Cooling device applied to general gasoline engine

Abstract

The invention discloses a cooling device applied to a general gasoline engine, which is applied to the technical field of general machinery and comprises a fan motor (3) and an impeller (6) mounted on a rotating shaft of the fan motor (3), and the impeller (6) faces the engine (2) to cool the engine (2); and the temperature control mechanism is used for controlling the rotating speed of the fan motor (3) according to the temperature of the engine (2). According to the cooling device applied to the general gasoline engine, the cooling capacity of the fan can be dynamically adjusted according to the cooling requirements of the engine under different working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of general machinery, and particularly to a cooling device applied to a general-purpose engine. Background Art

[0002] General machinery, that is, general-purpose machinery, refers to mechanical equipment widely used in multiple fields such as industrial production, agriculture, and construction. These devices usually have multiple functions and can meet the production needs of different fields.

[0003] A general-purpose engine, that is, a general-purpose small gasoline engine, refers to a gasoline engine other than those for vehicles and special purposes, and its rated power is generally below 30 kW. Such engines are mainly used as the power source for agricultural and forestry plant protection machinery, small agricultural implements, garden machinery, generating sets, construction machinery, outboard machinery, etc. Due to the small size, light weight, low price, and convenient use of general-purpose small gasoline engines, they play an important role in supporting various machines. Especially in backpack-type machinery, general-purpose small gasoline engines are the only power source.

[0004] In the existing structure of general-purpose engines, the fan is connected to the engine crankshaft, and the fan speed changes with the engine speed. This makes it impossible to fully match the fan cooling capacity with the actual cooling requirements of the engine, resulting in problems such as engine overheating due to insufficient cooling capacity and increased mechanical losses of the engine due to excessive cooling capacity.

[0005] In summary, how to effectively solve the problem that the fan cooling capacity cannot match the actual cooling requirements of the engine is an urgent problem for those skilled in the art at present. Summary of the Invention

[0006] The purpose of the present invention is to provide a cooling device applied to a general-purpose engine, which can dynamically adjust the fan cooling capacity according to the cooling requirements of the engine under different working conditions.

[0007] To solve the above technical problems, the present invention provides the following technical solutions:

[0008] A cooling device applied to a general-purpose engine includes a fan motor and an impeller mounted on the rotating shaft of the fan motor. The impeller faces the engine to cool the engine; it also includes a temperature control mechanism for controlling the rotation speed of the fan motor according to the engine temperature.

[0009] Optionally, the temperature control mechanism includes:

[0010] A temperature sensor for detecting the working temperature of the engine;

[0011] A temperature control unit connected to the temperature sensor, which is used to control the fan motor to stop or operate at a low rotational speed when the temperature sensor detects that the current operating temperature of the engine is lower than the optimal operating temperature range; and to control the fan motor to operate at a high rotational speed when the temperature sensor detects that the current operating temperature of the engine is higher than the optimal operating temperature range.

[0012] Optionally, the negative terminal of the fan motor is connected to the negative pole of the power supply, and the positive terminal of the fan motor is connected to at least two branches. One of them is a high-speed branch connected to the positive pole of the fan motor, and the other is a low-speed branch connected to the positive pole of the fan motor. The low-speed branch is in parallel with the high-speed branch, and a speed-regulating resistor is connected to the low-speed branch. The temperature control unit includes:

[0013] A branch control module connected to the low-speed branch and the high-speed branch, which is used to control the fan motor to stop or turn on the low-speed branch when it detects that the current operating temperature of the engine is lower than the optimal operating temperature range; and to control the fan motor to turn on the high-speed branch when the temperature sensor detects that the current operating temperature of the engine is higher than the optimal operating temperature range.

[0014] Optionally, the branch control module includes:

[0015] Relays respectively used to control the low-speed branch and the high-speed branch to turn on;

[0016] A selection component connected to the relay, which is used to control all the relays to turn off or control the low-speed branch relay to conduct when it detects that the current operating temperature of the engine is lower than the optimal operating temperature range; and to control the high-speed branch relay to conduct when it detects that the current operating temperature of the engine is higher than the optimal operating temperature range.

[0017] Preferably, the speed-regulating resistor is a sliding resistor, and a curve graph corresponding to the engine operating temperature and the effective resistance of the sliding resistor is preset in the branch selection component. The branch selection component includes:

[0018] A resistance determination component used to determine the effective resistance of the sliding resistor corresponding to the current operating temperature according to the current operating temperature of the engine and the curve graph;

[0019] A resistance driving component connected to the sliding resistor, which is used to drive the sliding resistor to be adjusted to the effective resistance position.

[0020] Preferably, the resistance driving component includes:

[0021] A power component used to provide power;

[0022] A transmission component connected to the power component for moving the adjusting part of the sliding resistor.

[0023] Preferably, an air guide cover is connected to the engine, the fan motor is connected to the air guide cover, a flywheel is connected to the crankshaft of the engine, and there is a gap between the end face of the impeller and the end face of the flywheel.

[0024] Preferably, the rotating shaft of the fan motor is concentric with the crankshaft of the engine, and the end face of the impeller is parallel to the end face of the flywheel.

[0025] Preferably, it further includes a gap control mechanism for controlling the size of the gap between the impeller and the flywheel according to the engine temperature.

[0026] Preferably, the fan motor is connected to the connection hole of the air guide cover, and the fan motor is movably connected to the connection hole. The gap control mechanism includes:

[0027] A gap control unit connected to the temperature sensor, which is used to adjust the impeller and the flywheel to a large gap when it detects that the current working temperature of the engine is lower than the optimal working temperature range, and adjust the impeller and the flywheel to a small gap when it detects that the current working temperature of the engine is higher than the optimal working temperature range.

[0028] The cooling device applied to the general-purpose engine provided by the present invention has a fan motor installed on the engine. An impeller is installed on the rotating shaft of the fan motor, and the impeller faces the engine, and the engine is cooled by convection. The temperature control mechanism is used to control the rotation speed of the fan motor according to the temperature of the engine. The temperature control mechanism includes a temperature sensor and a control unit, which can monitor the temperature of the engine and dynamically adjust the fan cooling capacity according to the cooling requirements under different working conditions of the engine.

[0029] The cooling device applied to the general-purpose engine provided by the present invention disconnects the impeller from the engine crankshaft, decouples the impeller speed from the engine speed, and the impeller speed does not change with the engine speed. The impeller speed is controlled by the fan motor, and the fan motor drives the impeller to rotate to cool the engine. Through gear adjustment, the fan motor can adjust the operating speed of the impeller according to parameters such as the engine working condition and temperature to meet the cooling requirements under different working conditions of the engine, ensure that the engine operates within the target temperature range, and optimize the problems of insufficient cooling performance caused by low fan speed during low-speed operation of the engine and increased engine mechanical losses caused by excessive cooling capacity. At the same time, after the engine stops, the fan motor can continuously drive the impeller to rotate and continue to provide air cooling for the engine to prevent the engine temperature from surging after shutdown, reduce energy consumption, and improve the performance and durability of the engine. Description of the Drawings

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0031] Figure 1 Schematic connection diagram of a cooling device applied to a general-purpose engine and a generator provided by a specific embodiment of the present invention;

[0032] Figure 2 Schematic structural diagram of a cooling device applied to a general-purpose engine;

[0033] Figure 3 Schematic diagram of a water-cooled motor of a generator;

[0034] Figure 4 Schematic diagram of an air-cooling system of a radiator;

[0035] Figure 5 Schematic diagram of an extender pressure balance device;

[0036] Figure 6 Schematic diagram of a balance device between a generator and an engine.

