Oil pump assembly for a dht and method of operation thereof

Abstract

A hydraulic pump assembly for DHT (Diverterless Hydrodynamic) and its operating method are disclosed, belonging to the field of vehicle transmission technology. The assembly includes a top cover assembly stacked along the assembly axis for integrating oil supply and hydraulic control functions; a valve body partition for orderly isolation of multiple hydraulic channels; a reaction support for supporting the integrated oil circuit and providing one-way protection; and fixing bolts for locking and securing. The top cover assembly, using the valve body top cover as its mounting base, integrates an electromagnetic switching valve, a temperature sensor, a pressure regulating valve, a locating pin, a flow divider valve, and a mechanical pump rotor assembly. The valve body partition employs a customized partition structure matched to the internal oil circuit layout. The reaction support, using the lower valve body plate as its mounting base, is equipped with a cup-shaped plug and a one-way valve assembly. This invention shortens the oil circuit path, reduces system leakage points and hydraulic pressure loss, and improves the control response speed and operational stability of the hydraulic system.

Description

Technical Field

[0001] This invention relates to an oil pump assembly for DHT and its working method, belonging to the field of vehicle transmission technology. Background Technology

[0002] The DHT (Dual-Hybrid Transmission) oil pump is the core power source of the hydraulic system, responsible for providing pressurized oil to the transmission system and completing the functions of oil supply, lubrication and cooling. Its performance directly determines the working efficiency and operational reliability of the transmission.

[0003] Currently, mainstream transmission oil pumps are mainly divided into two categories: mechanical fixed displacement pumps and electric / variable displacement pumps. Fixed displacement pumps have a simple structure and low manufacturing cost, but their output flow passively changes with the speed, resulting in large overflow losses and high system energy consumption under low load conditions. Variable displacement pumps and electric pumps can achieve on-demand oil supply and can adapt to the complex operating conditions of hybrid and new energy vehicles, but their adjustment mechanisms are complex, and they have many moving parts, resulting in defects such as easy jamming under high temperature conditions, easy leakage under high pressure conditions, and lagging control response.

[0004] In addition, existing oil pumps generally suffer from problems such as difficulty in cold start oil suction, susceptibility to oil impurities, large flow pulsation, and poor NVH performance. Furthermore, most existing oil pumps adopt a split structure, with the pump, control valve body, oil passages, and partitions arranged independently. This not only occupies a large amount of internal space in the transmission and results in a dispersed layout, hindering the overall compact and lightweight design of the transmission, but also leads to a large number of parts, complex mating surfaces and sealing links, cumbersome assembly processes, low production efficiency, and poor assembly consistency. The split structure also results in long oil passage paths and numerous transition joints, leading to significant hydraulic pressure loss, multiple system leakage points, and slow control response, directly affecting the transmission's shifting accuracy and hydraulic control stability. Independent installation of each component also results in insufficient system rigidity, low positioning accuracy, and susceptibility to vibration displacement and sealing failure during operation. Moreover, the poor component versatility necessitates rearranging the oil passages for different transmission models, significantly lengthening product development cycles and increasing manufacturing costs, becoming a core bottleneck restricting the performance improvement of DHT transmissions. Summary of the Invention

[0005] To address the problems existing in the background art, the present invention provides an oil pump assembly for DHT and its working method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: an oil pump assembly for DHT, comprising an upper cover assembly for integrating oil supply and hydraulic control functions, stacked along the assembly axis; a valve body partition for orderly isolation of multiple hydraulic channels; a reaction support for supporting integrated oil circuits and unidirectional protection functions; and fixing bolts for locking and fixing.

[0007] Furthermore, the fixing bolts include a first fastening assembly for locking the oil pump assembly as a whole to the transmission housing and a second fastening assembly for locking the upper cover assembly and valve body partition to the reaction support.

[0008] Furthermore, the upper cover assembly uses the valve body upper cover as the mounting base and integrates an electromagnetic switch valve for controlling the on / off of the clutch branch pressure oil, a temperature sensor for real-time oil temperature acquisition and signal feedback, a pressure regulating valve for stable regulation of system oil pressure and flow, a positioning pin for precise positioning of the assembly components, a flow divider valve for on-demand distribution of cooling oil flow, and a mechanical pump rotor assembly for realizing mechanical mode oil supply.

[0009] Furthermore, at least two sets of positioning pins are provided, respectively arranged between the upper cover assembly and the valve body partition, and between the valve body partition and the reaction support, to achieve precise positioning of the stacked components step by step.

