CN218536321U - Electric gear shifting actuating mechanism and electric bridge driving system - Google Patents

Abstract

The application provides actuating mechanism and bridge actuating system electrically shift, actuating mechanism electrically shift includes: a motor (10) having a motor shaft (11); a transmission unit (30) for driving the shift fork (50) in motion to perform a shifting function and comprising a crown gear (31); and a planetary gear set (20, 120) for transmitting the torque of the motor shaft (11) to the transmission unit (30), the planetary gear set (20, 120) comprising: primary sun gears (21, 121) provided at an output end of the motor shaft (11); and an output gear (27, 127) that meshes with the crown gear (31).

Description

Electric gear shifting actuating mechanism and bridge driving system

Technical Field

The present application relates to the field of electric bridge driving systems, and more particularly, to an electric shift actuator and an electric bridge driving system.

Background

An electric bridge (e-Axle) drive system is widely used in electric vehicles and the like. Fig. 1A and 1B show a partial cross-sectional view and a partial cross-sectional perspective view of one possible electrical shift actuator. As shown in fig. 1A and 1B, the electric shift actuator includes a motor 91, a pinion 93 connected to a motor shaft 92 of the motor 91 via a spline or the like in a non-rotatable manner, a crown gear 94 engaged with the pinion 93, a lead screw 95 connected to the crown gear 94 in a non-rotatable manner, a nut 96 converting a rotational motion of the lead screw 95 into a linear motion, and a shift fork 97 moving in accordance with the linear motion of the nut 96. The screw 95 and the nut 96 together form a ball screw assembly.

When the electric shift actuator is operated, the motor 91 rotates the motor shaft 92, transmits torque to the pinion 93, and then to the crown gear 94, the lead screw 95, and the nut 96, thereby linearly moving the nut 96. When the nut 96 moves linearly, the shift fork 97 is driven to move in the first direction X, so that the shift actuating function is performed.

The motor in the electric gear shifting actuating mechanism is a special motor with small volume, which causes high production cost and poor competitiveness of the electric gear shifting actuating mechanism. It is desirable to be able to use a general-purpose motor produced in large quantities instead of the above-described special-purpose motor.

SUMMERY OF THE UTILITY MODEL

The present application is directed to overcoming or at least alleviating the above-mentioned deficiencies of the prior art and to providing an electric shift actuator and a bridge driving system using the same.

An embodiment of the present application provides an electric shift actuator, which includes: a motor having a motor shaft; a transmission unit for driving the shift fork to move to perform a shifting function, and including a crown gear; and a planetary gear set for transmitting a torque of the motor shaft to the transmission unit, the planetary gear set including: the primary sun gear is arranged at the output end of the motor shaft; and an output gear engaged with the crown gear.

In at least one aspect, the planetary gear set further comprises: a primary planetary gear meshed with the primary sun gear; the primary planet gear can be rotatably mounted on the primary planet carrier, a guide pin protruding towards the output end of the motor shaft along the axial direction of the motor shaft is fixed on the primary planet carrier, a guide hole extending along the axial direction of the motor shaft is formed in the end face of the output end of the motor shaft, the guide pin is inserted into the guide hole, and the motor shaft can rotate relative to the guide pin.

In at least one technical scheme, electric gear shift actuating mechanism still includes and accomodates at least partially the motor, planetary gear set and the shell of drive unit, planetary gear set still includes one-level ring gear, and this one-level ring gear is fixed in the shell, one-level planetary gear is in this one-level ring gear meshes with this one-level ring gear in the one-level ring gear.

In at least one aspect, the primary sun gear is integrally formed with an output end of the motor shaft.

In at least one aspect, the planetary gear set is a primary planetary gear set or a secondary planetary gear set.

In at least one embodiment, the transmission unit further includes a screw rod extending in a first direction and connected to the crown gear in a rotationally fixed manner, and a nut for converting a rotational movement of the screw rod into a linear movement in the first direction, and when the nut is linearly moved, the nut drives the shift fork to move in the first direction, so as to perform a shifting function.

In at least one technical scheme, the nut includes working of plastics and metalwork, the inner periphery of working of plastics be formed with the transmission external screw thread of screw rod carries out screw drive's transmission internal thread, the metalwork is located the periphery of working of plastics, the metalwork be equipped with shift fork connection's lug.

In at least one technical scheme, the inner periphery of the metal piece is provided with a groove, the outer periphery of the plastic piece is provided with a protruding part, and the protruding part is embedded into the groove to prevent the metal piece and the plastic piece from moving axially relative to each other.