[0037] Reference numerals:

[0038] 1 - Cooling device; 2 - Engine; 3 - Fan motor; 4 - Speed-regulating resistor; 5 - Air guide cover; 6 - Impeller; 7 - Rotor; 8 - Motor chamber; 9 - Intermediate end cover; 10 - Crankshaft; 11 - Crankcase; 12 - Water inlet nozzle; 13 - Water outlet nozzle; 14 - Water inlet and outlet dividing member; 15 - Water inlet; 16 - Water outlet; 17 - Outer water jacket; 18 - O-ring; 19 - Inner water jacket; 20 - Fastener; 21 - Flywheel; 22 - Oil seal; 23 - Waterproof and breathable membrane; 24 - Rear end cover; 25 - Stator; 26 - Radiator. Specific embodiments

[0039] The core of the present invention is to provide a cooling device applied to a general-purpose engine, and this cooling device applied to a general-purpose engine can dynamically adjust the fan cooling capacity according to the cooling requirements of the engine under different working conditions.

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0041] Please refer to Figures 1 to 6 , Figure 1 which is a schematic connection diagram of a cooling device and a generator provided for a specific embodiment of the present invention in a general-purpose engine; Figure 2 which is a schematic structural diagram of a cooling device applied to a general-purpose engine; Figure 3 which is a schematic diagram of a water-cooled motor of a generator; Figure 4 which is a schematic diagram of an air-cooling system of a radiator; Figure 5 which is a schematic diagram of an extender pressure balancing device; Figure 6 which is a schematic diagram of a balancing device between a generator and an engine.

[0042] In a specific embodiment, the cooling device provided by the present invention for a general-purpose engine includes a fan motor 3 and an impeller 6 mounted on the rotating shaft of the fan motor 3. The impeller 6 faces the engine 2 to cool the engine 2; it also includes a temperature control mechanism for controlling the rotation speed of the fan motor 3 according to the temperature of the engine 2.

[0043] In the above structure, the cooling device 1 includes a fan motor 3, an impeller 6 and a temperature control mechanism. The fan motor 3 is mounted on the engine 2, and the impeller 6 is mounted on the rotating shaft of the fan motor 3. The impeller 6 faces the engine 2 and cools the engine 2 by convection. The temperature control mechanism is used to control the rotation speed of the fan motor 3 according to the temperature of the engine 2. The temperature control mechanism includes a temperature sensor and a control unit, which can monitor the temperature of the engine 2 and dynamically adjust the fan cooling capacity according to the cooling requirements under different working conditions of the engine.

[0044] For the cooling device provided by the present invention for a general-purpose engine, the impeller 6 is disengaged from the crankshaft of the engine 2, and the rotation speed of the impeller 6 is decoupled from the rotation speed of the engine 2. The rotation speed of the impeller 6 does not change with the change of the rotation speed of the engine 2. The rotation speed of the impeller 6 is controlled by the fan motor 3, and the fan motor 3 drives the impeller 6 to rotate to cool the engine 2. The fan motor 3 can adjust the operation speed of the impeller 6 according to parameters such as the working condition and temperature of the engine 2 through gear adjustment, so as to meet the cooling requirements under different working conditions of the engine 2, ensure that the engine 2 works within the target temperature range, and optimize the problems of insufficient cooling performance caused by low fan speed during low-speed operation of the engine 2 and the increase of mechanical loss of the engine 2 caused by excessive cooling capacity. At the same time, after the engine 2 stops, the fan motor 3 can continuously drive the impeller 6 to rotate, continue to provide air cooling for the engine 2, prevent the temperature of the engine 2 from soaring after shutdown, reduce energy consumption, and improve the performance and durability of the engine 2.

[0045] Based on the above various specific embodiments, the temperature control mechanism includes:

[0046] a temperature sensor for detecting the working temperature of the engine 2;

[0047] A temperature control unit that is connected to a temperature sensor and is used to control the fan motor 3 to stop or operate at a low rotational speed when the temperature sensor detects that the current operating temperature of the engine 2 is lower than the optimal operating temperature range; and to control the fan motor 3 to operate at a high rotational speed when the temperature sensor detects that the current operating temperature of the engine 2 is higher than the optimal operating temperature range.

[0048] In practical applications, the temperature control mechanism adjusts the rotational speed of the fan motor 3 through the temperature sensor and the temperature control unit to keep the engine 2 operating within the optimal operating temperature range.

[0049] The temperature sensor continuously monitors the operating temperature of the engine 2 and converts it into an electrical signal. Commonly used temperature sensors include thermistors and thermocouples, which are sensitive to temperature changes and can accurately reflect the temperature state of the engine 2. The temperature control unit receives the signal from the temperature sensor and controls the rotational speed of the fan motor 3 according to the optimal operating temperature range of the engine 2. The optimal operating temperature range is preset in the temperature control unit, and the temperature values within this range satisfy the most suitable temperature for the operation of the engine 2.

[0050] When the temperature sensor detects that the temperature of the engine 2 is lower than the optimal operating temperature range, that is, the temperature of the engine 2 is relatively low, the temperature control unit issues an instruction to stop the fan motor 3 or operate it at a low speed to maintain the temperature of the engine 2, reduce energy consumption and noise; when the temperature is higher than the optimal operating temperature range, that is, the temperature of the engine 2 is relatively high, the temperature control unit increases the rotational speed of the fan motor 3 to accelerate the cooling effect and prevent overheating. An over-temperature protection device can also be designed to automatically cut off the power supply when the temperature of the engine 2 exceeds the safety threshold.

[0051] In the above embodiments, the temperature control mechanism can effectively control the temperature of the engine 2, keep the engine 2 operating within the optimal operating temperature range, reduce thermal stress, ensure its stable operation under various working conditions, improve energy efficiency and extend the service life of the engine 2. By precisely controlling the rotational speed of the fan motor 3, unnecessary energy consumption can be reduced and fuel economy can be improved.

[0052] Based on the above specific embodiments, the negative terminal of the fan motor 3 is connected to the negative pole of the power supply, and the positive terminal of the fan motor 3 is connected with at least two branches. One of them is a high-speed branch connected to the positive pole of the fan motor 3, and the other is a low-speed branch connected to the positive pole of the fan motor 3. The low-speed branch is in parallel with the high-speed branch, and a speed regulating resistor 4 is connected to the low-speed branch. The temperature control unit includes:

[0053] A branch control module that is connected to a low-speed branch and a high-speed branch and is used to control the fan motor 3 to stop or connect to the low-speed branch when it detects that the current operating temperature of the engine 2 is lower than the optimal operating temperature range; when the temperature sensor detects that the current operating temperature of the engine 2 is higher than the optimal operating temperature range, it controls the fan motor 3 to connect to the high-speed branch.

[0054] In practical applications, the temperature control mechanism is used to control the speed of the fan motor 3 to keep the engine 2 within the optimal operating temperature range. The negative terminal of the fan motor 3 is connected to the negative pole of the power supply, and the positive terminal is divided into two branches. One is the high-speed branch, and the other is the low-speed branch. These two branches are connected in parallel, and a speed-regulating resistor 4 is connected to the low-speed branch to adjust the current passing through this branch, thereby controlling the speed of the fan motor 3.

[0055] The temperature control unit includes a branch control module that can control the fan motor 3 to connect to the low-speed branch or the high-speed branch according to the signal of the temperature sensor. When the operating temperature of the engine 2 is lower than the optimal operating temperature range, it controls the fan motor 3 to stop or connect to the low-speed branch. At this time, the fan stops or runs at a low speed; when the temperature is higher than the optimal operating temperature range, it controls the fan motor 3 to connect to the high-speed branch and runs at a high speed to quickly reduce the temperature of the engine 2.

[0056] In the above embodiment, the speed of the fan motor 3 is automatically adjusted to keep the engine 2 operating within the optimal operating temperature range.

