advantageous than the commercialized products.

2 shows the configuration of the cooling system of the drive engine 1 and the cooling and exhaust system of the hydraulic system. 2, the seawater supplied by the drive pulley installed on the crankshaft of the engine and the seawater pump 32 driven through the V-belt is an oil cooler 25, a fresh water cooler 34 for cooling the hydraulic oil of the hydraulic system. ) Is mixed with the exhaust gas through an exhaust manifold (not shown) and discharged outside the stern wall in front of the propulsion apparatus. Cooling the exhaust manifold prevents overheating of the drive engine 1, lowers the exhaust back pressure, and mixes with the cooling sea water to discharge it under the surface, which is affected by the traveling speed of the ship, so that the hydrodynamic negative pressure is formed at the exhaust discharge port. In addition to improving the noise, noise can be significantly reduced. Since the drive engine 1 is installed inside an enclosed engine room, it is impossible to adopt an air-cooling type as in an automobile engine. Therefore, the fresh water discharged after cooling the drive engine 1 in the fresh water cooler 34 that indirectly cools with sea water is cooled. In order to maintain a proper cooling temperature of the fresh water, a temperature control valve 35 is installed, and these cooling fresh water are forced to the fresh water pump 36 driven by the power of the driving engine 1. In order to prevent corrosion of the oil cooler 33, the fresh water cooler 34, and the sea water cooling tube which are in contact with sea water, an anticorrosive zinc plate 33 is attached to the sea water inlet and outlet of the cooler, and the exhaust manifold is made of stainless steel having high heat and corrosion resistance. Made of steel

3A, 3B, and 3C show side, rear and top views of the stern propulsion device driven by the hydraulic motor, respectively. A hydraulic cylinder (29, 42) and a lifting link (31) which lift the main body by more than 90 degrees up and down and steer about 30 degrees left and right between the fixed plate (7) bolted to the stern wall (6) and the stern propeller main body. Is installed and a hydraulic hose 11 for supplying hydraulic pressure to the exhaust gas pipe 5 for discharging the exhaust gas of the drive engine and the hydraulic motor 4 is connected to the stern propulsion device through the stern wall 6. The propeller main body 14, 15, 16 is attached to the stern wall 6, so if the weight is heavy, it is difficult to maintain the balance of the hull, so it is made of aluminum alloy that reduces the weight by 60% compared to steel and the hydraulic motor ( 4) In order to lubricate the propulsion shaft 9 connected to the propulsion shaft 9 and the propulsion shaft coupling 39 and the support bearing therebetween, a sealing seal 7 is installed in the through hole of the lower body 6 so that lubricating oil is leaked to the outside and marine pollution is caused. To prevent them from doing so. Since the lubricating oil of the propulsion system is always in contact with the sea surface during operation, the heat dissipation generated here is sufficiently dissipated. Therefore, a separate cooler is omitted, and an anti-corrosive zinc plate of proper capacity is used to prevent corrosion of the main body and shaft system made of aluminum alloy. (31) is attached to the fixed plate (7) and the upper and lower body (14, 16). The hydraulic motor 4 is connected by the propulsion shaft coupling 19 at the front end of the propulsion shaft 20 and the steering arm / pin 13 is attached to the frame of the upper body 14 to be lifted by the hydraulic cylinders 9 and 42. The link 10 and steering yoke 12 are actuated to allow the propulsion device to be steered in the left and right 30 degree ranges or hingedly to maintain a lifting angle of about 90 degrees up and down. Since the rotational speed of the propeller 21 is driven at a high speed of about 2,500 rpm, the rotational speed of the hydraulic motor 4 which directly drives this should also be adjusted to the flow rate and the hydraulic pressure of the working oil supplied from the hydraulic pump to be rotatable about 2,500 rpm.

