CN112519572A

CN112519572A - Two keep off electric bridge actuating system and vehicle

Info

Publication number: CN112519572A
Application number: CN201910887500.4A
Authority: CN
Inventors: 王天斌; 刘磊
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2019-09-19
Filing date: 2019-09-19
Publication date: 2021-03-19

Abstract

The invention provides a novel two-gear electric bridge driving system and a vehicle. The two-speed bridge drive system includes a first planetary gear mechanism, a second planetary gear mechanism, and a synchromesh mechanism that are coaxially arranged with each other. By means of the synchromesh mechanism, torque from the outside can be selectively transmitted to the second sun gear shaft through the first sun gear shaft or the first carrier, and then transmitted to the differential through the second carrier. In this way, the two-speed bridge drive system according to the present invention omits the intermediate shaft and integrates the two planetary gear mechanisms together, so that a desired high gear ratio can be achieved in a more compact structure, as compared with the two-speed bridge drive system according to the related art.

Description

Two keep off electric bridge actuating system and vehicle

Technical Field

The invention relates to the field of vehicles, in particular to a two-gear bridge driving system for a vehicle and the vehicle comprising the two-gear bridge driving system.

Background

Currently, bridge drive systems can be used for electric-only vehicles and hybrid vehicles for the driving of the vehicle.

Fig. 1 is a schematic diagram showing a connection structure of a two-speed bridge drive system according to the related art, in which the directions indicated by hollow arrows are the transmission directions of torque. As shown in fig. 1, the two-speed bridge drive system includes a planetary gear mechanism, a shift mechanism, an intermediate transmission mechanism, and a differential mechanism.

Specifically, the planetary gear mechanism includes a sun gear SU, a plurality of planetary gears PG, a ring gear R, and a carrier P that mesh with each other. The sun gear SU is fixed to a sun gear shaft S for receiving torque from the outside. The plurality of planet wheels PG are located on the radial outer side of the sun wheel SU and on the radial inner side of the gear ring R, and the plurality of planet wheels PG are always in a meshed state with the sun wheel SU and the gear ring R. A plurality of planet gears PG are mounted to a planet gear carrier P. The ring gear R is connected with the transmission case such that the ring gear R is fixed relative to the transmission case. Thus, the planetary gear mechanism can preliminarily change the gear ratio.

The gear shifting mechanism is a synchronous meshing mechanism and comprises a sliding sleeve SS, a gear sleeve TS, a synchronizing ring SR and a synchronizing gear. By selectively sliding and engaging the sliding sleeve SS toward the synchronizing gears located on both sides of the gear sleeve TS, speed synchronization can be achieved, thereby completing shifting. Thus, through the gear shifting of the gear shifting mechanism, two output gears of directly outputting torque from the sun gear shaft S and outputting torque from the planet gear carrier P can be realized; and when the shift mechanism is in the neutral position, the entire bridge drive system is not transmitting torque and is therefore in neutral.

The intermediate transmission mechanism includes a sleeve shaft TT, a first intermediate gear G11, a second intermediate gear G12, a countershaft MS, and an output gear G13. The sleeve shaft TT is fixed to the gear sleeve TS. The first intermediate gear G11 is fixed to the sleeve shaft TT, and the first intermediate gear G11 and the second intermediate gear G12 are always in a meshed state. The second intermediate gear G12 and the output gear G13 are both fixed to the countershaft MS. The output gear G13 is always in mesh with the differential input gear. In this way, the intermediate shaft MS and the second intermediate gear G12 and the output gear G13 thereon can further change the gear ratio after the planetary gear mechanism to achieve a desired high gear ratio.

The differential mechanism includes a bevel gear differential DM and two half shafts extending from the differential DM toward both sides. The housing of the bevel gear differential DM is fixed to the differential input gear.