[0057] Based on the above various specific embodiments, the branch control module includes:

[0058] Relays respectively used to control the connection of the low-speed branch and the high-speed branch;

[0059] A selection component connected to the relay and used to control all relays to turn off or control the low-speed branch relay to conduct when it detects that the current operating temperature of the engine 2 is lower than the optimal operating temperature range; when it detects that the current operating temperature of the engine 2 is higher than the optimal operating temperature range, it controls the high-speed branch relay to conduct.

[0060] In practical applications, the relay is used to control the connection and disconnection of the low-speed branch and the high-speed branch. The relay includes an electromagnet and a switch contact, and can remotely control the on-off state of the circuit. Preferably, a double-pole double-throw relay can be selected, which can simultaneously control the connection states of the low-speed and high-speed branches.

[0061] The branch selection component is used to control the on - off state of the relay according to the operating temperature of the engine 2, so as to select the conduction of the low - speed or high - speed branch. Specifically, it can control the on - off of the relay according to the preset optimal operating temperature range. When it is detected that the current operating temperature of the engine 2 is lower than the optimal operating temperature range, all relays are controlled to turn off or the low - speed branch relay is controlled to conduct; when it is detected that the current operating temperature of the engine 2 is higher than the optimal operating temperature range, the high - speed branch relay is controlled to conduct. This control method can dynamically adjust the fan cooling capacity according to the cooling requirements of the engine under different working conditions, and the control is convenient.

[0062] Based on the above - mentioned specific embodiments, the speed - regulating resistor 4 is a sliding resistor, and a curve graph corresponding to the operating temperature of the engine 2 and the effective resistance of the sliding resistor is preset in the branch selection component. The branch selection component includes:

[0063] A resistance determination component for determining the effective resistance of the sliding resistor corresponding to the current operating temperature according to the current operating temperature of the engine 2 and the curve graph;

[0064] A resistance driving component connected to the sliding resistor and used to drive the sliding resistor to be adjusted to the effective resistance position.

[0065] In practical applications, the speed - regulating resistor 4 can be a sliding resistor or a thermistor whose resistance value changes with temperature, and both can enable the circuit to automatically adjust the speed of the fan motor 3 when the temperature changes, so as to maintain the optimal operating temperature of the engine 2.

[0066] Taking the sliding resistor as an example for illustration below, the branch selection component includes a resistance determination component and a resistance driving component to achieve effective control of the sliding resistor.

[0067] The resistance determination component is responsible for determining the corresponding effective resistance value of the sliding resistor according to the current operating temperature of the engine 2 and the preset curve graph. The curve graph can be a physical chart or a digital model stored in the microcontroller, which is used to guide the adjustment of the resistance value. The resistance driving component is connected to the sliding resistor and is responsible for driving the sliding resistor to be adjusted to the effective resistance position. This usually involves a motor or an electronic control unit that can adjust the position of the sliding resistor according to the instructions of the resistance determination component, thereby changing the resistance value.

[0068] Based on the above - mentioned embodiments, the speed - regulating resistor 4 connected to the low - speed branch can be adjusted as needed. By adjusting the sliding resistor, the low - speed operating speed of the fan motor 3 can be finely adjusted to perform fine temperature control when keeping the temperature of the engine 2 close to the optimal operating temperature range. This design can not only improve the efficiency and service life of the engine 2, but also automatically adjust according to the actual working conditions to achieve intelligent temperature control.

[0069] Based on the above specific embodiments, the resistance driving assembly includes:

[0070] A power assembly for providing power;

[0071] A transmission assembly connected to the power assembly and used to move the adjusting part of the sliding resistor.

[0072] In practical applications, the resistance driving assembly includes a power assembly and a transmission assembly. The power assembly is a unit that provides power, which can be a motor or an electronic control unit, and can provide the necessary power to drive the movement of the adjusting part of the sliding resistor. For example, a small servo motor can be used as the power assembly, and the position of the sliding resistor can be adjusted by precisely controlling the rotation of the motor.

[0073] The transmission assembly is a mechanical structure connecting the power assembly and the adjusting part of the sliding resistor. Its function is to convert the rotation or movement of the power assembly into the precise movement of the adjusting part of the sliding resistor. The transmission assembly can include mechanical components such as gears, lead screws, sliders, and connecting rods. These components work together to ensure that the adjusting part of the sliding resistor can move precisely according to the instructions of the power assembly, thereby changing the resistance value. For example, the combination of a lead screw and a slider can convert the rotational motion of the motor into a linear motion to adjust the position of the sliding contact in the sliding resistor to achieve effective control of the sliding resistor.

[0074] Based on the above embodiments, the resistance driving assembly can precisely control the position of the sliding resistor and achieve precise adjustment of the resistance value.

[0075] In a preferred embodiment, a user display can be provided to display the current temperature and fan status and allow the user to manually adjust the temperature settings or fan modes.

[0076] Based on the above specific embodiments, an air guide cover 5 is connected to the engine 2, the fan motor 3 is connected to the air guide cover 5, a flywheel is connected to the crankshaft of the engine 2, and there is a gap between the end face of the impeller 6 and the end face of the flywheel.

[0077] In practical applications, the air guide cover 5 is installed at the front end of the engine 2 and behind the fan motor 3. The fan motor 3 is connected to the engine 2 through the air guide cover 5. The air guide cover 5 wraps the fan motor 3 and the impeller 6, and guides the airflow generated by the impeller 6 to the engine 2 to improve the cooling effect and cooling efficiency.

[0078] The flywheel is connected to the crankshaft of the engine 2 and rotates together with the crankshaft. The flywheel stores kinetic energy to maintain the smooth operation of the engine 2, reduce vibration, and provide power during the ignition gap. A certain gap is maintained between the end face of the impeller 6 and the end face of the flywheel to avoid contact and friction during operation, which can reduce wear and energy loss, and also avoid the noise generated by contact. The size of the gap needs to be precisely controlled. An overly large gap may lead to a decrease in air flow efficiency, while an overly small gap may cause contact between the impeller 6 and the flywheel, resulting in damage.

[0079] In the above structure, through precise design and adjustment, the effective cooling of the engine 2 can be ensured, its service life can be extended, and the overall performance can be improved.

[0080] Based on the above various specific embodiments, the rotating shaft of the fan motor 3 is concentric with the crankshaft of the engine 2, and the end face of the impeller 6 is parallel to the end face of the flywheel.

[0081] In a specific embodiment, the layout of the fan motor 3 and the crankshaft of the engine 2 is concentric and parallel. The rotating shaft of the fan motor 3 and the crankshaft of the engine 2 share the same center point, reducing space occupancy and ensuring that the rotating components of the fan motor 3 and the crankshaft maintain consistent dynamic balance during operation; it is convenient to maintain a uniform gap between the two, reduce wear caused by unbalanced operation or vibration, and can effectively manage the air flow and improve the cooling efficiency.

[0082] Based on the above various specific embodiments, the cooling device applied to the general-purpose engine further includes a gap control mechanism for controlling the size of the gap between the impeller 6 and the flywheel according to the temperature of the engine 2. Through the coordinated work of the power component and the transmission component, combined with the precise control of the temperature sensor and the control system, and the real-time monitoring of the feedback mechanism, the gap control mechanism can automatically adjust the gap between the impeller 6 and the flywheel according to the temperature change of the engine 2 to maintain the best performance of the engine 2 and extend its service life.

[0083] Based on the above various specific embodiments, the fan motor 3 is connected to the connection hole of the air guide cover 5, and the fan motor 3 is movably connected to the connection hole. The gap control mechanism includes:

[0084] A gap control unit connected to the temperature sensor, which is used to adjust the impeller 6 and the flywheel to a large gap when it detects that the current working temperature of the engine 2 is lower than the optimal working temperature range, and adjust the impeller 6 and the flywheel to a small gap when it detects that the current working temperature of the engine 2 is higher than the optimal working temperature range.

