Variable flow coolant pump assembly for an internal combustion automotive engine

Abstract

The application discloses a variable flow coolant pump assembly for internal combustion engine of automobile, which comprises a belt pulley assembly, a drive shaft, a pump body, an impeller cover, an impeller and a thermostat. One end of the drive shaft is connected with the belt pulley assembly, and the other end is provided with the impeller. The impeller cover is arranged outside the impeller. A spring is arranged between the impeller cover and the pump body. One end of the spring is arranged on the end face of the pump body, and the other end of the spring is arranged on the impeller cover. The position of the impeller cover is moved by the coolant temperature. The output flow of the coolant pump is changed by the working movement position of the thermostat. The self-adaptive adjustment of the coolant output flow is realized. The coolant output flow is automatically adjusted to meet the heat dissipation demand of the engine under different working conditions of the engine, so that the best fuel economy of the engine is achieved, and the lubrication of the engine in the cold start stage is increased, and the friction loss is reduced.

Description

Technical Field

[0001] This invention relates to the field of coolant pumps for internal combustion engine vehicles, and in particular to a variable flow coolant pump assembly for internal combustion engine vehicles. Background Technology

[0002] In the automotive engine cooling system, the water pump is one of the core components. Its main function is to drive the coolant to circulate between the engine coolant channels, radiator and other components, to remove the excess heat generated during engine operation, and to ensure that the engine always operates within the optimal operating temperature range, thereby ensuring the engine's power performance, fuel economy and service life.

[0003] Currently, most coolant pumps used in automotive engines are constant-flow water pumps, meaning their output flow rate remains constant regardless of engine conditions such as cold start, idling, or high-speed driving. The pump's flow rate is directly proportional to the engine speed, and the pump itself cannot change its output flow rate. However, the engine's cooling requirements vary significantly under different operating conditions: During a cold start, the engine needs to warm up quickly to its normal operating temperature. At this time, a large amount of coolant circulation is not required. If the water pump continues to operate at a constant flow rate, it will result in slow engine warm-up, increased fuel consumption and exhaust emissions, and additional wear caused by poor lubrication. When the engine is running at high speed and under high load, it generates a large amount of heat, requiring a larger flow rate of coolant for cooling. In this case, if the flow rate of a constant-displacement water pump is too small, it often cannot meet the cooling requirements, easily leading to engine overheating, affecting normal engine operation, and even causing engine damage.

[0004] To address the aforementioned shortcomings of fixed-displacement water pumps, the industry has gradually developed variable-flow water pumps. By adjusting the circulation flow rate of the coolant, these pumps adapt to the cooling requirements of the engine under different operating conditions, achieving a balance between energy saving and efficient heat dissipation. Existing variable-flow water pumps often have complex flow regulation structures. Some use motors or solenoid valves to drive the regulation mechanism, which not only increases the manufacturing cost and installation difficulty but also suffers from insufficient reliability and increased energy consumption. Other variable-flow water pumps achieve output flow regulation through mechanical structures, but the regulation accuracy is low, and they often suffer from poor structural stability, cumbersome assembly, and high assembly failure rates, making it difficult to balance regulation performance and operational reliability.

[0005] refer to Figure 9 and Figure 10 The existing technology relies on hydraulic pressure to move the impeller cover and close the impeller output space. This structure cannot fully return the impeller cover after the return spring wears down. After long-term use, the ethylene glycol crystals in the coolant will increase the resistance of the guide structure, making it even more difficult for the return spring to return the impeller cover. The water pump will be in a low output flow state for a long time, resulting in high engine temperature.

[0006] Therefore, there is an urgent need for a variable output flow water pump assembly that is simple in structure, highly reliable, requires no external control, and has a reasonable orientation. Summary of the Invention

[0007] This invention proposes a simple and reliable variable output flow coolant pump assembly for internal combustion automotive engines, which solves the problems of poor adaptability of existing fixed displacement water pumps and complex structure and insufficient reliability of existing variable flow water pumps.

