Electric power steering pump damping mechanism

Abstract

The utility model discloses a kind of electric power steering pump damping mechanisms, which belong to vehicle steering system technical field.It mainly includes steering assist pump and mounting bracket, damping rubber is equipped between steering assist pump and mounting bracket, steering assist pump, damping rubber and mounting bracket are fixedly connected by fastening assembly;Center hole for fastening assembly through is opened along its axial direction in damping rubber, the outside of center hole is equipped with multiple stiffness adjustment holes evenly distributed, the central axis of stiffness adjustment hole is parallel with the central axis of damping rubber.The utility model damping rubber produces variable stiffness characteristic when being stressed, stiffness gradually increases when being stressed compression, realize the stepless regulation of stiffness, can accurately match the vibration demand of different working conditions of steering assist pump, effectively absorb axial and radial vibration, greatly improve the whole car NVH level.The utility model is mainly used for the damping of vehicle steering system.

Description

Technical Field

[0001] This utility model belongs to the technical field of vehicle steering systems, and more specifically, it relates to a vibration damping mechanism for an electric power steering pump. Background Technology

[0002] Electric power steering pumps are a common component in automotive steering systems, primarily used to provide steering assistance and reduce the driver's hand strain. Currently, there are two main types of electric power steering pumps: electric gear pumps and electric vane pumps. During use, the electric power steering pump is fixed to the vehicle frame via a mounting bracket. A rubber sleeve isolates the mounting bracket from the pump, filtering vibrations and reducing noise. However, its stiffness curve has a large, single slope, meaning it cannot adjust its stiffness as vibration intensifies, resulting in poor vibration isolation.

[0003] Currently, rubber bushing structures are mainly integral cylindrical. In addition, patent CN216904543U discloses a motor damping structure for an automotive electric power steering system. This motor damping pad includes a rubber pad body, an upper cover integrally formed with the upper part of the rubber pad body, and a lower cover integrally formed with the lower part of the rubber pad body. The upper and lower covers are metal components and have threaded holes for connection with mounting bolts. The outer side of the motor damping pad has a wrench mating surface for use with a wrench. This damping structure exhibits strong metal-to-metal adhesion when installed with the motor and vehicle frame, preventing rubber distortion due to uneven stress between metal parts.

[0004] However, the above solution still has the following shortcomings: 1. The rubber pad body is a symmetrical cylindrical structure, and both it and the overall cylindrical rubber sleeve have the problem of large stiffness curve slope, resulting in poor vibration isolation effect; moreover, the stiffness curve slope is a single slope, which cannot change the stiffness as the vibration intensifies, making it difficult to guarantee the isolation of vibration under multiple frequency bands, resulting in large differences in the performance of the vehicle's NVH under different working conditions; 2. The radial vibration attenuation rate of the rubber pad body is low, which can easily cause resonance between the mounting bracket and the frame, and long-term use will aggravate bolt loosening and structural wear. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a vibration damping mechanism for an electric power steering pump. The damping rubber of the mechanism has variable stiffness characteristics when subjected to force, and the stiffness gradually increases when compressed, so as to realize stepless adjustment of stiffness. It can accurately match the vibration requirements of the power steering pump under different working conditions, effectively absorb axial and radial vibrations, and significantly improve the NVH level of the whole vehicle.

[0006] The electric power steering pump vibration damping mechanism includes a power steering pump and a mounting bracket. A damping rubber is provided between the power steering pump and the mounting bracket. The power steering pump, the damping rubber, and the mounting bracket are fixedly connected by a fastening assembly. A central hole for the fastening assembly to pass through is opened in the damping rubber along its axial direction. A plurality of uniformly distributed stiffness adjustment holes are provided on the outside of the central hole. The central axis of the stiffness adjustment holes is parallel to the central axis of the damping rubber.

[0007] Preferably, the radial cross-section of the central hole is a concave hexagonal structure, and there are six stiffness adjustment holes, which correspond to the edges of the concave hexagonal structure.

[0008] Preferably, the damping rubber has a groove in the middle along the circumferential direction, an upper ring platform is provided on one side of the groove, and a lower ring platform is provided on the other side of the groove, with a circular arc transition between the groove and the upper and lower ring platforms.

[0009] Preferably, the upper ring platform has a top step at the end away from the slot, and the outer side of the top step transitions to the upper ring platform with an arc; the lower ring platform has a bottom step at the end away from the slot, and the outer side of the bottom step transitions to the lower ring platform with an arc; the height of the top step is higher than that of the bottom step.