[0010] Furthermore, the oil inlet of the diversion valve is connected to the main cooling oil circuit of the system, and the oil outlet of the diversion valve corresponds to the cooling branch of the component to be cooled, which is used to distribute the cooling oil flow of the drive motor and the generator as needed.

[0011] Furthermore, the mechanical pump rotor assembly adopts an offset pump body arrangement structure.

[0012] Furthermore, the valve body partition adopts a customized partition structure that matches the internal oil circuit layout, so as to ensure that the multiple hydraulic channels between adjacent stacked components do not interfere with each other.

[0013] Furthermore, the reaction support uses the lower plate of the valve body as the mounting base and is equipped with a bowl-shaped plug for sealing the oil circuit process hole and a one-way valve assembly for preventing backflow of oil in the inlet oil circuit of the electronic pump.

[0014] Furthermore, the conduction direction of the one-way valve assembly is such that the oil outlet of the electronic pump points to the internal main oil passage of the oil pump assembly body, which is used to realize one-way flow of oil and protect the electronic pump from high-pressure backflow impact.

[0015] The present invention provides a method for operating an oil pump assembly for a DHT (Digital Hydroelectric Power Supply), the method comprising the following steps:

[0016] S1. The controller collects the real-time operating condition parameters of the transmission and selects the corresponding oil supply mode according to the operating condition parameters. The oil supply mode includes two switchable modes: mechanical pump oil supply mode and electronic pump oil supply mode.

[0017] S2. By selecting the oil supply mechanism corresponding to the oil supply mode, pressurized oil is continuously supplied to the internal integrated oil circuit of the oil pump assembly;

[0018] S3. The pressurized oil entering the internal integrated oil circuit is controlled by the hydraulic control element integrated on the upper cover assembly to control the oil circuit opening and closing, regulate the system oil pressure and distribute the cooling flow, providing hydraulic drive, lubrication and cooling supply for the clutch, transmission components and heat-generating components of the DHT.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] This invention effectively solves the defects of existing DHT oil pumps' split layout, such as large space occupation, numerous parts, cumbersome assembly processes, and poor assembly consistency, by adopting an integrated structure in which the upper cover assembly, valve body partition, and reaction support are stacked. Through the integrated design of the internal oil circuit, the oil circuit path is significantly shortened, reducing system leakage points and hydraulic pressure loss, and improving the control response speed and operational stability of the hydraulic system. The distributed fastening structure and the coordinated setting of positioning pins improve the overall structural rigidity and assembly positioning accuracy of the oil pump assembly, avoiding vibration displacement and sealing failure problems during operation. Simultaneously, by adapting to dual oil supply modes and integrated hydraulic control components within the integrated structure, the oil pump's oil supply adaptability and control accuracy under different operating conditions are balanced, reducing system energy consumption and improving product versatility and operational reliability. This effectively overcomes the technical bottleneck of existing DHT oil pumps, which struggle to simultaneously meet the requirements of low energy consumption, high response, high reliability, and lightweight design. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention;

[0022] Figure 2 yes Figure 1 Exploded view;

[0023] Figure 3 This is a structural schematic diagram of the upper cover assembly;

[0024] Figure 4 This is a schematic diagram of a reaction support structure. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0026] An oil pump assembly for DHT includes an upper cover assembly 3 for integrating oil supply and hydraulic control functions, stacked along the assembly axis; a valve body partition 4 for orderly isolation of multiple hydraulic channels; a reaction support 5 for supporting integrated oil circuits and unidirectional protection functions; and a fixing bolt 2 for locking and securing.

[0027] The top cover assembly 3, valve body partition 4, and reaction support 5 are locked and fixed together by fixing bolts 2.

[0028] Furthermore, the fixing bolt 2 includes a first fastening component for locking the oil pump assembly to the transmission housing as a whole, and a second fastening component for locking the upper cover assembly 3 and the valve body partition 4 to the reaction support 5.

[0029] The first fastening component is a long external hexagonal bolt, and the second fastening component is a short internal hexagonal bolt. Multiple sets of fixing bolts 2 are evenly distributed along the circumference of the pump body. By tightening at multiple points evenly, the clamping force and sealing reliability of the pump body joint surface are effectively improved, the risk of high-pressure oil leakage is significantly reduced, and the sealing stability and structural integrity of the oil pump under continuous working conditions are ensured.

[0030] Long external hexagonal bolts pass through the through mounting holes opened on the upper cover assembly 3, valve body partition 4, and reaction support 5 in sequence. The ends of the bolts engage and lock with the preset threaded holes on the transmission housing, thus fixing the oil pump assembly to the transmission housing as a whole.

