Electric loader gearbox, control method thereof and electric loader

Abstract

An electric loader gearbox comprises a motor, an input gear set and a planet row, the input gear set and the planet row are connected with the motor, and the planet row is composed of a sun gear connected with the input gear set, a planet gear meshed with the sun gear, a planet carrier assembled on the planet gear and a gear ring meshed with the planet gear. The gearbox is characterized by further comprising an output shaft in spline fit with the planet carrier and a gear shifting assembly assembled on the output shaft, the gear shifting assembly is fixedly connected with the gearbox shell and the gear ring, and the gear ring is locked by the gearbox shell or locked with the planet carrier into a whole along with gear engaging of the gear shifting assembly. According to the invention, rapid switching between a high-speed torque-resisting gear and a low-speed high-torque gear is realized, the number of gears is reduced, a variable speed control structure and a variable speed control process are simplified, so that the loader can keep the optimal performance under different loads and speeds, the transmission efficiency is improved, the energy consumption is reduced, the space volume and the overall weight of a gearbox are reduced, and the degree of freedom of whole vehicle arrangement is improved. The invention further provides an electric loader and a control method of the gearbox of the electric loader.

Description

Technical Field

[0001] The present invention relates to an electric loader transmission, a control method thereof, and an electric loader, belonging to the technical field of electric loaders. Background Art

[0002] Loaders are used for loading, pushing, and construction operations of bulk materials such as soil, sand and gravel, and coal, etc., and are widely used in various construction sites. The transmission system of traditional wheel loaders uses an internal combustion engine as the power source and a hydraulic transmission as the transmission device, which mainly consists of an engine, a hydraulic torque converter, a power shift transmission, a drive shaft, a drive axle, etc. The hydraulic torque converter has a low transmission efficiency, and its average efficiency during normal operation is only about 30%. The output torque of the hydraulic torque converter can only be adjusted indirectly through the diesel engine throttle, and the traction force and vehicle speed cannot be adjusted and controlled separately, which makes the control difficult. At the same time, due to the narrow speed change range of the hydraulic torque converter, in order to meet a wider speed regulation range, a multi-speed transmission must be used, which makes the structure of the transmission complex. At the same time, there are problems of frequent shifting and large shifting impact during driving, and the overall operating comfort of the machine is relatively poor. To conform to the concept of energy conservation and environmental protection, new energy technology is becoming more and more popular in the field of electric loaders. The engine of the electric loader is changed from an internal combustion engine to an electric motor, and the control method remains unchanged. The power transmission system of this method still has the following problems: 1. The transmission assembly has a large volume, a complex structure, low efficiency, an unmatched speed ratio, and high manufacturing and maintenance costs. Traditional multi-speed transmissions are not suitable for electric loaders due to their high cost caused by multiple gears.

[0003] 2. The speed and torque range of electric loaders is wider, but a transmission still needs to be equipped to broaden the torque and speed range for economic and dynamic considerations.

[0004] 3. Compared with passenger cars, the operating environment and working conditions of electric loaders are more severe. When working, it is necessary to output power with a low speed and a large torque. If the transmission ratio of the transmission is small, an electric motor with a low speed and a large torque needs to be selected, and such an electric motor has a large size and a relatively high cost. Summary of the Invention

[0005] The electric loader transmission provided by the present invention realizes the rapid switching between high-speed low-torque gears and low-speed high-torque gears, reduces the number of gears, simplifies the speed change control structure and process, enables the loader to maintain the best performance under different loads and speeds, improves the transmission efficiency, reduces energy consumption, improves the economy and dynamic performance of the loader, reduces the space volume and overall weight of the transmission, and improves the freedom of vehicle layout. The present invention also provides a control method for an electric loader and a transmission of a moving loader.