[0010] Preferably, the end faces of the top step and the bottom step are both flat, and the stiffness adjustment hole passes through the arc transition between the top step and the bottom step.

[0011] Preferably, the mounting bracket has mounting holes for engaging with the vibration damping rubber, and these holes correspond to the center hole.

[0012] Preferably, the fastening assembly includes a bolt, a washer, and an inner skeleton bushing. The inner skeleton bushing passes through a central hole, and the bolt passes through the washer, the damping rubber, the mounting bracket, and the inner skeleton bushing, and is threaded into the mounting seat of the power steering pump.

[0013] Preferably, three damping rubbers are provided between the power steering pump and the mounting bracket, and the three damping rubbers are respectively disposed on both sides and one end of the power steering pump.

[0014] Compared with the prior art, the beneficial effects of this utility model are: 1. The damping rubber has a concave hexagonal central hole and a circular stiffness adjustment hole that work together to produce variable stiffness characteristics under stress. The stiffness gradually increases under compression, achieving stepless stiffness adjustment. That is, it has low stiffness under small vibrations and high stiffness under large vibrations, thus accurately matching the vibration requirements of the power steering pump under different operating conditions. It effectively absorbs axial and radial vibrations, significantly reduces the transmission of vibration to the vehicle body, optimizes the overall vehicle noise, vibration and acoustic roughness performance, and improves driving comfort.

[0015] 2. Multiple stiffness adjustment holes are located on the outside of the central hole, which can significantly reduce the radial stiffness of the damping rubber, improve vibration isolation efficiency, and enhance the overall vehicle comfort performance.

[0016] 3. The vibration damping rubber adopts a stepped design at both ends, and the stiffness adjustment hole has a variable cross-section structure at both ends. This makes the vibration damping rubber have a small axial stiffness when small axial vibrations occur. As the vibration increases, the axial stiffness gradually increases, further realizing stepless adjustment of stiffness. At the same time, the length of the stiffness adjustment hole is maximized, which improves the range of radial stiffness adjustment.

[0017] 4. The inner skeleton bushing in the fastening assembly enhances the load-bearing strength of the central hole, preventing the bolts from crushing the rubber, and the gasket disperses the preload to prevent local damage; the three vibration damping rubbers form a triangular support, evenly bearing the weight of the booster pump and the vibration load, preventing the booster pump from tilting or vibration from concentrating, preventing the failure of a single vibration damping rubber due to overload, and ensuring the long-term stable operation of the mechanism. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a side view of the present invention. Figure 3 for Figure 2 A schematic diagram showing the distribution of the three damping rubbers in the middle; Figure 4 This is a schematic diagram showing the disassembled parts of this utility model; Figure 5 A disassembled diagram showing the mounting bracket, vibration damping rubber, and fastening components; Figure 6 A schematic diagram of the top structure of the vibration-damping rubber; Figure 7 This is a schematic diagram of the bottom structure of the vibration-damping rubber.

[0019] In the diagram, 1. Power steering pump; 2. Vibration damping rubber; 201. Lower ring platform; 202. Slot; 203. Upper ring platform; 204. Top step; 205. Center hole; 206. Stiffness adjustment hole; 207. Bottom step; 3. Mounting bracket; 301. Mounting hole; 4. Bolt; 5. Washer; 6. Inner frame bushing. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings: The directional terms used in the detailed description paragraphs are only for the convenience of those skilled in the art to understand the technical solutions described in this application based on the visual orientation shown in the accompanying drawings. Unless otherwise expressly specified and limited, the terms "setting," "installation," "connection," etc., should be interpreted broadly, and those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0021] like Figures 1 to 7 As shown, an electric power steering pump vibration damping mechanism includes a power steering pump 1 and a mounting bracket 3. The power steering pump 1 contains a rotary motor for providing steering assistance to the vehicle. During use, the rotational speed of the rotary motor changes with different operating conditions, causing the power steering pump 1 to vibrate, and the magnitude of the vibration also changes continuously. Therefore, a vibration damping mechanism is needed for real-time vibration isolation. In this embodiment, a damping rubber 2 is provided between the power steering pump 1 and the mounting bracket 3. The mounting bracket 3 serves as a connecting carrier, with one end fixed to the vehicle frame and the other end supporting the power steering pump 1 through the damping rubber 2, thereby limiting excessive displacement of the power steering pump 1. The damping rubber 2 can absorb the vibration generated by the power steering pump 1 during operation in real time, blocking the transmission of vibration to the mounting bracket 3 and the vehicle body. During installation, the power steering pump 1, the damping rubber 2, and the mounting bracket 3 are fixedly connected by a fastening assembly. The fastening assembly can achieve a rigid connection between the three, ensuring assembly stability and preventing relative loosening of the power steering pump 1, the damping rubber 2, and the mounting bracket 3 when the vehicle is bumpy. At the same time, it avoids the damping rubber 2 from failing due to excessive vibration displacement.