[0085] In practical applications, first of all, a temperature sensor is required to monitor the working temperature of the engine 2 in real time. This sensor sends temperature data to the clearance control unit, which serves as the basis for controlling the clearance between the impeller 6 and the flywheel. The clearance control unit is the core of the clearance control mechanism. It receives signals from the temperature sensor and determines the clearance size between the impeller 6 and the flywheel according to the optimal working temperature range of the engine 2. When it detects that the current working temperature of the engine 2 is lower than the optimal working temperature range, the control unit sends an instruction to the power component to increase the clearance between the impeller 6 and the flywheel to the large clearance state; conversely, when the temperature is higher than the optimal working temperature range, the control unit sends an instruction to the power component to reduce the clearance between the impeller 6 and the flywheel to the small clearance state.

[0086] Based on the above embodiments, the clearance control mechanism can automatically adjust the clearance between the impeller 6 and the flywheel according to the temperature change of the engine 2 to maintain the optimal performance of the engine 2 and extend its service life; this automatic adjustment mechanism helps to improve the efficiency and reliability of the engine 2, while reducing wear and damage caused by improper clearances.

[0087] In a preferred embodiment, the outer periphery of the fan motor 3 has at least a far connection part and a near connection part, and the far connection part and the near connection part can be positioned and connected to the connection holes of the air guide cover 5. The clearance control unit includes:

[0088] A power component for providing power;

[0089] A transmission component connected to the power component for realizing the axial movement of the fan motor 3 along the connection hole.

[0090] In practical applications, the clearance control unit is similar in structure to the resistance drive assembly, and the movement of the fan motor 3 is similar to the movement of the adjustment part of the sliding resistor. The power component can be a motor or other types of actuators. It provides power according to the instructions of the clearance control unit to adjust the clearance between the impeller 6 and the flywheel. This component is responsible for realizing the actual physical adjustment action.

[0091] The transmission component is responsible for transmitting the power of the power component to the impeller 6 or the flywheel to realize the adjustment of the clearance. This may include gears, chains, hydraulic or pneumatic systems, etc., which convert rotational or linear motion into the required adjustment actions. The clearance control unit can precisely control the position of the fan motor 3 to realize the switching connection between the far connection part and the near connection part of the fan motor 3, and further realize the control of the clearance size between the impeller 6 and the flywheel according to the temperature of the engine 2.

[0092] Based on the cooling device provided in the above embodiments, the present invention further provides a hybrid lawn mower, which includes a cooling device, and the cooling device is any one of the cooling devices in the above embodiments. Since the hybrid lawn mower adopts the cooling device in the above embodiments, the beneficial effects of the hybrid lawn mower can be referred to the above embodiments.

[0093] In a specific embodiment, a cooling system applied to a hybrid lawn mower includes a fan assembly installed in an engine housing for cooling the engine, a radiator 26 and a cooling water pump that are communicated with the cooling water inlets of a generator and a controller for cooling the generator and the controller, and a connection hole is formed on the engine housing; it further includes a duct with one end connected to the connection hole and the other end facing the radiator 26.

[0094] The cooling system combines water cooling and air cooling, with a relatively high heat exchange efficiency, meeting the heat dissipation requirements of the generator and the controller; in the water cooling system, the amount of coolant is small, the air pressure in the water cooling system is lower, reducing the expansion water tank and the cost; the radiator 26 uses the fan assembly of the engine for forced heat dissipation, and guides the cold air in the housing to the radiator 26 through the duct, increasing the gas flow rate, enhancing the overall cooling capacity of the cooling system, accelerating the cooling speed of the cooling system, enabling the generator and the controller to reach system thermal equilibrium during operation, preventing the generator and the controller from overheating, and extending the performance and service life of the generator and the controller; the radiator 26 does not require a separate cooling fan, reducing a separate cooling fan, with a simpler structure and lower cost; reducing the failure rate that the radiator 26 cannot cool down due to the damage of the cooling fan; the connection port of the engine has a high universality rate, being suitable for connecting the duct to the original engine, with convenient connection.

[0095] Based on the above various specific embodiments, it further includes a flow control device, which is used to adjust the opening degree of the duct in a proportional relationship with the generator temperature and / or the controller temperature. The flow control device in the hybrid lawn mower dynamically adjusts the opening degree of the duct, and controls the cold air flow acting on the radiator 26 through the duct according to the temperature changes of the generator and the controller, ensuring the effective operation of the cooling system, thereby maintaining the engine, the generator and the controller at an appropriate working temperature.

[0096] Based on the above various specific embodiments, the flow control device includes:

[0097] A first temperature sensor for detecting the generator temperature;

[0098] A second temperature sensor for detecting the controller temperature;

[0099] An opening adjustment mechanism installed inside the air duct, connected to the first temperature sensor and the second temperature sensor, and used to adjust the cross-sectional area opening of the air duct according to the relationship that is directly proportional to the generator temperature and / or the controller temperature. This adjustment mechanism ensures that the generator and the controller can operate at an appropriate temperature, prevents overheating, and also improves the cooling efficiency.

[0100] Based on each of the above specific embodiments, it further includes a flow rate control device, which is used to adjust the rotational speed of the drive motor of the fan assembly according to the relationship that is directly proportional to the generator temperature and / or the controller temperature and the rotational speed of the fan assembly. This adjustment mechanism ensures that the generator and the controller can operate at an appropriate temperature, prevents overheating, and also improves the cooling efficiency. By combining the wind speed adjustment and the air volume adjustment, the efficient management of the cooling system of the hybrid lawn mower is realized, ensuring the stability and reliability of the equipment under various working conditions.

[0101] Based on each of the above specific embodiments, the motor rotational speed of the fan assembly has a high rotational speed gear and a low rotational speed gear, and the flow rate control device includes:

[0102] A rotational speed control mechanism connected to the first temperature sensor and the second temperature sensor, and used to control the motor of the fan assembly to operate at the high rotational speed gear when the generator temperature and / or the controller temperature is higher than the set value; and to control the motor of the fan assembly to operate at the low rotational speed gear when the generator temperature and / or the controller temperature is lower than the set value.

[0103] Based on each of the above specific embodiments, it further includes a distance adjustment device, which is used to adjust the distance from the air outlet of the air duct to the radiator 26 according to the relationship that is inversely proportional to the generator temperature and / or the controller temperature and the distance from the air outlet of the air duct to the radiator 26. That is, when the generator temperature and / or the controller temperature is higher than the preset high temperature set value, the distance adjustment mechanism will reduce the distance from the air outlet to the radiator 26 to be closer to the radiator 26 to improve the cooling efficiency. When the temperature is lower than the preset low temperature set value, the distance adjustment mechanism will increase the distance from the air outlet to the radiator 26 to reduce the cooling intensity. The distance adjustment device can automatically respond to temperature changes and quickly adjust the distance from the air outlet to the radiator 26 to keep the generator and the controller within the optimal working temperature range, ensuring that the cooling requirements of the hybrid lawn mower under different working conditions are met, and at the same time optimizing the energy use efficiency.

[0104] Based on each of the above specific embodiments, the distance adjustment device includes:

[0105] A moving drive mechanism connected to the first temperature sensor and the second temperature sensor, which is used to drive the radiator 26 to move according to an inverse relationship between the generator temperature and / or the controller temperature and the distance from the air outlet of the air duct to the radiator 26. When the generator temperature and / or the controller temperature is higher than the set value, the moving drive mechanism will reduce the distance from the air outlet to the radiator 26 to enhance the cooling effect; when the temperature is lower than the set value, it will increase the distance from the air outlet to the radiator 26 to reduce the cooling intensity. The distance adjustment device ensures that the cooling requirements of the hybrid lawn mower under different working conditions are met by intelligently adjusting the position of the air outlet of the air duct, and at the same time optimizes the energy use efficiency.