In at least one aspect, the plastic member and the metal member are formed as one body by insert molding.

The embodiment of the present application further provides an electric bridge driving system, which includes the electric gear shifting executing mechanism according to any one of the above technical solutions.

By adopting the technical scheme, the special motor can be replaced by the universal motor. Thus, the manufacturing cost of the electric shift actuator can be greatly reduced.

Drawings

Fig. 1A and 1B show a partial cross-sectional view and a partial cross-sectional perspective view of one possible electrical shift actuator.

Fig. 2 shows a schematic diagram of an electric shift actuator according to an embodiment of the present application.

Fig. 3A and 3B show a perspective view and a cross-sectional view, respectively, of a portion of the structure of a planetary gear set of an electric shift actuator according to an embodiment of the present application.

Fig. 3C and 3D show perspective views of the ring gear and the carrier, respectively, of the planetary gear set of the electrical shift actuator according to an embodiment of the present application.

Fig. 4A, 4B and 4C show a perspective view, a perspective cutaway view and a cross-sectional view, respectively, of a transmission unit of an electrical shift actuator according to an embodiment of the present application.

Fig. 5A, 5B, 5C and 5D show a perspective view, a perspective cut-away view, a cross-sectional view and a rear view, respectively, of a nut of a transmission unit of an electric shift actuating mechanism according to an embodiment of the present application, wherein fig. 5D is viewed from the right side in fig. 5C.

Fig. 6 is a perspective view showing a partial structure of a planetary gear set of an electric shift actuator according to one modified example of the embodiment of the present application.

Description of the reference numerals

91: a motor; 92: a motor shaft; 93: a pinion gear; 94: a crown gear; 95: a lead screw; 96: a nut; 97: a gear shifting fork;

10: a motor; 11: a motor shaft; 12: a guide hole; 20: a planetary gear set; 21: a primary sun gear; 22: a primary planetary gear; 23: a primary planet carrier; 24: a primary gear ring; 25: a first hole; 26: a second hole; 27: an output gear; 28: a guide pin; 29: a planetary gear shaft; 30: a transmission unit; 31: a crown gear; 32: a screw; 321: a transmission external thread; 33: a nut; 36: a plastic part; 361: driving the internal thread; 362: a protrusion portion; 37: a metal member; 371: a lug; 372: a groove; 38: a ball bearing; 40: a housing; 50: a gear shifting fork; 120: a planetary gear set; 121: a primary sun gear; 122: a primary planetary gear; 123: a primary planet carrier; 124: a secondary sun gear; 125: a secondary planetary gear; 126: a secondary planet carrier; 127: an output gear; x: a first direction; y: a second direction; z: and a third direction.

Detailed Description

Exemplary embodiments of the present application are described below with reference to the accompanying drawings. It should be understood that the detailed description is only intended to teach one skilled in the art how to practice the present application, and is not intended to be exhaustive or to limit the scope of the application.

In the following description, a first direction X, which coincides with the axial direction of the screw 32 (shown in fig. 2, etc.) in the electric shift actuator, a second direction Y, which coincides with the axial direction of the motor shaft 11 (shown in fig. 2, etc.), and a third direction Z, which are perpendicular to each other, are used.

Embodiments of the present application provide an electric bridge drive system that includes an electric shift actuator for performing a shift actuation function of a vehicle, which may be a pure electric vehicle or a hybrid electric vehicle, or the like. Next, an electric shift actuator according to an embodiment of the present application will be described with reference to fig. 2 to 5D.

As shown in fig. 2, the electric shift actuator of the embodiment of the present application includes a motor 10, a planetary gear set 20, and a transmission unit 30. In addition, the electrical shift actuator includes a housing 40 that at least partially houses the motor 10, the planetary gear set 20, and the transmission unit 30. The outer dimensions of the housing 40 may be substantially the same as some existing electrical shift actuators, and the inner dimensions may be appropriately adjusted depending on the motor 10, planetary gear set 20, and transmission unit 30.