[0022] The damping rubber 2 has a central hole 205 along its axial direction for the fastening component to pass through. The central hole 205 provides an axial passage for the fastening component, ensuring that the fastening component and the damping rubber 2 are coaxially assembled, and avoiding uneven force on the damping rubber 2 due to misalignment. In this embodiment, the radial cross section of the central hole 205 is a concave hexagonal structure, that is, the six sides of the hexagon are concave arc structures, which can generate variable stiffness characteristics when subjected to force.

[0023] Multiple evenly distributed stiffness adjustment holes 206 are provided on the outer side of the central hole 205. The stiffness adjustment holes 206 adjust the stiffness by changing the effective bearing area of ​​the damping rubber 2, thereby reducing radial stiffness, improving vibration isolation efficiency, and enhancing the overall vehicle comfort performance. The stiffness adjustment holes 206, in conjunction with the central hole 205, can gradually increase stiffness under compression, achieving stepless stiffness adjustment. That is, low stiffness for small vibrations and high stiffness for large vibrations, ensuring radial stepless variable stiffness adjustment that matches the magnitude of vibration, significantly improving the overall vehicle NVH level.

[0024] The uniform distribution of stiffness adjustment holes 206 ensures consistent circumferential stiffness of the damping rubber 2, avoiding eccentric vibration caused by local stress concentration. The central axis of the stiffness adjustment holes 206 is parallel to the central axis of the damping rubber 2, ensuring that the main force direction of the stiffness adjustment holes 206 is consistent with the main bearing direction (axial direction) of the damping rubber 2, avoiding torsional stress caused by rubber deformation due to the inclination of the hole axis, and extending the service life of the rubber.

[0025] In this embodiment, there are six stiffness adjustment holes 206, and the stiffness adjustment holes 206 correspond to the edge lines of the concave hexagonal structure, so that the stiffness adjustment holes 206 are evenly and symmetrically distributed in the circumferential direction and aligned with the edge lines of the hexagon, ensuring that the influence of each adjustment hole on the stiffness of the rubber is consistent, further optimizing the uniformity of stiffness in the circumferential direction, and avoiding the steering power pump 1 from wobbling vibration due to uneven stiffness.

[0026] The mounting bracket 3 has mounting holes 301 for engaging with the damping rubber 2. The mounting holes 301 are used to radially fix the damping rubber 2 on the mounting bracket 3, preventing the damping rubber 2 from moving laterally with the vibration of the power steering pump 1 and ensuring the radial stability of the overall mechanism. The mounting holes 301 correspond to the center hole 205, ensuring that the fastening components can pass through the mounting holes 301 and the center hole 205 coaxially when installed, avoiding the damping rubber 2 from being subjected to lateral forces due to misalignment of the holes during assembly, and preventing the rubber from twisting and deforming.

[0027] like Figure 6 and Figure 7 As shown, a groove 202 is provided in the middle of the damping rubber 2 along the circumferential direction. The groove 202 facilitates a snap-fit ​​with the mounting hole 301 of the mounting bracket 3, realizing the radial positioning of the damping rubber 2 on the mounting bracket 3, preventing the damping rubber 2 from shifting laterally with the power steering pump 1 when the vehicle is moving, and ensuring the stability of the assembly position. An upper ring platform 203 is provided on one side of the groove 202. The upper ring platform 203 is used to fit against the end face of the mounting hole of the mounting bracket 3, thereby increasing the contact area with the damping rubber 2. The larger the contact area, the shorter the vibration transmission path. The more evenly the vibration damping effect is dispersed, the better, while avoiding excessive local pressure that could cause the rubber to crush. On the other side of the slot 202, there is a lower ring platform 201. The slot 202 and the upper ring platform 203 and the lower ring platform 201 are connected by a rounded transition. The end face of the mounting hole that fits with the upper ring platform 203 is also a rounded transition. This can eliminate the stress concentration points at sharp corners on the rubber structure. When the vibration damping rubber 2 is deformed by force, tearing stress is easily generated at sharp corners. The structure with rounded transition can disperse the stress to the curved area, thus extending the fatigue life of the vibration damping rubber 2.