[0008] The technical solution of this invention is implemented as follows: A variable flow coolant pump assembly for an internal combustion engine includes a pulley assembly, a drive shaft, a pump body, and an impeller cover. The drive shaft is mounted on the pump body, with one end connected to the pulley assembly and the other end fitted with an impeller. The impeller cover is mounted on the outside of the impeller. An elastic element is provided between the impeller cover and the pump body, with one end mounted on the pump body end face and the other end abutting against the impeller cover. The impeller cover is characterized by: a guide sleeve mounted outside the drive shaft; an inner cylinder adapted to the guide sleeve to form an axially movable structure, allowing the inner cylinder to reciprocate along the length of the shaft; a fixed plate is mounted on the impeller cover, and a thermostat, which expands and contracts due to coolant temperature, is mounted on the fixed plate. The fixed plate is mounted on the pump body via a fixed post, and the lower section of the thermostat is mounted on the impeller cover, with the fixed end of the thermostat mounted on the fixed plate.

[0009] Preferably, at least two thermostats are provided, arranged symmetrically with respect to the drive shaft.

[0010] Preferably, the inner cylinder of the impeller cover is equipped with a bushing that can move flexibly outside the guide sleeve.

[0011] Preferably, there are four fixing posts, distributed on the four sides of the guide sleeve.

[0012] Preferably, the elastic element is fitted on the outside of one of the guide sleeve, impeller cover, fixed column, or thermostat, and the elastic element is a spring.

[0013] Preferably, in the initial state, the impeller cover forms a flow channel between the pump body and the impeller.

[0014] Working principle: When the coolant temperature rises, the thermostat core is heated by the coolant, and the internal paraffin expands, driving the ejector pin to extend. One end of the ejector pin is fixed to the mounting plate, and the thermostat core moves the entire impeller cover to a high position, where the water pump is at maximum flow output. When the coolant temperature drops, the elastic element (reset spring) pushes the impeller cover to a low position, where the water pump is at minimum output.

[0015] Power source: The impeller cover is driven by a thermostat core commonly used in internal combustion engine cooling systems. This design is simple in structure and highly reliable. A dual thermostat core drive system ensures that the impeller cover can still move even if a single thermostat core fails, improving reliability by an order of magnitude.

[0016] Guide structure: A guide sleeve is set on the outside of the drive shaft to avoid the high-speed rotating shaft, thus avoiding possible additional friction and interference to the shaft. A bushing is installed in the center of the impeller cover, and the bushing can move flexibly outside the guide sleeve. The guide structure is simple and reliable.

[0017] A key advantage over other variable flow coolant pumps is that they automatically adjust based on coolant temperature, eliminating the need for external control. (Currently, existing variable flow coolant pumps use a long control chain: temperature sensor - vehicle ECU - solenoid valve - hydraulic / pneumatic drive to move the impeller cover, resulting in an unreasonable guiding structure and high failure rate. External control also requires penetrating the pump housing, which can easily lead to leaks.)

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. Achieves precise coolant flow rate adjustment to adapt to the cooling needs of the engine under various operating conditions, resulting in significant energy savings and reduced consumption. This assembly, by incorporating a fixed plate and control components (thermostat) within the impeller housing, allows for flexible adjustment of the coolant circulation flow rate by moving the impeller housing via the thermostat. This effectively solves the problem of existing fixed-displacement water pumps having a fixed flow rate and being unable to adapt to different engine operating conditions. During engine cold starts, the impeller housing is in a low position, and the coolant pump is at its minimum output, helping the engine quickly warm up to normal operating temperature, reducing fuel consumption and exhaust emissions, and increasing lubrication to reduce friction loss during cold starts. During high-speed, high-load engine operation, the coolant flow rate can be automatically adjusted to increase, ensuring timely engine cooling and preventing overheating damage, thus balancing engine stability and energy efficiency.

[0019] 2. The flow regulation structure is simple and reliable, reducing manufacturing costs and assembly difficulty. This assembly preferably uses a thermostat core as the control component. The thermostat core is fixedly mounted on the impeller cover, and its moving end is connected to the impeller cover. No additional drive mechanism is required, resulting in a simple structure and convenient assembly. This not only reduces the manufacturing cost of the water pump but also avoids problems such as increased energy consumption and insufficient reliability caused by other drives. Furthermore, at least two thermostat cores are symmetrically arranged around the drive shaft, ensuring uniform force on the impeller cover and preventing displacement or jamming during adjustment. This further improves the smoothness and accuracy of flow regulation, ensuring long-term stable operation of the regulation structure. Moreover, this design incorporates a dual thermostat core drive. When one thermostat core fails, the other thermostat core can still drive the impeller cover to move, increasing the product's reliability by an order of magnitude.

