A novel synchronizer and synchronization method applicable to an electric drive axle and an electric vehicle

Abstract

The present invention discloses a novel synchronizer and a synchronization method applicable to an electric drive axle and an electric vehicle, which relates to the technical field of automotive transmissions and includes: a sliding sleeve, the inner side of which is coaxially engaged with a spline hub. The outer edge of the spline hub is recessed radially inward to form a mounting chamber, and a mounting seat is arranged in the mounting chamber and connected to the sliding sleeve; a pre-synchronization assembly is arranged in the mounting seat. During the electronic synchronization process, it is no longer necessary to achieve "zero rotational speed difference" and "zero angular displacement difference" between the sliding sleeve and the gear. When a preset rotational speed difference is reached between the sliding sleeve and the gear, the synchronization operation can be started. At the same time, the rotational speed of the sliding sleeve is adjusted, and the sliding sleeve is moved and docked in the direction of the engaging gear, shortening the synchronization time. When axial and angular impacts are generated when the sliding sleeve is engaged with the engaging gear, the impact can be offset by a spring, thereby greatly reducing the shift impact and improving the AMT shift quality of the electric drive axle.

Description

Technical Field

[0001] The invention relates to the technical field of automobile transmission, and in particular to a novel synchronizer and a synchronization method suitable for an electric drive axle and an electric vehicle. Background Art

[0002] The motors in electric vehicles and electric drive axles have excellent low-speed control capabilities and precise working mode switching capabilities. In order to simplify the structure, reduce manufacturing costs and improve integration, electric vehicles and electric drive axles are currently developing towards clutchless AMT (automatic mechanical transmission). The shift quality of clutchless AMT transmission is mainly reflected in the shift time and shift impact. Due to the defect of power interruption when AMT shifts, the shift time should be shortened as much as possible. However, shortening the shift time will bring greater shift impact. Therefore, while shortening the shift time, reducing the shift impact is the key to improving the shift quality of electric drive axle AMT.

[0003] Studies have shown that the speed synchronization phase accounts for nearly 50% of the entire shift time. Shortening the speed synchronization phase can significantly shorten the shift time.

[0004] The method of combining mechanical synchronization and electronic synchronization is the best speed synchronization method at present. The relative speed is actively controlled by the motor, while the synchronizer components inside the transmission are retained. Generally, the motor is used to control the pre-synchronization, so that the clutch and the gear gear reach "zero speed difference" and "zero angle difference", and then mechanical synchronization is used to achieve precise synchronization. It has the following defects:

[0005] ① The mechanical synchronization part directly uses the traditional synchronizer, which has a complex structure. In addition, the current electric vehicles have eliminated the clutch, resulting in large inertia and severe wear of the mechanical synchronizer.

[0006] ② The electronic synchronization part needs to meet the requirements of "zero speed difference" and "zero angle difference", which makes the electronic synchronization control algorithm complex and the precise synchronization control difficult, which in turn causes the shifting time to be prolonged.

[0007] In view of this, how to provide a synchronizer and a synchronization method that can shorten the time of the speed synchronization stage and reduce the gear shifting shock is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0008] The purpose of the present invention is to provide a new synchronizer and synchronization method suitable for electric drive axles and electric vehicles to solve the problems existing in the prior art.

[0009] To achieve the above object, the present invention provides a novel synchronizer suitable for an electric drive axle and an electric vehicle, comprising:

[0010] A sliding sleeve, whose inner side is coaxially engaged with a spline hub, and an installation chamber is formed by the outer edge of the spline hub being recessed radially inward; the sliding sleeve is in transmission connection with a shifting motor;

[0011] A gear for a gear position, a engaging gear is arranged on one side corresponding to the sliding sleeve, the sliding sleeve can move axially and engage with the engaging gear, and the gear for the gear position is in transmission connection with a driving motor; the spline hub is connected to a transmission shaft through a spline, and a bearing is arranged between the transmission shaft and the gear for the gear position;

[0012] A mounting seat, which is arranged in the installation chamber and connected to the sliding sleeve;

[0013] A pre-synchronization assembly, which is arranged in the mounting seat, its connecting end faces the engaging gear, and a convex tooth groove is formed on the side surface of the engaging gear corresponding to the connecting end; when the rotational speed difference between the sliding sleeve and the engaging gear reaches a preset rotational speed difference, the shifting motor drives the sliding sleeve to approach the engaging gear axially, the convex tooth groove rotates to a position corresponding to the connecting end, and the connecting end snaps into the convex tooth groove.

