Electrically driven rear sub-gearbox shift actuator

Abstract

The application discloses an electric commercial vehicle rear auxiliary gearbox shifting actuator, which is driven by a DC brushless motor to rotate a lead screw, and is driven by a lead screw nut to move a shifting fork shaft transversely, and is driven by a lever structure to drive a shifting fork, so as to drive a high-low gear sliding sleeve to move to a high gear cone hub or a low gear cone hub, in the process, the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the high-low gear sliding sleeve, and the high-low gear sliding sleeve is always in engagement with the

Description

Technical Field

[0001] This invention relates to the field of vehicle shifting technology, and more specifically, to a shifting actuator for the rear auxiliary gearbox of an electric commercial vehicle. Background Technology

[0002] Heavy commercial vehicles typically use 12-speed or 16-speed gearboxes. To reduce axial dimensions, multi-speed gearboxes usually combine a main gearbox and an auxiliary gearbox. The auxiliary gearbox generally contains mechanical components such as a sun gear, planet gears, planet carriers, and a ring gear. Traditional auxiliary gearbox shifting actuators sometimes use wet brakes and sometimes use synchronizers with traditional structures. Both are very large, which increases the size of the auxiliary gearbox.

[0003] In traditional rear auxiliary gearbox planetary gear mechanism, when the shifting actuator is a wet brake, it consists of multiple steel plate assemblies that are circumferentially fixed to the gearbox and multiple friction plate assemblies that are circumferentially fixed to the rotating parts. This occupies a large volume, which increases the size of the gearbox. The wet brake requires the replenishment of oil and the need to set up a separate oil passage, which increases the manufacturing cost.

[0004] When using a traditional synchronizer as the shifting actuator, the complex structure of the traditional synchronizer will result in certain shifting losses, and the large axial dimension of the traditional synchronizer will increase the axial dimension of the rear auxiliary gearbox.

[0005] Currently, the drive forms of gear shifting actuators are mainly divided into pneumatic, hydraulic, and electric types. Although pneumatic types have high shifting force, the shifting process is difficult to control due to the compressibility of gas, the control process is rough, and high airtightness is required. Hydraulic types have good control precision, but require oil circuits and oil pump devices, and leakage can easily cause pollution. In addition, both pneumatic and hydraulic types require external channels, which increases costs, and the shifting impact is large and the shifting is not precise enough. Electric types have higher transmission efficiency, more precise control, and can operate using on-board power. Summary of the Invention

[0006] The purpose of this invention is to design and develop a gear shifting actuator for the rear auxiliary box of an electric commercial vehicle. By using a gear shifting motor to drive the gear shifting fork shaft in combination with a lever structure, the shifting force is increased while achieving precise control of the shifting stroke. The combination of spring, high-gear synchronizing ring and low-gear synchronizing ring simplifies the structure while enabling rapid and accurate gear shifting and reducing shifting impact.

[0007] The technical solution provided by this invention is as follows:

[0008] A gear shifting actuator for the rear auxiliary storage compartment of an electric commercial vehicle, comprising:

[0009] Casing; and

[0010] The shift motor is fixed inside the housing;

[0011] A lead screw, which is connected to the output end of the shift motor;

[0012] The shift fork shaft is detachably connected to the nut of the lead screw;

[0013] The shift fork includes a fork head end and a fork opening end. The fork head end is engaged with the shift fork shaft, and the middle part of the fork opening end is rotatably fixed in the housing.

[0014] The high and low gear sliding sleeve has its outer side meshing with the gear ring of the planetary mechanism, and the high and low gear sliding sleeve is rotatably engaged with the fork end;

[0015] A high-gear synchronous ring is disposed inside the high-low gear sliding sleeve and selectively meshes with it. One end of the high-gear synchronous ring is provided with a plurality of first fixed protrusions spaced apart in sequence.

[0016] A low-gear synchronizing ring is disposed inside the high-low gear sliding sleeve and selectively meshes with it. One end of the low-gear synchronizing ring is provided with a plurality of second fixed protrusions spaced apart in sequence.

[0017] Multiple springs are respectively arranged one-to-one between the multiple first fixed protrusions and second fixed protrusions, so that the gear teeth of the high-gear synchronous ring and the low-gear synchronous ring are misaligned;

[0018] A high-end cone hub is disposed at the other end of the high-end synchronizing ring, and the high-end cone hub is connected to the planet carrier of the planetary mechanism;

[0019] A low-gear cone hub is disposed at the other end of the low-gear synchronizing ring, and the low-gear cone hub is fixed inside the housing;

[0020] The high- and low-gear sliding sleeves can be selectively connected to the high-gear cone hub or the low-gear cone hub.