[0031] Short hex bolts pass through the corresponding mounting holes on the upper cover assembly 3 and the valve body partition 4 in sequence. The ends of the bolts engage and lock with the threaded holes on the reaction support 5, thus fastening the upper cover assembly 3, the valve body partition 4 and the reaction support 5 into an integrated structure.

[0032] Furthermore, the upper cover assembly 3 uses the valve body upper cover as the mounting base and integrates an electromagnetic switch valve 6 for controlling the on / off of the clutch branch pressure oil, a temperature sensor 7 directly integrated inside the transmission oil pump for real-time oil temperature acquisition and signal feedback, a pressure regulating valve 8 for stable regulation of system oil pressure and flow, a positioning pin 9 for precise positioning of assembly components to ensure relative position accuracy, prevent misalignment or offset during operation, improve assembly structural rigidity and assembly consistency, a flow divider valve 10 for on-demand distribution of cooling oil flow to ensure that both the drive motor and engine can obtain cooling flow that meets performance requirements, achieving balanced and reliable heat dissipation, and a mechanical pump rotor assembly 11 for mechanical mode oil supply.

[0033] The main body of the upper cover assembly 3 is the valve body upper cover. The lower surface of the valve body upper cover is machined with oil passage grooves with a preset direction. After the oil passage grooves are attached to the upper surface of the valve body partition 4, they form a closed hydraulic oil passage. The valve body upper cover integrates and installs a mechanical pump rotor assembly 11, an electromagnetic switch valve 6, a temperature sensor 7, a pressure regulating valve 8, and a flow divider valve 10.

[0034] The electromagnetic switch valve 6 is inserted into the first valve hole in the valve body cover. The oil inlet of the first valve hole is connected to the main oil circuit of the valve body cover, and the oil outlet of the first valve hole is connected to the clutch control branch oil circuit. The electrical control terminal of the electromagnetic switch valve 6 is electrically connected to the vehicle controller.

[0035] Temperature sensor 7 is inserted into the sensor mounting hole in the valve body cover. The sensor mounting hole is connected to the main oil circuit of the valve body cover. The detection end of temperature sensor 7 extends into the oil in the main oil circuit. The signal output end of temperature sensor 7 is electrically connected to the vehicle controller.

[0036] The pressure regulating valve 8 is inserted into the second valve hole opened in the valve body cover. The second valve hole is connected to the main oil circuit of the valve body cover. The valve core of the pressure regulating valve 8 is slidably fitted with the inner wall of the second valve hole. One end of the valve core is subjected to the oil pressure of the main oil circuit, and the other end of the valve core abuts against the pressure regulating spring. The other end of the pressure regulating spring abuts against the inner wall of the second valve hole. The axis of the pressure regulating spring coincides with the sliding axis of the valve core.

[0037] Furthermore, at least two sets of positioning pins 9 are provided, with the two sets of positioning pins 9 located at opposite corners of the pump body. They are respectively arranged between the mating surfaces of the upper cover assembly 3 and the valve body partition 4, and between the valve body partition 4 and the reaction support 5, to achieve precise positioning of the stacked components step by step.

[0038] The positioning pin 9 is a cylindrical pin, and its outer wall is fitted with the inner wall of the positioning pin hole corresponding to each component. One end of the positioning pin 9 is inserted into the positioning pin hole of the reaction support 5, and the other end passes through the corresponding positioning pin holes of the valve body partition 4 and the upper cover assembly 3 in sequence, limiting the relative position and coaxiality between the three.

[0039] Furthermore, the diversion valve 10 is inserted into the third valve hole opened in the valve body cover. The oil inlet of the diversion valve 10 is connected to the main cooling oil circuit of the system in the valve body cover, and the oil outlet of the diversion valve 10 corresponds to the cooling branch of the component to be cooled, which is used to distribute the cooling oil flow of the drive motor and the generator as needed.

[0040] Furthermore, the mechanical pump rotor assembly 11 adopts an offset pump body arrangement structure. Through the eccentric mounting structure of the pump body and the drive shaft, the tooth ratio and transmission ratio of the oil pump drive gear and the main shaft gear can be freely designed according to the working conditions of the transmission, without being limited by structural space and coaxial arrangement. This allows for flexible adjustment of the transmission ratio and oil supply characteristics to adapt to the working conditions of the transmission.