[0014] Further, the pre-synchronization assembly includes:

[0015] A pre-synchronization column, whose front end is the connecting end, and the tail end is connected to a spring washer through a spring;

[0016] A cavity adapted to the shape of the pre-synchronization column is defined in the mounting seat, the pre-synchronization column, the spring and the spring washer are all located in the cavity, the spring washer is fixedly connected to the mounting seat, and the front end of the pre-synchronization column extends out of the cavity.

[0017] Further, a clamping portion is arranged at the front end of the pre-synchronization column, the engaging gear is recessed radially inward to form the convex tooth groove, when the sliding sleeve approaches the engaging gear axially, the convex tooth groove rotates to a position corresponding to the clamping portion, and the clamping portion is engaged with the wall surface of the convex tooth groove.

[0018] Further, the angular width of the convex tooth groove is greater than the angular width of the clamping portion.

[0019] Further, the gear for the gear position includes a high-gear gear and a low-gear gear, the sliding sleeve is located between the high-gear gear and the low-gear gear, the clamping portion corresponding to the high-gear gear is inclined to the counterclockwise direction, and the clamping portion corresponding to the low-gear gear is inclined to the clockwise direction.

[0020] The present invention also provides a synchronization method applicable to an electric drive axle and an electric vehicle, applying the novel synchronizer applicable to an electric drive axle and an electric vehicle, including the following steps:

[0021] S1: The shift sleeve is in the neutral position. The drive motor adjusts the rotational speed of the engaging gear to the target rotational speed. Meanwhile, the shift motor drives the shift sleeve to move towards the engaging gear.

[0022] S2: The drive motor starts to release torque and does not actively output torque. When the rotational speed difference between the shift sleeve and the engaging gear reaches the preset rotational speed difference, the shift sleeve approaches the engaging gear, and the clamping portion of the pre-synchronization column snaps into the convex tooth groove and engages with the wall surface of the convex tooth groove. Then the drive motor starts to output torque.

[0023] S3: The drive motor continues to maintain the state of not actively outputting torque. The shift motor drives the shift sleeve to continue moving towards the engaging gear, and the spring compresses. The external gear ring of the engaging gear meshes with the shift sleeve, and the synchronization is completed.

[0024] Further, in step S1: The target rotational speed of the shift sleeve is ;

[0025]

[0026] wherein, is the resistance torque of the vehicle moving forward, is the equivalent moment of inertia at the output end of the electric drive axle.

[0027] Further, in step S2, the preset rotational speed difference is ;

[0028]

[0029] wherein, is the intermediate transmission ratio of the drive motor power output to the engaging gear, is the equivalent moment of inertia at the input end of the electric drive axle, is the output torque of the drive motor, is the resistance torque of the vehicle moving forward, is the equivalent moment of inertia at the output end of the electric drive axle. is the torque generated by the pre-synchronization of the pre-synchronization column and the engaging gear.

[0030] Further, in step S2, when the shift sleeve is in contact with the engaging gear and the convex tooth groove corresponds to the clamping portion, the clamping portion snaps into the convex tooth groove.

[0031] Further, in step S2, when the shift sleeve is in contact with the engaging gear and the convex tooth groove does not correspond to the clamping portion, the clamping portion contacts the side surface of the engaging gear. The engaging gear and the shift sleeve rotate relative to each other. When the convex tooth groove rotates to correspond to the clamping portion, the clamping portion snaps into the convex tooth groove.