Although the bridge drive system shown in fig. 1 is capable of two-stage two-gear drive, it has the following disadvantages:

i. the intermediate shaft MS causes the transmission to be oversized and needs a large space during installation; and

it is difficult to obtain the desired high gear ratio without the intermediate shaft MS.

Disclosure of Invention

The present invention has been made in view of the above-mentioned drawbacks of the prior art. It is an object of the present invention to provide a new type of two-speed bridge drive system which enables a higher transmission ratio to be achieved with a compact construction compared to the two-speed bridge drive systems according to the prior art described above. Another object of the present invention is to provide a vehicle including the two-speed bridge drive system described above.

In order to achieve the above object, the present invention adopts the following technical solutions.

The invention provides a two-gear bridge driving system, which comprises:

the first planetary gear mechanism comprises a first sun gear, a plurality of first planet gears, a first planet carrier and a first gear ring, wherein the first sun gear and the plurality of first planet gears are always in a meshed state, a first sun gear shaft of the first sun gear is used for receiving torque, the plurality of first planet gears and the first gear ring are always in a meshed state, the plurality of first planet gears are mounted on the first planet carrier, and the first gear ring is fixed relative to a shell of the transmission;

a second planetary gear mechanism including a second sun gear, a plurality of second planetary gears, a second planetary gear carrier, and a second ring gear, the second sun gear and the plurality of second planetary gears being constantly in mesh, the plurality of second planetary gears and the second ring gear being constantly in mesh, the plurality of second planetary gears being mounted to the second planetary gear carrier, the second planetary gear carrier being for outputting torque, the second ring gear being fixed with respect to a housing of the transmission; and

a synchromesh mechanism capable of selectively drivingly coupling a second sun shaft of the second sun with the first sun shaft or the second sun shaft with the first carrier.

Preferably, the second planet gear is a duplicate gear, one gear of each duplicate gear is always engaged with the second sun gear, and the other gear of each duplicate gear is always engaged with the second ring gear.

More preferably, the synchromesh mechanism includes:

a gear sleeve fixed with the second sun gear shaft;

the sliding sleeve is positioned on the radial inner side of the gear sleeve and is always in a meshed state with the gear sleeve, and the sliding sleeve can slide towards two sides of the gear sleeve; and

a synchronizer ring located radially inward of the sliding sleeve and engageable with the sliding sleeve.

More preferably, the synchromesh mechanism further includes:

a first synchronizing gear fixed to the first carrier to correspond to the synchronizing ring, and engageable with the sliding sleeve to synchronize the first carrier with the second sun gear shaft; and

a second synchronizing gear fixed to the first sun gear shaft to correspond to the synchronizing ring, and engageable with the sliding sleeve to synchronize the first sun gear shaft with the second sun gear shaft.

More preferably, the two-gear bridge drive system further includes:

the differential is in transmission coupling with the second planetary gear carrier; and

first and second axle shafts extending from the differential toward both sides of the differential.

More preferably, the first and second axle shafts are offset relative to the first and second sun gear shafts, and

the two-speed bridge drive system further includes an output gear fixed to the second carrier such that the second carrier is able to transfer torque to the differential via the output gear.

More preferably, the first and second half shafts are arranged coaxially with both the first and second sun gear shafts, and

the second carrier is fixed to the case of the differential such that the second carrier can transmit torque to the differential via the case of the differential.

More preferably, the first sun gear shaft and the second sun gear shaft are both hollow shafts, and the first half shaft passes through the first sun gear shaft and the second sun gear shaft.

The invention further provides a vehicle comprising the two-gear bridge driving system in any one of the above technical solutions.

Preferably, the vehicle comprises an electric machine, the output shaft of which is drivingly coupled to the first sun gear shaft of the two-speed bridge drive system.