[0021] Preferably, the shifting motor is a DC brushless motor.

[0022] Preferably, one end of the nut of the lead screw has an annular stepped flange.

[0023] Preferably, one end of the shift fork shaft has an arc-shaped groove;

[0024] The arc-shaped groove engages with the annular stepped flange.

[0025] Preferably, it also includes:

[0026] An annular groove is provided on the outer side of the high and low gear sliding sleeve;

[0027] The fork end engages with the annular groove in a rotating manner.

[0028] Preferably, both ends of the inner teeth of the high and low gear sliding sleeves are tapered structures.

[0029] Preferably, the outer teeth of both the high-gear synchronizing ring and the low-gear synchronizing ring have an inclined surface structure;

[0030] The high and low gear sliding sleeves and the high gear synchronization ring or the low gear synchronization ring can be locked selectively.

[0031] Preferably, the outer teeth of both the high-gear and low-gear cone hubs are conical.

[0032] Preferably, the inner sides of both the high-gear and low-gear synchronous rings are friction cone surfaces, and both the high-gear and low-gear synchronous rings are provided with spiral grooves on their inner sides.

[0033] The beneficial effects of this invention are as follows:

[0034] (1) The present invention designs and develops an electric commercial vehicle rear auxiliary box shifting actuator, which adopts a DC brushless motor, detects the rotor position and calculates the displacement of the shifting fork shaft, thereby realizing precise control of the shifting stroke.

[0035] (2) The electric commercial vehicle rear auxiliary box shifting actuator designed and developed by the present invention drives the shift fork shaft through the motor drive screw nut structure. The transmission structure is simple and efficient. A lever mechanism is set at the position of the shift fork to increase the shifting force and reduce the driving pressure on the motor while ensuring the force required for shifting and reducing the motor power.

[0036] (3) The electric commercial vehicle rear auxiliary gear shifting actuator designed and developed by the present invention adopts a new type of high and low gear synchronizer with 6 fixed protrusions for mounting springs, which simplifies the overall structure of the synchronizer and is conducive to the lightweighting of the gearbox. The synchronizer shifts gears quickly and accurately, and can also reduce the impact caused by shifting gears and extend the service life of the gearbox. The structure is compact, thus achieving the purpose of reducing costs. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the shifting mechanism of the rear auxiliary box shifting actuator of the electric commercial vehicle described in this invention.

[0038] Figure 2 This is a schematic diagram of the assembly structure of the shift fork described in this invention.

[0039] Figure 3 This is a schematic diagram of the synchronizer of the rear auxiliary gearbox shifting actuator of the electric commercial vehicle described in this invention.

[0040] Figure 4This is an exploded structural diagram of the synchronizer described in this invention.

[0041] Figure 5 This is a schematic diagram of the cross-sectional structure of the synchronizer described in this invention.

[0042] Figure 6 This is a schematic diagram of the high and low gear sliding sleeve of the present invention.

[0043] Figure 7 This is a schematic diagram of the assembly structure of the high-speed synchronous ring and the low-speed synchronous ring described in this invention.

[0044] Figure 8 This is a schematic diagram of the longitudinal cross-sectional structure of the synchronizer described in this invention.

[0045] Figure 9 This is a schematic diagram of the gear shifting structure described in this invention. Detailed Implementation

[0046] The present invention will now be described in further detail so that those skilled in the art can implement it based on the description.

[0047] The present invention provides a gear shifting actuator for the rear auxiliary box of an electric commercial vehicle, comprising a housing, a gear shifting mechanism and a synchronizer.

[0048] like Figure 1 , Figure 2 As shown, the shifting mechanism includes: a shifting motor 101, a lead screw 102, a nut 103, a shift fork shaft 111, and a shift fork 112. The shifting motor 101 is fixed inside the housing 100. The lead screw 102 is connected to the output end of the shifting motor 101 and can rotate circumferentially. One end of the nut 103 has an annular stepped flange, and the nut 103 is fitted over the lead screw 102, forming a lead screw-nut structure. Rotation of the lead screw 102 can drive axial movement of the nut 103. The shift fork shaft 111 has an arc-shaped groove that engages with the annular stepped flange of the nut 103, allowing the shift fork shaft 111 to be detachably connected to the nut 103 of the lead screw. The shift fork 112 includes a fork head end and a fork mouth end. The fork head end engages with the shift fork shaft 111, and the fork mouth end engages with the synchronizer, which is rotatable. The intersection of the fork head end and the fork mouth end is a lever fulcrum, allowing the shift fork shaft 111 to move in the opposite direction to the high and low gear sliding sleeve.