[0041] The mechanical pump rotor assembly 11 is installed within a rotor receiving cavity opened in the valve body cover, comprising an inner rotor and an outer rotor that mesh with each other. The inner rotor has an internal spline machined into its inner bore, which meshes with the external spline of the oil pump drive shaft for transmission. The outer wall of the outer rotor is clearance-fitted with the inner wall of the rotor receiving cavity, allowing it to rotate circumferentially along the inner wall of the cavity. The axis of the rotor receiving cavity is eccentrically positioned with respect to the axis of the oil pump drive shaft, forming an offset pump body structure. The oil inlet of the rotor receiving cavity is connected to the oil supply circuit of the transmission oil pan, and the oil outlet is connected to the main oil circuit of the valve body cover.

[0042] Furthermore, the valve body partition 4 adopts a customized partition structure that matches the internal oil circuit layout, providing a basis for the integrated design of complex oil circuits. This allows multiple hydraulic channels between adjacent stacked components to operate without interference, improving the feasibility and compactness of the oil circuit layout.

[0043] The valve body partition 4 is clamped between the upper cover assembly 3 and the reaction support 5. The partition plate has through oil holes that are connected to the oil passages on the upper and lower sides. The partition structure on the plate corresponds one-to-one with the oil passage grooves of the upper cover assembly 3 and the reaction support 5, isolating adjacent hydraulic oil passages and blocking the oil flow between different oil passages.

[0044] Furthermore, the reaction support 5 uses the lower plate of the valve body as the mounting base and is equipped with a bowl-shaped plug 12 for sealing the oil circuit process hole to achieve oil circuit sealing, prevent pressure oil leakage, and ensure the sealing performance and pressure stability of the hydraulic system, as well as a one-way valve assembly 13 for preventing backflow of oil in the inlet oil circuit of the electronic pump, ensuring the normal operation of the electronic pump and the safety of the system oil supply.

[0045] The main body of the reaction support 5 is the lower plate of the valve body. The upper surface of the lower plate of the valve body is machined with oil passage grooves with a preset direction. After the oil passage grooves are attached to the lower surface of the valve body partition 4, they form a closed hydraulic oil passage.

[0046] The lower plate of the valve body has a process hole formed by oil passage machining. A cup-shaped plug 12 is press-fitted into the process hole. The outer wall of the cup-shaped plug 12 is tightly fitted with the inner wall of the process hole, sealing the opening end of the process hole.

[0047] An electronic pump inlet oil passage is provided on the lower plate of the valve body. A one-way valve assembly 13 is installed in the electronic pump inlet oil passage. The valve seat of the one-way valve assembly 13 is interference-fitted with the inner wall of the oil passage.

[0048] Furthermore, the one-way valve assembly 13 is directed so that the oil outlet of the electronic pump points to the main oil passage inside the oil pump assembly body, which is used to realize the one-way flow of oil and protect the electronic pump from high-pressure backflow impact. The oil outlet of the electronic pump is connected to the inlet end of the oil inlet passage of the electronic pump.

[0049] The present invention provides a method for operating an oil pump assembly for a DHT (Digital Hydroelectric Power Supply), the method comprising the following steps:

[0050] S1. The controller collects the real-time operating condition parameters of the transmission and selects the corresponding oil supply mode according to the operating condition parameters. The oil supply mode includes two switchable modes: mechanical pump oil supply mode and electronic pump oil supply mode.

[0051] When the transmission is in normal operating condition, select the mechanical pump oil supply mode;

[0052] Select the electronic pump oil supply mode when the transmission is in start-stop, cold start, or low load conditions.

[0053] S2. By selecting the oil supply mechanism corresponding to the oil supply mode, pressurized oil is continuously supplied to the internal integrated oil circuit of the oil pump assembly;

[0054] When the mechanical pump oil supply mode is selected, the pressure oil supply is as follows: the oil pump drive shaft drives the inner rotor of the mechanical pump rotor assembly 11 to rotate. The inner rotor drives the outer rotor to rotate synchronously through tooth meshing. By utilizing the periodic volume change of the sealed cavity formed by the rotation of the inner and outer rotors, oil suction is completed in the low-pressure area and oil pressure is completed in the high-pressure area, and pressure oil is continuously supplied to the internal integrated oil circuit.

[0055] When the electronic pump oil supply mode is selected, the pressure oil supply is as follows: the controller sends a start command to the electronic pump, and the pressure oil output by the electronic pump enters the internal integrated oil circuit through the one-way valve assembly 13 in the forward direction. At the same time, the reverse cut-off function of the one-way valve assembly 13 prevents the oil from flowing back into the electronic pump.

[0056] S3, the pressurized oil entering the internal integrated oil circuit, through the hydraulic control element integrated on the upper cover assembly 3, completes the oil circuit on / off control, system oil pressure regulation and cooling flow distribution, providing hydraulic drive, lubrication and cooling supply for the clutch, transmission components and heat-generating components of DHT.