By adopting the technical scheme, the invention provides a novel two-gear electric bridge driving system and a vehicle comprising the same. The two-speed bridge drive system includes a first planetary gear mechanism, a second planetary gear mechanism, and a synchromesh mechanism that are coaxially arranged with each other. By means of the synchromesh mechanism, torque from the outside can be selectively transmitted to the second sun gear shaft through the first sun gear shaft or the first carrier, and then transmitted to the differential through the second carrier. In this way, compared to the above-described two-speed bridge drive system according to the related art, the two-speed bridge drive system according to the present invention omits the intermediate shaft and integrates the two planetary gear mechanisms together, so that a desired high gear ratio can be achieved in a more compact structure.

Drawings

Fig. 1 is a schematic diagram showing a connection structure of a two-speed bridge driving system according to the related art.

Fig. 2 is a schematic diagram showing a connection structure of a two-speed bridge drive system according to a first embodiment of the present invention.

Fig. 3 is a schematic diagram showing a connection structure of a two-speed bridge driving system according to a second embodiment of the present invention.

Description of the reference numerals

SU sun gear S sun gear PG planet gear P planet gear carrier R ring gear MS intermediate shaft G11 first intermediate gear G12 second intermediate gear G13 output gear

SU1 first sun gear S1 first sun gear PG1 first planet gear P1 first planet carrier R1 first ring gear SU2 second sun gear S2 second sun gear PG2 second planet gear P2 second planet carrier R2 second ring gear G1 first synchronizing gear G2 second synchronizing gear G3 output gear G4 differential input gear

SR synchronizer ring SS sliding sleeve TS gear sleeve TT sleeve shaft

The DM differential HS1 has a first half shaft HS2 and a second half shaft.

Detailed Description

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

In the present invention, "transmission coupling" means that two members are connected to be able to transmit a driving force/torque, and may mean that the two members are directly connected or coupled via a transmission structure such as a gear mechanism to be able to transmit a driving force/torque between the two members, as not particularly described. In the present invention, when it is stated that the "gear" is fixed to the "shaft", it is generally meant that the gear and the shaft are capable of rotating together, but that the gear and the shaft are allowed not to be completely fixed in the axial direction of the shaft.

(Structure of two-speed bridge drive System according to the first embodiment of the present invention)

As shown in fig. 2, the two-speed bridge drive system according to the first embodiment of the invention includes a first planetary gear mechanism, a second planetary gear mechanism, a synchromesh mechanism, a differential DM, and two half shafts HS1, HS2, in which components other than the half shafts HS1, HS2 may be all integrated into the interior of the transmission.

Specifically, in the present embodiment, the first planetary gear mechanism includes a first sun gear SU1, a plurality of first planetary gears PG1, a first carrier P1, and a first ring gear R1. The first sun gear SU1 is always in mesh with the plurality of first planetary gears PG1 located radially outward thereof, and the first sun gear shaft S1 of the first sun gear SU1 is used to receive torque from an external source such as an electric motor (not shown). The plurality of first planetary gears PG1 are always in a meshed state with the first ring gear R1 located radially outward thereof. The plurality of first planetary gears PG1 are mounted to a first carrier P1, the first carrier P1 being used to transfer torque from the first sun gear shaft S1. The first ring gear R1 is fixed relative to the transmission case.

In the present embodiment, the second planetary gear mechanism includes a second sun gear SU2, a plurality of second planetary gears PG2, a second carrier P2, and a second ring gear R2. The second sun gear shaft S2 of the second sun gear SU2 is disposed coaxially with the first sun gear shaft S1, the second sun gear SU2 is constantly in mesh with the plurality of second planetary gears PG2 located radially outward thereof, and the second sun gear shaft S2 is configured to receive torque from the first planetary gear mechanism. The plurality of second planetary gears PG2 are always in mesh with the second ring gear R2 located radially outward thereof. A plurality of second planet gears PG2 are mounted to a second carrier P2, the second carrier P2 being used for transmitting torque to the differential DM. The second ring gear R2 is fixed relative to the housing of the transmission.