[0106] In a preferred embodiment, the moving drive mechanism includes:

[0107] A power component for providing power;

[0108] A transmission component connected to the power component for realizing the movement of the radiator 26.

[0109] The moving drive mechanism provides power through the power component and transmits the power to the radiator 26 through the transmission component to realize its movement, and the guiding mechanism ensures the accuracy of the movement. These components work together so that the radiator 26 can dynamically adjust the distance from the air outlet of the air duct according to the temperature changes of the generator and the controller to optimize the cooling efficiency.

[0110] Based on the above specific embodiments, the air outlet of the air duct faces the back of the radiator 26, and the air outlet surface of the air duct is parallel to the back of the radiator 26. Orienting the air outlet of the air duct towards the back of the radiator 26 and having the air outlet surface parallel to the back of the radiator 26 can help distribute the air flow more evenly, thereby providing a consistent cooling effect on the entire surface of the radiator 26; the air flow can flow along the surface of the radiator 26, increasing the surface area of contact between the air and the fins, thus improving the heat exchange efficiency; it can make more effective use of space, especially in a limited space, and can ensure a compact layout of the radiator 26 and the fan while maintaining high cooling performance.

[0111] Based on the above specific embodiments, the connection hole is opened on the engine housing and faces the back of the radiator 26, which is usually the place where heat is concentrated. The air duct is directly connected to the engine housing, and at the same time ensures that one end of the air duct can face the back of the radiator 26 so that the air flow can directly cool the radiator 26.

[0112] The air duct is in a straight pipe shape, which simplifies the manufacturing and installation processes, reduces the resistance of air flow, and improves the cooling efficiency. The straight pipe shape also helps to precisely control the air flow direction to ensure that the cooling air directly flows towards the radiator 26. When the air duct is a bent pipe, the bending angle is not greater than ninety degrees to reduce the significant wind resistance generated on the air flow passing through it and ensure the working efficiency of the radiator 26 device.

[0113] Based on the above various specific embodiments, the air duct gradually expands outward from the connection end to the air outlet, reducing the turbulence and eddy current of air flow, reducing the resistance of air flow, and increasing the flow rate and uniformity of the cooling air; and providing a larger area at the air outlet to cover more parts of the radiator 26 and enhance the cooling effect.

[0114] The center of the air outlet is on the same horizontal line as the center of the radiator 26. This alignment ensures that the air coming out of the air duct can directly and evenly flow through the entire surface of the radiator 26, ensuring that the cooling air directly flows towards the target area, with a larger contact area between the cold air and the radiator 26, avoiding local overheating or insufficient cooling, and improving the overall performance of the hybrid lawn mower cooling system.

[0115] In a specific embodiment, the water-cooled motor of the hybrid lawn mower includes an inner water jacket 19 and an outer water jacket 17 that are sleeved and connected. A sealed cavity is formed between the inner water jacket 19 and the outer water jacket 17. The outer water jacket 17 is connected with a water inlet nozzle 12 and a water outlet nozzle 13 that communicate with the cavity. The outer water jacket 17 is provided with a water inlet 15 and a water outlet 16 corresponding to the water inlet nozzle 12 and the water outlet nozzle 13; it also includes a water inlet and outlet dividing member 14 disposed in the cavity. The water inlet and outlet dividing member 14 divides the water inlet nozzle 12 and the water outlet nozzle 13 in the circumferential direction, so that after the cooling water flows into the cavity from the water inlet nozzle 12, it flows circumferentially along the side away from the water inlet and outlet dividing member 14 and flows out from the water outlet nozzle 13.

[0116] For the water-cooled motor of the hybrid lawn mower provided by the present invention, the cooling water circulation of the inner water jacket 19 and the outer water jacket 17 of the motor, combined with the cooling of the motor controller base plate by water cooling, has a higher heat dissipation efficiency compared to the air-cooled motor, realizes the efficient cooling of the motor and its controller base plate, can control the motor temperature within a reasonable range, keeps the whole machine in a suitable working environment temperature, keeps the whole machine running at a suitable working environment temperature, reduces the failures of the motor caused by high temperature, and extends the service life.

[0117] Based on the above various specific embodiments, the outer wall of the inner water jacket 19 has grooves, which are simple in structure and easy to process and maintain.

[0118] The water inlet and outlet dividing member 14 is disposed in the groove. Both ends of the water inlet and outlet dividing member 14 are connected to both ends of the groove. The top surface of the groove and the top surface of the water inlet and outlet dividing member 14 are in contact with the inner wall of the outer water jacket 17. The axial direction of the cavity is completely blocked, preventing the coolant from flowing on both sides of the water inlet and outlet dividing member 14, ensuring the unidirectional flow of the coolant, and improving the drainage and guiding property of the coolant. After the cooling water flows into the cavity from the water inlet nozzle 12, due to the blocking effect of the water inlet and outlet dividing member 14, it can only flow circumferentially along the side away from the water inlet and outlet dividing member 14. This design of unidirectional flow helps to ensure the uniform cooling effect of the entire motor and avoids the problem of uneven cooling effect that may be caused by the bidirectional flow of the coolant. The coolant can perform heat exchange more effectively when flowing through the motor because the coolant is forced to flow around the entire cavity, thereby improving the cooling efficiency and uniformity.

[0119] Based on the above various specific embodiments, the groove is an annular groove, and the water inlet and outlet dividing member 14 is connected in the annular groove. Preferably, the water inlet and outlet dividing member 14 is welded to the inner water jacket 19, and the water inlet and outlet dividing member 14 is connected to the outer water jacket 17 through a sealing ring, simplifying the structure of the water-cooled motor and making processing and maintenance easier. The combined use of the annular groove and the water inlet and outlet dividing member 14 reduces complex pipelines and connections, lowering the manufacturing cost and maintenance difficulty.

[0120] Based on the above various specific embodiments, the groove is a non-through groove, and the circumferential blockage of the non-through groove forms the water inlet and outlet dividing member 14. The design of the non-through groove is relatively simple and easy to process. This structure not only improves the cooling efficiency but also simplifies the manufacturing process and reduces the cost. Through the design of the non-through groove and the water inlet and outlet dividing member 14, the flow efficiency and uniformity of the coolant can be improved; the bidirectional flow of the coolant is prevented, ensuring that the coolant can fully contact the heat-generating part of the generator, thereby improving the cooling effect.

[0121] Based on the above various specific embodiments, the side edges of the water inlet and outlet dividing member 14 opposite in the circumferential direction are curved edges with concave and convex parts, such as S-shaped. At the water inlet nozzle 12 and the water outlet nozzle 13, the amount of coolant is large. The smooth curved edges provide a smooth guiding and drainage channel for the coolant, reducing the flow resistance, preventing the coolant from accumulating at the water inlet nozzle 12 and the water outlet nozzle 13, facilitating the inflow and outflow of the coolant, ensuring the uniform distribution of the coolant during the flow process, and optimizing the flow characteristics of the coolant.

[0122] Based on the above specific embodiments, the inlet and outlet nozzles 13 are respectively arranged in the recesses on both sides of the inlet and outlet water dividing member 14, which can optimize the space utilization and make the whole cooling system more compact; it can make the storage capacity of the coolant in the groove smaller, and the recess can be used as part of the hydrodynamic optimization to reduce the formation of turbulence and eddy currents, thereby reducing the resistance when the coolant flows, more precisely controlling the flow direction of the coolant, ensuring that the coolant flows along the predetermined path, and improving the cooling efficiency.

