Electrically-driven roller screw transmission gear shifting execution mechanism

Abstract

The invention provides an electrically-driven roller lead screw transmission gear shifting executing mechanism which comprises a motor, a gear shifting mechanism, a gear shifting mechanism and a gear shifting mechanism, and is characterized in that the motor comprises a motor rotor and a motor stator; the control unit is connected with the motor stator and inputs an electric signal to the motor stator so as to drive the motor rotor to rotate around a central shaft; the roller screw rotates along with the motor rotor; the roller lead screw nut is arranged on the roller lead screw in a sleeving mode, and a roller is arranged between the roller lead screw nut and the roller lead screw for transmission; and the shifting finger is fixedly connected with the roller screw nut, so that the shifting finger does synchronous linear reciprocating motion along with the roller screw nut. Compared with the prior art, the mode that the motor drives the planetary roller lead screw is adopted, and the purposes of being high in gear shifting speed, high in precision, low in noise and long in service life are achieved. In addition, the motor, the angle sensor and the controller are highly integrated, closed-loop control of the motor is achieved, the response speed is high, and the control precision is high.

Description

[Technical field]

[0001] The invention relates to the technical field of vehicle speed change, and in particular to an electrically driven roller screw transmission shift actuator. [Background technology]

[0002] Traditional commercial vehicle shift actuators need to use compressed air as a power source, and air compressors, air tanks, etc. need to be arranged on the vehicle, which wastes a certain amount of vehicle space. Traditional pneumatic shift actuators are not suitable for new energy or hybrid vehicles without air sources. The gear rack structure is used in traditional electric actuators, which has a complex structure, high processing cost, and low transmission accuracy. Traditional electric actuators use TCU (Telematics Control Unit) or ECU (Electronic Control Unit) to control the motor movement, which has problems such as poor control accuracy and slow response. The new electric actuator uses a ball screw structure. The structure of the ball screw is to add balls between the screw and the screw nut for transmission. Due to the large number of balls and small size, it has the disadvantages of low speed, low linear speed, high noise, and short life.

[0003] Therefore, it is necessary to propose an improved technical solution to solve the above problems. [Summary of the invention]

[0004] One of the purposes of the present invention is to provide an electrically driven roller screw transmission gear shift actuator, which adopts the mode of motor-driven planetary roller screw (referred to as roller screw), gets rid of the dependence of commercial vehicle actuators on vehicle-borne air sources, and achieves the goals of fast gear shifting speed, high precision, low noise and long life. In addition, the motor, angle sensor and controller are highly integrated to realize closed-loop control of the motor, with fast response speed and extremely high control precision, which improves vehicle performance while taking into account driving and riding comfort.

[0005] According to one aspect of the present invention, the present invention provides an electrically driven roller screw transmission shift actuator, which includes: a motor, which includes a motor rotor and a motor stator, and the motor stator is arranged on the periphery of the motor rotor; a control unit, which is connected to the motor stator, and the control unit inputs an electrical signal to the motor stator, thereby driving the motor rotor to rotate around a central axis; a roller screw, which rotates with the motor rotor; a roller screw nut, which is sleeved on the roller screw, and a roller is arranged between the roller screw nut and the roller screw for transmission, so as to convert the rotation of the roller screw into a linear reciprocating motion of the roller screw nut along the roller screw; a shift finger, which is fixedly connected to the roller screw nut, so that the shift finger follows the roller screw nut to perform synchronous linear reciprocating motion.

[0006] Furthermore, the electrically driven roller screw transmission shift actuator also includes an angle sensor, which is connected to the control unit; the angle sensor obtains the rotation angle information of the roller screw by sensing the change in magnetic field strength, and transmits the rotation angle information to the control unit; the control unit controls the rotation angle of the roller screw based on the rotation angle information, thereby achieving the control of the axial displacement of the shift finger.

[0007] Furthermore, the electrically driven roller screw transmission shift actuator also includes a shell, a accommodating chamber is defined in the shell, and the accommodating chamber has an opening at one end of the shell; the motor, roller screw and roller screw nut are accommodated in the accommodating chamber of the shell; a channel is formed in the accommodating chamber for the roller screw nut to perform linear reciprocating motion, and the roller screw nut is anti-torsionally arranged in the channel.