In the present embodiment, the synchromesh mechanism includes a gear sleeve TS, a sliding sleeve SS, a synchronizing ring SR, and two synchronizing gears (a first synchronizing gear G1 and a second synchronizing gear G2).

The sleeve gear TS is fixed to the second sun gear shaft S2 via a sleeve shaft TT. The sliding sleeve SS is located radially inside the gear sleeve TS and is always in an engaged state with the gear sleeve TS, and the sliding sleeve SS can slide toward both sides of the gear sleeve TS to engage with the corresponding synchronizing ring SR and the synchronizing gears G1, G2. The synchronizing ring SR is located radially inside the toothed sleeve TS and serves to achieve a presynchronization with the synchronizing gears G1, G2 before the sliding sleeve SS meshes with the synchronizing gears G1, G2, in particular a presynchronization of the synchronizing ring SR with the synchronizing gears G1, G2, which can be achieved, for example, by friction.

The first synchronizing gear G1 is fixed to the first carrier P1 to be paired with the synchronizing ring SR, the first synchronizing gear G1 is pre-synchronized with the synchronizing ring SR by friction, and after the pre-synchronization, the first synchronizing gear G1 can be engaged with the sliding sleeve SS to synchronize the first carrier P1 with the second sun gear shaft S2. Similarly, a second synchronizing gear G2 is fixed to the first sun gear shaft S1 to be paired with the synchronizing ring SR, the second synchronizing gear G2 is pre-synchronized with the synchronizing ring SR by friction, and after the pre-synchronization, the second synchronizing gear G2 can be engaged with the sliding sleeve SS to synchronize the first sun gear shaft S1 with the second sun gear shaft S2. In this way, the synchromesh mechanism can selectively drivingly couple the second sun gear shaft S2 with the first carrier P1 (first output gear) or the second sun gear shaft S2 with the first sun gear shaft S1 (second output gear). In addition, when the synchromesh mechanism is in the neutral position, torque from the first planetary gear mechanism cannot be input to the second sun gear shaft S2, so that neutral is achieved.

In the present embodiment, the differential DM is a bevel gear differential. The case of the bevel gear differential DM has a differential input gear G4, and the differential input gear G4 is always in engagement with an output gear G3 fixed to the second carrier P2. Thus, via the set of gear pairs (gears G3, G4), the second planet carrier P2 is able to transfer torque from the second sun gear shaft S2 to the differential DM.

In addition, in the present embodiment, the first and second half shafts HS1 and HS2 extending from the bevel gear differential DM toward both sides are offset with respect to the first and second sun gear shafts S1 and S2, and the first and second half shafts HS1 and HS2 are used to transmit torque from the differential DM to both wheels of the vehicle.

Thus, in the present embodiment, when engaged in the first output range, the transmission path of torque from the drive source, such as the motor, is as follows: the first sun gear shaft S1 → the first sun gear SU1 → the first planet gear PG1 → the first carrier P1 → the first synchronizing gear G1 → the sliding sleeve SS → the sleeve TS → the sleeve shaft TT → the second sun gear shaft S2 → the second sun gear SU2 → the second planet gear PG2 → the second carrier P2 → the output gear G3 → the differential input gear G4 → the differential DM → the half shafts HS1, HS 2.

When engaged in the second output range, a transmission path of torque from a drive source such as a motor is as follows: first sun gear shaft S1 → second synchronizing gear G2 → sliding sleeve SS → gear sleeve TS → sleeve shaft TT → second sun gear shaft S2 → second sun gear SU2 → second planet wheels PG2 → second carrier P2 → output gear G3 → differential input gear G4 → differential DM → half shafts HS1, HS 2.

In this way, the two-speed bridge drive system according to the first embodiment of the invention is sufficiently compact in construction, and at least when engaged in the first output gear, the two-speed bridge drive system according to the first embodiment of the invention is able to achieve the desired high transmission ratio in a compact construction.