[0123] Based on the above specific embodiments, the shapes of both sides of the inlet and outlet water dividing member 14 are the same and parallel, and the water passing area of the cavity in the circumferential direction covers 360°. The inlet and outlet water dividing member 14 is made as thin as possible. The shapes of both sides of the inlet and outlet water dividing member 14 are the same and parallel, that is, the recesses on both sides are axially offset, and the recesses on both sides have an overlapping length in the circumferential direction. The water passing area of the cavity in the circumferential direction covers 360°, that is, the coolant flow path covers the entire circumferential area, and the coolant can contact the heat generating components in all directions, thereby providing a uniform cooling effect, avoiding local overheating, and ensuring a uniform temperature distribution of the whole component.

[0124] Based on the above specific embodiments, the inner water jacket 19 is provided with slots on both sides of the groove, and O-rings 18 are arranged in the slots to seal the two ends of the inner water jacket 19 and the outer water jacket 17. The structure is compact, the assembly is simple, and the sealing is reliable; it can effectively prevent the leakage of the coolant and ensure the safety and efficiency of the cooling system.

[0125] Based on the above specific embodiments, a flow rate control device is further included. The flow rate control device is used to control the inlet flow rate at the inlet nozzle 12 according to the relationship that the water temperature at the outlet nozzle 13 is proportional to the inlet flow rate at the inlet nozzle 12. The flow rate control device can dynamically adjust the flow rate at the inlet nozzle 12 according to the change of the water temperature at the outlet nozzle 13 to achieve precise flow rate control, maintain the required temperature conditions, and improve the efficiency and response speed of the system.

[0126] Based on the above specific embodiments, a water temperature control device is further included. The water temperature control device is used to control the temperature of the cooling water entering the inlet nozzle 12 according to the relationship that the water temperature at the outlet nozzle 13 is inversely proportional to the temperature of the cooling water entering the inlet nozzle 12. The water temperature control device can dynamically adjust the temperature of the cooling water at the inlet nozzle 12 to respond to the change of the water temperature at the outlet nozzle 13, thereby maintaining the required temperature conditions and improving the efficiency and accuracy of the system.

[0127] In a specific embodiment, the pressure balancing device of the range extender of a hybrid lawn mower includes a crankcase 11 with a rear port, a motor chamber 8 with a front port, and an intermediate end cover 9 whose two end faces are hermetically connected to the rear port of the crankcase 11 and the front port of the motor chamber 8 respectively. The intermediate end cover 9 has a connection hole communicating the crankcase 11 and the motor chamber 8. The crankshaft 10 in the crankcase 11 passes through the connection hole and is connected to the rotor shaft of the motor chamber 8. The connection hole is connected with an oil seal 22 to seal the engine oil inside the crankcase 11. It also includes a pressure balancing device for making the air pressure in the motor chamber 8 equal to the air pressure in the crankcase 11.

[0128] The crankcase 11 is designed with a ventilation system, and its internal air pressure is communicated with the atmosphere, and its internal air pressure is equivalent to the atmospheric pressure. If the motor chamber 8 is in a completely sealed state, during the working process, the volume of the gas in the motor chamber 8 changes due to temperature, which in turn causes a change in air pressure. This causes a pressure difference between the two sides of the oil seal 22, thus destroying the working environment of the oil seal 22 and generating a risk of engine oil leakage. Therefore, a pressure balancing device is added to the motor chamber 8 to make the inside of the motor chamber 8 communicate with the outside atmosphere. When the air pressure in the motor chamber 8 is greater than the atmospheric pressure, the excess gas is discharged through the pressure balancing device. When the air pressure in the motor chamber 8 is less than the atmospheric pressure, air enters the motor chamber 8 through the pressure balancing device, balancing the air pressure inside the motor chamber 8 and the external environment, making the air pressure in the motor chamber 8 equal to the air pressure in the crankcase 11, and playing a role in protecting the oil seal 22.

[0129] For the pressure balancing device of the range extender of the hybrid lawn mower provided by the present invention, the rear port of the crankcase 11 and the front port of the motor chamber 8 share an intermediate end cover 9, canceling the front end cover of the generator, simplifying the structure, making the connection and assembly more convenient, reducing the weight of the range extender, and lowering the cost. At the same time, on the premise of meeting the working requirements of the engine oil seal 22 and the airtightness of the stator 25 and rotor 7 chambers of the generator, a pressure balancing device is added to balance the air pressure inside the motor chamber 8 and the external environment, thereby avoiding the oil leakage problem of the engine oil seal 22 caused by the change in air pressure in the motor chamber 8 and improving the performance and reliability of the range extender.

[0130] Based on the above various specific embodiments, the pressure balancing device includes:

[0131] A pressure sensor for detecting the air pressure in the motor chamber 8;

[0132] A pressure balancing mechanism connected to the pressure sensor and used to control the communication between the outside atmosphere and the motor chamber 8 when the detected air pressure in the motor chamber 8 is not equal to the atmospheric pressure, so that the outside atmospheric pressure is equal to the air pressure in the motor chamber 8.

[0133] The pressure balance device detects the air pressure difference through a pressure sensor and controls the gas flow through a pressure balance mechanism connected thereto. The air pressure balance device can respond to the air pressure difference in a timely manner, so that the air pressure inside and outside the closed space of the motor chamber 8 is kept balanced, that is, the air pressure in the motor chamber 8 is balanced with the air pressure in the crankcase 11, avoiding the oil leakage problem caused by the change of the air pressure in the motor chamber 8 of the engine oil seal 22, and ensuring the safe and stable operation of the range extender.

[0134] Based on the above specific embodiments, the pressure balance mechanism includes:

[0135] A calculation unit for calculating the difference information between the external atmospheric pressure and the current air pressure in the motor chamber 8;

[0136] A pressure balance unit connected to the calculation unit for controlling the ventilation direction and ventilation duration between the external atmosphere and the motor chamber 8 according to the difference information calculated by the calculation unit.

[0137] When the air pressure in the motor chamber 8 is not equal to the external atmospheric pressure, the pressure balance unit will control the flow direction and opening degree of the valve so that the air pressure in the motor chamber 8 is balanced with the external atmospheric pressure. Through the collaborative work of the calculation unit and the pressure balance unit, the pressure balance mechanism can accurately control the pressure balance between the motor chamber 8 and the external atmosphere to maintain the stability of the internal environment of the range extender and the normal operation of the equipment.

[0138] Based on the above specific embodiments, a through hole is provided on the rear end cover 24 of the motor chamber 8. The pressure balance unit includes a waterproof breathable film 23 installed at the through hole. The waterproof breathable film 23 has membrane pores that can pass gas molecules and isolate liquid molecules, achieving the dual effects of allowing gas molecules to pass while preventing liquid molecules, thereby achieving pressure balance and waterproof and breathable effects, ensuring that the air pressure in the motor chamber 8 is balanced with the atmospheric pressure in real time, and preventing the oil seal 22 from moving due to air pressure changes.

[0139] Based on the above specific embodiments, a housing is provided outside the waterproof breathable film 23. Multiple rings of annular grooves are provided on the outer wall of the housing, and sealing rings are provided in the annular grooves. The housing is connected to the through hole through the sealing ring, ensuring the sealing performance between the housing and the through hole, and preventing liquid and large particle substances from passing through the gap between the housing and the through hole;

[0140] The housing is in a stepped shape. The waterproof breathable film 23 is provided at the large diameter section, and the annular groove is provided at the small diameter section. The small diameter section is inserted into the through hole and the stepped surface abuts against the end surface of the rear end cover 24, ensuring the tight fit between the housing and the rear end cover 24 and enhancing the stability and sealing performance of the overall structure.