[0008] Furthermore, the electrically driven roller screw transmission shift actuator also includes a guide sleeve, which is interference pressed into the channel of the housing, and the guide sleeve is arranged on the roller screw nut; a plurality of limit grooves are arranged on the inner wall of the guide sleeve, and a plurality of limit protrusions matching the plurality of limit grooves are arranged on the outer wall of the roller screw nut; through the cooperation of the plurality of limit grooves and the plurality of limit protrusions, the roller screw nut is restricted to only perform linear reciprocating motion along the roller screw.

[0009] Furthermore, the electrically driven roller screw transmission shift actuator also includes a finger shift shaft, one end of the finger shift shaft passes through the opening of the shell and is sealedly connected to an end of the roller screw nut away from the motor, the other end of the finger shift shaft is located outside the shell, and the finger shift shaft follows the roller screw nut to perform synchronous linear reciprocating motion; a blind hole is provided at the end of the finger shift shaft connected to the roller screw nut, and a part of the roller screw that passes through the roller screw nut and away from the motor is accommodated in the blind hole; the finger is fixed on the finger shift shaft, and the finger is located outside the shell.

[0010] Furthermore, the roller screw nut and the finger shaft are connected together by laser welding; and the finger is fixedly connected to the finger shaft by an elastic cylindrical pin.

[0011] Furthermore, the electrically driven roller screw transmission shift actuator also includes a bushing, which is fixed in the channel of the housing and adjacent to the opening of the housing; when the finger shaft follows the roller screw nut to perform synchronous linear reciprocating motion, the finger shaft follows the roller screw nut to pass through the bushing, and the finger shaft and the roller screw nut are clearance-matched with the bushing.

[0012] Furthermore, the electrically driven roller screw transmission shift actuator also includes a bearing seat and a four-point contact bearing, and the bearing seat and the four-point contact bearing are accommodated in a accommodating cavity defined in the shell; the bearing seat and the four-point contact bearing are located between the roller screw nut and the motor; the four-point contact bearing is sleeved on the roller screw; the bearing seat is fixed in the shell, and the bearing seat is arranged on the periphery of the four-point contact bearing along the radial direction of the four-point contact bearing.

[0013] Furthermore, the control unit is integrated in the SCU controller; the roller screw includes a motor shaft and a screw portion, the motor shaft and the screw portion are coaxial and are an integrally formed structure; the motor rotor is sleeved on the motor shaft, and the motor shaft and the screw portion rotate synchronously with the motor rotor; the roller screw nut is sleeved on the screw portion, and the roller is arranged between the roller screw nut and the screw portion for transmission.

[0014] Furthermore, the electrically driven roller screw transmission shift actuator also includes a head assembly, which is fixedly connected to one end of the motor shaft away from the screw part; the head assembly is opposite to the angle sensor, and the angle sensor is used to sense the change in magnetic field strength of the head assembly to obtain the rotation angle information of the roller screw.

[0015] Compared with the prior art, the present invention adopts the method of using a motor to drive a planetary roller screw, which gets rid of the dependence of the commercial vehicle actuator on the vehicle air source, and achieves the goals of fast shifting speed, high precision, low noise and long life. In addition, the motor, angle sensor and controller are highly integrated to achieve closed-loop control of the motor, fast response speed and extremely high control precision, which improves the vehicle performance while taking into account the driving and riding comfort.

Brief Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0017] Figure 1 A cross-sectional view of an electrically driven roller screw transmission shift actuator in one embodiment of the present invention;

[0018] Figure 2 In one embodiment of the present invention, Figure 1 The schematic diagram of the structure of some components in the electrically driven roller screw transmission shift actuator shown;

[0019] Figure 3In one embodiment of the present invention, Figure 1 Schematic diagram of the connection structure between the roller screw and the motor rotor shown;

[0020] Figure 4 In one embodiment of the present invention, Figure 1 The schematic diagram of the radial section of the electrically driven roller screw transmission shift actuator at the roller screw nut is shown. [Specific implementation method]

[0021] 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.

