GB2559973A

GB2559973A - A parking brake assembly

Info

Publication number: GB2559973A
Application number: GB1702859.8A
Authority: GB
Inventors: Jardine Ben; Saint Glenn
Original assignee: Arrival Ltd
Current assignee: Arrival UK Ltd
Priority date: 2017-02-22
Filing date: 2017-02-22
Publication date: 2018-08-29
Anticipated expiration: 2037-02-22
Also published as: GB2559973B; GB201702859D0

Abstract

A vehicle comprises an electric motor 12 that has a rotor 24. A parking brake assembly 22 comprises an output shaft 20, a first braking member, preferably disc 30 and a second braking member, preferably brake pads 31. The output shaft 20 is configured to be fixed relative to said rotor 24such that said electric motor 12 is operable to rotate the output shaft 20. The parking brake is preferably actuated by motor 44. Gearbox 27 may be coupled to the output shaft 20. Providing a single parking brake 22 for the axle reduces size and weight of the vehicle.

Description

(71) Applicant(s):

Arrival Limited

Unit 2, Southam Road, Banbury, Oxfordshire, OX16 2DJ, United Kingdom (72) Inventor(s):

Ben Jardine Glenn Saint (56) Documents Cited:

WO 2006/115132 A1 JP 2013082320 A JP 2006199144 A

CN 103775567 A JP 2013052768 A (58) Field of Search:

INT CL B60K, B60L, B60T, H02K Other: EPODOC, WPI (74) Agent and/or Address for Service:

Venner Shipley LLP

200 Aldersgate, LONDON, EC1A4HD,

United Kingdom (54) Title of the Invention: A parking brake assembly

Abstract Title: Parking brake assembly on the output shaft of a rotor of an electric motor (57) A vehicle comprises an electricmotor 12 that has a rotor 24. A parking brake assembly 22 comprises an output shaft 20, a first braking member, preferably disc 30 and a second braking member, preferably brake pads 31. The output shaft 20 is configured to be fixed relative to said rotor 24such that said electric motor 12 is operable to rotate the output shaft 20. The parking brake is preferably actuated by motor 44. Gearbox 27 may be coupled to the output shaft 20. Providing a single parking brake 22 for the axle reduces size and weight of the vehicle.

/6

FIG. 1

2/6

FIG. 2

3/6

FIG. 3

4/6

Y.

28Α

FIG. 4 'X

5/6

FIG. 5

6/6

FIG. 6

-ιΑ Parking Brake Assembly

Technical Field

The present invention relates to a parking brake assembly. The present invention also 5 relates to a drive apparatus and to a vehicle comprising the same.

Background

Vehicle parking brakes generally comprise a brake disc mounted to a wheel of the vehicle such that rotation of the wheel causes a corresponding rotation of the brake disc. When the parking brake is engaged, a pair of brake pads are urged against the brake disc by an actuator such that the friction between the brake pads and brake disc prevents the brake disc, and thus the wheel, from rotating. Therefore, the vehicle is held in a stationary position.

The parking brake therefore provides a “braking torque” that resists rotation of the wheel connected to the brake disc, and thus prevents movement of the vehicle, when the parking brake is engaged. The braking torque is the torque required to overcome the friction between the brake disc and brake pads when the parking brake is engaged such that the wheel connected to the brake disc rotates. Heavier vehicles will require a larger braking torque to be provided by the parking brake to prevent the vehicle from moving when the vehicle is parked on an incline. One solution for increasing the braking torque is to increase the force with which the brake pads are urged against the brake disc. However, this increases the power consumption of the actuator and the size and weight of the parking brake.

It is known to provide multiple wheels of the vehicle each with a respective brake disc and corresponding brake pads to increase the braking provided by the parking brake. For example, a respective brake disc may be mounted to each of the front or rear wheels and a corresponding pair of brake pads acts on each of the brake discs to brake each of the front or rear wheels. However, providing multiple brake discs, pairs of brake discs and actuators increases the weight and complexity of the vehicle.

Summary

According to the present invention, there is provided a parking brake assembly for a vehicle comprising an electric motor that has a rotor, wherein the parking brake assembly comprises: an output shaft configured to be fixed relative to said rotor such that said electric motor is operable to rotate the output shaft; a first braking member coupled to the output shaft; and, a second braking member configured to act on the first braking member to resist rotation of the output shaft.

In one embodiment, the first braking member is located proximate to an end of the output shaft that is distal to the electric motor.

In one embodiment, the first braking member is configured to couple to the output shaft such that the first braking member extends about the rotational axis of the output shaft.

The first braking member may comprise a brake disc. The second braking member may comprise a brake pad. The first braking member may rotate about the same axis of rotation as the output shaft.

In one embodiment, the parking brake assembly further comprises a carrier that is configured to couple the first braking member to the output shaft. The carrier may comprise a shaft attachment portion configured to connect to the output shaft and a braking member attachment portion configured to connect to the first braking member.

The shaft attachment portion may comprise first and second gripping members configured to engage with a circumferential surface of the output shaft.

In one embodiment, the braking member attachment portion extends radially 25 outwardly from the shaft attachment portion.

In one embodiment, the braking member attachment portion comprises first and second connecting members and, preferably, the first and second connecting members each comprise a plate.