[0006] To achieve the above object, the technical solution adopted by the present invention is: The electric loader gearbox includes a motor, an input gear set connected to the motor, and a planetary gear train. The planetary gear train consists of a sun gear connected to the input gear set, planet gears meshing with the sun gear, a planet carrier assembled on the planet gears, and a ring gear meshing with the planet gears. It is characterized in that: it further includes an output shaft in spline fit with the planet carrier, and a shifting component assembled on the output shaft. The shifting component is fixedly connected to the gearbox housing and the ring gear respectively. The ring gear is locked by the gearbox housing or locked with the planet carrier as a whole when the shifting component is in gear.

[0007] Preferably, the shifting component includes a shifting gear rotatably mounted on the output shaft through a bearing and coaxially fixed to the ring gear, a shifting sleeve assembled on the shifting gear and movable axially, a working gear fixed to the gearbox housing and coaxially aligned with the shifting gear, and a shifting gear for vehicle movement coaxially fixed on the output shaft and coaxially aligned with the shifting gear. The shifting gear is located between the working gear and the shifting gear for vehicle movement. When the shifting sleeve moves leftward to engage with the working gear, the ring gear is locked to the gearbox housing. When the shifting sleeve moves rightward to engage with the shifting gear for vehicle movement, the ring gear is locked with the planet carrier as a whole.

[0008] Preferably, the input gear set includes an input gear fixed to the output end of the motor, a constantly meshing gear meshing with the input gear, and a compound gear shaft. The constantly meshing gear is coaxially fixed to one end of the compound gear shaft, and the sun gear is coaxially fixed to the other end of the compound gear shaft.

[0009] Preferably, the compound gear shaft is a hollow shaft. The output shaft passes through the planetary gear train, with one end extending from the compound gear shaft and the other end extending from the ring gear.

[0010] Preferably, a brake is assembled on the output shaft.

[0011] Preferably, the input gear shaft, the planetary gear train, the shifting component, and the brake are arranged in sequence from front to back on the output shaft.

[0012] An electric loader, characterized in that: it includes the above-mentioned electric loader gearbox.

[0013] The control method of the above-mentioned electric loader gearbox is characterized in that: the gear positions of the shifting component are set as the working gear and the shifting gear for vehicle movement, and the initial position of the shifting component is the neutral position between the working gear and the shifting gear for vehicle movement; When the electric loader needs to work, control the shifting component to engage the working gear to lock the ring gear to the gearbox housing. The power output by the motor is transmitted to the planetary gear train through the input gear set, and is decelerated by the large speed ratio of the planetary gear train to form a low-speed and high-torque power transmission to the output shaft, and the output shaft outputs power to drive the electric loader to work; When the electric loader needs to move, the shifting component is controlled to engage the vehicle moving gear to lock the ring gear and the planet carrier into a whole. The power output by the motor is transmitted to the planetary gear set through the input gear set. In the planetary gear set, only a small speed ratio reduction between the sun gear and the planet gear is formed and then directly driven to the output shaft. The output shaft outputs power to drive the electric loader to transfer from one working point to another working point.

[0014] Preferably, when parking, the shifting component is shifted to the neutral gear and the output shaft is braked by a brake to prevent rotation.

[0015] The beneficial effects of the invention are as follows: In the electric loader gearbox of the present invention, the output shaft is in spline fit with the planet carrier and rotates synchronously with the planet carrier. The shifting component is installed on the output shaft and is fixedly connected to the gearbox housing and the ring gear respectively. When the shifting component engages the gear to lock the ring gear and the gearbox housing, the power of the motor is transmitted from the input gear set to the planetary gear set, and a large speed ratio reduction is formed by the planetary gear set to transmit the power of low speed and high torque to the output shaft, realizing the power output of low speed and high torque and meeting the high torque power requirements of the loader working conditions. When the shifting component engages the gear to lock the ring gear and the planet carrier into a whole, the power of the motor is transmitted to the planetary gear set through the input gear set. In the planetary gear set, only a small speed ratio reduction between the sun gear and the planet gear is formed and then directly driven to the output shaft, realizing the power output of high speed and low torque and meeting the fast moving requirements of the electric loader vehicle moving conditions; the cooperation of the planetary gear set, the output shaft and the shifting component is used to realize the rapid switching between the high speed and low torque gear and the low speed and high torque gear, reduce the number of gears, simplify the speed change control structure and process, utilize the high-efficiency interval and reversible characteristics of the motor, cancel the reverse gear structure, utilize the transmission characteristics of the large speed ratio of the planetary gear set, realize the load operation requirements of low speed and high torque, reduce costs and improve the transmission efficiency, enable the loader to maintain the best performance at different loads and speeds, improve the transmission efficiency, reduce energy consumption, improve the economy and power performance of the loader, and utilize the compact structure characteristics of the planetary gear set to reduce the space volume and overall weight of the gearbox and improve the degree of freedom of the vehicle layout. Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the transmission structure of the electric loader gearbox.