[0022] The "one embodiment" or "embodiment" referred to herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The "in one embodiment" that appears in different places in this specification does not all refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments. Unless otherwise specified, the words "coupled", "connected", "connected" and "connected" in this document that indicate electrical connection all mean direct or indirect connection. For example, A is connected to B, which includes both direct electrical connection between A and B and connection between A and B through electrical components or circuits.

[0023] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "front", "back", "left", "right", "vertical", "perpendicular", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0024] Please refer to Figure 1 , which is a cross-sectional view of an electrically driven roller screw transmission shift actuator in one embodiment of the present invention. Figure 2 As shown, it is the present invention in one embodiment as Figure 1 The schematic diagram of the structure of some components in the electrically driven roller screw transmission shift actuator is shown. Figure 1 and Figure 2 The electrically driven roller screw transmission shift actuator shown includes a motor 110 , a control unit 120 , a roller screw 130 , a roller screw nut 140 , and a shift finger 150 .

[0025] Among them, the motor 110 includes a motor rotor 112 and a motor stator 114, and the motor stator 114 is arranged on the periphery of the motor rotor 112; the control unit 120 is connected to the motor stator 114, and the control unit 120 inputs an electrical signal to the motor stator 114, and the change of the magnetic field in the motor stator 114 drives the rotation of the motor rotor 112, thereby driving the motor rotor 112 to rotate around a central axis; the roller screw 130 rotates with the motor rotor 112; the roller screw nut 140 is sleeved on the roller screw 130, and a roller 160 is arranged between the roller screw nut 140 and the roller screw 130 for transmission, so as to convert the rotation of the roller screw 130 into a linear reciprocating motion of the roller screw nut 140 along the roller screw 130; the finger 150 is fixedly connected to the roller screw nut 140, so that the finger 150 follows the roller screw nut 140 to perform synchronous linear reciprocating motion.

[0026] Figure 1 and Figure 2 The electrically driven roller screw transmission shift actuator shown also includes an angle sensor 170, which is connected to the control unit 120. The angle sensor 170 obtains the rotation angle information of the roller screw 130 by sensing the change in magnetic field strength, and transmits the rotation angle information to the control unit 120. The control unit 120 controls the rotation angle of the roller screw 130 based on the rotation angle information, thereby controlling the axial displacement of the shift finger 150 and improving the shifting accuracy.

[0027] Please refer to Figure 3 As shown, it is the present invention in one embodiment as Figure 1 The schematic diagram of the connection structure between the roller screw and the motor rotor is shown in FIG. Figure 3 In the illustrated embodiment, the roller screw 130 includes a motor shaft 132 and a screw 134, which are coaxial and integrally formed. The motor rotor 112 is sleeved on the motor shaft 132, and the motor shaft 132 and the screw 134 rotate synchronously with the motor rotor 112. Figure 1 and Figure 2 In the embodiment shown, the roller screw nut 140 is sleeved on the screw part 134, and a roller 160 is arranged between the roller screw nut 140 and the screw part 134 for transmission. In this way, the present invention integrates the motor rotor 112 and the roller screw 130 together, and the motor 110 directly drives the roller screw 130 to rotate, eliminating the intermediate transmission link and improving the transmission efficiency; because the roller screw 130 has a smaller lead, the accuracy will be greatly improved compared with the traditional actuator.

[0028] exist Figure 1In the illustrated embodiment, the electrically driven roller screw transmission shift actuator provided by the present invention also includes a head assembly 200, which is fixedly connected to one end of the motor shaft 132 away from the screw portion 134, and the head assembly 200 is opposite to the angle sensor 170. The angle sensor 170 is used to sense the change in the magnetic field strength of the head assembly 200 to obtain the rotation angle information of the roller screw 130.

