Double-fan air-cooled diesel engine

Abstract

The utility model relates to the technical field of air-cooled diesel engines, and discloses a double-fan air-cooled diesel engine which comprises a diesel engine body, an air duct assembly is installed on the upper portion of the surface of the diesel engine body, an air cavity is formed in an inner cavity, and a fan shield is arranged at an air inlet. The right air inlet of the diesel engine body is provided with a first fan, the axis of the first fan is connected with a second fan in series through a fan connecting shaft, constant-speed reverse rotation is achieved through a main belt pulley, a fan belt pulley and a belt, and operation vibration and noise are reduced. Front, rear, upper and lower air guide covers, a cylinder cover and a cylinder sleeve air guide plate are mounted on the surface and inside the air duct assembly, cylinder sleeve radiating fins are arranged on the surface of the cylinder sleeve air guide plate, and a radiating part is arranged on the lower surface of the air duct assembly. According to the structure, through cooperation of an axial contra-rotating combination and a multi-stage flow guide structure, air volume increase, static pressure enhancement and heat dissipation efficiency optimization are achieved, and the structure has the advantages of low rotating speed and noise reduction and rapid productization feasibility. In addition, the spiral flow guide plate is matched with the flow guide blades to achieve vortex inhibition.

Description

Technical Field

[0001] This invention relates to the field of air-cooled diesel engine technology, specifically to a dual-fan air-cooled diesel engine. Background Technology

[0002] Air-cooled diesel engines are engines that use air as the cooling medium. During operation, the engine generates a large amount of heat. Unlike a water tank, the engine relies entirely on the powerful airflow generated by the fan to cool the engine body. They are widely used in construction machinery, engineering machinery, agricultural machinery, military vehicles and other fields.

[0003] However, in recent years, with increasingly stringent emission regulations, turbocharging and intercooling technologies, EGR technology, and other technologies have become standard features in low-emission engines. These two technologies also need to be incorporated into the cooling system, further increasing the workload of the fan cooling system. Moreover, the fan is an important component of the engine cooling system, and its performance directly affects the engine's heat dissipation effect, thereby affecting the engine's performance. Fan performance typically refers to airflow and static pressure. Airflow represents the flow rate output by the fan per unit time, while static pressure characterizes the fan's ability to overcome radiator resistance. Insufficient airflow and static pressure will lead to engine thermal imbalance, causing overheating and malfunction. Air-cooled engines generally use a single fan, forming an intake cooling system with the fan shroud and air deflectors, with rotational speed obtained via connecting shafts and pulleys. For single-stage fans, when engine cooling demand increases, given a fixed engine speed, effective methods include using smaller fan blades, increasing the fan outer diameter, adjusting the fan blade shape and number of blades. However, increasing fan speed with smaller fan blades is detrimental to fan strength and noise. Adjusting fan blade shape and diameter parameters is limited by engine compartment space and cannot be matched with existing fan products, also limiting the potential for improved fan performance. Developing new fans increases R&D costs and extends the development cycle.

[0004] Furthermore, due to the irregular shape of the inner wall of the air cavity or the lack of effective guidance during the flow process, the airflow direction may change abruptly and a speed difference may be generated, which in turn will cause local turbulence and vortex generation. These vortices will not only cause the airflow energy to be ineffectively dissipated in the turbulence, reducing the effective air volume and affecting the heat exchange efficiency, but the vibration excitation source generated by the vortex impact will increase the operating noise. At the same time, under long-term action, it will also aggravate the fatigue damage risk of the air guide component. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a dual-fan air-cooled diesel engine. This addresses the issues raised in the background section, where turbocharging and intercooling technologies, such as EGR, have become standard features in low-emission engines. However, these technologies also require integration into the cooling system, further increasing the workload of the fan cooling system. This leads to engine thermal imbalance, overheating, and malfunction, limiting the potential for improved fan performance. Furthermore, developing new fans increases R&D costs and timelines. The vibration excitation from eddy current impacts increases operating noise, and long-term operation exacerbates the fatigue damage risk of the air guide components.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution: a dual-fan air-cooled diesel engine, comprising:

[0009] A diesel engine body, wherein a duct assembly is installed on the upper surface of the diesel engine body, the inner cavity of the duct assembly is provided with a duct cavity, and a fan cover is installed on the air inlet of the duct assembly.

