Dual-bearing motor driving system with combined disc spring
By configuring a combined disc spring and dual bearings in the motor drive system of the automotive wire-controlled driving system, the problems of abnormal noise and wear during motor shaking, noise and zero position search are solved, and higher driving rigidity and consistency of zero point position are achieved.
Patent Information
- Application Number
- CN202510340860.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-21
- Publication Date
- 2025-06-13
AI Technical Summary
The existing automotive wire-controlled driving system is prone to motor shaking and noise when the large torque is output, and there are problems of abnormal noise, wear and damage during the zero position.
A dual-bearing motor drive system with a combined disc spring is adopted. By configuring a first bearing flange, a first bearing, a second bearing and a second bearing retaining ring at both ends of the rotor, the motor drive rigidity is increased; a first buffer member and a combined disc spring are arranged at the end of the rotor to absorb the impact of the wire master hitting the bottom of the cylinder, reducing structural strength, and preventing abnormal noise and wear.
It effectively reduces motor shaking and noise during large torque output, ensures the consistency of the zero position when the motor returns to zero, avoids metal collision between the wire master and the motor rotor boss, and completely solves the problem of hitting the cylinder bottom.
Smart Images
Figure CN120150414A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a technology in the field of automotive electro-hydraulic braking, specifically a dual-bearing motor drive system with a combined disc spring. Background Art
[0002] With the rapid development of vehicle intelligence and by-wire technology, electro-hydraulic braking systems have received attention. It is required that the electronic control part of the braking system has ultra-low noise, high safety and high reliability. The most critical control link is the motor zero position search. The current common solution is that the metal boss of the motor rotor rigidly touches the metal boss of the nut, completing the motor zero position search. As a result, every time the driver releases the pedal after braking during driving, and every time the electro-hydraulic braking system is powered on, the nut has to uniformly retract to the motor zero position, and the metal bosses of the motor rotor and the nut emit metal impact sounds, which is an NVH noise problem that needs to be solved in the industry. Especially in the case of unexpected power failure of the motor, the electric cylinder quickly releases pressure, the nut accelerates backward to the motor zero position, and directly impacts the metal boss of the motor rotor, that is, hits the bottom of the cylinder, resulting in functional failures of the motor and the braking system. In addition, since the hollow shaft rotor cannot be equipped with a bearing at the front end of the motor, a single bearing is generally configured at the end of the motor to form a rotor cantilever beam structure, which is prone to motor jitter and noise problems when large torque is output. Summary of the Invention
[0003] Aiming at the defects of motor jitter and noise during large torque output in the prior art, as well as abnormal sounds, wear and damage during the zero position search, the present invention proposes a dual-bearing motor drive system with a combined disc spring. By configuring a first bearing flange, a first bearing, a second bearing, and a second bearing retaining ring at both ends of the hollow rotor, the driving rigidity of the motor is increased, and the motor jitter and noise during large torque output are reduced. A first buffer member, a first disc spring, and a second disc spring are configured at the end of the rotor. On the one hand, the material strength of the disc spring itself can ensure that when the motor returns to zero, the nut will not deform or wear when it touches the disc spring, ensuring the consistency of the zero position. On the other hand, the overall structural strength of the rotor limit can be reduced, absorbing and buffering the impact of the nut hitting the bottom of the cylinder and completely solving the industry pain point of hitting the bottom of the cylinder.
[0004] The present invention is realized through the following technical solutions:
[0005] The present invention relates to a dual-bearing motor drive system with a combined disc spring, including: a housing, a stator, a rotor, a nut, and a lead screw sequentially arranged inside it, wherein: the rotor and the lead screw are respectively rotatably arranged in the housing and one end of the rotor is connected to the lead screw, the nut is movably arranged on the lead screw and axially limited by an anti-rotation sleeve; when the stator is powered on, the rotor drives the lead screw to rotate in the housing through forward and reverse rotations, and makes the balls roll simultaneously in the inner spiral raceway of the nut and the outer spiral raceway of the lead screw, and the nut commutator flows the balls forward and backward, and the lead screw drives the nut to rotate through rolling friction.
[0006] Three convex guide rails are arranged on the outer circumference of the nut and are matched with the grooves of the anti-rotation sleeve to prevent the nut from rotating. The axial component of the rolling friction force makes the nut move back and forth linearly along the lead screw.
[0007] The stator is rotatably arranged through a pair of bearing mechanisms respectively arranged on both sides inside the housing.
[0008] A first buffer is arranged on the lead screw to limit the displacement of the nut. The first buffer is provided with a through hole at the axis and is configured to form an interference fit with the outer circle at the lower end of the lead screw.
