Electrically-driven roller screw transmission gear shifting execution mechanism

Abstract

The utility model provides an electrically-driven roller screw transmission gear shifting executing mechanism which comprises a motor, a gear shifting mechanism, a gear shifting mechanism and a gear shifting mechanism. 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, a 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] This utility model relates to the field of vehicle transmission technology, and in particular to an electrically driven roller screw transmission shifting actuator. [Background Technology]

[0002] Traditional commercial vehicle gear shift actuators require compressed air as a power source, necessitating the installation of air compressors and air tanks on the vehicle, resulting in wasted space. They are unsuitable for new energy or hybrid vehicles without air power sources. Traditional electric actuators employ a rack and pinion structure, which is complex, costly to manufacture, and has low transmission accuracy. Traditional electric actuators use TCU (Telematics Control Unit) or ECU (Electronic Control Unit) to control the motor, leading to poor control accuracy and slow response. Newer electric actuators utilize ball screw structures, which involve inserting balls between the screw and nut for transmission. However, due to the large number and small size of these balls, they suffer from low rotational speed, low linear speed, high noise, and short lifespan.

[0003] Therefore, it is necessary to propose an improved technical solution to address the above problems. [Utility Model Content]

[0004] One of the objectives of this invention is to provide an electrically driven roller screw transmission shifting actuator. This actuator uses a motor-driven planetary roller screw (hereinafter referred to as roller screw), eliminating the dependence of commercial vehicle actuators on onboard pneumatic power sources and achieving the goals of fast shifting speed, high precision, low noise, and long service life. Furthermore, the high integration of the motor, angle sensor, and controller enables closed-loop control of the motor, resulting in fast response and extremely high control precision, improving vehicle performance while also ensuring driving and passenger comfort.

[0005] According to one aspect of this utility model, an electrically driven roller screw transmission shifting actuator is provided, comprising: a motor including a motor rotor and a motor stator, the motor stator being disposed around the motor rotor; a control unit connected to the motor stator, the control unit inputting an electrical signal to the motor stator to drive the motor rotor to rotate around a central axis; a roller screw that follows the rotation of the motor rotor; a roller screw nut sleeved on the roller screw, with rollers provided between the roller screw nut and the roller screw for transmission, so as to convert the rotation of the roller screw into linear reciprocating motion of the roller screw nut along the roller screw; and a shift finger fixedly connected to the roller screw nut, so that the shift finger follows the roller screw nut in synchronous linear reciprocating motion.

[0006] Furthermore, the electrically driven roller screw transmission shifting 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 changes 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 controlling the axial displacement of the shift finger.

[0007] Furthermore, the electrically driven roller screw transmission shifting actuator also includes a housing, the housing having a defined receiving cavity, the receiving cavity having an opening at one end of the housing; the motor, roller screw, and roller screw nut are housed in the receiving cavity of the housing; the receiving cavity has a channel for the roller screw nut to perform linear reciprocating motion, and the roller screw nut is anti-torsionally disposed in the channel.

[0008] Furthermore, the electrically driven roller screw transmission shifting actuator also includes a guide sleeve, which is press-fitted into the channel of the housing and sleeved on the roller screw nut; the inner wall of the guide sleeve is provided with a plurality of limiting grooves, and the outer wall of the roller screw nut is provided with a plurality of limiting protrusions that match the plurality of limiting grooves; through the cooperation of the plurality of limiting grooves and the plurality of limiting 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 shifting actuator also includes a shift finger shaft. One end of the shift finger shaft passes through the opening of the housing and is sealed to the end of the roller screw nut away from the motor. The other end of the shift finger shaft is located outside the housing. The shift finger shaft follows the roller screw nut in synchronous linear reciprocating motion. A blind hole is provided at the end of the shift finger shaft connected to the roller screw nut. The portion of the roller screw that extends out of the roller screw nut and is away from the motor is accommodated in the blind hole. The shift finger is fixed on the shift finger shaft and is located outside the housing.

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

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

[0012] Furthermore, the electrically driven roller screw transmission shifting actuator also includes a bearing housing and a four-point contact bearing, which are housed in a defined receiving cavity within the housing; the bearing housing 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 housing is fixed within the housing and is arranged radially around the four-point contact bearing.

[0013] Furthermore, the control unit is integrated into the SCU controller; the ball screw includes a motor shaft and a ball screw, which are coaxial and integrally formed; the motor rotor is sleeved on the motor shaft, and the motor shaft and the ball screw rotate synchronously with the motor rotor; the ball screw nut is sleeved on the ball screw, and the ball screw nut and the ball screw are connected by rollers for transmission.