[0020] 3. A guide structure is installed around the drive shaft on the pump body. The guide structure includes a guide sleeve. The impeller cover has a central hole through which the guide sleeve passes. A bushing is installed inside the central hole. The bushing and the impeller cover can move together outside the guide sleeve.

[0021] 4. Meanwhile, the mounting threaded holes of the fixing plate are set on all four sides, which can further improve the stress balance and movement stability of the impeller cover, thereby enhancing the overall structural stability and operational reliability of the water pump and extending the service life of the water pump.

[0022] In summary, this automotive variable flow water pump assembly features a simple structure, convenient assembly, and reliable adjustment. It not only solves many technical defects of existing water pumps but also effectively adapts to the heat dissipation needs of automotive engines under different operating conditions. It balances energy saving and consumption reduction with operational stability, making it highly practical and worthy of promotion. It can meet the development needs of automotive engines to quickly reach the optimal operating temperature during cold starts and to achieve efficient heat dissipation and energy saving during high-load operation. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of a variable flow coolant pump assembly for an internal combustion engine in this embodiment.

[0025] Figure 2 This is a schematic diagram of the drive shaft structure for a variable flow coolant pump assembly used in an internal combustion engine.

[0026] Figure 3 Planar structure for a variable flow coolant pump assembly for internal combustion engine vehicles Figure 1 .

[0027] Figure 4 for Figure 3 Cross-sectional view along the AA direction.

[0028] Figure 5 Planar structure for a variable flow coolant pump assembly for internal combustion engine vehicles Figure 2 .

[0029] Figure 6 for Figure 5 Cross-sectional view along the BB direction.

[0030] Figure 7 This is a schematic diagram of the mounting plate structure for the variable flow coolant pump assembly.

[0031] Figure 8 This is a schematic diagram showing the movement direction of the impeller cover of the variable flow coolant pump assembly.

[0032] Figure 9 This is a schematic diagram of a pump being de-energized in the prior art.

[0033] Figure 10 This is a schematic diagram of a conventional pump operating under power. Detailed Implementation

[0034] The following will refer to the appendices in the embodiments of the present invention. Figure 1-10 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Example

[0035] like Figure 1-8 As shown, this embodiment discloses a variable flow coolant pump assembly for an internal combustion engine, including a pulley assembly 100, a drive shaft 104, a pump body 101, and an impeller cover 102. The drive shaft 104 is mounted on the pump body 101. One end of the drive shaft 104 is connected to the pulley assembly 100, and the other end is mounted on an impeller 103. The impeller cover 102 is mounted on the outer side of the impeller. An elastic element 105 is provided between the impeller cover 102 and the pump body 101. One end of the elastic element 105 is mounted on the end face of the pump body 101, and the other end abuts against the impeller cover 102. Preferably, the elastic element 105 is a spring and is sleeved on the outer side of the drive shaft 104 to provide a uniform restoring force.

[0036] A guide sleeve 111 is mounted on the drive shaft 104, and the guide sleeve 111 is located outside the drive shaft 104. The impeller shroud 102 has an impeller shroud inner cylinder 110 that is adapted to the guide sleeve 111. Specifically, the inner diameter of the impeller shroud inner cylinder 110 is larger than the outer diameter of the guide sleeve 111, and the two are coaxially fitted. Further, a bushing 112 is installed on the inner wall of the impeller shroud inner cylinder 110, and the bushing 112 can move flexibly outside the guide sleeve 111. The bushing 112 is made of wear-resistant material, which ensures smooth movement and avoids direct contact between the impeller shroud inner cylinder 110 and the guide sleeve 111, thus preventing wear.