[0009] A pair of disc springs are further arranged on the lead screw to fix the position of the first buffer. At the same time, the bell mouth of the first disc spring is in full-circumference contact with the end face of the nut, and the outer edge of the bell mouth of the second disc spring is in full-circumference contact with the lower plane of the first buffer, respectively buffering the backward impact of the nut axially.
[0010] The end face of the first buffer fits with the conical mouth of the first disc spring to limit the axial movement of the first disc spring.
[0011] The end face of the tail end of the rotor fits with the outer edge of the conical mouth of the second disc spring to limit the axial movement of the second disc spring.
[0012] The anti-rotation sleeve and the valve block are connected and fixed by configuring three anti-rotation pins. The anti-rotation pins are provided with second buffers to buffer the impact of the nut and the anti-rotation sleeve during instantaneous commutation or start-up, and at the same time play the role of reducing noise.
[0013] An interference fit is formed between the lower cylinder of the anti-rotation pin and the hole of the valve block and is pressed in by riveting.
[0014] The upper end of the anti-rotation pin is provided with an outer stepped surface for clamping the anti-rotation sleeve, playing a role of fixing and limiting. Technical effects
[0015] While configuring a first bearing flange and a first bearing at the front end of the rotor to form a front support, a first buffer and a combined disc spring are configured at the end of the rotor in the present invention. Compared with the prior art, in the present invention, a first bearing and a first bearing are configured at the front end, which cleverly avoids the lead screw and the nut and can pass through the central hole of the first bearing flange. At the same time, the driving rigidity of the motor is increased, and the defects of pressure building jitter and noise of the existing motor are solved. Configuring the first buffer and the combined disc spring, on the one hand, the material strength of the disc spring itself can ensure that when the motor returns to zero, the rotor will not be deformed and worn when hitting the disc spring, ensuring the consistency of the zero position; on the other hand, the overall structural strength of the rotor limit can be reduced, and the impact of the nut hitting the cylinder bottom can be absorbed and buffered, solving the quality problems of abnormal noise, wear and breakage of the existing metal stop block structure. Description of the drawings
[0016] Figure 1 Schematic diagram of the two-dimensional cross-section of the present invention;
[0017] Figure 2 Schematic diagram of the three-dimensional structure assembly of the present invention;
[0018] Figure 3 Schematic diagram of the housing of the present invention;
[0019] Figure 4 Schematic diagram of the rotor of the present invention;
[0020] Figure 5 Schematic diagram of the first bearing flange of the present invention;
[0021] Figure 6 Schematic diagram of the first bearing of the present invention;
[0022] Figure 7 Schematic diagram of the first buffer member of the present invention;
[0023] Figure 8 Schematic diagram of the first disc spring of the present invention;
[0024] Figure 9 Schematic diagram of the second disc spring of the present invention;
[0025] Figure 10 Schematic diagram of the second bearing of the present invention;
[0026] Figure 11 Schematic diagram of the second bearing retaining ring of the present invention;
[0027] Figure 12 Schematic diagram of the anti-rotation sleeve of the present invention;
[0028] Figure 13 Schematic diagram of the second buffer member of the present invention;
[0029] Figure 14 Schematic diagram of the anti-rotation pin of the present invention;
[0030] Figure 15 Schematic diagram of the working of the embodiment;
[0031] Figure 16 Test curve graph of the actual cylinder bottom impact of the present invention;
[0032] In the figure: 1 power supply terminal, 2 housing, 3 first bearing flange, 4 first bearing, 5 rotor, 6 stator, 7 second bearing, 8 second bearing retaining ring, 9 dust-proof end cover, 10 flange nut, 11 lock washer, 12 second disc spring, 13 first buffer member, 14 first disc spring, 15 nut, 16 lead screw, 17 anti-rotation sleeve, 18 second buffer member, 19 anti-rotation pin, 20 valve block. Detailed implementation manners
[0033] As shown Figure 1 in the figure, this embodiment relates to a dual-bearing motor drive system with a combined disc spring, including: a housing 1, a stator 6, a rotor 5, a nut 15, and a lead screw 16 sequentially arranged inside it, where: the rotor 5 and the lead screw 16 are respectively rotatably arranged in the housing 1 and one end of the rotor 5 is connected to the lead screw 16, the nut 15 is movably arranged on the lead screw 16 and axially limited by an anti-rotation sleeve; when the stator is powered on, the rotor 5 drives the lead screw 16 to rotate in the housing by rotating in two opposite directions, and makes the balls roll in the spiral raceway inside the nut 15 and the spiral raceway outside the lead screw 16 at the same time. The ball flow commutator of the nut 15 flows the balls forward and backward, and drives the nut 15 to rotate through the rolling friction force of the lead screw 16;
[0034] Three convex guide rails are arranged on the outer circumference of the nut 15 to cooperate with the grooves of the anti-rotation sleeve to limit the movement of the nut, and the axial component of the rolling friction force makes the nut move back and forth linearly along the lead screw.