The structure of the two-speed bridge drive system according to the first embodiment of the present invention is specifically described above, and the structure of the two-speed bridge drive system according to the second embodiment of the present invention will be specifically described below.

(Structure of two-speed bridge drive System according to second embodiment of the present invention)

The basic structure of the two-speed bridge drive system according to the second embodiment of the present invention is similar to that of the two-speed bridge drive system according to the first embodiment of the present invention, and only the differences therebetween will be described below.

As shown in fig. 3, in the present embodiment, each of the second planetary gears PG2 is a double gear, one gear (the left gear in the drawing) of each double gear is always in mesh with the second sun gear SU2, and the other gear (the right gear in the drawing) of each double gear is always in mesh with the second ring gear R2. The diameter of the one gear is larger than the diameter of the other gear in each duplicate gear. By providing such a duplicate gear, the transmission ratio can be further improved.

In the present embodiment, the second planetary carrier P2 is directly fixed to the housing of the bevel gear differential DM by, for example, welding or bolts.

In the present embodiment, the first half shaft HS1 and the second half shaft HS2 are arranged coaxially with both the first sun gear shaft S1 and the second sun gear shaft S2. The first and second sun gear shafts S1 and S2 are hollow shafts, and a first half shaft HS1 extends through the first and second sun gear shafts S1 and S2.

Thus, in the present embodiment, when the first output range is engaged, the transmission path of torque from the drive source, such as the motor, is as follows: first sun gear shaft S1 → first sun gear SU1 → first planet wheel PG1 → first carrier P1 → first synchronizing gear G1 → sliding sleeve SS → tooth sleeve TS → sleeve shaft TT → second sun gear shaft S2 → second sun gear SU2 → second planet wheel PG2 → second carrier P2 → differential DM → half shafts HS1, HS 2.

When the second output range is engaged, a transmission path of torque from a drive source such as a motor is as follows: first sun gear shaft S1 → second synchromesh gear G2 → sliding sleeve SS → gear sleeve TS → sleeve shaft TT → second sun gear shaft S2 → second sun gear SU2 → second planet wheels PG2 → second planet wheel carrier P2 → differential DM → half shafts HS1, HS 2.

The two-speed bridge drive system according to the second embodiment of the present invention can achieve a similar function to the two-speed bridge drive system according to the first embodiment of the present invention, and the overall structure is more compact.

In addition, the invention also provides a vehicle comprising the two-gear electric bridge driving system. The vehicle comprises an electric motor as a drive source, the output shaft of which is drivingly coupled to the first sun gear shaft S1 of the two-gear bridge drive system, preferably both being directly connected in a coaxial manner.

Although the technical solutions of the present invention have been described in detail in the above embodiments, the following descriptions are also required.

i. Although not specifically described in the above embodiments, it should be understood that the NVH performance of the entire system is also improved since the intermediate shaft is omitted from the two-speed bridge drive system according to the present invention, so that the bearing support structure is highly rigid.

Although not explicitly described in the above embodiments, it should be understood that, in the present invention, the solution of "coaxial configuration" not only allows the motor housing and the transmission housing to be at least partially shared, but also the first sun gear shaft S1 and the output shaft of the motor can share the shaft sleeve, thereby saving costs, but also such configuration is more advantageous for supporting the bridge drive system.

The function of the synchronizer ring is explained in the above embodiments, and it should be understood by those skilled in the art that one synchronizer ring may be provided corresponding to each synchronizer gear.