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

[0015] Compared with existing technologies, this invention uses a motor-driven planetary roller screw, eliminating the dependence of commercial vehicle actuators on onboard air supply, achieving the goals of fast shifting speed, high precision, low noise, and long service life. Furthermore, the high integration of the motor, angle sensor, and controller enables closed-loop control of the motor, resulting in fast response and extremely high control precision, improving vehicle performance while ensuring driving and passenger comfort. [Attached Image Description]

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them:

[0017] Figure 1 This is a cross-sectional view of an electrically driven roller screw transmission shifting actuator according to one embodiment of the present invention;

[0018] Figure 2 In one embodiment of this utility model, as shown Figure 1 The diagram shows the structure of some components in the electrically driven roller screw transmission shifting actuator.

[0019] Figure 3 In one embodiment of this utility model, as shown Figure 1 The diagram shows the connection structure between the roller screw and the motor rotor.

[0020] Figure 4 In one embodiment of this utility model, as shown Figure 1 The diagram shows a radial cross-section of the electrically driven roller screw transmission shifting actuator at the roller screw nut.

Detailed Implementation Methods

[0021] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] The term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments. Unless otherwise specified, the terms coupling, connection, linking, and interconnection used herein to indicate electrical connection mean direct or indirect connection. For example, A being connected to B includes both a direct electrical connection between A and B and a connection between A and B via electrical components or circuits.

[0023] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "back", "positive", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0024] Please refer to Figure 1 The image shown is a cross-sectional view of an electrically driven roller screw transmission shifting actuator according to one embodiment of the present invention. Please refer to... Figure 2 As shown, this is one embodiment of the present invention. Figure 1 The diagram shows the structure of some components in the electrically driven roller screw transmission shifting actuator. Figure 1 and Figure 2 The electrically driven roller screw transmission shifting 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] The motor 110 includes a motor rotor 112 and a motor stator 114, with the stator 114 positioned around the motor rotor 112. A control unit 120 is connected to the motor stator 114 and inputs an electrical signal to it. Changes in the magnetic field within the stator 114 cause the motor rotor 112 to rotate, thus enabling it to rotate around a central axis. A ball screw 130 rotates with the motor rotor 112. A ball screw nut 140 is fitted onto the ball screw 130, and a roller 160 is positioned between the ball screw nut 140 and the ball screw 130 for transmission, converting the rotation of the ball screw 130 into linear reciprocating motion of the ball screw nut 140 along the ball screw 130. A shift finger 150 is fixedly connected to the ball screw nut 140, allowing the shift finger 150 to perform synchronous linear reciprocating motion with the ball screw nut 140.

[0026] Figure 1 and Figure 2 The electrically driven roller screw transmission shifting 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, this is one embodiment of the present invention. Figure 1 The diagram shows the connection structure between the roller screw and the motor rotor. Figure 3 In the illustrated embodiment, the roller screw 130 includes a motor shaft portion 132 and a screw portion 134, which are coaxial and integrally formed. The motor rotor 112 is sleeved on the motor shaft portion 132, and the motor shaft portion 132 and the screw portion 134 rotate synchronously with the motor rotor 112. Correspondingly, in Figure 1 and Figure 2 In the illustrated embodiment, a roller screw nut 140 is sleeved on the screw section 134, and a roller 160 is provided between the roller screw nut 140 and the screw section 134 for transmission. Thus, this invention integrates the motor rotor 112 and the roller screw 130 together, allowing the motor 110 to directly drive the roller screw 130 to rotate, eliminating intermediate transmission links and improving transmission efficiency. Furthermore, due to the smaller lead of the roller screw 130, the accuracy is significantly improved compared to traditional actuators.

[0028] exist Figure 1In the embodiment shown, the electric drive roller screw transmission shifting actuator provided by this utility model also includes a magnetic head assembly 200. The magnetic head assembly 200 is fixedly connected to the end of the motor shaft 132 away from the screw 134, and the magnetic head assembly 200 is opposite to the angle sensor 170. The angle sensor 170 is used to sense the change in magnetic field strength of the magnetic head assembly 200 in order to obtain the rotation angle information of the roller screw 130.

[0029] In one specific embodiment of this utility model, the control unit 120 is integrated into the SCU controller (i.e., auxiliary controller), achieving a high degree of integration. Correspondingly, Figure 1 The specific description of the operation of the electrically driven roller screw transmission shifting actuator shown is as follows: 1. After receiving the electrical signal from the SCU controller 120, the motor 110 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 the 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 shifting 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 electrically driven roller screw transmission shifting actuator provided by this utility model further includes a housing 180, within which a receiving cavity 182 is defined, and an opening 184 is formed at one end of the receiving cavity 182. A motor 110, a roller screw 130, and a roller screw nut 140 are housed within the receiving cavity 182 of the housing 180. A channel 1822 is formed in the receiving cavity 182 for the roller screw nut 140 to perform linear reciprocating motion, and the roller screw nut 140 is anti-torsionally disposed within this channel 1822. The purpose of the anti-torsional placement of the roller screw nut 140 within the channel 1822 is to restrict the roller screw nut 140 to only perform linear reciprocating motion along the roller screw 130. A control unit 120 is arranged on the housing 180 and is fixedly connected to the housing 180.