[0049] The shift motor 101 is a DC brushless motor.

[0050] like Figure 2As shown, the shift fork shaft 111 is provided with a slot, and the fork head end of the shift fork 112 is placed in the slot. The fork head end can move with the shift fork shaft 111. Two symmetrical positioning pins 113 are provided in the middle of the fork end. One end of each positioning pin 113 is embedded and fixed on the housing 100, and the other end of each positioning pin 113 passes through the middle of the fork end. The shift fork 112 can rotate around the positioning pin 113, which is the lever fulcrum.

[0051] The fork end is provided with a shift fork slider 114. One end of the shift fork slider 114 is a shaft that is embedded in the shift fork 112. The shift fork slider 114 can rotate freely relative to the shift fork 112. The other end is used to move the synchronizer.

[0052] When the shift fork shaft 111 moves, it drives the fork head to move. Due to the fixing effect of the locating pin 113, the force on the fork head is increased. Due to the lever effect, the actual movement trajectory of the fork head is arc-shaped. Directly acting on the synchronizer can easily cause damage. By setting the shift fork slider 114, the force on the synchronizer is ensured to be in a straight line, reducing synchronizer wear.

[0053] like Figure 3 , Figure 4 , Figure 5 As shown, the synchronizer includes: a high-low gear sliding sleeve 120, a high-gear synchronization ring 130, a low-gear synchronization ring 140, a high-gear cone hub 150, a low-gear cone hub 160, and multiple springs 170.

[0054] Among them, such as Figure 6 As shown, the outer edge of the high and low gear sliding sleeve 120 has distributed gear teeth that mesh with the gear ring teeth of the planetary mechanism. The inner edge of the high and low gear sliding sleeve 120 has distributed gear teeth, and both ends of the inner edge gear teeth of the high and low gear sliding sleeve 120 are conical structures. The outer side of the high and low gear sliding sleeve 120 has an annular groove, and the fork end is engaged in the annular groove and the high and low gear sliding sleeve 120 is rotatable.

[0055] like Figure 7 As shown, the outer edge of the high-gear synchronous ring 130 has distributed gear teeth, and the outer edge gear teeth of the high-gear synchronous ring 130 have a beveled structure. The beveled structure can match and mesh with the inner edge gear tooth conical surface structure of the high and low gear sliding sleeve 120. The inner edge of the high-gear synchronous ring 130 has a friction cone surface and is provided with a spiral groove. One end of the high-gear synchronous ring 130 is provided with a plurality of first fixed protrusions 131 at intervals. The plurality of first fixed protrusions 131 are large protrusions and small protrusions arranged at intervals. The large protrusions and small protrusions are provided with circular grooves in their circumference.

[0056] The structure of the low-gear synchronization ring 140 is exactly the same as that of the high-gear synchronization ring 130. The low-gear synchronization ring is located inside the high-low gear sliding sleeve 120 relative to the high-gear synchronization ring 130. One end of the low-gear synchronization ring 140 is provided with a plurality of second fixed protrusions 141 at intervals. The plurality of second fixed protrusions 131 are large protrusions and small protrusions at intervals. The large protrusions and small protrusions are provided with circular grooves in the circumference.

[0057] like Figure 8 As shown, the large protrusions of the plurality of first fixed protrusions 131 and the small protrusions of the plurality of second fixed protrusions 141 are arranged in pairs. The small protrusions of the plurality of first fixed protrusions 131 and the large protrusions of the plurality of second fixed protrusions 141 are arranged in pairs. A spring 170 is provided in the circular grooves opposite to the paired large and small protrusions. The large and small protrusions press the spring 170 tightly. Due to the elastic force of the spring 170, the high-gear synchronous ring 130 and the low-gear synchronous ring are circumferentially separated by a certain angle, and the gear teeth are always offset by half a tooth. Only one of the two synchronous rings always engages with the high-low gear sliding sleeve 120. When one side of the synchronous ring meshes with the gear teeth of the high-low gear sliding sleeve 120, the conical surface of the gear teeth of the other side of the synchronous ring is opposite to the conical surface of the gear teeth of the high-low gear sliding sleeve 120, and does not engage with the inner edge gear teeth of the high-low gear sliding sleeve 120.