[0141] Based on the above specific embodiments, the pressure balance unit includes a two-way control valve installed at the through hole, which is used to control the opening of the through hole when the detected air pressure in the motor chamber 8 is not equal to the atmospheric pressure. The two-way control valve can allow gas molecules to pass through while isolating liquid molecules. This control valve can automatically open or close when the pressure difference exceeds a preset range, thereby adjusting the pressure balance between the motor chamber 8 and the external atmospheric pressure, and can quickly respond to pressure changes and close the control valve after the pressure is balanced to maintain the airtightness of the chamber.

[0142] In a preferred embodiment, the two-way control valve and the waterproof breathable membrane 23 can be installed in parallel at the through hole. When the air pressure in the motor chamber 8 is not equal to the external atmospheric pressure and rapid adjustment is required, the two-way control valve will automatically open or close according to the signal of the pressure sensor to control the inflow or outflow of gas. The two-way control valve provides a fast response ability and can quickly balance the pressure in extreme cases; at the same time, the waterproof breathable membrane 23 provides a continuous breathable function, allowing gas molecules to pass through to maintain the pressure balance in the chamber, reducing the dependence on the control valve, reducing energy consumption, and achieving more precise pressure control and protection.

[0143] The combination of the two-way control valve and the waterproof breathable membrane 23 combines active control and passive ventilation, providing a more reliable pressure balance method with high efficiency, flexibility and reliability.

[0144] Based on the above specific embodiments, it further includes a seal detection device for detecting whether the oil seal 22 moves relative to the middle end cover 9. When the seal detection device detects that the oil seal 22 moves due to the change in the internal air pressure of the motor chamber 8, maintenance or replacement can be carried out in a timely manner to ensure the airtightness and reliability of the range extender.

[0145] Based on the above specific embodiments, the seal detection device includes:

[0146] A position sensor for detecting the moving direction and moving distance of the oil seal 22 relative to the middle end cover 9;

[0147] A seal reset mechanism connected to the position sensor, which is used to control the pressure difference between the air pressure in the motor chamber 8 and the air pressure in the crankcase 11 according to the moving direction and moving distance to drive the oil seal 22 to move reversely and reset. By changing the pressure difference, a reverse force is generated, and sufficient reverse force can push the oil seal 22 to move reversely and return it to the correct position, thereby restoring the sealing performance.

[0148] In the above embodiments, the seal detection device integrates the detection and automatic reset functions, and is mainly used to monitor and maintain the position of the oil seal 22 relative to the middle end cover 9 in the range extender. Through the automatic reset function, the position deviation of the oil seal 22 can be corrected in time, potential failures caused by poor sealing can be reduced; manual intervention can be reduced, and the automation level of the system can be improved; the reliability and service life of the range extender can be improved, and the maintenance cost can be reduced.

[0149] Based on the above specific embodiments, the seal reset mechanism includes:

[0150] An information storage unit for storing the correspondence between the distance required for the reset of the oil seal 22 and the pressure difference between the motor chamber 8 and the crankcase 11;

[0151] A seal reset unit connected to the information storage unit and used to control the pressure difference between the air pressure in the motor chamber 8 and the air pressure in the crankcase 11 according to the preset correspondence between the moving distance and the pressure difference to drive the oil seal 22 to move in the reverse direction and reset.

[0152] Through the automatic reset function, the position deviation of the oil seal 22 can be corrected in time, potential failures caused by poor sealing can be reduced, and the reliability and service life of the range extender can be improved; manual intervention is reduced, and the automation level of the system is improved.

[0153] Based on the above specific embodiments, it further includes a reminder device connected to the pressure balance device and the seal detection device. The reminder device is used to give an alarm prompt when it is detected that the air pressure in the motor chamber 8 is not equal to the atmospheric pressure or the oil seal 22 moves relative to the middle end cover 9.

[0154] The reminder device can reduce equipment failures caused by air pressure imbalance or sealing problems, and improve the reliability and safety of the equipment. Through timely reminders, potential serious problems can be avoided, and maintenance costs and downtime can be reduced.

[0155] In a specific embodiment, the balance device of the generator and the engine is applied to a hybrid lawn mower. The crankshaft 10 of the engine is connected to the motor shaft of the generator, and includes a flywheel 21 installed at the connection end of the crankshaft 10 and a rotor 7 connected to the motor shaft. The motor shaft is provided with a connection hole at one end close to the crankshaft 10, the motor shaft is concentric with the connection hole, and the connection end of the crankshaft 10 is connected in the connection hole and the crankshaft 10 and the motor shaft are rigidly connected.

[0156] In the hybrid lawn mower, the connection between the engine and the generator adopts a rigid connection method. The flywheel 21 and the rotor 7 play the role of "dual flywheels 21", and the rotational inertia on the crankshaft 10 of the engine is fully balanced by the mutual matching between the engine flywheel 21 and the generator rotor 7, the torque fluctuation on the engine is reduced, the anti-torsion ability between the generator and the engine is improved, and the engine output torque is made more stable.

[0157] Moreover, a connection hole is provided at one end of the motor shaft close to the crankshaft 10. The center line of the motor shaft and the center line of the connection hole are on the same straight line, that is, the motor shaft and the crankshaft 10 are on the same straight line. The motor shaft is directly connected to the engine crankshaft 10, ensuring high rotational speed and torque transmission efficiency and reducing space occupation. The connecting end of the crankshaft 10 is connected within the connection hole, that is, the crankshaft 10 and the motor shaft are connected inside the motor shaft. This design can reduce the axial space occupation of the motor shaft, make the structure more compact, greatly improve the total power density, and at the same time reduce the production and manufacturing costs.

[0158] Based on the above various specific embodiments, the connection hole is a through hole penetrating the length of the motor shaft. The balancing device further includes a fastener 20 connected to the other end inside the connection hole. A threaded hole is provided on the connecting end face of the crankshaft 10. The end of the fastener 20 is threadedly connected to the threaded hole. The head of the fastener 20 abuts against the rear end face of the motor shaft. The rotation direction of the threaded hole is opposite to the rotation direction of the motor shaft.

[0159] In the above embodiments, the motor shaft is a hollow shaft. The fastener 20 is used to achieve the rigid connection between the engine crankshaft 10 and the motor shaft. Cooperating with the flywheel 21 at the front end of the crankshaft 10, the engine crankshaft 10 has high anti-torsion ability; by arranging a connection part inside the motor shaft, the axial space occupation of the motor shaft can be reduced, making the whole device more compact; the connection method is simple, the spline and the generator connection end bearing are cancelled, the number of components and the manufacturing complexity are reduced, and the cost is lowered.

[0160] Based on the above various specific embodiments, the diameter of the fastener 20 is smaller than the diameter of the connecting end of the crankshaft 10. The through hole is a stepped hole including a large-diameter hole and a small-diameter hole. The crankshaft 10 is connected to the large-diameter hole, and the fastener 20 is connected to the small-diameter hole. The end of the fastener 20 is threadedly connected to the threaded hole on the end face of the crankshaft 10, which not only connects the crankshaft 10 and the motor shaft with the fastener 20, but also provides better structural stability and strength. The small-diameter hole is in clearance fit with the fastener 20 to ensure the stability and safety of the fastener 20, and at the same time meet the requirements of assembly and operation.