[0057] The hydraulic control and flow distribution specifically include:

[0058] The hydraulic drive control of the clutch is achieved by controlling the on / off of the clutch branch pressure oil and switching the oil circuit through the electromagnetic switch valve 6.

[0059] The oil pressure in the internal integrated oil circuit is regulated by the pressure regulating valve 8 to maintain stable system oil pressure and prevent system overpressure.

[0060] The pressure oil in the cooling oil circuit is distributed and regulated by the diversion valve 10, and the corresponding cooling flow is allocated to the components to be cooled as needed.

[0061] During operation, the temperature sensor 7 collects the oil temperature signal of the internal integrated oil circuit in real time and feeds the oil temperature parameters back to the controller, providing data basis for the selection of oil supply mode and adjustment of hydraulic parameters.

[0062] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0063] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An oil pump assembly for DHT, characterized in that: It includes an upper cover assembly (3) stacked along the assembly axis for integrating oil supply and hydraulic control functions, a valve body partition (4) for orderly isolation of multiple hydraulic channels, a reaction support (5) for supporting integrated oil circuits and unidirectional protection functions, and a fixing bolt (2) for locking and fixing.

2. The oil pump assembly for DHT according to claim 1, characterized in that: The fixing bolt (2) includes a first fastening component for locking the oil pump assembly to the transmission housing and a second fastening component for locking the upper cover assembly (3) and the valve body partition (4) to the reaction support (5).

3. The oil pump assembly for DHT according to claim 1, characterized in that: The upper cover assembly (3) uses the valve body upper cover as the mounting base and integrates an electromagnetic switch valve (6) for controlling the on / off of the clutch branch pressure oil, a temperature sensor (7) for real-time acquisition and signal feedback of oil temperature in the oil circuit, a pressure regulating valve (8) for stable regulation of system oil pressure and flow, a positioning pin (9) for precise positioning of assembly components, a flow divider valve (10) for on-demand distribution of cooling oil flow, and a mechanical pump rotor assembly (11) for realizing mechanical mode oil supply.

4. The oil pump assembly for DHT according to claim 3, characterized in that: At least two sets of positioning pins (9) are provided, respectively arranged between the mating surfaces of the upper cover assembly (3) and the valve body partition (4), and between the valve body partition (4) and the reaction support (5), to achieve precise positioning of the stacked components step by step.

5. An oil pump assembly for DHT according to claim 4, characterized in that: The inlet of the diverter valve (10) is connected to the main cooling oil circuit of the system, and the outlet of the diverter valve (10) corresponds to the cooling branch of the component to be cooled, and is used to distribute the cooling oil flow of the drive motor and the generator as needed.

6. An oil pump assembly for DHT according to claim 5, characterized in that: The mechanical pump rotor assembly (11) adopts an offset pump body arrangement structure.

7. An oil pump assembly for DHT according to claim 6, characterized in that: The valve body partition (4) adopts a customized partition structure that matches the internal oil circuit layout, so as to ensure that the multiple hydraulic channels between adjacent stacked components do not interfere with each other.

8. An oil pump assembly for DHT according to claim 4, characterized in that: The reaction support (5) is mounted on the lower plate of the valve body and is equipped with a bowl-shaped plug (12) for sealing the oil circuit process hole and a one-way valve assembly (13) for preventing backflow of oil in the inlet oil circuit of the electronic pump.

9. An oil pump assembly for DHT according to claim 8, characterized in that: The one-way valve assembly (13) is directed so that the oil outlet of the electronic pump points to the main oil passage inside the oil pump assembly body, which is used to realize one-way flow of oil and protect the electronic pump from high-pressure backflow impact.

10. A method of operating an oil pump assembly for DHT according to any one of claims 1-9, characterized in that: The method includes the following steps: S1. The controller collects the real-time operating condition parameters of the transmission and selects the corresponding oil supply mode according to the operating condition parameters. The oil supply mode includes two switchable modes: mechanical pump oil supply mode and electronic pump oil supply mode. S2. By selecting the oil supply mechanism corresponding to the oil supply mode, pressurized oil is continuously supplied to the internal integrated oil circuit of the oil pump assembly; S3. The pressure oil entering the internal integrated oil circuit completes the oil circuit on / off control, system oil pressure regulation and cooling flow distribution through the hydraulic control element integrated on the upper cover assembly (3), providing hydraulic drive, lubrication and cooling supply for the clutch, transmission components and heat-generating components of DHT.

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