[0017] Figure 2 It is a schematic diagram of the transmission structure of the electric loader gearbox when the shifting sleeve is combined with the working gear.

[0018] Figure 3 It is a schematic diagram of the transmission structure of the electric loader gearbox when the shifting sleeve is combined with the vehicle moving gear. Detailed Embodiments

[0019] The following will Figures 1 to 3 make a detailed description of the embodiments of the present invention.

[0020] Electric loader transmission, comprising a motor 1, an input gear set 2 connected to the motor 1, and a planetary gear set 3. The planetary gear set 3 consists of a sun gear 31 connected to the input gear set 2, a planetary gear 32 meshing with the sun gear 31, a planet carrier 33 assembled on the planetary gear 32, and a ring gear 34 meshing with the planetary gear 32. It is characterized in that: it further includes an output shaft 4 in spline fit with the planet carrier 33, and a shifting component 5 assembled on the output shaft 4. The shifting component 5 is fixedly connected to the transmission housing 6 and the ring gear 34 respectively. The ring gear 34 is locked by the transmission housing 6 or locked with the planet carrier 33 as a whole when the shifting component 5 is in gear.

[0021] For the above-mentioned electric loader transmission, the output shaft 4 is in spline fit with the planet carrier 33 and rotates synchronously with the planet carrier 33. The shifting component 5 is assembled on the output shaft 4 and fixedly connected to the transmission housing 6 and the ring gear 34 respectively. When the shifting component 5 is in gear and locks the ring gear 34 with the transmission housing 6, the power of the motor 1 is transmitted from the input gear set 5 to the planetary gear set 3, and is decelerated by a large speed ratio of the planetary gear set 3 to form a low-speed and high-torque power transmission to the output shaft 7, realizing the low-speed and high-torque power output and meeting the high-torque power demand of the loader operating conditions. When the shifting component 5 is in gear and locks the ring gear 34 with the planet carrier 33 as a whole, the power of the motor is transmitted to the planetary gear set 3 through the input gear set. Only a small speed ratio reduction between the sun gear and the planetary gear is formed in the planetary gear set 3 and then directly drives to the output shaft 4, realizing the high-speed and low-torque power output and meeting the fast moving demand of the electric loader during vehicle moving conditions; the cooperation of the planetary gear set 3, the output shaft 4 and the shifting component 2 realizes the fast switching between the high-speed and low-torque gear and the low-speed and high-torque gear, reduces the number of gears, simplifies the speed change control structure and process, utilizes the high-efficiency interval and reversible characteristics of the motor, cancels the reverse gear structure, and utilizes the large transmission ratio characteristics of the planetary gear set to realize the low-speed and high-torque load operation demand, reduces costs and improves the transmission efficiency, enables the loader to maintain the best performance at different loads and speeds, improves the transmission efficiency, reduces energy consumption, improves the economy and power performance of the loader, and utilizes the compact structure characteristics of the planetary gear set to reduce the space volume and overall weight of the transmission, and improves the freedom of vehicle layout.