[0031] Please refer to Figure 4 As shown, this is one embodiment of the present invention. Figure 1 The diagram shows a radial cross-sectional view of the electrically driven roller screw transmission shifting actuator at the roller screw nut. Figure 1 and Figure 4In the illustrated embodiment, the electrically driven roller screw transmission shifting actuator provided by this utility model further includes a guide sleeve 190. The guide sleeve 190 is press-fitted into the channel 1822 of the housing 180 and restricts its rotation. The guide sleeve 190 is sleeved on the roller screw nut 140. A plurality of limiting grooves 192 are provided on the inner wall of the guide sleeve 190, and a plurality of limiting protrusions 142 matching the limiting grooves 192 are provided on the outer wall of the roller screw nut 140. Through the cooperation of the limiting grooves 192 and the limiting protrusions 142, the circumferential rotation of the roller screw nut 140 is restricted, so that when the roller screw 130 rotates, it drives the roller screw nut 140 to generate axial movement (i.e., restricting the roller screw nut 140 to only perform linear reciprocating motion along the roller screw 130). Figure 3 In the specific embodiment shown, the inner wall of the guide sleeve 190 is provided with three limiting grooves 192, and the outer wall of the roller screw nut 140 is provided with three limiting protrusions 142 that match the three limiting grooves 192.

[0032] Because the exposed parts of the roller screw 130 must avoid areas prone to gearbox oil splashes to prevent grease dilution and impact on screw life, therefore, in Figure 1 and Figure 2 In the illustrated embodiment, the electrically driven roller screw transmission shifting actuator provided by this utility model further includes a shift finger shaft 210. One end of the shift finger shaft 210 passes through the opening 184 of the housing 180 and is sealed to the end of the roller screw nut 140 away from the motor 110. The other end of the shift finger shaft 210 is located outside the housing 180. The shift finger shaft 210 follows the roller screw nut 140 in synchronous linear reciprocating motion. A blind hole 212 is provided at the end of the shift finger shaft 210 connected to the roller screw nut 140. The portion of the roller screw 130 that protrudes from the roller screw nut 140 and is away from the motor 110 is accommodated in the blind hole 212. The shift finger 150 is fixed on the shift finger shaft 210 and is located outside the housing 180. Figure 1 and Figure 2 In the specific embodiment shown, the roller screw nut 140 and the shift finger shaft 210 are connected together by laser welding 260 to form an independent lubrication system. This prevents transmission oil from splashing onto the roller screw 130 through the blind hole 212 in the shift finger shaft 210. The shift finger 150 is connected to the shift finger shaft 210. To prevent loosening, the shift finger 150 can be fixedly connected to the shift finger shaft 210 with an elastic cylindrical pin 220.

[0033] exist Figure 1In the illustrated embodiment, the electrically driven roller screw transmission shifting actuator provided by this utility model further includes a bushing 230. The bushing 230 is fixed in the channel 1822 of the housing 180 and adjacent to the opening 184 of the housing 180. When the shift pin 210 follows the roller screw nut 140 in synchronous linear reciprocating motion, the shift pin 210 passes through the bushing 230 along with the roller screw nut 140, and the shift pin 210 and the roller screw nut 140 are clearance-fitted with the bushing 230. The bushing 230 not only provides radial support for the shift pin 210 and the roller screw nut 140, but also prevents the roller screw 130 from becoming eccentric under vibration.

[0034] exist Figure 1 In the illustrated embodiment, the electrically driven roller screw transmission shifting actuator provided by this utility model further includes a bearing housing 240 and a four-point contact bearing 250, which are housed in the receiving cavity 182 of the housing 180. The bearing housing 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 housing 240 is fixed in the housing 180 and is arranged radially around the four-point contact bearing 250. In this way, the roller screw 130 can be radially supported by the four-point contact bearing 250, while simultaneously bearing the axial shifting force (or the four-point contact bearing 250 can be fixed and supported simultaneously in both the axial and radial directions). This prevents the roller screw 130 from shifting during operation and causing abnormal wear on the mechanical structure.

[0035] The electrically driven screw transmission shifting actuator provided by this utility model can solve the following technical problems:

[0036] 1. The traditional gear and rack structure of the actuator is replaced with a roller screw structure (which includes roller screw 130, roller screw nut 140 and 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 each vehicle model for shifting force can be met.