[0029] In a specific embodiment of the present invention, the control unit 120 is integrated into the SCU controller (i.e., the auxiliary controller), and the integration is high. Figure 1 The specific description of the action of the electrically driven roller screw transmission shift actuator shown is as follows: 1. After the motor 110 receives the electrical signal sent by the SCU controller 120, it drives the motor rotor 112 to rotate; 2. The motor rotor 112 drives the roller screw 130 to rotate; 3. Through the transmission of the roller 160, the rotational motion of the roller screw 130 is converted into a linear reciprocating motion of the roller screw nut 140 along the roller screw 130; 4. The roller screw nut 140 drives the shift finger 150 to perform the final shift action; 5. The angle sensor 170 feeds back the action information (i.e., the rotation angle information of the roller screw 130) to the SCU controller 120 in real time, and the SCU controller 120 adjusts the speed and torque of the motor rotor 112.

[0030] exist Figure 1 In the illustrated embodiment, the electric-driven roller screw transmission shift actuator provided by the present invention further includes a housing 180, in which a housing chamber 182 is defined, and the housing chamber 182 is formed with an opening 184 at one end of the housing 180; the motor 110, the roller screw 130 and the roller screw nut 140 are accommodated in the housing chamber 182 of the housing 180; a channel 1822 is formed in the housing chamber 182 for the roller screw nut 140 to perform linear reciprocating motion, and the roller screw nut 140 is anti-twistingly arranged in the channel 1822. The purpose of the roller screw nut 140 being anti-twistingly arranged in the channel 1822 is to limit the roller screw nut 140 to only perform linear reciprocating motion along the roller screw 130. The control unit 120 is arranged on the housing 180, and the control unit 120 is fixedly connected to the housing 180.

[0031] Please refer to Figure 4 As shown, it is the present invention in one embodiment as Figure 1 The radial cross-sectional diagram of the electric drive roller screw transmission shift actuator at the roller screw nut is shown. Figure 1 and Figure 4In the illustrated embodiment, the electrically driven roller screw transmission shift actuator provided by the present invention also includes a guide sleeve 190, which is interference pressed into the channel 1822 of the housing 180 and limits its rotation, and the guide sleeve 190 is sleeved on the roller screw nut 140; a plurality of limiting grooves 192 are arranged on the inner wall of the guide sleeve 190, and a plurality of limiting protrusions 142 matching the plurality of limiting grooves 192 are arranged on the outer wall of the roller screw nut 140. The limiting grooves 192 and the limiting protrusions 142 cooperate with each other to limit the circumferential rotation of the roller screw nut 140, so that the roller screw nut 140 is driven to generate axial movement when the roller screw 130 rotates (i.e., the roller screw nut 140 is limited to only perform linear reciprocating motion along the roller screw 130). Figure 3 In the specific embodiment shown, three limiting grooves 192 are provided on the inner wall of the guide sleeve 190 , and three limiting protrusions 142 matching the three limiting grooves 192 are provided on the outer wall of the roller screw nut 140 .

[0032] Since the exposed part of the roller screw 130 must avoid the position where the gearbox oil splashes to prevent the grease from being diluted and affecting the life of the screw, Figure 1 and Figure 2 In the illustrated embodiment, the electrically driven roller screw transmission shift actuator provided by the present invention also includes a finger shaft 210, one end of which passes through the opening 184 of the housing 180 and is sealedly connected to the end of the roller screw nut 140 away from the motor 110, and the other end of the finger shaft 210 is located outside the housing 180, and the finger shaft 210 follows the roller screw nut 140 to perform synchronous linear reciprocating motion; a blind hole 212 is provided at the end of the finger shaft 210 connected to the roller screw nut 140, and the portion of the roller screw 130 that passes through the roller screw nut 140 and away from the motor 110 is accommodated in the blind hole 212; the finger 150 is fixed on the finger shaft 210, and the finger 150 is located outside the housing 180. Figure 1 and Figure 2 In the specific embodiment shown, the roller screw nut 140 and the finger shaft 210 are connected together by laser welding 260 to form an independent lubrication system, so that the blind hole 212 set in the finger shaft 210 can prevent the transmission oil from splashing onto the roller screw 130; the finger 150 is connected to the finger shaft 210, and to prevent it from loosening, the elastic cylindrical pin 220 can be used to fix the finger 150 on the finger shaft 210.