[0010] The first fan is located at the right air intake of the diesel engine body. A fan pulley is installed on the surface of the first fan. A fan connecting shaft is installed at the shaft of the first fan. A second fan is installed at the other end of the fan connecting shaft. A crankshaft is installed at the output end of the diesel engine body. A main pulley is installed at the output end of the crankshaft. A belt is connected between the main pulley and the fan pulley.

[0011] A front air guide plate is installed at the first fan. A rear air guide plate is installed on the surface of the diesel engine body at a position corresponding to the second fan. An upper air guide shroud is installed on the upper part of the surface of the air duct assembly. A lower air guide shroud is installed on the lower part of the surface of the air duct assembly. A cylinder head air guide plate is installed inside the air duct assembly. A cylinder liner air guide plate is installed on the outer surface of the air duct assembly. A cylinder liner heat sink is installed on the surface of the cylinder liner air guide plate. A heat dissipation component is installed on the lower surface of the air duct assembly.

[0012] A spiral guide plate is installed on the inner wall of the air cavity, and guide vanes are provided on both sides of the interior of the air cavity.

[0013] Preferably, both the first fan and the second fan are installed inside a fan shroud, and the first fan, the second fan and the inner cavity of the fan shroud are the same size. The first fan and the second fan are installed in opposite directions, so that the first fan and the second fan can blow air into the air cavity simultaneously.

[0014] Preferably, the first fan and the second fan are coaxially connected via a fan connecting shaft, so that the first fan and the second fan can rotate synchronously.

[0015] Preferably, the fan connecting shaft has a flange mounted on its surface. The fan connecting shaft is connected to the first fan and the second fan through the flange. The fan connecting shaft can also be connected to the fan through threaded connection and spline connection. It can be adapted to various engine models such as three-cylinder, four-cylinder, and six-cylinder engines according to different engine sizes, making the fan connecting shaft structure simple and easy to process.

[0016] Preferably, each of the guide vanes has an installation cylinder installed in the middle, and the surface of each installation cylinder has a slot. The fan connecting shaft passes through the inside of the slot, so that the fan connecting shaft can rotate stably.

[0017] Preferably, the surface of the mounting cylinder is evenly provided with fixing rods, and the outer ends of the fixing rods are all installed on the inner wall of the air cavity, which improves the stability of the guide vanes.

[0018] Beneficial effects

[0019] Compared with the prior art, the present invention provides a dual-fan air-cooled diesel engine, which has the following beneficial effects:

[0020] 1. The dual-fan air-cooled diesel engine forms an axial counter-rotating combination by the first fan installed at the air inlet of the diesel engine body and the second fan connected in series via the fan connecting shaft. The main pulley drives the fan pulley to achieve constant speed and reverse rotation, so that the angular momentum of the two fans cancels each other out, thereby reducing operating vibration and noise and reducing the workload of the fan cooling system.

[0021] The air chamber formed by the inner cavity of the air duct assembly, together with the airflow channels constructed by the front air guide plate, the rear air guide plate, and the upper and lower air guide shrouds, creates a continuous pressurization effect in the air duct through a two-stage pressurized flow field. Combined with the cylinder head air guide plate and the cylinder liner air guide plate surface, the cylinder liner heat exchange is enhanced. Finally, the heat energy is discharged through the heat dissipation components. This structure reuses existing fans and air guide components. Without the need for new molds, it achieves a comprehensive effect of increased air volume, enhanced static pressure, and optimized heat dissipation efficiency through the synergy of reverse airflow organization and multi-stage air guide structure. At the same time, it has the advantages of low-speed noise reduction and rapid productization feasibility, and avoids the engine from overheating and failing to work properly.