[0037] The thermostat 108 is fixedly installed on the impeller cover 102. The side wing 1082 of the thermostat is set on the countersunk hole 1021 opened in the impeller cover 102. The moving end 1081 of the thermostat is installed on the lower end face of the impeller cover. The thermostat is used as the control component of the impeller cover. By utilizing the temperature sensing characteristics of the core of the thermostat, the impeller cover can be automatically and accurately driven without the need for an additional power drive mechanism, which simplifies the flow regulation structure. A fixing plate 107 is mounted on the impeller cover 102, and the fixing plate 107 is mounted on the pump body 101 via fixing posts 106. Preferably, there are four fixing posts 106, evenly distributed at the four corners of the fixing plate 107 (circumferentially distributed with the drive shaft 104 as the center) to ensure a stable connection of the fixing plate 107. A thermostat 108, which expands and contracts in response to coolant temperature, is mounted on the fixing plate 107. The thermostat 108 is a wax-type thermostat core used in existing internal combustion engine cooling systems, filled with paraffin wax. When the temperature rises, the paraffin wax expands, pushing the ejector pin outwards; when the temperature drops, it contracts, causing the ejector pin to return to its original position. The lower section (i.e., the outer shell) of the thermostat 108 is mounted on the impeller cover 102, and the fixed end (i.e., the ejector pin end) of the thermostat 108 abuts against the fixing plate 107. In other words, the thermostat 108 connects the impeller cover 102 and the fixing plate 107. The fixing columns of the fixing plate are set on four sides, which can further improve the stress balance and movement stability of the impeller cover, thereby enhancing the overall structural stability and operational reliability of the water pump and extending the service life of the water pump.

[0038] To improve reliability, at least two thermostats 108 are provided, and they are arranged symmetrically with respect to the drive shaft 104. In this embodiment, two thermostats 108 are provided (e.g., Figure 2 As shown), they are located on the left and right sides of the drive shaft 104, respectively. The two thermostats 108 extend and retract synchronously, jointly driving the impeller cover 102 to move. Even if one thermostat fails, the other thermostat can still drive the impeller cover 102 to move, ensuring that the water pump's flow regulation function is not lost.

[0039] The initial state of this solution is as follows: Figure 8As shown, the impeller shroud has a flow channel F between the pump body and the impeller, meaning the area between the pump body and the impeller is not completely sealed. This is to allow a certain amount of coolant to flow in during low engine temperatures, preventing overheating of the engine due to insufficient coolant circulation and insufficient coolant temperature around the thermostat core in the variable flow water pump impeller shroud. The entire process is relatively smooth. If the coolant temperature rises, the thermostat will open the flow channel F wider, providing a larger coolant flow to the engine to help cool it down and prevent engine damage. Figure 9 and 10 The existing products have the drawback that, because they are actively controlled, the engine temperature can change rapidly in a short period of time, causing thermal shock to engine parts.

[0040] Work process When the water pump is working, the pulley assembly 100 drives the drive shaft 104 and the impeller to rotate. The impeller cover 102 is located outside the impeller. By changing the axial position of the impeller cover 102 relative to the impeller, the outlet cross section of the coolant can be changed, thereby adjusting the output flow rate.

[0041] When the coolant temperature rises, the paraffin inside the thermostat 108 expands due to heat, pushing the ejector pin outwards. Figure 8 As shown in the direction at point D. Because the ejector pin end abuts against the fixed plate 107 (the fixed plate 107 is fixed to the pump body 101 by the fixed column 106 and remains stationary), the outer casing of the thermostat 108 drives the impeller cover 102 to move away from the fixed plate 107. Figure 8 As shown, the impeller shroud 102 moves in the direction E, that is, it moves along the guide sleeve 111 towards the inside of the pump body 101. At this time, the elastic element 105 is compressed, the impeller shroud 102 is in a high position (away from the impeller 103), and the water pump is in the maximum flow output state. The bushing 112 of the inner cylinder 110 of the impeller shroud slides smoothly along the guide sleeve 111, without contacting the high-speed rotating drive shaft 104, thus avoiding friction and interference.

[0042] When the coolant temperature drops, the paraffin inside the thermostat 108 contracts, the ejector pin retracts, and simultaneously the restoring force of the elastic element 105 pushes the impeller cover 102 to move in the opposite direction. The impeller cover 102 returns to its original position, and the water pump operates at minimum flow rate, which facilitates rapid warm-up of the engine during cold starts.

