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EP-4741687-A1 - A TRANSMISSION ARRANGEMENT FOR A VEHICLE

EP4741687A1EP 4741687 A1EP4741687 A1EP 4741687A1EP-4741687-A1

Abstract

A transmission arrangement (300) for a vehicle, comprising: - an input component (132) drivingly connected to an electric motor, - a first planetary gear system (140), a first sun gearwheel (141) and a first ring gearwheel (144) being rotationally connectable to the input component by a first sleeve (146) and a second sleeve (145), respectively, and a first planet carrier (142) being rotationally connected to an output component (81), - a crawler unit (390) drivingly connectable between the first planetary gear system (140) and the output component, the first sleeve being configured to selectively rotationally connect the first sun gearwheel to a stationary member (149a, 149b), the second sleeve being configured to selectively rotationally connect the first ring gearwheel to the stationary member via a third sleeve (395), the third sleeve being rotationally connected to the stationary member, and being configured to selectively rotationally connect one gear member of the crawler unit to the stationary member to cause the first ring gearwheel to rotate in an opposite direction compared to the first planet gearwheel carrier.

Inventors

  • FOLKESSON, JOHAN
  • HEDMAN, ANDERS

Assignees

  • Volvo Truck Corporation

Dates

Publication Date
20260513
Application Date
20241108

Claims (15)

  1. A transmission arrangement (300, 9300) for a vehicle (1), comprising: - an input component (132, 8132) configured to be drivingly connected to an electric motor (10, 810), - a first planetary gear system (140) comprising a first sun gearwheel (141), a first ring gearwheel (144), and a first planet carrier (142) carrying a first set of planet gearwheels (143), wherein the first sun gearwheel (141) and the first ring gearwheel (144) are selectively rotationally connectable to the input component (132, 8132) by a first sleeve (146) and a second sleeve (145), respectively, and wherein the first planet carrier (142) is rotationally connected to an output component (81, 981), - a crawler unit (390) comprising a plurality of gear members, the crawler unit (390) being configured to selectively drivingly connect the first ring gearwheel (144) to the output component (81, 981), wherein the first sleeve (146) is further configured to selectively rotationally connect the first sun gearwheel (141) to a stationary member (149a, 149b) of the transmission arrangement, and wherein the second sleeve (145) is further configured to selectively rotationally connect the first ring gearwheel (144) to the stationary member (149a, 149b) via a third sleeve (395), wherein the third sleeve (395) is rotationally connected to the stationary member (149a, 149b), and wherein the third sleeve (395) is further configured to selectively rotationally connect one of the plurality of gear members of the crawler unit (390) to the stationary member (149a, 149b) to cause the first ring gearwheel (144) to rotate in an opposite direction compared to a rotational direction of the first planet gearwheel carrier (142).
  2. The transmission arrangement of claim 1, wherein the third sleeve (395) is axially displaceable relative to the stationary member (149a, 149b) between a first position in which it is engageable by the second sleeve (145), and a second position in which it rotationally connects the one of the plurality of gear members of the crawler unit (390) to the stationary member (149a, 149b), preferably wherein, in its second position, the third sleeve (395) is non-engageable by the second sleeve (145).
  3. The transmission arrangement of claim 2, further comprising a first shift rod (51) motionally connected to a first shift fork (5) configured to move the first sleeve (146), a second shift rod (61) motionally connected to a second shift fork (6) configured to move the second sleeve (145), and a third shift rod (71) motionally connected to a third shift fork (7) configured to move the third sleeve (395).
  4. The transmission arrangement of claim 3, wherein the first, second and third shift forks (5, 6, 7) are pivoting shift forks.
  5. The transmission arrangement of claim 3 or 4, wherein the first shift rod (51) is configured to move the first sleeve (146) between a first position in which it rotationally connects the first sun gearwheel (141) to the stationary member (149a, 149b), a neutral position, and a second position in which it rotationally connects the first sun gearwheel (141) to the input component (132, 8132).
  6. The transmission arrangement of any one of claims 3-5, wherein the second shift rod (61) is configured to move the second sleeve (145) between a first position in which it rotationally connects the first ring gearwheel (144) to the input component (132, 8132), a neutral position, and a second position in which it can engage the third sleeve (395).
  7. The transmission arrangement of claims 5 and 6, wherein the first and second shift rods (51, 61) are arranged to physically prevent simultaneous positioning of the first sleeve (146) in its first position and the second sleeve (145) in its second position, and wherein the first and third shift rods (51, 71) are arranged to physically prevent simultaneous positioning of the first sleeve (146) in its first position and the third sleeve (395) in its second position.
  8. The transmission arrangement of claim 7, wherein the first and second shift rods (51, 61) are coaxial and have shift rod ends (51e, 61e) configured to come into contact with one another and prevent simultaneous movement of the first sleeve (146) into its first position and of the second sleeve (145) into its second position, and/or wherein the first shift rod (51) and the third shift rod (71) are coaxial and have shift rod ends (51e, 71e1) configured to come into contact with one another and prevent simultaneous movement of the first sleeve (146) into its first position and of the third sleeve (395) into its second position.
  9. The transmission arrangement of any one of claims 3-8, wherein at least one of the shift rods (51, 61, 71) comprises at least one lateral extension (51x1, 51x1, 51x2, 61x1, 61x2, 71x1, 71x2), each lateral extension (51x1, 51x2, 61x1, 61x2, 71x1, 71x2) being configured to come into contact with a portion of another one of the shift rods (51, 61, 71).
  10. The transmission arrangement of any one of claims 3-9, wherein the first, second and third shift rods (51, 61, 71) are arranged to physically prevent simultaneous rotational connection of the first sleeve (146) to the input component (132, 8132), the second sleeve (145) to the input component (132, 8132), and the third sleeve (395) to the one of the plurality of gear members of the crawler unit (390).
  11. The transmission arrangement of claim 10, wherein the second and third shift rods (61, 71) are configured to come into contact with one another and prevent the third sleeve (395) from moving to its second position when the second sleeve (145) rotationally connects the input component (132, 8132) to the first ring gearwheel (144), and vice versa, preferably wherein the second shift rod (61) and the third shift rod (71) are coaxial and have shift rod ends (61e2, 71e1) configured to come into contact with one another.
  12. The transmission arrangement of any one of the preceding claims, wherein the crawler unit (390) comprises a second planetary gear system (390), the plurality of gear members of the crawler unit (390) comprising a second sun gearwheel (391), a second ring gearwheel (394), and a second planet carrier (392) carrying a second set of planet gearwheels (393), preferably wherein the third sleeve (395) is configured to selectively rotationally connect the second planet carrier (392) to the stationary member (149a, 149b), and/or wherein the second ring gearwheel (394) is rotationally connected to the first planet carrier (142), and the second sun gearwheel (391) is rotationally connected to the first ring gearwheel (144).
  13. The transmission arrangement of any one of the preceding claims, wherein the output component (81) is a differential planet carrier (81) of a differential gear set (80) configured to distribute torque to a first drive shaft (89a) and a second drive shaft (89b) arranged coaxially with the first planetary gear system (140).
  14. A powertrain (200, 8200) for an electrically propelled vehicle (1), the powertrain (200, 8200) comprising: - an electric motor (10, 810), and - a transmission arrangement (300, 9300) according to any one of the preceding claims, wherein the input component (132, 8132) of the transmission arrangement is drivingly connected or connectable to the electric motor (10, 810).
  15. A vehicle (1) comprising the transmission arrangement (300, 9300) according to any of claims 1-13, or the powertrain (200, 8200) according to claim 14.