[0022] Among them, the shifting component 5 includes a shifting gear 51 rotatably mounted on the output shaft 2 through a bearing and coaxially fixed with the gear ring 34, a shifting sleeve 52 assembled on the shifting gear 51 and axially movable, a working gear 53 fixed to the transmission housing 6 and coaxially aligned with the shifting gear 51, and a shifting gear 54 coaxially fixed on the output shaft 4 and coaxially aligned with the shifting gear 51. The shifting gear 51 is located between the working gear 53 and the shifting gear 54. When the shifting sleeve 52 moves leftward to engage with the working gear 53, the gear ring 34 is locked to the transmission housing. When the shifting sleeve 52 moves rightward to engage with the shifting gear 54, the gear ring 34 and the planet carrier 33 are locked together as a whole. The shifting sleeve 52 is assembled on the shifting gear 51 and is located between the working gear 53 and the shifting gear 54. In the initial state, it is not engaged with either the working gear 53 or the shifting gear 54. When the shifting sleeve 52 moves leftward on the shifting gear 51 to engage with the working gear 53, the gear ring 34 is locked by the transmission housing 6 and does not rotate. The power of the motor 1 is transmitted to the planetary gear set 3 through the input gear set 2. After being decelerated and torque-increased by a large speed ratio of the planetary gear set 3, the power is transmitted to the output shaft 4, and the power output from the output shaft 4 is suitable for the working conditions of the loader. When the shifting sleeve 52 moves rightward on the shifting gear 51 to engage with the shifting gear 54, the gear ring 34 and the planet carrier 33 are locked together as a whole. The electric power is transmitted to the planetary gear set 3 through the input gear set 2. Since the planet carrier 33 and the gear ring 34 are locked together, only a small speed ratio reduction between the sun gear and the planet gears is formed in the planetary gear set 3. The planet gear 32 will directly drive the gear ring 34 and the planet carrier 33 to rotate synchronously, and the power is directly transmitted to the output shaft 4 in a direct drive manner, forming a high-speed and low-torque power transmission to the output shaft 4. The power output from the output shaft 4 is suitable for the shifting conditions of the loader when transferring from one working point to another working point.

[0023] Among them, the input gear set 2 includes an input gear 21 fixed to the output end of the motor, a constant-mesh gear 22 meshing with the input gear 21, and a compound gear shaft 23. The constant-mesh gear 22 is coaxially fixed to one end of the compound gear shaft 23, and the sun gear 31 is coaxially fixed to the other end of the compound gear shaft 23. The input gear 21 rotates synchronously with the motor and transmits the power to the constant-mesh gear 22. The constant-mesh gear 22 drives the compound gear shaft 23 and the sun gear 21 to rotate synchronously, realizing the stable transmission of the power to the planetary gear set 3.

[0024] Among them, the compound gear shaft 23 is a hollow shaft. The output shaft 4 passes through the planetary gear set 3, with one end extending from the compound gear shaft 23 and the other end extending from the gear ring 34. The output shaft 4 passes through the planetary gear set 3 and passes out of the compound gear shaft 23. The output shaft 4 is coaxially arranged in the planetary gear set 3, reducing the axial and radial dimensions of the transmission, improving the structural compactness, reducing the space volume of the transmission, so as to improve the degree of freedom of the transmission arrangement in the whole machine.

[0025] Among them, a brake 7 is assembled on the output shaft 4. When the shift sleeve 52 is located between the working gear 53 and the shifting gear 54 and is not engaged with either of them, it is in the neutral position. Since the ring gear 34 is fixed to the shifting gear 51 and the shifting gear 51 can rotate on the output shaft 4, if the motor 1 outputs power in the neutral state, the power is transmitted through the input gear set 2 to the planetary gear train 3, which will cause the ring gear 34 and the shifting gear 51 to rotate on the output shaft 4, but the power will not be transmitted to the output shaft 4. The planet gear 32 will only rotate on its own under the drive of the sun gear and will not drive the planet carrier 33 to rotate. At this time, the torque received by the planet carrier 33 is very small, so the torque transmitted from the planet carrier 33 to the output shaft 4 is very small and will not drive the output shaft to rotate. The force between the planet carrier 33 and the output shaft 4 in the neutral state is very small, which can prevent the spline teeth between the planet carrier 33 and the output shaft 4 from deforming due to large force. Since the planet carrier is not locked at this time, to ensure that the loader stops stably without slipping, the brake 7 needs to lock and brake the output shaft 4 to prevent the output shaft 4 from rotating and ensure that the loader is in a stable parking state without slipping.