[0033] exist Figure 1In the illustrated embodiment, the electric-driven roller screw transmission shift actuator provided by the present invention further includes a bushing 230, which is fixed in the channel 1822 of the housing 180 and is adjacent to the opening 184 of the housing 180. When the finger shaft 210 follows the roller screw nut 140 to perform synchronous linear reciprocating motion, the finger shaft 210 follows the roller screw nut 140 to pass through the bushing 230, and the finger shaft 210 and the roller screw nut 140 are clearance-matched with the bushing 230. The bushing 230 can not only radially support the finger shaft 210 and the roller screw nut 140, but also prevent the roller screw 130 from being eccentric under vibration.

[0034] exist Figure 1 In the illustrated embodiment, the electric-driven roller screw transmission shift actuator provided by the present invention further includes a bearing seat 240 and a four-point contact bearing 250, which are accommodated in the accommodating chamber 182 of the housing 180; the bearing seat 240 and the four-point contact bearing 250 are located between the roller screw nut 140 and the motor 110; the four-point contact bearing 250 is sleeved on the roller screw 130; the bearing seat 240 is fixed in the housing 180, and the bearing seat 240 is arranged at the periphery of the four-point contact bearing 250 along the radial direction of the four-point contact bearing 250. In this way, the roller screw 130 can use the four-point contact bearing 250 for radial support, and can bear the axial shift force at the same time (or the four-point contact bearing 250 is fixed, which can simultaneously play a fixing and supporting role in the axial and radial directions), which can prevent the roller screw 130 from moving during the working process and causing abnormal wear on the mechanical structure.

[0035] The electric drive screw transmission shift actuator provided by the present invention can solve the following technical problems:

[0036] 1. The gear rack structure of the traditional actuator is replaced by a roller screw structure (which includes a roller screw 130, a roller screw nut 140 and a roller 160). The roller screw 130 can directly convert the rotation of the motor 110 into the axial linear motion of the shift finger 150. By using roller screws 130 with different leads, the different requirements of shifting force for various vehicle models can be met.

[0037] 2. Since the splash of gearbox oil will dilute the grease on the roller screw 130 and shorten the life of the roller screw 130, it is necessary to separate the gearbox and the working area of ​​the roller screw 130 to ensure the shifting working range without affecting the life of the roller screw 130.

[0038] 3. The roller screw nut 140 is integrated with the shift finger 150, and the rotation torque of the motor 110 is converted into axial linear motion by limiting the rotation of the roller screw nut 140 to drive the shift fork to shift gears. The motor 110 is used for direct drive to reduce the intermediate transmission links as much as possible to reduce the loss of transmission efficiency.

[0039] 4. The motor 110, the angle sensor 170, and the controller (ie, the control unit 120) are highly integrated to read the actual actions of the motor 110 and the finger 150 to achieve closed-loop control.

[0040] In summary, the present invention adopts the method of using a motor to drive a planetary roller screw, which eliminates the dependence of commercial vehicle actuators on the onboard air source, and achieves the goals of fast shifting speed, high precision, low noise, and long life. In addition, the motor, angle sensor, and controller are highly integrated to achieve closed-loop control of the motor, fast response speed, extremely high control precision, flexible layout, and eliminate dependence on TCU (Telematics Control Unit), improving vehicle performance while taking into account driving and riding comfort.

[0041] It should be noted that any changes made by those skilled in the art to the specific embodiments of the present invention do not deviate from the scope of the claims of the present invention. Accordingly, the scope of the claims of the present invention is not limited to the above specific embodiments.

Claims

1. An electrically driven roller screw transmission shift actuator, characterized in that: It includes: A motor, comprising a motor rotor and a motor stator, wherein the motor stator is arranged on the periphery of the motor rotor; A control unit connected to the motor stator, the control unit inputting an electrical signal to the motor stator, thereby driving the motor rotor to rotate around a central axis; A roller screw, which rotates following the motor rotor; A roller screw nut is sleeved on the roller screw, and a roller is arranged between the roller screw nut and the roller screw for transmission, so as to convert the rotation of the roller screw into a linear reciprocating motion of the roller screw nut along the roller screw; The shift finger is fixedly connected to the roller screw nut so that the shift finger follows the roller screw nut to perform synchronous linear reciprocating motion.