The motor 10 according to the embodiment of the present application may be a general-purpose motor that is mass-produced, instead of the special motor 91 shown in fig. 1A and 1B. As shown in fig. 2, 3A, and 3B, the motor 10 of the present application has a motor shaft 11, and an output end (a lower end in fig. 2, 3A, and 3B) of the motor shaft 11 is provided with a primary sun gear 21 as a part of the planetary gear set 20. In the illustrated structure, a plurality of teeth are formed on the outer circumference of the output end of the motor shaft 11 as the primary sun gear 21, that is, the primary sun gear 21 is integrally formed with the output end of the motor shaft 11. However, the present invention is not limited to this, and for example, the primary sun gear 21 may be fixed to the output end of the motor shaft 11 via a spline or the like as an independent member. The primary sun gear 21 transmits the torque of the motor shaft 11 to the other gears of the planetary gear set 20.

In addition, since the motor 10 according to the embodiment of the present invention is a general-purpose motor that is mass-produced, mass-produced parts such as an antistatic cap, a screw for fixing the motor 10 to the housing 40, and the like, which are not shown, can be used, which also contributes to reduction in manufacturing cost of the electric shift actuator.

As one feature of the present application, an embodiment of the present application employs a planetary gear set 20 instead of the pinion gear 93 in fig. 1A, 1B. Specifically, in order to replace the dedicated motor 91 in fig. 1A and 1B with the general-purpose motor 10 produced in mass production and to make the shift stroke/load the same as in the case of using the dedicated motor, the present application designs a planetary gear set 20.

As shown in fig. 3A to 3D, the planetary gear set 20 may be a one-stage planetary gear set for transmitting the torque of the motor shaft 11 to the transmission unit 30. The planetary gear set 20 may include the primary sun gear 21, the plurality of primary planet gears 22, the primary planet carrier 23, the primary ring gear 24, and the output gear 27 described above.

Among them, a plurality of primary planet gears 22 are rotatably mounted on one surface (upper surface in fig. 3A, 3B) of the primary carrier 23 around planet gear shafts 29 fixed to the primary carrier 23, respectively, and mesh with the primary sun gear 21, respectively. The primary ring gear 24 is fixed within the housing 40 and surrounds the plurality of primary planet gears 22, with the primary planet gears 22 meshing with the primary ring gear 24 within the primary ring gear 24. The output gear 27 is fixed to the other surface (lower surface in fig. 3A and 3B) of the primary carrier 23, and meshes with a crown gear 31 of a transmission unit 30 described later. In the illustrated configuration, the number of the primary planetary gears 22 is three, but the present invention is not limited to this, and another number of primary planetary gears 22 may be provided.

As shown in fig. 3D, a first hole 25 into which a guide pin 28 is press-fitted is formed in the center of the primary carrier 23, and a plurality of second holes 26 into which pinion shafts 29 are press-fitted are formed around the first hole 25. The guide pin 28 is fixed to the primary carrier 23 by being press-fitted into the first hole 25, and projects toward the output end of the motor shaft 11 in the axial direction of the motor shaft 11. The guide pins 28 and the pinion shafts 29 are not limited to being fixed to the first-stage carrier 23 by press fitting, and may be fixed to the first-stage carrier 23 by welding or the like, or may be formed integrally with the first-stage carrier 23.

As shown in fig. 3B, the end surface of the output end of the motor shaft 11 is provided with a guide hole 12 extending in the axial direction of the motor shaft 11, a guide pin 28 is inserted into the guide hole 12, and the motor shaft 11 is rotatable relative to the guide pin 28. In assembling the electric shift actuator, for example, the planetary gear set 20 is first installed in the housing 40, and then the position of the motor 10 is adjusted to align the guide hole 12 with the guide pin 28, and the motor 10 is inserted into the housing 40 and fixed in this state. By providing the guide pin 28 and the guide hole 12 that cooperate with each other, assembly of the electric shift actuator can be made easier.

When the motor 10 is operated, the primary sun gear 21 provided at the motor shaft 11 rotates, and then the plurality of primary planetary gears 22 revolve while rotating, and the primary planetary carrier 23 and the output gear 27 rotate, and rotate the crown gear 31 of the transmission unit 30. Thereby, the torque of the motor shaft 11 is transmitted to the transmission unit 30 by the planetary gear set 20.

As shown in fig. 2 and 4A to 4C, the transmission unit 30 of the embodiment of the present application is used to drive the shift fork 50 to perform a shifting function, and includes a crown gear 31, a screw 32, and a nut 33. The crown gear 31 transmits the torque of the motor shaft 11 to the transmission unit 30 by meshing with the output gear 27 of the planetary gear set 20. Further, a ball bearing 38 is press-fitted to the outer periphery of the crown gear 31, and the crown gear 31 is rotatably supported in the housing 40 via the ball bearing 38.