[0026] Among them, the input gear shaft 2, the planetary gear train 3, the shifting assembly 5 and the brake 7 are arranged in sequence from front to back on the output shaft 4. Make full use of the axial space of the output shaft 4, effectively reduce the axial and radial dimensions of the gearbox, improve the structural compactness, and further improve the degree of freedom of the gearbox arrangement in the whole machine.

[0027] The present invention also provides an electric loader, which is characterized in that it includes the above-mentioned electric loader gearbox. It meets the high-torque power demand of the loader operation condition and the fast movement demand of the vehicle shifting condition, realizes the rapid switching between the high-speed low-torque gear and the low-speed high-torque gear, and the loader can maintain the best performance under different loads and speeds, improve the transmission efficiency, reduce the energy consumption, and improve the economy and power performance of the loader.

[0028] The present invention also provides a control method for the above-mentioned electric loader gearbox, which is characterized in that the gear position of the shifting assembly is set as the working gear and the shifting gear, and the initial position of the shifting assembly is the neutral position between the working gear and the shifting gear; When the electric loader needs to operate, control the shifting assembly 5 to engage the working gear to lock the ring gear 34 on the gearbox housing 6. The power output by the motor 1 is transmitted through the input gear set 2 to the planetary gear train 3, and is decelerated by a large speed ratio of the planetary gear train 3 to form a low-speed high-torque power and transmitted to the output shaft 4, and the output shaft 4 outputs power to drive the electric loader to operate; When the electric loader needs to shift the vehicle, control the shifting assembly 5 to engage the shifting gear to lock the ring gear 34 and the planet carrier 33 into a whole. The power output by the motor 1 is transmitted through the input gear set 2 to the planetary gear train 3, and is directly driven by the planetary gear train 3 and transmitted to the output shaft 4, and the output shaft 4 outputs power to drive the electric loader to transfer from one operation point to another operation point.

[0029] For the control method described above, when the shifting component 5 engages the gear to lock the ring gear 34 to the transmission housing 6, the power of the motor 1 is transmitted from the input gear set 5 to the planetary gear set 3. The planetary gear set 3 decelerates at a large speed ratio to form a low-speed and high-torque power transmission to the output shaft 4, realizing the low-speed and high-torque power output and meeting the high-torque power demand of the loader operating conditions. When the shifting component 5 engages the gear to lock the ring gear 34 and the planet carrier 33 into a whole, the power of the motor is transmitted to the planetary gear set 3 through the input gear set, and is directly driven by the planetary gear set 3 to the output shaft 4, realizing the high-speed and low-torque power output and meeting the fast-moving demand of the electric loader for vehicle relocation. The cooperation of the planetary gear set 3, the output shaft 4 and the shifting component 2 realizes the rapid switching between the high-speed and low-torque gear and the low-speed and high-torque gear, reduces the number of gears, and simplifies the transmission control process.

[0030] Among them, when parking, the shifting component 5 is shifted to neutral and the brake 7 is used to brake and prevent the output shaft from rotating. When the shifting sleeve 52 is shifted to neutral, it is located between the working gear 53 and the vehicle-relocation gear 54 and is not engaged with either of them. Since the ring gear 34 is fixed to the shifting gear 51 and the shifting gear 51 can rotate on the output shaft 4, if the motor 1 outputs power, since the ring gear 34 can rotate on the output shaft 4, the power is transmitted from the input shaft gear set 2 to the planetary gear set 3. The planet gears can only drive the ring gear 34 to rotate on the output shaft 4, but will not transmit the power to the output shaft 4. The planet gears can only rotate by themselves and will not drive the planet carrier 33 to rotate. The torque received by the planet carrier 33 at this time is very small, so the torque transmitted by the planet carrier 33 to the output shaft 4 is very small and cannot drive the output shaft 4 to rotate. Since the planet carrier is not locked at this time, to ensure that the loader stops stably without slipping, the brake 7 needs to lock and brake the output shaft 4 to prevent the output shaft 4 from rotating and ensure that the loader is in a stable parking state without slipping. When the loader shifts gears in the parking state, it is necessary to first control the brake 7 to cancel the braking of the output shaft 4, and then shift the shifting component 5 from neutral to the vehicle-relocation gear or the working gear.