[0035] The anti-rotation sleeve 17 and the valve block 20 are fixedly connected by configuring three anti-rotation pins 19, and the anti-rotation pins 19 are sleeved with a second buffer 18 to buffer the impact of the nut 15 and the anti-rotation sleeve 17 during instantaneous commutation or startup, and at the same time play the role of reducing noise. The lower end cylinder of the anti-rotation pin 19 and the hole of the valve block 20 are configured as an interference fit and are pressed in by riveting. The upper end of the anti-rotation pin 19 is configured with an outer stepped surface for clamping the anti-rotation sleeve 17 to play a role of fixing and limiting.
[0036] The stator 6 is rotatably arranged by a pair of bearing mechanisms respectively arranged on both sides inside the housing 1, where: the first bearing 4 is arranged at the front end of the motor, and the inner hole of the housing 1 and the outer circle of the first bearing flange 3 are configured as an interference size and are fixedly connected by being pressed in by an external force; the second bearing 7 is arranged at the rear end of the motor, and the outer ring of the second bearing 7 and the housing 1 are configured as an interference fit and are fixedly connected by being pressed in by an external force.
[0037] The side step of the first bearing flange 3 fits with the outer ring end face of the first bearing 4 to limit the first bearing 4 from axially moving outward. At the same time, the inner hole of the first bearing flange 3 and the outer cylindrical surface of the first bearing 4 are configured as an interference fit and are fixedly connected by being pressed in by an external force to keep the outer ring of the first bearing 4 stationary; the inner ring of the first bearing 4 and the outer circle of the rotor 5 are configured as an interference fit and are pressed in by an external force to make the end face of the inner ring of the first bearing 4 fit with the shoulder of the rotor 5 to limit the first bearing 4 from axially moving inward.
[0038] The described second bearing retaining ring 8 is threadedly connected to the housing 1. The end face of the second bearing retaining ring 8 is in contact with the outer ring end face of the second bearing 7, restricting the second bearing 4 from axially moving outward; the inner ring of the second bearing 7 and the outer circle of the rotor 5 are configured to have an interference fit, and through external force pressing, the end face of the inner ring of the second bearing 7 is in contact with the shoulder of the rotor 5, restricting the second bearing 7 from axially moving inward.
[0039] A first buffer member 13 for restricting the displacement of the nut 15 is provided on the described lead screw 16. A through hole is provided at the axis of the first buffer member 13, and it is configured to have a transition fit with the lower outer circle of the lead screw 16.
[0040] A pair of disc springs are further provided on the described lead screw 16 to fix the position of the first buffer member 13. At the same time, the bell mouth of the first disc spring 14 is in full - circumference contact with the end face of the nut 15, and the outer edge of the bell mouth of the second disc spring 12 is in full - circumference contact with the lower plane of the first buffer member 13, axially buffering the backward impact of the nut 15 respectively.
[0041] One or more limiting notches are provided at the lower outer circle of the described lead screw 16. The limiting notches are configured to fit into the special - shaped holes of the first disc spring 14. A through hole is provided at the axis corresponding to the first disc spring 14 for fitting onto the lower end of the lead screw 16 and forming an interference fit to achieve circumferential limitation.
[0042] The end face of the described first buffer member 13 is in contact with the tapered mouth of the first disc spring 14 to restrict the first disc spring 14 from axially moving.
[0043] The described second disc spring 14 has a through hole at its axis. Two symmetric cylinders protrude downward from the lower plane of the corresponding first buffer member 13, pass through the two through holes of the second disc spring 12, and are inserted into the two blind holes at the tail end of the rotor 5, which can not only restrict the circumferential movement of the first disc spring 14 but also transmit torque between the first buffer member 13 and the rotor 5.
[0044] The end face of the tail end of the described rotor 5 is in contact with the outer edge of the tapered mouth of the second disc spring 12 to restrict the second disc spring 12 from axially moving.
[0045] As Figure 15 shown, the working process of this device is as follows: When the electronic brake system and the motor are powered on, the rotor 5 drives the first buffer member 13 and the lead screw 16 to rotate reversely, and the nut 15 retreats along the lead screw 16 until the boss of the nut 15 is in contact and limited by the outer side of the first disc spring 14, realizing the motor to find the zero position.