As still another feature of the present application, the embodiment of the present application employs a sliding screw pair composed of the screw 32 and the nut 33 instead of the ball screw pair composed of the screw 95 and the nut 96 in fig. 1A and 1B. Specifically, as shown in fig. 4A to 4C, the sliding screw pair according to the embodiment of the present disclosure includes a screw 32 extending in the first direction X and connected to the crown gear 31 in a rotation-proof manner, and a nut 33 for converting a rotational motion of the screw 32 into a linear motion in the first direction X, and when the nut 33 is linearly moved, the shift fork 50 is moved in the first direction X, so as to perform a shifting function. The threaded spindle 32 is connected in a rotationally fixed manner to the crown gear 31, for example by way of a press fit. A nut 33 is located on the screw 32 to transmit torque. The assembly process of the sliding screw transmission pair of the embodiment of the application is much simpler than the condition of adopting a ball screw pair in the past, the manufacturing cost is low, and the later maintenance is simple.

As shown in fig. 5A to 5D, the nut 33 may include a plastic piece 36 and a metal piece 37, and the plastic piece 36 and the metal piece 37 are formed as one body by insert molding. As will be described later, the plastic member 36 and the screw 32 are driven to reduce the driving friction; further, by connecting the metal fitting 37 to the shift fork 50, the transmission can be performed efficiently while securing rigidity.

The inner periphery of the plastic member 36 is formed with a female transmission screw 361 for screw-transmitting with the male transmission screw 321 of the screw 32. The internal driving screw 361 may be a trapezoidal screw or a rectangular screw, and correspondingly, the external driving screw 321 of the screw 32 may be a trapezoidal screw or a rectangular screw.

The metal member 37 is manufactured by forging or the like, for example, and is provided on the outer periphery of the plastic member 36 by insert molding, and the metal member 37 is provided with a lug 371 for connecting with the shift fork 50. Specifically, two lugs 371 are respectively located on opposite sides of the metal piece 37 in the second direction Y for providing a sufficient contact area for the shift fork 50 to grip.

When the motor 10 operates, power is transmitted from the motor 10 to the shift fork 50 via the planetary gear set 20, the crown gear 31, the screw 32, and the nut 33, and a shift actuating function is performed. Further, the end surface of one end of the metal member 37 in the first direction X (i.e., the end where the lug 371 is not provided) has a non-circular shape, and in the illustrated embodiment, has a polygonal shape. Accordingly, the rotation of the metal fitting 37 can be easily restricted by bringing the outer peripheral surface of the metal fitting 37 into contact with a detent pin, not shown, attached to the housing 40, whereby the nut 33 can be moved only linearly without being rotated.

In addition, the inner circumference of the metal piece 37 is provided with a groove 372, the outer circumference of the plastic piece 36 is provided with a protrusion 362, and the protrusion 362 is embedded into the groove 372 to prevent the metal piece 37 and the plastic piece 36 from moving axially relative to each other. In addition, as shown in FIG. 5D, the end surface of the plastic member 36 at one end in the first direction X (i.e., the end away from the lug 371) has a non-circular shape, in the illustrated embodiment, a hexagonal shape. Accordingly, the overall shape of the protruding portion 362 on the outer periphery of the plastic member 36 and the concave groove 372 on the inner periphery of the metal member 37 can be hexagonal, and relative displacement (rotation) between the plastic member 36 and the metal member 37 in the circumferential direction due to torque in the circumferential direction can be suppressed.

In the above-described embodiment, the configuration in which the planetary gear set is a one-stage planetary gear set has been described, but the present application is not limited thereto. For example, the planetary gear set may be a multi-stage planetary gear set above a two-stage planetary gear set. For example, as a modification, as shown in fig. 6, the planetary gear set 120 may be a two-stage planetary gear set, and the planetary gear set 120 includes a primary sun gear 121, a plurality of primary planet gears 122, a primary planet carrier 123, a secondary sun gear 124, a plurality of secondary planet gears 125, a secondary planet carrier 126, and an output gear 127. As in the above-described embodiment, a guide pin protruding toward the output end of the motor shaft 11 in the axial direction of the motor shaft 11 is fixed to the primary carrier 123, and a guide hole, not shown, into which the guide pin is inserted is opened in the end surface of the output end of the motor shaft 11. Further, although not shown, a ring gear that surrounds the plurality of primary pinion gears 122 and meshes with the plurality of primary pinion gears 122 and/or a ring gear that surrounds the plurality of secondary pinion gears 125 and meshes with the plurality of secondary pinion gears 125 may be provided.