[0022] 2. In this dual-fan air-cooled diesel engine, the spiral guide vane extends spirally along the inner wall of the air cavity. Its continuous curved surface structure guides the airflow to form an axial spiral propulsion trajectory. Combined with the guide vanes symmetrically arranged on both sides of the air cavity, the airflow is radially constrained and circumferentially rectified, so that the airflow is kept in a laminar state in the air cavity and flows directionally along a preset spiral path. This avoids the generation of local turbulence and vortices caused by sudden changes in airflow direction or velocity differences. At the same time, the spiral rise angle of the spiral guide vane and the angle of attack of the guide vanes form an aerodynamic coupling, which suppresses the tendency of airflow to separate in the corner area of ​​the air cavity. Finally, the vortex suppression effect is achieved through fluid dynamics optimization, thereby weakening the vibration excitation source caused by vortex impact, reducing operating noise and mitigating the risk of fatigue damage to the air guide components. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention;

[0024] Figure 2 This is a schematic diagram of the rear view structure of the present invention;

[0025] Figure 3 This is a schematic diagram of the left-side structure of the present invention;

[0026] Figure 4 This is a schematic diagram of the right-side structure of the present invention;

[0027] Figure 5 This is a schematic diagram of the cylinder liner heat sink structure of the present invention;

[0028] Figure 6 This is a schematic diagram of the dual-fan structure of the present invention;

[0029] Figure 7 This is a schematic diagram of the gas flow rate of the present invention;

[0030] Figure 8 This is a top view of the structure of the present invention;

[0031] Figure 9 This is a front view structural diagram of the present invention;

[0032] Figure 10 This is a schematic diagram of the air cavity structure of the present invention;

[0033] Figure 11 This is a schematic diagram of the fan structure of the present invention.

[0034] In the diagram: 1. Diesel engine body; 2. First fan; 3. Fan pulley; 4. Fan connecting shaft; 5. Second fan; 6. Fan shroud; 7. Air duct assembly; 8. Air chamber; 9. Front air guide plate; 10. Rear air guide plate; 11. Upper air guide shroud; 12. Lower air guide shroud; 13. Cylinder head air guide plate; 14. Cylinder liner air guide plate; 15. Cylinder liner heat sink; 16. Heat dissipation component; 17. Flange; 18. Spiral guide plate; 19. Guide vane; 20. Mounting cylinder; 21. Slot; 22. Fixing rod. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] This invention provides a technical solution: a dual-fan air-cooled diesel engine. Please refer to [link / reference]. Figure 1 This includes a diesel engine body 1, with a duct assembly 7 mounted on the upper surface of the diesel engine body 1. Please refer to [link / reference]. Figure 7 The air duct assembly 7 has an air cavity 8 inside. Please refer to [link / reference]. Figure 1 The air inlets of the air duct assembly 7 are all equipped with fan covers 6;

[0037] The first fan 2 is located at the right air intake of the diesel engine body 1. Please refer to [link / reference]. Figure 11 The surface of the first fan 2 is equipped with a fan pulley 3, please refer to [reference needed]. Figure 6 A fan connecting shaft 4 is mounted at the center of the first fan 2, and a second fan 5 is mounted at the other end of the fan connecting shaft 4. Please refer to [link / reference]. Figure 1 A crankshaft 101 is installed at the output end of the diesel engine body 1, and a main pulley 102 is installed at the output end of the crankshaft 101. A belt is connected between the main pulley 102 and the fan pulley 3.

[0038] Please see Figure 4 The front air guide plate 9 is located at the first fan 2. Please refer to [link / reference]. Figure 3 A rear air guide plate 10 is installed on the surface of the diesel engine body 1 at a position corresponding to the second fan 5. Please refer to [link / reference]. Figure 9 An upper air guide shroud 11 is installed on the upper part of the surface of the air duct assembly 7, and a lower air guide shroud 12 is installed on the lower part of the surface of the air duct assembly 7. Please refer to [link / reference]. Figure 10 The cylinder head air guide plate 13 is installed inside the air duct assembly 7. Please refer to [link / reference]. Figure 2 The outer surface of the air duct assembly 7 is fitted with a cylinder liner air guide plate 14, and the surface of the cylinder liner air guide plate 14 is fitted with cylinder liner heat sink fins 15. Please refer to [link / reference]. Figure 1A heat dissipation component 16 is installed on the lower surface of the air duct assembly 7;

[0039] Please see Figure 5 The surface of the cylinder liner heat sink 15 is uniformly provided with heat dissipation grooves;

[0040] Please see Figure 8 Spiral guide plate 18 is provided on the inner wall of air cavity 8, and guide vanes 19 are provided on both sides of the interior of air cavity 8.

