CN105020349A - Two-gear automatic mechanical transmission for electric car - Google Patents

Abstract

The present invention proposes a two-speed mechanical automatic transmission for an electric vehicle, which includes a two-speed mechanical transmission and a shift operating mechanism. The core is that the shift operating mechanism is an automatic operating mechanism, including a housing, a shift shaft, The gear shifting actuator composed of a gear head, a motor with a worm gear reduction mechanism is arranged at one end of the gear shift shaft, and the worm gear of the worm gear reduction mechanism is in transmission connection with one end of the gear shift shaft; the other end of the gear shift shaft is provided with a rotation angle position sensor, The angle position sensor is fixedly connected with the shift shaft; the angle position sensor monitors the shift position and sends the signal to the control unit to judge the shift position. The invention completes automatic shifting, shifts quickly, and has no clutch slip loss; its structure is simple, and the scheme of the gearshift motor and the angle position sensor is reliable and effective. The scheme directly measures the shift shaft, which is more accurate and eliminates the Interference factors such as the transmission gap between the motor and the shift shaft can more effectively complete the adjustment and control of the shift torque during the shift process.

Description

A two-speed mechanical automatic transmission for electric vehicles

technical field

The invention relates to a two-speed mechanical transmission for electric vehicles, in particular to a two-speed mechanical automatic transmission for electric vehicles.

Background technique

Automobiles are an indispensable means of transportation for human beings. However, with the increasingly serious environmental pollution and the continuous reduction of non-renewable resources, the development of energy-saving and new energy vehicles has become an inevitable choice for all countries in the world. At present, my country's focus is to promote the industrialization of pure electric vehicles and plug-in hybrid vehicles, so as to improve the overall technical level of my country's automobile industry.

Among them, there are three main transmission schemes adopted by the electric vehicle power system:

The first option is to use a fixed reduction ratio and rely entirely on the motor to achieve the task of variable speed. According to the characteristic curve of the motor, it is difficult to make the motor work in the high-efficiency range while ensuring the power performance with a fixed reduction ratio, resulting in large current at start-up and low speed, high power consumption, weak climbing, and poor high-speed power. Since there is no neutral position, For some motors without energy feedback, it will cause the motor to generate electricity to backlash the controller when going downhill, causing the controller to be damaged.

The second option is to use the transmission system of traditional fuel vehicles. Compared with the internal combustion engine itself, the motor has the characteristics of high efficiency and a wide range. Traditional transmissions generally have four to six gears, which are overkill for pure electric vehicles, and at the same time complicate the structure and increase the cost.

The third option is to use a two-speed transmission; use a large reduction ratio when driving at low speeds to achieve better starting performance, and use a small reduction ratio when driving at high speeds to meet the maximum speed requirements. Due to the rationality of the program, many people have successfully explored in this area. Table 1 below shows the search results for related inventions:

Table I: serial number Application Number Invention name 1 201210384849.4 A kind of electric vehicle speed changer and speed change method thereof 2 201420430009.1 EV automatic transmission 3 201410093459.0 Single row planetary gear train two-speed mechanical automatic transmission for electric vehicles 4 201120265790.8 A mechanical transmission for an electric vehicle 5 201110067473.X An electric vehicle drive transmission mechanism 6 201210185035.8 Transverse power drive unit for pure electric vehicles with 2-speed mechanical automatic transmission 7 201310282237.9 A kind of electric vehicle transmission and transmission method 8 201210071244.X An electric vehicle automatic transmission

Patents 1 and 7 use a torque converter with a fixed reduction ratio or a planetary gear mechanism to provide a wider range of speed changes to make up for the lack of a single speed ratio, but the low efficiency and complex structure of the torque converter itself hinder its wide application.

Patent 2 uses hydraulic device control to switch between high and low gears. The complexity of the hydraulic system itself, the requirements for sealing, and the difficulty in adjusting the shift force make it less advantageous than the electric shift mechanism.

Patent 4 proposes a new solution for the parking brake of the mechanical transmission of electric vehicles.

Patent 3 uses a single-row planetary gear mechanism to realize two-speed shifting, and Patent 5 provides a scheme that uses multiple clutches and realizes gear shifting through their separation and engagement. The above-mentioned schemes all need to complete the shift action by means of the hydraulic control system. Patent 6 discloses a two-speed mechanical automatic transmission with a dry clutch, and the clutch is different from the traditional layout. Operation of the clutch and coupling sleeve enables power shifting without interruption. The clutch assembly used in the automatic transmission disclosed in Patent No. 8 contains active friction plates, passive friction plates and clutch pressure plates. The synchronizer sleeve is used for automatic shifting of gears. The above-mentioned schemes have all caused the increase of the complexity of the system structure and the difficulty of control.

Contents of the invention

Aiming at the two-speed mechanical transmission for electric vehicles, the present invention proposes a two-speed mechanical automatic transmission for electric vehicles, which only has two high and low gears, does not need a gear selection device and does not have a reverse gear, cancels the clutch, and utilizes the power motor of the electric vehicle to cooperate Speed adjustment completes gear shifting synchronization, and an automatic operating mechanism is set to realize automatic gear shifting. The invention can realize the simplification of the structure of the transmission and reduce the cost and self-weight of the vehicle on the basis of ensuring the related performance of the vehicle.