[0031] The technical solutions of the embodiments of the present invention are completely described above in conjunction with the accompanying drawings. It should be noted that the described embodiments are only a part of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

Claims

1. An electric loader gearbox, comprising a motor, an input gear set connected to the motor and a planetary gear set, wherein the planetary gear set is composed of a sun gear connected to the input gear set, planetary gears meshing with the sun gear, a planetary carrier mounted on the planetary gears and a ring gear meshing with the planetary gears, and is characterized in that: It also includes an output shaft that cooperates with the planet carrier spline and a shift assembly assembled on the output shaft. The shift assembly is fixedly connected to the transmission case and the ring gear respectively. The ring gear is locked by the transmission case or locked with the planet carrier as a whole when the shift assembly is engaged.

2. The electric loader gearbox according to claim 1, characterized in that: The shift assembly includes a shift gear rotatably mounted on the output shaft through a bearing and coaxially fixed with the ring gear, a shift gear sleeve assembled on the shift gear and movable axially, a working gear fixed to the transmission housing and coaxially aligned with the shift gear, and a shift gear coaxially fixed on the output shaft and coaxially aligned with the shift gear. The shift gear is located between the working gear and the shift gear. The shift gear sleeve moves to the left and combines with the working gear to lock the ring gear on the transmission housing. The shift gear sleeve moves to the right and combines with the shift gear to lock the ring gear and the planetary carrier into a whole.

3. The electric loader gearbox according to claim 1, characterized in that: The input gear set includes an input gear fixed to the output end of the motor, a constant mesh gear meshing with the input gear and a compound gear shaft, the constant mesh gear is coaxially fixed to one end of the compound gear shaft, and the sun gear is coaxially fixed to the other end of the compound gear shaft.

4. The electric loader gearbox according to claim 3, characterized in that: The compound gear shaft is a hollow shaft, the output shaft passes through the planetary gear, one end of the output shaft extends out from the compound gear shaft, and the other end extends out from the gear ring.

5. The electric loader gearbox according to claim 1, characterized in that: The output shaft is equipped with a brake.

6. The electric loader gearbox according to claim 5, characterized in that: The input gear shaft, planetary gear, shift assembly and brake are arranged in sequence from front to back on the output shaft.

7. Electric loader, characterized in that: A gearbox for an electric loader comprising the gearbox as claimed in any one of claims 1 to 6.

8. The control method of the electric loader gearbox according to any one of claims 1 to 6, characterized in that: The gear position of the shift assembly is set to the working gear and the moving gear, and the initial position of the shift assembly is the neutral position between the working gear and the moving gear; When the electric loader needs to work, the shift assembly is controlled to engage the working gear to lock the ring gear on the gearbox housing. The power output by the motor is transmitted to the planetary gear set through the input gear set, and the planetary gear set is decelerated by a large speed ratio to form a low-speed and high-torque power that is transmitted to the output shaft. The output shaft outputs power to drive the electric loader to work. When the electric loader needs to move, the shift assembly is controlled to shift the gear to lock the ring gear and the planetary carrier into a whole. The power output by the motor is transmitted to the planetary gear set through the input gear set. In the planetary gear set, only a small speed ratio is formed between the sun gear and the planetary gear, and then it is directly driven to the output shaft. The output shaft outputs power to drive the electric loader to move from one working point to another.

9. The control method of the electric loader gearbox according to claim 8, characterized in that: When parking, shift the gear assembly to neutral and use the brake to prevent the output shaft from rotating.

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