[0161] Based on the above various specific embodiments, the large-diameter hole is a tapered hole with an outward-opening opening. The connecting end of the crankshaft 10 is a tapered shaft. The connecting end of the crankshaft 10 and the tapered surface of the large-diameter hole are in tapered surface fit. The torque transmission of the tapered surface connection is mainly through the static friction force generated by the combined pressure between the connection surfaces, that is, the pre-tightening force of the fastener 20 transmits the torque through the friction force between the tapered hole and the tapered shaft mating surfaces; the tapered surface fit can increase the contact area between the motor shaft and the crankshaft 10, achieve high-strength connection, cooperate with the connection of the motor shaft and the crankshaft 10 by the fastener 20 and the flywheel 21, and has high anti-torsion ability; the bearing structure at the generator connection end is cancelled, and the structure is simple.

[0162] Based on the above specific embodiments, an intermediate straight hole is provided between the small-diameter hole and the tapered hole. The diameter of the intermediate straight hole is equal to the small-end diameter of the tapered hole. The intermediate straight hole can ensure smoother tapered fitting assembly and higher fitting accuracy. When machining the tapered hole, it can be first bored into a straight hole according to the small-end diameter with a set allowance, eliminating the need for machining the stepped hole of the tapered hole, shortening the cutting time, and improving production efficiency.

[0163] A chamfer is provided at the end of the tapered hole. The chamfer can provide a smooth transition area, facilitating alignment and insertion during the assembly of the crankshaft 10, and reducing friction and damage during the assembly process.

[0164] Based on the above specific embodiments, a counterbore connected to the small-diameter hole is provided on the rear end face of the motor shaft. The bolt head of the fastener 20 is placed inside the counterbore. The counterbore can make the fastener 20 flush with or lower than the rear end face of the motor shaft. The fastener 20 is installed inside the motor shaft, reducing the protrusion on the appearance of the fastener 20, which is not only aesthetically pleasing but also improves the compactness of the assembly position.

[0165] Based on the above specific embodiments, the connecting hole is an internal threaded hole, and the connecting end of the crankshaft 10 has an external thread. The connecting end of the crankshaft 10 is threadedly connected to the connecting hole. Together with the threaded connection between the fastener 20 and the threaded hole of the crankshaft 10, the crankshaft 10 and the motor shaft are connected, realizing the dual connection of the crankshaft 10 and the motor shaft, strengthening the connection strength between the motor shaft and the crankshaft 10, and having a high torsional resistance.

[0166] Based on the above specific embodiments, the connecting hole and the connecting end of the crankshaft 10 are in interference fit. When there is a certain fastening force between the connecting hole and the crankshaft 10, the stability and load-bearing capacity of the connection can be ensured. Together with the threaded connection between the connecting end of the crankshaft 10 and the connecting hole and the threaded connection between the fastener 20 and the threaded hole of the crankshaft 10, the crankshaft 10 and the motor shaft are connected, realizing the multiple connection of the crankshaft 10 and the motor shaft, strengthening the connection strength between the motor shaft and the crankshaft 10, and having a high torsional resistance.

[0167] Based on the above specific embodiments, the connection length between the connecting end of the crankshaft 10 and the connecting hole accounts for one-third to one-half of the length of the motor shaft. The longer connection length between the connecting end of the crankshaft 10 and the connecting hole can provide a larger contact area, thereby more effectively transmitting torque and ensuring a higher power transmission efficiency between the generator and the crankshaft 10. The longer the interference fit connection length, the more contact points there are, and the higher the reliability of the fit, thus improving the overall stability of the connection. It can provide better compensation, reducing fitting problems caused by temperature changes. It can increase the stiffness and strength of the connection, reducing the risk of deformation or damage caused by external forces.

[0168] In this specification, the various embodiments are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts among the embodiments can be referred to each other.

[0169] The cooling device applied to the general-purpose engine provided by the present invention has been introduced in detail above. Specific examples are used herein to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A cooling device for a general purpose engine, characterized in that: The invention comprises a fan motor (3), an impeller (6) mounted on a rotating shaft of the fan motor (3), the impeller (6) facing an engine (2) to cool the engine (2); and a temperature control mechanism for controlling the rotation speed of the fan motor (3) according to the temperature of the engine (2).

2. The cooling device for a general purpose engine according to claim 1, characterized in that: The temperature control mechanism comprises: a temperature sensor for detecting the operating temperature of the engine (2); A temperature control unit connected to the temperature sensor and used to control the fan motor (3) to stop or operate at a low rotation speed when the temperature sensor detects that the current operating temperature of the engine (2) is lower than the optimal operating temperature range; and to control the fan motor (3) to operate at a high rotation speed when the temperature sensor detects that the current operating temperature of the engine (2) is higher than the optimal operating temperature range.

3. The cooling device for a general purpose engine according to claim 2, characterized in that: The negative terminal of the fan motor (3) is connected to the negative pole of the power supply, and the positive terminal of the fan motor (3) is connected to at least two branches, one of which is a high-speed branch connected to the positive pole of the fan motor (3), and the other is a low-speed branch connected to the positive pole of the fan motor (3), the low-speed branch is connected in parallel with the high-speed branch, and a speed regulating resistor (4) is connected to the low-speed branch. The temperature control unit comprises: A branch control module connected to the low-speed branch and the high-speed branch, and used to control the fan motor (3) to stop or connect the low-speed branch when it is detected that the current operating temperature of the engine (2) is lower than the optimal operating temperature range; and to control the fan motor (3) to connect the high-speed branch when the temperature sensor detects that the current operating temperature of the engine (2) is higher than the optimal operating temperature range.

4. The cooling device for a general purpose engine according to claim 3, characterized in that: The branch control module comprises: Relays for controlling the connection of the low-speed branch and the high-speed branch respectively; A selection component connected to the relay and used to control the relays to be completely turned off or to control the low-speed branch relay to be turned on when it is detected that the current operating temperature of the engine (2) is lower than the optimal operating temperature range; and to control the high-speed branch relay to be turned on when it is detected that the current operating temperature of the engine (2) is higher than the optimal operating temperature range.

5. The cooling device for a general purpose engine according to claim 4, characterized in that: The speed regulating resistor (4) is a sliding resistor, and a curve diagram corresponding to the working temperature of the engine (2) and the effective resistance of the sliding resistor is preset in the branch selection component, and the branch selection component includes: a resistance determination component for determining the effective resistance of the sliding resistor corresponding to the current operating temperature according to the current operating temperature of the engine (2) and the curve graph; A resistance driving component connected to the sliding resistor and used for driving the sliding resistor to adjust to an effective resistance position.

6. The cooling device for a general purpose engine according to claim 5, characterized in that: The resistance driving component comprises: A power assembly for providing power; A transmission component connected to the power component and used to realize the movement of the adjustment part of the sliding resistor.

7. The cooling device for a general purpose engine according to claim 2, characterized in that: The engine (2) is connected to an air guide cover (5), the fan motor (3) is connected to the air guide cover (5), the crankshaft of the engine (2) is connected to a flywheel, and a gap is provided between an end face of the impeller (6) and an end face of the flywheel.

8. The cooling device for a general purpose engine according to claim 7, characterized in that: The rotating shaft of the fan motor (3) is concentric with the crankshaft of the engine (2), and the end surface of the impeller (6) is parallel to the end surface of the flywheel.

9. The cooling device for a general purpose engine according to claim 7, characterized in that: It also includes a gap control mechanism for controlling the size of the gap between the impeller (6) and the flywheel according to the temperature of the engine (2).

10. The cooling device for a general purpose engine according to claim 9, characterized in that: The fan motor (3) is connected to a connection hole of the air guide cover (5), the fan motor (3) is movably connected to the connection hole, and the gap control mechanism comprises: A clearance control unit connected to the temperature sensor and used to adjust the impeller (6) and the flywheel to a large clearance when detecting that the current operating temperature of the engine (2) is lower than the optimal operating temperature range; and to adjust the impeller (6) and the flywheel to a small clearance when detecting that the current operating temperature of the engine (2) is higher than the optimal operating temperature range.

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