[0032] The present invention discloses the following technical effects:

[0033] 1. A pre-synchronization component is embedded in the engaging sleeve. During the electronic synchronization process, it is no longer necessary to achieve "zero rotational speed difference" and "zero angular displacement difference" between the engaging sleeve and the gear. When the preset rotational speed difference is reached between the engaging sleeve and the gear, the synchronization operation can be started.

[0034] 2. The present invention adopts a method of simultaneously performing mechanical synchronization and electronic synchronization, that is, simultaneously adjusting the rotational speed of the engaging sleeve and moving and docking the engaging sleeve towards the engaging gear, which shortens the synchronization time.

[0035] 3. Regarding the shifting shock, the present invention adopts a pre-synchronization component composed of a pre-synchronization post, a spring, and a spring gasket. When the engaging sleeve is engaged with the engaging gear and generates axial and angular shocks, the spring can offset the shocks, thereby greatly reducing the shifting shock and improving the shifting quality of the electric drive axle AMT.

[0036] 4. Compared with the existing mechanical synchronization based on the friction principle, the present application adopts a synchronization structure and method in which the clamping part of the pre-synchronization post is clamped with the engaging gear, improving the power transmission efficiency and reducing the generation of heat in the electric drive axle. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0038] Figure 1 It is a schematic structural diagram of the present invention;

[0039] Figure 2 It is a schematic diagram of the cooperation of the high gear, the engaging gear, and the pre-synchronization component (after synchronization);

[0040] Figure 3 It is a schematic diagram of the cooperation of the pre-synchronization component, the spline hub, and the engaging sleeve (after synchronization);

[0041] Figure 4 It is a schematic diagram of the cooperation of the mounting seat and the pre-synchronization component;

[0042] Figure 5 It is a schematic diagram of the pre-synchronization component;

[0043] Figure 6 It is a schematic diagram of the installation of two groups of pre-synchronization components corresponding to the high gear and the low gear respectively;

[0044] Figure 7 It is an assembly sectional view of the engaging gear and the engaging sleeve;

[0045] Figure 8 It is a schematic diagram of the pre-synchronization column being inserted into the convex tooth groove;

[0046] Figure 9 It is a cross-sectional view of the structure after the engagement sleeve and the engagement gear are synchronized;

[0047] Figure 10 It is a schematic diagram of the pre-synchronization column and the engaging gear being connected when the pre-synchronization column and the convex tooth groove do not correspond to each other;

[0048] Figure 11 It is a structural schematic diagram when the convex tooth groove rotates relatively to correspond to the pre-synchronization column;

[0049] Among them, 1. coupling sleeve; 2. spline hub; 3. high gear; 4. low gear; 5. coupling gear; 501. convex tooth groove; 6. mounting seat; 7. pre-synchronization column; 701. clamping part; 8. spring; 9. spring gasket; 10. transmission shaft. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] The embodiment of the present invention provides a novel synchronizer suitable for an electric drive axle and an electric vehicle, comprising:

[0053] The outer side of the engagement sleeve 1 cooperates with the shifting operation structure, and the inner side is coaxially meshed with the spline hub 2. The outer edge of the spline hub 2 is radially concave to form a mounting chamber, and there are three mounting chambers that are evenly spaced. The engagement sleeve 1 is transmission-connected to the shifting motor, and the shifting motor is used to drive the engagement sleeve 1 to move toward the engagement gear 5.

[0054] The gear is provided with an engaging gear 5 on one side of the corresponding engaging sleeve 1. The engaging sleeve 1 can move axially and mesh with the engaging gear 5 to achieve the gear-engaging function. The gear is connected to the driving motor, and the driving motor can drive the gear to rotate. The spline hub 2 is connected to the transmission shaft 10 through the spline. Its function is to output the power transmitted by the coupling gear to the transmission shaft 10 through the spline, and also provide support for the entire synchronizer. A bearing is provided between the transmission shaft 10 and the gear.