[0028] The upper ring platform 203 has a top step 204 at the end away from the slot 202, and the outer side of the top step 204 transitions to the upper ring platform 203 with an arc. The lower ring platform 201 has a bottom step 207 at the end away from the slot 202, and the outer side of the bottom step 207 transitions to the lower ring platform 201 with an arc. The height of the top step 204 is higher than that of the bottom step 207, which provides more space for vibration reduction and deformation on the side of the power steering pump 1 mounting base. At the same time, the bottom step 207 restricts the excessive compression of the vibration damping rubber 2, thereby achieving a balance between vibration reduction effect and installation space adaptability. During manufacturing, the end face diameter of the top step 204 is smaller than the diameter of the upper ring platform 203, and the end face diameter of the bottom step 207 is smaller than the diameter of the lower ring platform 201. The top step 204, by fitting with the baffle of the inner skeleton bushing 6, and the bottom step 207, by fitting with the gasket 5, provide axial limiting for the power steering pump 1 mounting base and the mounting bracket 3, respectively, limiting excessive axial compression of the vibration damping rubber 2, while ensuring the stability of the axial distance between the power steering pump 1 and the mounting bracket 3. The rounded transition on the outer side of the step further eliminates stress concentration at sharp corners, preventing the rubber from cracking due to repeated deformation caused by vibration at the junction of the step and the ring platform.

[0029] like Figure 5 As shown, the fastening assembly includes a bolt 4, a washer 5, and an inner skeleton bushing 6. The bolt 4 provides sufficient preload. The washer 5 is fitted between the head of the bolt 4 and the damping rubber 2, increasing the bearing area of ​​the bolt head and preventing the bolt head from directly damaging the rubber surface. It also disperses the preload and prevents excessive local stress. The inner skeleton bushing 6 passes through the central hole 205. A baffle is fixed to one end of the inner skeleton bushing 6. The inner skeleton bushing 6 enhances the load-bearing capacity of the central hole 205 and prevents the bolt 4 from directly contacting the central hole 205 of the damping rubber 2, thus preventing the bolt 4 from wearing down the inner wall of the rubber when vibrating. During installation, the bolt 4 passes through the washer 5, the damping rubber 2, the mounting bracket 3, and the inner skeleton bushing 6, and engages with the threaded mounting of the power steering pump 1.

[0030] Both the top step 204 and the bottom step 207 have flat end faces. The flatness increases the contact area with the gasket 5 and the inner skeleton bushing 6, further dispersing the contact pressure while ensuring the accuracy of axial positioning. The stiffness adjustment hole 206 passes through the arc transition between the top step 204 and the bottom step 207. This creates a variable cross-section structure at both axial ends, allowing the damping rubber 2 to have low axial stiffness when experiencing small axial vibrations. As vibration increases, the axial stiffness gradually increases, achieving stepless stiffness adjustment and ensuring that the stiffness matches the vibration magnitude. Simultaneously, maximizing the length of the stiffness adjustment hole 206 improves the range of radial stiffness adjustment.

[0031] like Figures 2 to 4As shown, three damping rubbers 2 are provided between the power steering pump 1 and the mounting bracket 3, forming a triangular support structure. This structure can evenly bear the weight and vibration load of the power steering pump 1 at three points, preventing the power steering pump 1 from tilting and causing concentrated vibration. During installation, it is preferable to place the three damping rubbers 2 on both sides of the power steering pump 1 and the end closest to the power output, thereby covering the main vibration transmission area of ​​the power steering pump 1. This ensures that the vibration load borne by each damping rubber 2 is more even, preventing the failure of a single damping rubber 2 due to overload, and improving the overall vibration damping efficiency.

[0032] During installation, the three damping rubbers 2 are first installed in the mounting holes 301 of the mounting bracket 3, so that the slots 202 engage with the mounting holes 301, and the top step 204 is positioned opposite to the power steering pump 1. The inner frame bushing 6 passes through the center hole 205, and the baffle at one end of the inner frame bushing 6 abuts against the top step 204. The bolt 4 passes through the washer 5 and passes through the damping rubbers 2 and the inner frame bushing 6 from one end of the bottom step 207, and finally is threadedly connected to the mounting seat of the power steering pump 1.