4 shows a hydraulic system for directly driving the stern propulsion device with the hydraulic motor 4 and converting forward and backward driving and traveling speed. In the hydraulic pump 2 fixed to the hydraulic pump mount 3 of the drive engine 1, the hydraulic pressure supplied to the hydraulic motor 4 is adjusted by the hydraulic control valve 27, and the flow direction of the hydraulic oil is controlled by the control lever 29. It can be adjusted to enable forward and backward operation of the ship. In order to increase or decrease the running speed, the rotation speed of the drive engine 1 is remotely controlled by an engine speed control lever (not shown) from the control panel, and the circulation pump 30 connected to the hydraulic pump 2 drive shaft is connected to the hydraulic oil tank 26. After removing the foreign matter mixed with the hydraulic oil through the suction filter 22, the suction oil is increased to 25 atm, and the oil is circulated only in a certain direction, and the amount of leakage in the hydraulic system is supplemented or a part of the hydraulic oil is cooled down. Pass it through to cool the working oil to maintain the proper temperature. After passing through the oil cooler 25, the hydraulic oil flowing into the hydraulic oil tank 26 is installed at the upper portion of the hydraulic oil tank 26 so that the oil level switch 24 maintains a constant oil level. If the level is lowered, the alarm or the hydraulic system will be stopped to prevent major accidents. When a pressure higher than the set pressure is added to the hydraulic pump 2 and the circulation pump 30, the respective hydraulic control valve 27 and the circulation control valve 28 are installed to prevent damage to the system.

5A and 5B show an independent hydraulic system for remotely controlling the steering angle and lifting angle of the stern propulsion system. Referring to FIG. 5, a small ship stern propulsion device for supplying hydraulic pressure generated from a steering pump 40 connected to a steering wheel 39 to a steering cylinder 42 may be widely used in a steering system of an outboard motor or a water jet propulsion device. Since the steering pump 40 is a bidirectional discharge type, the discharge direction is changed according to the rotation direction of the steering wheel 27 to operate the steering link 43 connected to one steering cylinder 42 from side to side. The steering check valve 41 is installed to steer and prevent the steering pump 40, the steering wheel 39, and the steering cylinder 42 from moving in opposite directions depending on the load conditions. In the case of the lifting angle control system, the hydraulic oil contained in the lifting pump tank 49 is supplied to the two lifting cylinders 9 from the lifting pump 47 driven by the DC motor 48 to remotely lift the lifting link 10 up and down. To ensure that the stern propulsion system maintains the lifting angle in the proper position according to the depth. In order to prevent the position of the stern propulsion system from changing according to the load state of the stern propulsion system, a lifting check valve 46 is installed, and a lifting relief valve 47 and a discharge filter are provided to prevent excessive pressure in the system and mixing of foreign substances. Install (not shown). Furthermore, an impact load relief valve 38 is installed between the pump and the hydraulic cylinder to protect the hydraulic system by preventing excessive impact load.

The present device simplifies the arrangement of the driving engine and shaft system and propulsion system instead of the method of directly connecting the stern propulsion system of a small ship by a conventional engine and operates the driving engine at a shift speed. It is necessary to control the flow rate and discharge direction of the hydraulic pump in a forward and backward operation so that the conventional steering system and the propulsion system can be combined and the distance between the fixed plate of the stern propulsion system and the propeller is properly adjusted according to the size of the ship. Accordingly, the intermediate body is inserted between the upper body and the lower body coupled with the bolt so that the thruster generates thrust at an appropriate position of the preload so as to have a structure to increase the propulsion efficiency. In addition, small ships navigating the coast are profoundly different in tides, and damage to the propulsion due to offshore remnants or submarine projections is frequent, so that propulsion devices are supported by lifting cylinders instead of directly attached to the stern wall and fixed. If necessary, the driver can finely adjust the lifting angle of the device remotely so that the height of the propeller can be in any position so that the ship and propulsion device can be safely maintained and appropriately raised by utilizing the running inertia of the ship without depending on manpower. There is an advantage that can be raised up to the position. In addition, when the propulsion system is excessively impacted by waves or foreign objects during navigation, a shock-absorbing relief valve is installed to allow the hydraulic pressure inside the lifting hydraulic control cylinder to flow out so that the lifting angle is automatically adjusted. Prevents damage to the steering hydraulic system. In addition, the hydraulic pump directly connected to the steering rudder and the propulsion system according to the hydraulic pressure generated by the steering rudder to have a smooth steering function by manipulating the steering rudder in order to facilitate steering angle control when the vessel turns in the left and right directions while the ship is operating at high speed. Install a steering hydraulic system consisting of a hydraulic cylinder to maintain an arbitrary steering angle in the horizontal direction. More than 60,000 small ships (less than 3 tons) sailing the recent domestic coast are driven by gasoline engines, and most of the outboard units that are manually steered or lifted have high fuel consumption, and fuel costs account for a large portion of operating expenses due to the abolition of duty-free fuel oil prices. As it is increased and used as a mixture of gasoline fuel and lubricating oil, it is a marine pollution source of the incomplete combustion gas discharged from the engine. It is hoped to use a stern propulsion system capable of using diesel oil at / 3 level and having a low fuel consumption rate. Furthermore, the hydraulic motor direct stern propulsion system does not require the installation of flexible joints or the arrangement of propulsion shafts between the drive engine and the propulsion system, and eliminates the reduction gears, reverse electric gears and clutches attached to the propulsion system. It is improved and operation controllability is excellent.