[0055] The mounting base 6 is disposed in the mounting chamber and connected to the engaging sleeve 1;

[0056] The pre-synchronization assembly is disposed in the mounting base 6, and its connecting end faces the engaging gear 5. A convex tooth groove 501 is formed on the side surface of the engaging gear 5 corresponding to the connecting end. When the rotational speed difference between the engaging sleeve 1 and the engaging gear 5 reaches the preset rotational speed difference, the shift motor drives the engaging sleeve 1 to approach the engaging gear 5 axially, and the convex tooth groove 501 rotates to a position corresponding to the connecting end, and the connecting end is snapped into the convex tooth groove 501.

[0057] In this embodiment, the pre-synchronization assembly includes:

[0058] The pre-synchronization column 7, the front end of which is the connecting end, and the tail end is connected to the spring washer 9 through the spring 8; the spring 8 is a high-strength compression spring 8 and is connected to the pre-synchronization column 7 through a certain tension;

[0059] A cavity adapted to the shape of the pre-synchronization column 7 is defined in the mounting base 6. The pre-synchronization column 7, the spring 8 and the spring washer 9 are all located in the cavity. The spring washer 9 is fixedly connected to the mounting base 6 to help the spring 8 distribute the pressure evenly, avoid the failure or wear of the spring 8 caused by uneven pressure, and also reduce the friction between the spring 8 and the engaging gear 5 or other components, and extend the service life of the synchronizer. The front end of the pre-synchronization column 7 extends from the cavity to the outside to ensure that the front end of the pre-synchronization column 7 can be in contact with the engaging gear 5 preferentially during the shifting process. The cavity of the mounting base 6 is adapted to the shape of the pre-synchronization column 7, which can play a guiding role in the movement of the pre-synchronization column 7 and ensure the smoothness of the synchronization process. In this embodiment, a clamping portion 701 is provided at the front end of the pre-synchronization column 7, and the engaging gear 5 is recessed radially inward to form a convex tooth groove 501. When the engaging sleeve 1 approaches the engaging gear 5 axially, the convex tooth groove 501 rotates to a position corresponding to the clamping portion 701, and the clamping portion 701 is engaged with the wall surface of the convex tooth groove 501.

[0060] In this embodiment, the angular width of the convex tooth groove 501 is greater than the angular width of the clamping portion 701, which can reduce the gear impact during the pre-synchronization stage and improve the pre-synchronization speed.

[0061] In this embodiment, the gear includes a high gear 3 and a low gear 4. The engaging sleeve 1 is located between the high gear 3 and the low gear 4. The clamping portion 701 corresponding to the high gear 3 is inclined counterclockwise, and the clamping portion 701 corresponding to the low gear 4 is inclined clockwise.

[0062] In this embodiment, two sets of pre-synchronization assemblies are respectively provided in the engaging sleeve 1 corresponding to the high gear 3 and the low gear 4, and the two sets of pre-synchronization assemblies are symmetrically arranged in the cavity of the same mounting base 6.

[0063] The present invention also provides a synchronization method applicable to an electric drive axle and an electric vehicle, which uses a new synchronizer applicable to an electric drive axle and an electric vehicle, and includes the following steps:

[0064] S1: The driving motor stops outputting torque. By means of a sensor, it is determined that the output torque of the driving motor is zero. The engaging sleeve 1 is in the neutral position. The driving motor adjusts the rotational speed of the engaging gear 5 to the target rotational speed, and at the same time, the shifting motor drives the engaging sleeve 1 to move towards the engaging gear 5.

[0065] S2: The driving motor starts to release torque and does not actively output torque. When the rotational speed difference between the engaging sleeve 1 and the engaging gear 5 reaches the preset rotational speed difference, the engaging sleeve 1 approaches the engaging gear 5, and the clamping portion 701 of the pre-synchronization column 7 snaps into the convex tooth groove 501 and engages with the wall surface of the convex tooth groove 501. Then the driving motor starts to output torque.