[0043] The entire adjustment process is automatically controlled by the coolant temperature, requiring no external sensors, ECUs, or hydraulic / pneumatic lines. It features a simple structure and reliable sealing.

[0044] Based on the above embodiments, the elastic element 105 is not limited to a helical spring, but can also be a wave spring or a disc spring. The number of fixing columns 106 can be configured to three or six according to actual needs, as long as the fixing plate 107 can be firmly installed on the pump body 101. The number of thermostats 108 can also be three or four, evenly distributed around the drive shaft. The bushing 112 can be designed with a structure with lubrication grooves to further reduce friction.

[0045] Alternative solutions for the elastic element: In another feasible embodiment, the elastic element can also be fitted onto the outside of the impeller shroud inner cylinder. In this case, the spring fitted onto the impeller shroud inner cylinder has one end abutting against the impeller shroud body and the other end abutting against the corresponding step on the pump body, thus providing axial elastic force. In yet another alternative embodiment, the elastic element can be fitted onto the outside of the thermostat, i.e., the helical spring surrounds the thermostat housing, with the other end abutting against the corresponding step on the pump body; or in yet another alternative embodiment, the elastic element can be fitted onto the outside of the fixed column. All of the above arrangements can achieve the elastic pre-tightening and reset functions of the present invention and are equivalent substitutions of the present invention.

[0046] Finally, all components work in a closed loop: in the entire water pump assembly, the pulley assembly, drive shaft, and impeller constitute the power transmission and basic conveying mechanism; the elastic element ensures the impeller cover returns to its original position after the coolant temperature drops; the thermostat core and impeller cover constitute the flow regulation core; and the guide sleeve and bushing ensure precise adjustment and structural stability. Through the automatic sensing and adjustment of the thermostat core, the coolant flow rate can adapt to the engine operating conditions without manual or additional power intervention. This solves the compatibility defects of fixed displacement water pumps and takes into account energy saving, consumption reduction, and engine operating stability, achieving the goal of efficient and reliable water pump operation.

[0047] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural modifications made based on the description and drawings of the present invention, or direct / indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A variable flow coolant pump assembly for an internal combustion engine, comprising a pulley assembly, a drive shaft, a pump body, and an impeller cover, wherein the drive shaft is mounted on the pump body, one end of the drive shaft is connected to the pulley assembly, and the other end is mounted on an impeller, the impeller cover is mounted on the outside of the impeller, and an elastic element is provided between the impeller cover and the pump body, one end of the elastic element being mounted on the end face of the pump body, and the other end abutting against the impeller cover, characterized in that: A guide sleeve is installed outside the drive shaft. The impeller cover has an inner cylinder that fits the guide sleeve, forming an axial movement structure so that the inner cylinder of the impeller cover can reciprocate along the length of the shaft. A fixing plate is installed on the impeller cover. A thermostat that expands and contracts due to the temperature of the coolant is installed on the fixing plate. The fixing plate is installed on the pump body via a fixing column. The lower section of the thermostat is installed on the impeller cover, and the fixed end of the thermostat is installed on the fixing plate.

2. The variable flow coolant pump assembly for an internal combustion engine of an automobile according to claim 1, characterized in that: The thermostat is provided in at least two parts, arranged symmetrically with the drive shaft as the center.

3. The variable flow coolant pump assembly for an internal combustion engine of an automobile according to claim 1, characterized in that, The impeller cover inner cylinder is fitted with a bushing that can move flexibly outside the guide sleeve.

4. The variable flow coolant pump assembly for an internal combustion engine of an automobile according to claim 1, characterized in that, There are four fixed posts, distributed on the four sides of the guide sleeve.

5. The variable flow coolant pump assembly for an internal combustion engine of an automobile according to claim 1, characterized in that, The elastic element is fitted onto the outer side of one of the following: the inner cylinder of the impeller cover, the fixed column, or the thermostat. The elastic element is a spring.

6. The variable flow coolant pump assembly for an internal combustion engine of an automobile according to claim 1, characterized in that, In the initial state, the impeller cover forms a flow channel between the impeller and the pump body.

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