[0041] The first fan 2, located at the air inlet of the diesel engine body 1, and the second fan 5, connected in series via the fan connecting shaft 4, form an axial counter-rotating combination. The main pulley 102 drives the fan pulley 3 to achieve constant-speed counter-rotation, so that the angular momentum of the two fans cancels each other out to reduce operating vibration and noise. The air cavity 8 formed in the inner cavity of the air duct assembly 7, together with the airflow channel constructed by the front air guide plate 9, the rear air guide plate 10, the upper air guide shroud 11, and the lower air guide shroud 12, makes the two-stage pressurized flow field form a continuous pressurization effect in the air duct. Combined with the cylinder head air guide plate 13 and the cylinder liner air guide plate 14 surface cylinder liner heat exchange fins 15 to enhance local heat exchange, and finally achieve heat energy exhaust through the heat dissipation component 16. This structure reuses existing fans and air guide components. Without the need to open new molds, it achieves a comprehensive effect of increased air volume, enhanced static pressure, and optimized heat dissipation efficiency through the counter-rotating airflow organization and multi-stage air guide structure. At the same time, it also has the advantages of low-speed noise reduction and rapid productization feasibility.

[0042] The fan matching requirements can be met by using existing products. There is no need to develop new fan molds. Existing products can be combined. The dual-fan combination design can form a two-stage pressurized flow field in the air duct. The two fans rotating in opposite directions at the same speed will not generate eddies. The angular momentum cancels each other out, effectively reducing fan vibration and noise. Compared with a single-stage fan, it increases air volume and static pressure, has higher heat dissipation efficiency, low noise at low speed, low cost, short development cycle, and strong operability.

[0043] The spiral guide plate 18 extends spirally along the inner wall of the air cavity 8. Its continuous curved surface structure guides the airflow to form an axial spiral propulsion trajectory. Together with the guide vanes 19 symmetrically arranged on both sides of the air cavity 8, it provides radial constraint and circumferential rectification of the airflow, so that the airflow remains in a laminar state in the air cavity 8 and flows directionally along a preset spiral path. This avoids the generation of local turbulence and vortices caused by abrupt changes in airflow direction or velocity differences. At the same time, the spiral rise angle of the spiral guide plate 18 and the angle of attack of the guide vanes 19 form an aerodynamic coupling, which suppresses the tendency of airflow to separate in the corner area of ​​the air cavity 8. Finally, the vortex suppression effect is achieved through fluid dynamics optimization, thereby weakening the vibration excitation source caused by vortex impact, reducing operating noise and mitigating the risk of fatigue damage to the air guide components.

[0044] Please see Figure 1The first fan 2 and the second fan 5 are both installed inside the fan cover 6, and the first fan 2, the second fan 5 and the inner cavity of the fan cover 6 are the same size. The output airflow of the first fan 2 and the second fan 5 are installed in opposite directions, so that the first fan 2 and the second fan 5 can blow air into the air cavity 8 synchronously.

[0045] Please see Figure 6 The first fan 2 and the second fan 5 are coaxially connected by a fan connecting shaft 4, so that the first fan 2 and the second fan 5 can rotate synchronously.

[0046] The fan connecting shaft 4 is mounted with a flange 17. The fan connecting shaft 4 is connected to the first fan 2 and the second fan 5 through the flange 17. The fan connecting shaft 4 can also be connected to the fan by threaded connection and spline connection. It can be adapted to various engine models such as three-cylinder, four-cylinder and six-cylinder according to different engine sizes, making the structure of the fan connecting shaft 4 simple and easy to process.

[0047] Please see Figure 8 Each guide vane 19 has a mounting cylinder 20 installed in the middle. The surface of the mounting cylinder 20 is provided with a slot 21. The fan connecting shaft 4 passes through the inside of the slot 21, so that the fan connecting shaft 4 can rotate stably.