[0046] When the driver steps on the brake pedal, the wire-controlled brake controller receives the pedal displacement signal input by the pedal travel sensor, and drives the motor rotor 5 to drive the first buffer member 13 and the lead screw 16 to rotate forward. The nut 4 separates from the outer end face of the first disc spring 14 and advances along the lead screw 16. At this time, the electric cylinder starts to build pressure. After reaching the target output pressure, the rotor 5 stops rotating;
[0047] When the driver releases the brake pedal, the wire-controlled brake controller receives the pedal displacement signal input by the pedal travel sensor, and drives the motor rotor 5 to drive the first buffer member 13 and the lead screw 16 to rotate reversely. The nut 15 retreats along the lead screw 16. At this time, the electric cylinder starts to release pressure. After reducing to the target output pressure or dropping to 0 Bar, the nut 15 retreats to fit with the outer side surface of the first disc spring 14 or leaves a fixed distance;
[0048] When the motor accidentally loses power, there is no current input to the power terminal 1, the electromagnetic field generated by the stator 4 disappears, and the rotor 5 no longer provides torque output, so that the pressure of the electric cylinder is quickly released, pushing the nut 15 to accelerate and retreat along the lead screw 24 to the end of the motor. The boss of the nut 15 impacts and contacts the first disc spring 14, the first buffer member 13, and the second disc spring 12 in sequence, and completes buffering through the self-elastic deformation of the first disc spring 14 and the second disc spring 12 to protect the bottom of the rotor 4 cylinder from being damaged.
[0049] After specific actual experiments, in the case of accidental power loss of the motor, the electric cylinder quickly releases pressure, and the nut accelerates and retreats to the zero position of the motor. By using the first disc spring, the first buffer member, and the second disc spring, respectively, when the electric cylinder builds pressure to reach 16 Mpa, 17 Mpa, and 18 Mpa and then releases and impacts, the experimental data that can be obtained are: the deformation amounts of the disc spring assemblies are all 1.1 mm, which meet the elastic deformation design values and can well protect the nut and the motor.
[0050] The above specific implementation can be locally adjusted in different ways by those skilled in the art without departing from the principles and purposes of the present invention. The protection scope of the present invention is subject to the claims and is not limited by the above specific implementation. Each implementation within its scope is subject to the present invention.
Claims
1. A dual-bearing motor drive system with a combined disc spring, characterized in that: include: A housing, a stator, a rotor, a nut and a lead screw which are sequentially arranged inside the housing, wherein: the rotor and the lead screw are rotatably arranged in the housing respectively and the rotor is connected to one end of the lead screw, the nut is movably arranged on the lead screw and axially limited in an anti-rotation sleeve; when the stator is powered on, the rotor drives the lead screw to rotate in the housing by rotating in both forward and reverse directions, and makes the balls roll on the spiral raceway inside the nut and the spiral raceway outside the lead screw at the same time, the nut commutator makes the balls flow out forward and flow in backward, and the lead screw drives the nut to rotate by rolling friction.
2. The dual-bearing motor drive system with combined disc spring according to claim 1, characterized in that: The stator is rotatably arranged by a pair of bearing mechanisms respectively arranged on both sides of the shell.
3. The dual-bearing motor drive system with combined disc spring according to claim 1, characterized in that: The lead screw is provided with a first buffer for limiting the displacement of the nut. The first buffer is provided with a through hole at the axis center, which is configured to form a transition fit with the outer circle of the lower end of the lead screw.
4. The dual-bearing motor drive system with combined disc springs according to claim 1, characterized in that: A pair of disc springs are provided on the lead screw to fix the position of the first buffer. At the same time, the bell mouth of the first disc spring is in full contact with the end face of the nut, and the outer edge of the bell mouth of the second disc spring is in full contact with the lower end plane of the first buffer, respectively buffering the retreat impact of the nut along the axial direction.
5. The dual-bearing motor drive system with combined disc springs according to claim 1, characterized in that: The end surface of the first buffer member fits with the conical opening of the first disc spring to limit the axial movement of the first disc spring.
6. The dual-bearing motor drive system with combined disc springs according to claim 1, characterized in that: The tail end surface of the rotor is fitted with the outer edge of the conical opening of the second disc spring to limit the axial movement of the second disc spring.
7. The dual-bearing motor drive system with combined disc springs according to claim 1, characterized in that: The anti-rotation sleeve and the valve block are connected and fixed by configuring three anti-rotation pins. The anti-rotation pins are provided with a second buffer to buffer the impact of instantaneous reversal or startup of the nut and the anti-rotation sleeve, and at the same time have the effect of reducing noise.
8. The dual-bearing motor drive system with combined disc springs according to claim 1, characterized in that: An interference fit is formed between the cylinder at the lower end of the anti-rotation pin and the valve block hole, and the pin is pressed in through riveting.
9. The dual-bearing motor drive system with combined disc springs according to claim 1, characterized in that: The upper end of the anti-rotation pin is provided with an outer step surface for clamping the anti-rotation sleeve, which plays a role of fixing and limiting.