Claims

1. A two-speed bridge drive system, comprising:

a first planetary gear mechanism comprising a first sun gear (SU1), a plurality of first planet gears (PG1), a first carrier (P1) and a first ring gear (R1), the first sun gear (SU1) and the plurality of first planet gears (PG1) being always in mesh and a first sun gear shaft (S1) of the first sun gear (SU1) being for receiving torque, the plurality of first planet gears (PG1) and the first ring gear (R1) being always in mesh, the plurality of first planet gears (PG1) being mounted to the first carrier (P1), the first ring gear (R1) being fixed relative to a housing of the transmission;

a second planetary gear mechanism including a second sun gear (SU2), a plurality of second planetary gears (PG2), a second carrier (P2), and a second ring gear (R2), the second sun gear (SU2) and the plurality of second planetary gears (PG2) being always in a meshed state, the plurality of second planetary gears (PG2) and the second ring gear (R2) being always in a meshed state, the plurality of second planetary gears (PG2) being mounted to the second carrier (P2), the second carrier (P2) being for outputting torque, the second ring gear (R2) being fixed with respect to a casing of the transmission; and

a synchromesh mechanism capable of selectively drivingly coupling a second sun shaft (S2) of the second sun gear (SU2) with the first sun shaft (S1) or drivingly coupling the second sun shaft (S2) with the first carrier (P1).

2. The two-speed bridge drive system according to claim 1, wherein the second planetary gears (PG2) are duplicate gears, one of the duplicate gears is always in mesh with the second sun gear (SU2), and the other of the duplicate gears is always in mesh with the second ring gear (R2).

3. The two-speed bridge drive system according to claim 1 or 2, wherein the synchromesh mechanism comprises:

a gear sleeve (TS) fixed with the second sun gear shaft (S2);

a Sliding Sleeve (SS) which is located radially inside the gear sleeve (TS) and is always in a meshing state with the gear sleeve (TS), the Sliding Sleeve (SS) being slidable toward both sides of the gear sleeve (TS); and

a Synchronization Ring (SR) located radially inside the Sliding Sleeve (SS) and engageable with the Sliding Sleeve (SS).

4. The two-speed bridge drive system according to claim 3, wherein the synchromesh mechanism further comprises:

a first synchronizing gear (G1) fixed to the first carrier (P1) to correspond to the Synchronizing Ring (SR), and the first synchronizing gear (G1) is engageable with the Sliding Sleeve (SS) to synchronize the first carrier (P1) with the second sun gear shaft (S2); and

a second synchronizing gear (G2) fixed to the first sun gear shaft (S1) to correspond to the Synchronizing Ring (SR), and the second synchronizing gear (G2) is engageable with the Sliding Sleeve (SS) to synchronize the first sun gear shaft (S1) with the second sun gear shaft (S2).

5. The two-speed bridge drive system according to claim 1 or 2, further comprising:

a Differential (DM) drivingly coupled with the second carrier (P2); and

a first half-shaft (HS1) and a second half-shaft (HS2), the first half-shaft (HS1) and the second half-shaft (HS2) extending from the Differential (DM) toward both sides of the Differential (DM).

6. The two-speed bridge drive system according to claim 5, wherein the first half shaft (HS1) and the second half shaft (HS2) are offset with respect to the first sun shaft (S1) and the second sun shaft (S2), and wherein

The two-speed bridge drive system further comprises an output gear (G3) fixed to the second carrier (P2) such that the second carrier (P2) is able to transmit torque to the Differential (DM) via the output gear (G3).

7. The two-speed bridge drive system according to claim 5, wherein the first half shaft (HS1) and the second half shaft (HS2) are coaxially arranged with both the first sun shaft (S1) and the second sun shaft (S2), and wherein

The second planet carrier (P2) is fixed to the housing of the Differential (DM) such that the second planet carrier (P2) is able to transmit torque to the Differential (DM) via the housing of the Differential (DM).

8. The two-speed bridge drive system according to claim 7, wherein the first sun gear shaft (S1) and the second sun gear shaft (S2) are both hollow shafts, and the first half shaft (HS1) passes through the first sun gear shaft (S1) and the second sun gear shaft (S2).

9. A vehicle comprising a two-speed bridge drive system according to any one of claims 1 to 8.

10. The vehicle of claim 9, comprising an electric machine having an output shaft drivingly coupled to a first sun gear shaft of the two-speed bridge drive system.