[0058] The high-gear cone hub 150 is located at the other end of the high-gear synchronizing ring 130, and the outer edge of the high-gear cone hub 150 is distributed with gear teeth, so that the high and low gear sliding sleeves 120 can selectively mesh with the high-gear cone hub 150, and the high-gear cone hub 150 is connected to the planet carrier of the planetary mechanism.

[0059] The low-gear cone hub 160 is disposed at the other end of the low-gear synchronizing ring 140, and the outer edge of the low-gear cone hub 160 is distributed with gear teeth, so that the high-low gear sliding sleeve 120 can selectively mesh with the low-gear cone hub 160, and the low-gear cone hub 160 is fixed in the housing.

[0060] The outer teeth of both the high-end cone hub 150 and the low-end cone hub 160 are cone-shaped.

[0061] The working process of the electric commercial vehicle rear auxiliary box gear shifting actuator described in this invention is as follows:

[0062] When the shift motor 101 receives a shift command, the shift motor 101 starts to rotate in the forward or reverse direction. The rotation of the lead screw 102 drives the nut 103 to move axially, which in turn causes the shift fork shaft 111 to move axially. After passing through the shift fork 112 lever mechanism, the high and low gear sliding sleeve 120 is driven to move axially in the opposite direction to the shift fork shaft 111.

[0063] Taking shifting from a high gear to a low gear as an example:

[0064] Before shifting gears, the high and low gear sliding sleeve 120 is in the high gear position. The inner edge teeth of the high and low gear sliding sleeve 120 mesh with the teeth of the high gear cone hub 150. Because the high gear cone hub 150 is fixedly connected to the planet carrier of the planetary mechanism, the high and low gear sliding sleeve 120 meshes with the gear ring. At this time, the planet carrier and the gear ring are engaged, and the transmission ratio of the planetary mechanism is the high gear transmission ratio 1.

[0065] like Figure 9 As shown, when shifting to a lower gear, the high / low gear sliding sleeve 120 moves towards the low gear synchronizer ring 10 under the action of the shifting force F, as shown in stage 1. At this time, there is a speed difference Δw between the low gear cone hub 160 and the low gear synchronizer ring 140. Then, the inner edge tooth cone surface of the high / low gear sliding sleeve 120 contacts the outer edge inclined surface of the low gear synchronizer ring 140, which is pre-synchronization, as shown in stage 2. The shifting force F continues to act, causing the high / low gear sliding sleeve 120 to further push the low gear synchronizer ring 140 towards the low gear cone hub 160. As hub 160 moves, the second stage of synchronization begins. The low-gear cone hub 160 continues until the low-gear synchronizer ring 140 contacts it. The spiral grooves disrupt the oil film, generating friction. The shifting force F continues to act, decomposing on the inner edge tooth cone surface of the high / low gear sleeve 120 and the outer edge gear inclined surface of the low-gear synchronizer ring 140. The shifting force F generates a shifting torque Tz on the inclined surface between the high / low gear sleeve 120 and the low-gear synchronizer ring 140, increasing friction. A frictional torque Tr1 is generated, and the spring 170 also generates a conical torque Tr2. The shifting torque Tz is opposite in direction to the frictional torque Tr1 and the conical torque Tr2, thereby locking the locking surface (the contact surface between the inclined surface of the low-gear synchronizing ring 140 and the conical surface of the high-low gear sliding sleeve). As the speed difference Δw between the low-gear conical hub 160 and the low-gear synchronizing ring 140 gradually disappears, the frictional torque Tr1 gradually disappears, and the locking process begins to release. The shifting torque Tz is greater than the conical torque Tr2, and the low-gear synchronizing ring 140 rotates a certain angle relative to the high-low gear sliding sleeve 120. The conical teeth of the two engage, and the high-gear synchronizing ring 130 disengages. Due to the action of the conical torque Tr2, it rotates a certain angle relative to the high-low gear sliding sleeve 120 (see stage 3). The high-low gear sliding sleeve 120 continues to move, and its inner edge conical teeth contact the gear conical surface of the low-gear conical hub 160. The gears of the two engage, and synchronization is completed (see stages 4 and 5).