[0033] In use, the mounting bracket 3 is connected to the car frame. After the power steering pump 1 is started, it vibrates. Since the radial section of the central hole 205 is a concave hexagon, the arc edge will deform to different degrees depending on the magnitude of the vibration when subjected to force. That is, under small vibration, the arc edge deforms less, the overall stiffness of the damping rubber is low, and it can flexibly buffer high-frequency small-amplitude vibrations, such as the vibration of the power steering pump when it is running at low speed. Under large vibration, the arc edge deforms more, the concave structure gradually becomes flatter, the effective bearing area of ​​the rubber increases, and the stiffness increases accordingly. It can stably resist low-frequency large-amplitude vibrations, such as the vibration caused by the high-speed operation of the power steering pump or road bumps.

[0034] Meanwhile, six stiffness adjustment holes 206 evenly distributed on the outer side of the central hole 205 reduce radial stiffness by decreasing the effective bearing area of ​​the damping rubber, thereby improving radial vibration isolation efficiency. Simultaneously, the stiffness adjustment holes 206 penetrate the arc transition between the top step 204 and the bottom step 207, forming a variable cross-section structure in the axial direction. Under small axial vibrations, the variable cross-section deforms flexibly, resulting in low axial stiffness and rapid vibration absorption. Under large axial vibrations, the deformation at the variable cross-section is limited by the hole wall, and the axial stiffness gradually increases, preventing excessive rubber compression failure. In other words, through the cooperation of the central hole 205 and the stiffness adjustment holes 206, the stiffness of the damping rubber 2 gradually increases under compression, achieving real-time matching between stiffness and vibration magnitude. Whether the power booster pump is idling or under high load, optimal vibration damping effect can be maintained, significantly reducing vibration transmission rate and improving the overall vehicle NVH level.

[0035] Finally, although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. 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. A vibration damping mechanism for an electric power steering pump, comprising a power steering pump (1) and a mounting bracket (3), characterized in that: A damping rubber (2) is provided between the power steering pump (1) and the mounting bracket (3). The power steering pump (1), the damping rubber (2) and the mounting bracket (3) are fixedly connected by a fastening assembly. A central hole (205) for the fastening assembly to pass through is provided in the damping rubber (2) along its axial direction. A number of uniformly distributed stiffness adjustment holes (206) are provided on the outside of the central hole (205). The central axis of the stiffness adjustment hole (206) is parallel to the central axis of the damping rubber (2).

2. The vibration damping mechanism for the electric power steering pump according to claim 1, characterized in that: The radial section of the central hole (205) is a concave hexagonal structure, and there are six stiffness adjustment holes (206), which correspond to the edges of the concave hexagonal structure.

3. The vibration damping mechanism for the electric power steering pump according to claim 2, characterized in that: The damping rubber (2) has a groove (202) in the middle along the circumferential direction. An upper ring platform (203) is provided on one side of the groove (202), and a lower ring platform (201) is provided on the other side of the groove (202). The groove (202) is connected to the upper ring platform (203) and the lower ring platform (201) by a circular arc transition.

4. The electric power steering pump vibration damping mechanism according to claim 3, characterized in that: The upper ring platform (203) is provided with a top step (204) at the end away from the slot (202), and the outer side of the top step (204) is connected to the upper ring platform (203) by an arc; the lower ring platform (201) is provided with a bottom step (207) at the end away from the slot (202), and the outer side of the bottom step (207) is connected to the lower ring platform (201) by an arc, and the height of the top step (204) is higher than that of the bottom step (207).

5. The electric power steering pump vibration damping mechanism according to claim 4, characterized in that: The end faces of the top step (204) and the bottom step (207) are both flat, and the stiffness adjustment hole (206) passes through the arc transition between the top step (204) and the bottom step (207).

6. The electric power steering pump vibration damping mechanism according to claim 5, characterized in that: The mounting bracket (3) has a mounting hole (301) for engaging with the vibration damping rubber (2) and is corresponding to the center hole (205).

7. The electric power steering pump vibration damping mechanism according to any one of claims 1 to 6, characterized in that: The fastening assembly includes a bolt (4), a washer (5), and an inner frame bushing (6). The inner frame bushing (6) passes through a central hole (205), and the bolt (4) passes through the washer (5), the damping rubber (2), the mounting bracket (3), and the inner frame bushing (6), and is threaded into the mounting seat of the power steering pump (1).

8. The electric power steering pump vibration damping mechanism according to claim 7, characterized in that: Three damping rubbers (2) are provided between the power steering pump (1) and the mounting bracket (3), and the three damping rubbers (2) are respectively located on both sides and one end of the power steering pump (1).

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