[0066] S3: The driving motor continues to maintain the state of not actively outputting torque. The shifting motor drives the engaging sleeve 1 to continue moving towards the engaging gear 5, and the spring 8 is compressed. The external tooth ring of the engaging gear 5 meshes with the engaging sleeve 1, and the synchronization ends.

[0067] In step S1: The target rotational speed of the engaging sleeve 1 is ;

[0068]

[0069] wherein, is the resistance torque of the vehicle moving forward, is the equivalent moment of inertia at the output end of the electric drive axle.

[0070] In step S2, the preset rotational speed difference is ;

[0071]

[0072] wherein, is the intermediate transmission ratio of the driving motor power output to the engaging gear, is the equivalent moment of inertia at the input end of the electric drive axle, is the output torque of the driving motor, is the resistance torque of the vehicle moving forward, is the equivalent moment of inertia at the output end of the electric drive axle. is the torque generated by the pre-synchronization of the pre-synchronization column and the engaging gear, and its specific magnitude is determined by the shifting force applied by the shifting motor to the engaging sleeve, the position dimensions and the inclination angle of the convex tooth groove arranged on the engaging gear.

[0073] Compared with the high-precision requirement of zero rotational speed difference in electronic synchronization, the embodiment of the present invention allows there to be The rotational speed difference. Through tests, the rotational speed difference tolerance of this embodiment can reach about 25%.

[0074] Mechanical synchronization is divided into two working conditions: ideal and non-ideal. In the ideal state, the engaging sleeve 1 is in contact with the engaging gear 5, and the convex tooth groove 501 corresponds to the clamping portion 701 as Figure 7 shown. The clamping portion 701 directly snaps into the convex tooth groove 501 as Figure 8 shown. After the synchronization is completed, as Figure 9 shown.

[0075] In the non-ideal state, the engaging sleeve 1 is in contact with the engaging gear 5, and the convex tooth groove 501 does not correspond to the clamping portion 701 as Figure 10 shown. The clamping portion 701 first contacts the side surface of the engaging gear 5. There is relative rotation between the engaging gear 5 and the engaging sleeve 1 (formed based on the rotational speed difference). When the convex tooth groove 501 rotates to correspond to the clamping portion 701, the clamping portion 701 snaps into the convex tooth groove 501 as Figure 11 shown. The subsequent state changes are the same as Figures 7 - 9 .

[0076] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0077] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A new type of synchronizer suitable for electric drive axles and electric vehicles, characterized in that: include: An engagement sleeve (1) has an inner side coaxially meshed with a spline hub (2), and an outer edge of the spline hub (2) is radially concave to form a mounting chamber; the engagement sleeve (1) is drivingly connected to a gear shifting motor; A gear shift gear, an engaging gear (5) being arranged on one side corresponding to the engaging sleeve (1), the engaging sleeve (1) being movable in the axial direction and meshing with the engaging gear (5), the gear shift gear being transmission-connected to the driving motor; the spline hub (2) being connected to the transmission shaft (10) via a spline, a bearing being arranged between the transmission shaft (10) and the gear shift gear; A mounting seat (6) disposed in the mounting chamber and connected to the coupling sleeve (1); A pre-synchronization component is arranged in the mounting seat (6), with a connection end thereof facing the engagement gear (5), and a convex tooth groove (501) is provided on a side surface of the engagement gear (5) corresponding to the connection end; when the speed difference between the engagement sleeve (1) and the engagement gear (5) reaches a preset speed difference, the shifting motor drives the engagement sleeve (1) to approach the engagement gear (5) in the axial direction, and the convex tooth groove (501) rotates to a position corresponding to the connection end, and the connection end is engaged in the convex tooth groove (501); The pre-synchronization component comprises: A pre-synchronization column (7), the front end of which is a connection end, and the rear end of which is connected to a spring washer (9) via a spring (8); The mounting seat (6) defines a cavity that matches the shape of the pre-synchronization column (7); the pre-synchronization column (7), the spring (8) and the spring gasket (9) are all located in the cavity; the spring gasket (9) is fixedly connected to the mounting seat (6); and the front end of the pre-synchronization column (7) extends outward from the cavity; The front end of the pre-synchronization column (7) is provided with a clamping portion (701), and the engaging gear (5) is radially concave to form the convex tooth groove (501); when the engaging sleeve (1) approaches the engaging gear (5) in the axial direction, the convex tooth groove (501) rotates to a position corresponding to the clamping portion (701), and the clamping portion (701) is clamped with the wall surface of the convex tooth groove (501); The angular width of the convex tooth groove (501) is greater than the angular width of the clamping portion (701).