[0066] This invention relates to an electric commercial vehicle rear auxiliary gear shifting actuator. It employs a brushless DC motor, detects the rotor position to calculate the shift fork shaft displacement, and achieves precise control of the shift stroke. The shift fork shaft is driven by a motor-driven lead screw and nut structure, resulting in a simple and efficient transmission structure. A lever mechanism is placed at the shift fork location to increase shifting force while reducing the pressure on the motor drive, thus ensuring sufficient force for shifting and reducing motor power. A novel high-low gear synchronizer with six spring-mounted fixing protrusions simplifies the overall synchronizer structure, contributing to a lighter transmission. This synchronizer provides rapid and precise shifting, reduces shift shock, extends transmission life, and features a compact structure, achieving cost reduction.

[0067] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A gear shifting actuator for the rear auxiliary storage compartment of an electric commercial vehicle, characterized in that, include: case; as well as The shift motor is fixed inside the housing; A lead screw, which is connected to the output end of the shift motor; The shift fork shaft is detachably connected to the nut of the lead screw; The shift fork includes a fork head end and a fork opening end. The fork head end is engaged with the shift fork shaft, and the middle part of the fork opening end is rotatably fixed in the housing. The high and low gear sliding sleeve has its outer side meshing with the gear ring of the planetary mechanism, and the high and low gear sliding sleeve is rotatably engaged with the fork end; A high-gear synchronizing ring is disposed inside the high-low gear sliding sleeve, and the outer gear teeth of the high-gear synchronizing ring can selectively mesh with the inner gear teeth of the high-low gear sliding sleeve. A plurality of first fixed protrusions are sequentially spaced at one end of the high-gear synchronizing ring. A low-gear synchronizing ring is disposed inside the high-low gear sliding sleeve, and the outer gear teeth of the low-gear synchronizing ring can selectively mesh with the inner gear teeth of the high-low gear sliding sleeve. A plurality of second fixed protrusions are sequentially spaced at one end of the low-gear synchronizing ring. Multiple springs are respectively arranged one-to-one between the multiple first fixed protrusions and second fixed protrusions, so that the gear teeth of the high-gear synchronous ring and the low-gear synchronous ring are misaligned; A high-end cone hub is disposed at the other end of the high-end synchronizing ring, and the high-end cone hub is connected to the planet carrier of the planetary mechanism; A low-gear cone hub is disposed at the other end of the low-gear synchronizing ring, and the low-gear cone hub is fixed inside the housing; The inner gear teeth of the high and low gear sliding sleeve can selectively connect to the outer gear teeth of the high gear cone hub or the low gear cone hub. Two symmetrical positioning pins are provided in the middle of the fork end. One end of each positioning pin is embedded and fixed to the housing, and the other end of each positioning pin passes through the middle of the fork end. The shift fork can rotate around the positioning pins. A shift fork slider is provided in the fork end. One end of the shift fork slider is a shaft that is embedded in the shift fork. The shift fork slider can rotate freely relative to the shift fork. The other end is used to move the synchronizer.

2. The electric commercial vehicle rear auxiliary box gear shifting actuator as described in claim 1, characterized in that, The shifting motor is a DC brushless motor.

3. The electric commercial vehicle rear auxiliary box gear shifting actuator as described in claim 2, characterized in that, The nut of the lead screw has an annular stepped flange at one end.

4. The electric commercial vehicle rear auxiliary box gear shifting actuator as described in claim 3, characterized in that, One end of the shift fork shaft has an arc-shaped groove; The arc-shaped groove engages with the annular stepped flange.

5. The electric commercial vehicle rear auxiliary box gear shifting actuator as described in claim 4, characterized in that, Also includes: An annular groove is provided on the outer side of the high and low gear sliding sleeve; The fork end engages with the annular groove in a rotating manner.

6. The electric commercial vehicle rear auxiliary box gear shifting actuator as described in claim 5, characterized in that, Both ends of the inner teeth of the high and low gear sliding sleeves are tapered.

7. The electric commercial vehicle rear auxiliary box gear shifting actuator as described in claim 6, characterized in that, The outer teeth of both the high-gear and low-gear synchronous rings are inclined surfaces. The high and low gear sliding sleeves and the high gear synchronization ring or the low gear synchronization ring can be locked selectively.

8. The electric commercial vehicle rear auxiliary box gear shifting actuator as described in claim 7, characterized in that, The outer teeth of both the high-end and low-end cone hubs have a conical surface structure.

9. The electric commercial vehicle rear auxiliary box gear shifting actuator as described in claim 8, characterized in that, The inner sides of both the high-gear and low-gear synchronous rings are friction cone surfaces, and both the high-gear and low-gear synchronous rings are provided with spiral grooves on their inner sides.

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