[0048] Fixing rods 22 are evenly distributed on the surface of the mounting cylinder 20. The outer ends of the fixing rods 22 are all installed on the inner wall of the air cavity 8, which improves the stability of the guide vanes 19.

[0049] In operation, the diesel engine starts, and the crankshaft 101 drives the fan pulley 3 to rotate via a belt, which in turn drives the first fan 2 and the second fan 5 to rotate coaxially and at the same speed. The two fans start working, and the air generated by the suction fans flows through the air cavity 8 formed by the air guide shroud and air guide plate, passes through various heat dissipation components 16, and is discharged outside the engine body. The components that need to be cooled mainly include: cylinder liners, oil coolers, turbocharger intercoolers, and EGR air coolers. Among them, the engine cylinder liners are densely covered with heat dissipation fins, which are incorporated into the air cavity 8 by the front and rear air guide plates and the cylinder head and cylinder liner air guide plates 14. The air drawn into the air cavity 8 by the suction fans carries away heat as it passes through the cylinder liner heat dissipation fins 15, thereby achieving the purpose of cooling the engine cylinders. Other radiators are incorporated into the heat dissipation air cavity 8 by means of perforations in the air guide shroud, which is an existing mature technology and will not be described in detail.

[0050] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A twin-fan air-cooled diesel engine characterized by, include: A diesel engine body (1) is provided with a duct assembly (7) installed on the upper surface of the diesel engine body (1). The duct assembly (7) has an air cavity (8) in its inner cavity and a fan cover (6) installed at the air inlet of the duct assembly (7). A first fan (2) is located at the right air inlet of the diesel engine body (1). A fan pulley (3) is mounted on the surface of the first fan (2). A fan connecting shaft (4) is mounted at the shaft of the first fan (2). A second fan (5) is mounted at the other end of the fan connecting shaft (4). A crankshaft (101) is mounted at the output end of the diesel engine body (1). A main pulley (102) is mounted at the output end of the crankshaft (101). A belt is connected between the main pulley (102) and the fan pulley (3). A front air guide plate (9) is provided at the first fan (2). A rear air guide plate (10) is installed on the surface of the diesel engine body (1) at the position corresponding to the second fan (5). An upper air guide shroud (11) is installed on the upper part of the surface of the air duct assembly (7). A lower air guide shroud (12) is installed on the lower part of the surface of the air duct assembly (7). A cylinder head air guide plate (13) is installed inside the air duct assembly (7). A cylinder liner air guide plate (14) is installed on the outer surface of the air duct assembly (7). A cylinder liner heat sink (15) is installed on the surface of the cylinder liner air guide plate (14). A heat dissipation component (16) is installed on the lower surface of the air duct assembly (7). A spiral guide plate (18) is provided on the inner wall of the air cavity (8), and guide vanes (19) are provided on both sides of the interior of the air cavity (8).

2. A twin-fan air-cooled diesel engine according to claim 1, characterized in that: The first fan (2) and the second fan (5) are both installed inside the fan cover (6), and the inner cavity of the first fan (2), the second fan (5) and the fan cover (6) are the same size. The output airflow of the first fan (2) and the second fan (5) are installed in opposite directions.

3. A twin-fan air-cooled diesel engine according to claim 1, characterized in that: The first fan (2) and the second fan (5) are coaxially connected via a fan connecting shaft (4).

4. A twin-fan air-cooled diesel engine according to claim 1, characterized in that: The fan connecting shaft (4) is fitted with a flange (17), and the fan connecting shaft (4) is connected to the first fan (2) and the second fan (5) through the flange (17).

5. A twin-fan air-cooled diesel engine according to claim 1, characterized in that: Each of the guide vanes (19) is equipped with an installation cylinder (20) in the middle. The surface of each installation cylinder (20) is provided with a slot (21), and the fan connecting shaft (4) passes through the inside of the slot (21).

6. A twin-fan air-cooled diesel engine according to claim 5, characterized in that: The surface of the mounting cylinder (20) is evenly provided with fixing rods (22), and the outer ends of the fixing rods (22) are all installed on the inner wall of the air cavity (8).

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