[0037] 2. Since the splashing of transmission fluid will dilute the grease on the ball screw 130, resulting in a shortened life of the ball screw 130, it is necessary to separate the working areas of the transmission and the ball screw 130 to ensure the shifting range without affecting the life of the ball screw 130.

[0038] 3. The roller screw nut 140 and the shift fork 150 are integrated together. By restricting the rotation of the roller screw nut 140, the rotational torque of the motor 110 is converted into axial linear motion to drive the shift fork for shifting gears. Direct drive by the motor 110 minimizes intermediate transmission links to reduce transmission efficiency loss.

[0039] 4. Integrate the motor 110, angle sensor 170, and controller (i.e. control unit 120) to read the actual movements of the motor 110 and the dial 150, thereby achieving closed-loop control.

[0040] In summary, this invention utilizes a motor-driven planetary roller screw, eliminating the reliance on onboard pneumatic power sources for commercial vehicle actuators. This achieves fast shifting speed, high precision, low noise, and long service life. Furthermore, the high integration of the motor, angle sensor, and controller enables closed-loop motor control, resulting in rapid response, extremely high control precision, and flexible layout. It also eliminates reliance on a TCU (Telematics Control Unit), improving vehicle performance while ensuring driving and passenger comfort.

[0041] It should be noted that any modifications made by those skilled in the art to the specific embodiments of this utility model do not depart from the scope of the claims of this utility model. Accordingly, the scope of the claims of this utility model is not limited to the foregoing specific embodiments.

Claims

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

2. The electrically driven roller screw transmission shifting 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 ball screw by sensing changes in magnetic field strength, and transmits the rotation angle information to the control unit; The control unit controls the rotation angle of the ball screw based on the rotation angle information, thereby controlling the axial displacement of the shift finger.

3. The electrically driven roller screw transmission shifting actuator according to claim 2, characterized in that, It also includes a housing, The housing has a receiving cavity defined therein, and the receiving cavity has an opening at one end of the housing; The motor, the ball screw, and the ball screw nut are housed in the receiving cavity of the housing; The cavity contains a channel for the ball screw nut to perform linear reciprocating motion, and the ball screw nut is anti-torsionally disposed in the channel.

4. The electrically driven roller screw transmission shifting actuator according to claim 3, characterized in that, It also includes a guide sleeve, The guide sleeve is press-fitted into the channel of the housing, and the guide sleeve is sleeved on the roller screw nut; The inner wall of the guide sleeve is provided with several limiting grooves, and the outer wall of the roller screw nut is provided with several limiting protrusions that match the several limiting grooves. The combination of the aforementioned limiting grooves and limiting protrusions restricts the roller screw nut to only perform linear reciprocating motion along the roller screw.

5. The electrically driven roller screw transmission shifting actuator according to claim 3, characterized in that, It also includes a finger pivot. One end of the shift finger shaft passes through the opening of the housing and is sealed to the end of the ball screw nut away from the motor. The other end of the shift finger shaft is located outside the housing. The shift finger shaft follows the ball screw nut in synchronous linear reciprocating motion. A blind hole is provided at one end of the shift pin shaft that is connected to the ball screw nut, and the portion of the ball screw that extends out of the ball screw nut and is away from the motor is accommodated in the blind hole. The shift finger is fixed to the shift finger shaft, and the shift finger is located outside the housing.

6. The electrically driven roller screw transmission shifting actuator according to claim 5, characterized in that, The roller screw nut and the shift finger shaft are connected together by laser welding; The shift finger is fixedly connected to the shift finger shaft using a flexible cylindrical pin.

7. The electrically driven roller screw transmission shifting actuator according to claim 5, characterized in that, It also includes bushings, The bushing is fixed in a channel of the housing and adjacent to an opening of the housing; When the shift finger shaft follows the ball screw nut in synchronous linear reciprocating motion, the shift finger shaft passes through the bushing along with the ball screw nut, and the shift finger shaft and the ball screw nut are in clearance fit with the bushing.

8. The electrically driven roller screw transmission shifting actuator according to claim 3, characterized in that, It also includes bearing housings and four-point contact bearings. The bearing housing and the four-point contact bearing are housed within a defined receiving cavity inside the housing; The bearing housing 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 housing is fixed inside the housing and is arranged radially around the four-point contact bearing.

9. The electrically driven roller screw transmission shifting actuator according to any one of claims 1-8, characterized in that, The control unit is integrated into the SCU controller; The roller screw includes a motor shaft and a screw section. The motor shaft and the lead screw are coaxial and are 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 section, and the roller is provided between the roller screw nut and the screw section for transmission.

10. The electrically driven roller screw transmission shifting actuator according to claim 9, characterized in that, It also includes a magnetic head assembly. The magnetic head assembly is fixedly connected to the 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 in the magnetic field strength of the magnetic head assembly to obtain the rotation angle information of the ball screw.

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