When the motor is operated, the primary sun gear 121 provided on the motor shaft 11 rotates, and accordingly the plurality of primary planet gears 122 revolve while rotating, the primary planet carrier 123 and the secondary sun gear 124 rotate, the plurality of secondary planet gears 125 revolve while rotating, the secondary planet carrier 126 and the output gear 127 rotate, and the crown gear of the transmission unit is driven to rotate. Thereby, the torque of the motor shaft 11 is transmitted to the transmission unit using the planetary gear set 120.

Some advantageous effects of the above-described embodiments of the present application will be briefly described below.

(i) Each embodiment of this application has adopted planetary gear set to replace pinion in the past, can obtain bigger drive ratio, can be moreover under the prerequisite that does not change by a wide margin electric gear shift actuating mechanism's overall structure, replace special motor for general motor, and can guarantee to shift the stroke/load and use the condition of special motor the same. Therefore, by using the universal motor and other mass-produced parts (such as a motor fixing screw, an anti-static cap and the like), the manufacturing cost of the electric gear shifting actuating mechanism can be greatly reduced, and the universal use of product parts is facilitated. In addition, the assembly process is basically the same as that of the traditional electric gear shifting actuating mechanism, and the manufacturing cost is favorably controlled.

(ii) This application adopts the vice ball screw of replacing in the past of slip screw drive, from this, can reduce manufacturing cost effectively, and can simplify the assembly process, and the maintenance in later stage also becomes simple. In addition, the nut of the sliding screw transmission pair is formed by the plastic part and the metal part, so that the transmission friction can be reduced by the plastic part, and the rigidity of the whole nut can be ensured by the metal part.

The present application is not limited to the above-described embodiments, and those skilled in the art can make various modifications to the above-described embodiments of the present application without departing from the scope of the present application under the teaching of the present application.

Claims (10)

1. An electric shift actuator, comprising:

a motor having a motor shaft;

a transmission unit for driving the shift fork to move to perform a shifting function, and including a crown gear; and

a planetary gear set for transmitting a torque of the motor shaft to the transmission unit,

the planetary gear set includes: the primary sun gear is arranged at the output end of the motor shaft; and an output gear engaged with the crown gear.

2. The electrical shift actuator of claim 1, wherein the planetary gear set further comprises: a primary planetary gear meshed with the primary sun gear; and a primary planet carrier to which the primary planet gear is rotatably mounted,

the first-stage planet carrier is fixed with a guide pin which protrudes towards the output end of the motor shaft along the axial direction of the motor shaft,

the end face of the output end of the motor shaft is provided with a guide hole extending along the axial direction of the motor shaft, the guide pin is inserted into the guide hole, and the motor shaft can rotate relative to the guide pin.

3. The electrical shift actuator of claim 2, further comprising a housing at least partially housing the motor, the planetary gear set, and the transmission unit,

the planetary gear set also comprises a primary gear ring which is fixed in the shell, and the primary planetary gear is meshed with the primary gear ring in the primary gear ring.

4. The electrical shift actuator of any one of claims 1-3, wherein the primary sun gear is integrally formed with the output end of the motor shaft.

5. The electrical shift actuator of any of claims 1-3, wherein the planetary gear set is a primary planetary gear set or a secondary planetary gear set.

6. The electrical shift actuator of claim 1, wherein the transmission unit further includes a threaded rod extending in a first direction and non-rotatably coupled to the crown gear and a nut for converting rotational movement of the threaded rod into linear movement in the first direction,

when the nut moves linearly, the shifting fork is driven to move along the first direction, and a shifting function is executed.

7. The electrical shift actuator of claim 6, wherein the nut includes a plastic member and a metal member, wherein an inner periphery of the plastic member is formed with an inner transmission thread that is in threaded transmission with the outer transmission thread of the screw, the metal member is provided at an outer periphery of the plastic member, and the metal member is provided with a lug that is connected to a shift fork.

8. The electrical shift actuator of claim 7, wherein the metal member has a recess formed on an inner periphery thereof and the plastic member has a protrusion formed on an outer periphery thereof, the protrusion engaging the recess to prevent relative axial movement between the metal member and the plastic member.

9. The electrical shift actuator of claim 7 or 8, wherein the plastic member and the metal member are integrally formed by insert molding.

10. Bridge drive system, comprising an electrical shift actuator according to any of claims 1 to 9.

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