Hereinafter, the use and characteristics of the ship propulsion device according to the present invention will be described in detail.

This propulsion system has the function of forward and backward operation of steering ship and steering and propulsion lifting device. It is equipped with double suction fixed capacity swash plate piston type hydraulic pump to the drive engine installed inside the closed engine room. It is supplied to the hydraulic motor of the four-axis constant capacity piston type built into the main body of the propulsion system through the configured hydraulic piping, and the flow direction of the hydraulic oil is changed by remotely controlling the inclination angle of the inclined plate of the hydraulic pump rotating in a constant direction so that the hydraulic motor Rotation in the reverse direction changes the thrust force of the propeller directly connected to the hydraulic motor so that the ship can be operated in the forward and backward directions. The speed of the ship can be controlled by remotely controlling the fuel injection amount of the drive engine and the rotation speed of the hydraulic pump can be changed to adjust the discharge amount of the hydraulic oil.The hydraulic control valve and relief valve are installed to maintain the pressure of the hydraulic system properly. In order to prevent the hydraulic system from overheating due to the increase of the hydraulic oil temperature or the viscosity of the hydraulic oil, the output of the hydraulic oil is reduced and it is sucked in the hydraulic oil tank by the fixed-capacity type gear type circulation pump installed in the main body of the hydraulic pump and driven by the hydraulic pump drive shaft. As a result, the leakage is supplied to the closed circuit at a pressure of about 25 atm, and part of the discharged amount is cooled by the oil cooler together with the leakage. The driving engine, which is a power generating device, is a water-cooled high-speed diesel engine. Indirectly cooling the cooling water and lubricating oil of the engine body from each cooler to seawater, and the seawater cooling these coolers is driven by a pulley installed on the crankshaft of the drive engine. It is supplied by a volumetric rubber impeller-type seawater pump connected to the air conditioner, and after cooling the cooler, is discharged outboard along with the exhaust gas of the driving engine through the exhaust manifold. The reason for cooling the exhaust manifold is that the engine body is prevented from being heated by the exhaust gas having a high temperature of about 600 ° C, the exhaust noise is reduced and the exhaust efficiency is increased. In order to prevent corrosion, the coolant, exhaust gas pipe, and stern drive system through which seawater passes must be equipped with anticorrosive zinc plate of proper capacity and anticorrosive coating.The material of exhaust manifold uses stainless steel with good corrosion resistance because hot gas and seawater are in contact. . The hydraulic system driving the stern propulsion system is hermetically sealed and maintains a high pressure of about 250 atm, so the piping system between the hydraulic motor and the hydraulic pump is made of high strength steel to withstand the high pressure. Filters, coolers, storage tanks, and level meters in circulation pump systems maintain a relatively low pressure but select structures and materials that withstand 10 atm. The closed system of the hydraulic system reduces the power consumption of the drive engine, makes the hydraulic system compact, and increases the rotational speed of the hydraulic motor that drives the propeller to 2,500 rpm or higher for high speed operation. Because it shrinks. In order to prevent the temperature rise of the hydraulic oil, the oil cooler was conventionally installed at the outlet after passing through the hydraulic control valve, but it was installed at the outlet of the circulation pump to cool the entire amount of the hydraulic fluid circulated by the circulation pump. It consists of a two-way discharge type steering pump that generates hydraulic pressure in the steering wheel's operation direction and one hydraulic cylinder that remotely controls the stern drive device within 30 degrees from side to side.The lifting angle control system uses a lifting pump directly connected to a DC motor. Since the hydraulic pressure generated by operating the change-over switch is supplied to two hydraulic cylinders so that it can be remotely controlled in a 90 degree range in the vertical direction, the operator can change the shift, forward and backward, steering and lifting angles at the central control panel of the ship's steering room. It is easy to steer.