2. A novel synchronizer suitable for electric drive axles and electric vehicles according to claim 1, characterized in that: The gears comprise a high gear (3) and a low gear (4); the engagement sleeve (1) is located between the high gear (3) and the low gear (4); the engaging portion (701) corresponding to the high gear (3) tilts in a counterclockwise direction, and the engaging portion (701) corresponding to the low gear (4) tilts in a clockwise direction.

3. A synchronization method applicable to an electric drive axle and an electric vehicle, characterized in that: A novel synchronizer suitable for an electric drive axle and an electric vehicle according to any one of claims 1 to 2 is applied, comprising the following steps: S1: the engagement sleeve (1) is in a neutral position, the drive motor adjusts the rotation speed of the engagement gear (5) toward the target rotation speed, and at the same time the shift motor drives the engagement sleeve (1) to move toward the engagement gear (5); S2: the driving motor starts to release torque and does not actively output torque; when the speed difference between the engagement sleeve (1) and the engagement gear (5) reaches a preset speed difference, the engagement sleeve (1) moves closer to the engagement gear (5), and the engaging portion (701) of the pre-synchronizing column (7) engages with the convex tooth groove (501) and the wall surface of the convex tooth groove (501), and the preset speed difference is within 25%; S3: the driving motor continues to maintain a state of not actively outputting torque; the shifting motor drives the coupling sleeve (1) to continue to move in the direction of the coupling gear (5), and the spring (8) is compressed; the outer gear ring of the coupling gear (5) meshes with the coupling sleeve (1), and synchronization ends.

4. A synchronization method applicable to an electric drive axle and an electric vehicle according to claim 3, characterized in that: In step S1: the target speed of the clutch sleeve (1) is ; in, is the resistance torque of the vehicle moving forward, is the equivalent moment of inertia of the output end of the electric drive axle.

5. A synchronization method applicable to an electric drive axle and an electric vehicle according to claim 3, wherein The characteristic is that, in step S2, the preset speed difference is ; in, The intermediate transmission ratio for outputting the power of the driving motor to the engaging gear (5) is is the equivalent moment of inertia of the electric drive axle input, The output torque of the driving motor is is the resistance torque of the vehicle moving forward, is the equivalent moment of inertia of the output end of the electric drive axle, The torque generated by pre-synchronizing the pre-synchronizing column (7) with the engaging gear (5).

6. A synchronization method applicable to an electric drive axle and an electric vehicle according to claim 3, characterized in that: In step S2, when the engagement sleeve (1) is connected to the engagement gear (5) and the convex tooth groove (501) corresponds to the clamping portion (701), the clamping portion (701) is clamped into the convex tooth groove (501).

7. A synchronization method applicable to an electric drive axle and an electric vehicle according to claim 3, characterized in that: In step S2, when the engagement sleeve (1) is connected to the engagement gear (5) and the convex tooth groove (501) does not correspond to the clamping portion (701), the clamping portion (701) is connected to the side surface of the engagement gear (5); the engagement gear (5) and the engagement sleeve (1) rotate relative to each other, and when the convex tooth groove (501) rotates to correspond to the clamping portion (701), the clamping portion (701) is clamped into the convex tooth groove (501).

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