2. The electrically driven roller screw transmission shift actuator according to claim 1, characterized in that: It also includes an angle sensor, The angle sensor is connected to the control unit; The angle sensor obtains the rotation angle information of the roller screw by sensing the change of magnetic field strength, and transmits the rotation angle information to the control unit; The control unit controls the rotation angle of the roller screw based on the rotation angle information, thereby controlling the axial displacement of the finger.

3. The electrically driven roller screw transmission shift actuator according to claim 2, characterized in that: It also includes a housing, A receiving cavity is defined in the shell, and the receiving cavity is formed with an opening at one end of the shell; The motor, the roller screw and the roller screw nut are accommodated in the accommodating cavity of the housing; A channel is formed in the accommodating cavity for the roller screw nut to perform linear reciprocating motion, and the roller screw nut is arranged in the channel to resist torsion.

4. The electrically driven roller screw transmission shift actuator according to claim 3, characterized in that: It also includes a guide sleeve, The guide sleeve is pressed into the channel of the housing by interference fit, and the guide sleeve is sleeved on the roller screw nut; The guide sleeve inner wall is provided with a plurality of limit grooves, and the roller screw nut outer wall is provided with a plurality of limit protrusions matching the plurality of limit grooves; The plurality of limiting grooves and the plurality of limiting protrusions cooperate to limit the roller screw nut to only perform linear reciprocating motion along the roller screw.

5. The electrically driven roller screw transmission shift actuator according to claim 3, characterized in that: It also includes a finger shaft, One end of the finger shaft passes through the opening of the housing and is sealedly connected to an end of the roller screw nut away from the motor, and the other end of the finger shaft is located outside the housing, and the finger shaft follows the roller screw nut to perform synchronous linear reciprocating motion; One end of the finger shaft connected to the roller screw nut is provided with a blind hole, and the part of the roller screw passing through the roller screw nut and away from the motor is accommodated in the blind hole; The finger is fixed on the finger shaft, and the finger is located outside the shell.

6. The electrically driven roller screw transmission shift actuator according to claim 5, characterized in that: Connecting the roller screw nut and the finger shaft together by laser welding; The finger is fixedly connected to the finger shaft by an elastic cylindrical pin.

7. The electrically driven roller screw transmission shift actuator according to claim 5, characterized in that: It also includes a bushing, The bushing is fixed in the passage of the housing and adjacent to the opening of the housing; When the finger shaft follows the roller screw nut to perform synchronous linear reciprocating motion, the finger shaft follows the roller screw nut to pass through the bushing, and the finger shaft and the roller screw nut are clearance-matched with the bushing.

8. The electrically driven roller screw transmission shift actuator according to claim 3, characterized in that: It also includes a bearing seat and a four-point contact bearing. The bearing seat and the four-point contact bearing are accommodated in a receiving cavity defined in the housing; The bearing seat and the four-point contact bearing are located between the roller screw nut and the motor; The four-point contact bearing is sleeved on the roller screw; The bearing seat is fixed in the housing, and the bearing seat is arranged at the periphery of the four-point contact bearing along the radial direction of the four-point contact bearing.

9. The electrically driven roller screw transmission shift actuator according to any one of claims 1 to 8, characterized in that: The control unit is integrated in the SCU controller; The roller screw comprises a motor shaft portion and a screw portion, The motor shaft and the lead screw are coaxial and integrally formed; The motor rotor is sleeved on the motor shaft, and the motor shaft and the lead screw rotate synchronously with the motor rotor; The roller screw nut is sleeved on the screw part, and the roller is arranged between the roller screw nut and the screw part for transmission.

10. The electrically driven roller screw transmission shift actuator according to claim 9, characterized in that: It also includes a magnetic head assembly, The magnetic head assembly is fixedly connected to one end of the motor shaft away from the lead screw; The magnetic head assembly is opposite to the angle sensor, and the angle sensor is used to sense the change of the magnetic field intensity of the magnetic head assembly to obtain the rotation angle information of the roller screw.

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