The conventional propulsion system that installs such steering gear and propeller separately on the bottom of the ship, or the hydraulic motor direct drive type stern propulsion system that combines the functions of the outboard machinery installed outside the stern wall by integrating the propulsion engine and the driving engine, the driving engine The main body of the propulsion device installed in the engine room of the ship and having the function of steering and steering is fixed to the stern wall. The body is equipped with a hydraulic motor and a sealing device to prevent the inflow of seawater from the propulsion shaft and the propulsion shaft directly connected to it. The thruster is installed on the propulsion shaft exposed. Since the main body of the propulsion system has a wide streamline cross-sectional area in the front-rear direction and a narrow streamline in the left-right direction, it has the function of steering when steering left and right, and the rotational direction and speed of the hydraulic motor according to the flow direction and flow rate of the hydraulic oil supplied from the hydraulic pump. To change the propeller directly forward and backward or shift, and to control the hydraulic cylinder which adjusts the height of the propeller according to the steering angle and the depth of the main body remotely. Can improve. Since the drive engine directly drives the hydraulic pump and does not separately install the reversing, reduction gear, or flexible coupling, the drive engine in the engine room and the installation position of the hydraulic pump attached to it can be selected arbitrarily. There is this.

Although the present invention has been described based on the preferred embodiments, various modifications and improvements can be made within the scope of the technical idea of the present invention, and those skilled in the art will recognize that such variations and improvements also belong to the present invention. .

Claims (5)

An engine installed at a predetermined position inside the stern wall of the ship; A hydraulic pump installed at one side of the engine to generate hydraulic pressure; Top suspended from the stern wall, pivotable up and down, left and right, and separated from each other through lifting / steering means including lifting links, lifting cylinders, steering links and steering cylinders for forward and backward propulsion and left and right steering of the vessel. A main body including a middle and a lower main body; A hydraulic motor provided inside the main body and connected by the hydraulic pump and the hydraulic hose to rotate the propeller installed at the rear end of the propulsion main body using the hydraulic pressure generated from the hydraulic pump; A hydraulic system for moving the propulsion body back and forth using hydraulic pressure; A cooling system for cooling the engine and the hydraulic system; And And discharge means for discharging the exhaust gas generated from the engine to a passage such as sea water cooling the engine and the hydraulic system. The propeller of claim 1, wherein the propulsion main body is coupled to the lifting means and coupled to an upper body, a central body coupled to the upper body and a bolt, and detachable to the central body and a propulsion shaft extending therefrom from the hydraulic motor. Ship propulsion device comprising a lower body equipped with. The ship propulsion device according to claim 2, wherein the propulsion shaft is equipped with a support bearing and a sealing seal. 2. The hydraulic system of claim 1, wherein the hydraulic system includes a hydraulic oil tank containing hydraulic oil, a hydraulic control valve for adjusting the hydraulic pressure supplied from the hydraulic pump to the hydraulic motor, and hydraulic oil for selectively adjusting the forward or reverse operation of the vessel. A control lever for adjusting the flow direction of the hydraulic pump, and installed coaxially with the hydraulic pump, suctioning the hydraulic oil from the hydraulic oil tank to circulate the hydraulic oil in one direction, replenishing the leakage of the hydraulic oil, and a part of the hydraulic oil is a cooler and a filter. And a circulation pump for allowing the passage of the oil to maintain the temperature of the hydraulic oil properly and to remove foreign substances contained in the hydraulic oil. The cooling system of claim 4, wherein the cooling system exchanges heat with seawater pump driven through a drive pulley and a V-belt installed on the crankshaft of the engine, and seawater introduced by the seawater pump to cool the hydraulic oil of the hydraulic system. And a fresh water cooler for exchanging fresh water circulated by the fresh water pump and fresh water circulated by the sea water pump.