Description

TECHNICAL FIELD The disclosure relates generally to transmission arrangements. In particular aspects, the disclosure relates to a transmission arrangement for a vehicle, a powertrain, and a vehicle. The disclosure can be applied to heavy-duty vehicles, such as trucks, buses, and construction equipment, among other vehicle types. The disclosure is particularly applicable to electric vehicles. Although the disclosure may be described with respect to a particular vehicle, the disclosure is not restricted to any particular vehicle. BACKGROUND In recent years, there has been a trend towards developing powertrains with at least one electric prime mover, i.e., with at least one electric motor for propulsion of the vehicle. For heavy duty vehicles propelled by electric motors, a transmission that enables a plurality of gear states, with gear ratios spanning a large range, is required to achieve startability as well as efficiency at cruising speed. For starting and crawling, the transmission needs to provide a large speed reduction, whereas at cruising speed, it is normally desirable to use as few gear meshes as possible to reduce power losses and improve driving range. It is further desirable to provide a transmission which is compact. In view of this, there is a strive to develop improved technology relating to electric powertrains for vehicles. SUMMARY According to a first aspect of the disclosure, a transmission arrangement for a vehicle is provided. The transmission arrangement comprises: an input component configured to be drivingly connected to an electric motor,a first planetary gear system comprising a first sun gearwheel, a first ring gearwheel, and a first planet carrier carrying a first set of planet gearwheels, wherein the first sun gearwheel and the first ring gearwheel are selectively rotationally connectable to the input component by a first sleeve and a second sleeve, respectively, and wherein the first planet carrier is rotationally connected to an output component,a crawler unit comprising a plurality of gear members, the crawler unit being configured to selectively drivingly connect the first ring gearwheel to the output component,wherein the first sleeve is further configured to selectively rotationally connect the first sun gearwheel to a stationary member of the transmission arrangement, and wherein the second sleeve is further configured to selectively rotationally connect the first ring gearwheel to the stationary member via a third sleeve,wherein the third sleeve is rotationally connected to the stationary member, and wherein the third sleeve is further configured to selectively rotationally connect one of the plurality of gear members of the crawler unit to the stationary member to cause the first ring gearwheel to rotate in an opposite direction compared to a rotational direction of the first planet gearwheel carrier. The first aspect may seek to provide an in at least some aspects improved transmission arrangement for a vehicle powered by an electric motor. In particular, it may seek to provide such a transmission arrangement which is compact and robust, and which provides selectable gear ratios over a large speed reduction range. A technical benefit may include a compact transmission arrangement enabling a number of selectable speed ratios, including a large speed reduction suitable for crawling. With the non-rotating third sleeve, rotationally connected to the stationary member, such as to a transmission housing, and the second sleeve configured to rotationally connect the first ring gearwheel to the stationary member via the third sleeve, it is further possible to provide a transmission arrangement with a reduced risk of undesired locking of the gear members due to undesired simultaneous rotational connection to the stationary member. In comparison with a transmission arrangement in which the second sleeve is configured to directly rotationally connect the first ring gearwheel to the stationary member, without using the third sleeve, this may improve robustness and facilitate gear shifting. In the following and throughout the description, the wording "rotationally connected to" and "rotationally connect" should be interpreted such that a component of the transmission arrangement is connected to another component of the transmission arrangement in such a way that the components rotate in the same direction and with the same rotational speed. The components thus rotate in the same direction and with the same rotational speed when being rotationally connected to each other. The term "rotationally connectable to" should be interpreted as "selectively connectable for common rotation with". By a "driving connection" of two rotating parts is to be understood that torque can be transmitted between the parts, and that the rotational speeds of the parts are proportional. When two rotating parts are drivingly connected, torque can be transmitted between the parts. This may be achieved by two gea