Technical idea: The two-speed mechanical transmission for electric vehicles only needs two high and low gears. The motor can be used to reverse the direction of the car. The transmission does not need to be reversed, so it only needs to be equipped with a shift control device without a gear selection device. .

The technical solution of the present invention: a two-speed mechanical automatic transmission for an electric vehicle, including a two-speed mechanical transmission and a shifting control mechanism, characterized in that:

The structure of the two-speed mechanical transmission: an input shaft and an output shaft are supported in parallel in the gearbox body, and the output shaft of the power motor directly drives the transmission input shaft; a low-speed gear set, a high-speed gear set and a synchronizer are arranged in the gearbox body. The shifting mechanism controls the synchronizer to select low gear, high gear or neutral gear;

The shift control mechanism is an automatic control mechanism, including a shift actuator composed of a housing, a shift shaft, and a shift dial. A motor with a worm gear reduction mechanism is arranged at one end of the shift shaft, and the worm gear reduction mechanism The turbine is connected to one end of the shift shaft in transmission; the other end of the shift shaft is provided with a rotation angle position sensor, which is fixedly connected to the shift shaft; the rotation angle position sensor monitors the shift position and sends the signal to the control unit to judge shift position.

Beneficial effects: the present invention makes full use of the characteristics of the power motor to realize automatic starting and infinitely variable speed, and cooperates with the two-speed transmission and the control device to complete automatic shifting, the shifting is rapid, and there is no slipping loss of the clutch; the use of the power motor and the transmission Excellent performance, expanding the range of speed and torque, with the simplest structure and the lowest cost, to meet the needs of both low-speed high-torque and high-speed driving; for motors with energy feedback, energy recovery can also be achieved, for those without energy feedback function The motor can use the neutral gear to complete sliding; the structure of the transmission is simple, and compared with the existing mechanical transmission, there are not many changes in the structure, and the production continuity is good. Compared with the original switch signal or integrated sensor on the motor to detect the gear signal, this scheme directly measures the shift shaft, which is more accurate, eliminates interference factors such as the transmission gap between the motor and the shift shaft, and can be completed more effectively. Adjustment and control of the shifting torque during the shifting process.

Description of drawings

Fig. 1 is the structural representation of two-speed mechanical transmission among the present invention;

Fig. 2 is a structural schematic diagram of the gear shifting mechanism in the present invention.

Detailed ways

In conjunction with Fig. 1 and Fig. 2, the present invention is further described as follows: a two-speed mechanical automatic transmission for an electric vehicle, including a two-speed mechanical transmission, a gear shifting mechanism,

The structure of the two-speed mechanical transmission: the input shaft 3 and the output shaft 5 are supported in parallel in the gearbox body 1, and the output shaft of the power motor 1 directly drives the input shaft 3; the gearbox body 1 is provided with a low-speed gear set 7 and a high-speed The gear set 4 and the synchronizer 6, the synchronizer 6 is controlled by the gear shifting mechanism to select a low gear, a high gear or a neutral position;

The shifting operation mechanism is an automatic operation mechanism, including a shift actuator composed of a housing 12, a shift shaft 11, and a shift dial 14. A motor with a worm gear reduction mechanism 9 is arranged at one end of the shift shaft 11. 8. The worm gear 9-1 of the worm gear reduction mechanism 9 is in transmission connection 10 with one end of the shift shaft 11; the other end of the shift shaft is provided with a rotation angle position sensor 13, and the rotation angle position sensor 13 is fixedly connected with the shift shaft 11; the rotation angle position The sensor 13 monitors the shift position and sends the signal to the control unit to judge the shift position.

The motor 8 and the angular position sensor 13 with the worm gear reduction mechanism 9 mentioned above are all mature products in the prior art, and the indicators such as the power of the motor and the detection range of the angular position sensor should be fully considered when matching.

As shown in Figure 2, the specific structure of the transmission connection 10 between the turbine wheel 9-1 and one end of the shift shaft 11 is: a spline pair fit or a tooth-shaped key fit. The transmission connection can also be other structures, as long as the transmission can be realized, such as a shaft coupling and the like.

The combination of the two-speed mechanical transmission and the shifting mechanism in the present invention is a conventional technology, and will not be described in detail here.

Claims (2)

1. two gear automatic speed changer for machine used for electric vehicle, comprise two gear mechanical transmissions, shift control mechanism, it is characterized in that:

The structure of two gear mechanical transmissions: parallel support has input shaft, output shaft in gearbox casing, the output shaft Direct driver transmission input shaft of power motor; Be provided with bottom gear gear train and top gear gear train and synchronizer in gearbox casing, select bottom gear or top gear or neutral position by shift control mechanism control synchro;

Described shift control mechanism is automatic controller, comprise the gear shifting actuating mechanism of housing, shifting shaft, gear shifting pulling head formation, arrange a motor carrying turbine worm reducer structure in shifting shaft one end, the turbine of turbine worm reducer structure with shifting shaft one end in being in transmission connection; The shifting shaft the other end is provided with angle position sensor, and angle position sensor is fixedly connected with shifting shaft; Signal is also passed to control unit by angle position Sensor monitoring drive range, to judge drive range.

2. one according to claim 1 two gear automatic speed changer for machine used for electric vehicle, it is characterized in that the turbine of described turbine worm reducer structure with shifting shaft one end in the concrete structure be in transmission connection: in being that spline pair coordinates or serrations coordinates.