In one embodiment, the parking brake assembly further comprises an actuator configured to move the second braking member relative to the first braking member to act on the first braking member. The actuator may comprise a parking brake motor.

The output shaft may be connected directly to the rotor. Alternatively, the output shaft may be connected to the rotor via an intermediate component, e.g. an intermediate

-3shaft or coupling, which is fixed relative to the rotor and output shaft such that the output shaft is fixed relative to the rotor. In one embodiment, the output shaft extends continuously between the first braking member and the rotor of the electric motor.

According to the present invention, there is also provided a drive apparatus comprising a parking brake assembly according to the invention and an electric motor having a rotor, wherein the output shaft is fixed relative to the rotor of the electric motor such that the electric motor is operable to drive the output shaft.

The drive apparatus may further comprise a gearbox that is coupled to the output shaft. The gearbox may be coupled to the output shaft at a location between the electric motor and the first braking member. In one embodiment, the output shaft extends through the gearbox. In one embodiment, the gearbox is mounted to the electric motor.

In one embodiment, the drive apparatus further comprises a housing that contains the gearbox and the electric motor.

In one embodiment, the gearbox has a gear ratio of at least 6:1 and, preferably, at least 9:1. In some embodiments, the gearbox has a gear ratio in the range of 6:1 to 25:1 and, preferably, 9:1 to 19:1. In some embodiments, the gearbox has a gear ratio of about 9:1, 14:1 or 19:1. Optionally, the gearbox maybe a single-speed gearbox.

According to the present invention, there is also provided a vehicle comprising a drive apparatus according to the invention. In one embodiment, the vehicle comprises a further drive apparatus according to the invention. For example, the vehicle may comprise first and second drive apparatus according to the invention. In one such embodiment, the first drive apparatus drives the front wheels of the vehicle and the second drive apparatus drives the rear wheels of the vehicle. In one embodiment, the vehicle comprises a differential that is coupled to the gear box of the drive apparatus.

Brief Description of the Drawings

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 is a perspective view of a chassis of an electric vehicle;

-4Fig. 2 is a schematic cross-sectional top view of a drive apparatus according to an embodiment of the invention;

Fig. 3 is a front perspective view of the drive apparatus of Fig. 2;

Fig. 4 is a front perspective view of an electric motor and gearbox of the drive apparatus of Fig. 2;

Fig. 5 is a front perspective view of a carrier of the drive apparatus of Fig. 2; and,

Fig. 6 is a rear perspective view of a brake disc of the drive apparatus of Fig. 2.

Detailed Description io Fig. l shows a chassis io of an electric vehicle. The chassis io comprises a pair of chassis rails n to which are mounted first and second drive apparatus 12,13, first and second battery modules 14,15 and a range extender module 16.

The first drive apparatus 12 is mounted towards the front of the chassis 10 and is arranged to drive the front wheels 17 of the vehicle. The second drive apparatus 13 is mounted towards the rear of the chassis 10 and is arranged to the drive the rear wheels 18 of the vehicle. The first battery module 14, second battery module 15 and range extender module 16 are mounted between the first and second drive apparatus 12,13, towards the middle of the chassis 10.

The first and second drive apparatus 12,13 are similar and therefore, for the sake of brevity, only the first drive apparatus 12 will be described in detail hereinafter. In some embodiments, the first and second drive apparatus 12,13 are identical. However, it will be appreciated that this is not necessary and the first and second drive apparatus 12,13 may, for instance, differ in shape/size/power output.

The first drive apparatus 12 is shown in more detail in Figs. 2 to 6 and comprises an electric motor 19, an output shaft 20, a gearbox 21 and a parking brake 22.

The electric motor 19 comprises an outer casing 23 that contains a rotor 24 and a stator 25. The rotor 24 is configured to rotate about a first axis X-X. The first and second battery modules 14,15 supply electrical power to the electric motors 19 of the first and second drive apparatus 12,13. However, in an alternative embodiment (not shown), a single battery module supplies electrical power to the first and second drive apparatus.

-5The range extender module 16 may be configured to supply electrical power to the battery modules 14,15 to recharge the battery modules 14,15. Alternatively, or additionally, the range extender module 16 may be configured to supply electrical power directly to the first and second drive apparatus 12,13.

The gearbox 21 comprises an outer casing 26 that contains first and second gears 27A, 27B. The first and second gears 27A, 27B engage such that the first gear 27A is rotatable to drive the second gear 27B.

The gearbox 21 is connected to a differential 28 (shown in Figs. 3 and 4) that is coupled to the front wheels 17. The second gear 27B of the gearbox 21 is connected to the differential 28 by a driveshaft 21A. The differential 28 comprises first and second output portions 28A, 28B that are each connected to a respective front wheel 17 via a respective front axle (not shown). Thus, the first and second output portions 28A, 28B are rotatable to drive the front wheels 17 to move the vehicle.

The first and second output portions 28A, 28B of the differential 28 define a second axis Y-Y, referred to hereinafter as the drive axis Y-Y. The output portions 28A, 28B maybe any appropriate structure capable of mechanically coupling to a component, e.g.

to an axle to cause rotational movement of the axle upon rotation of the second gear 27B. For example, the first and second output portions 28A, 28B may each comprise a female splined structure configured to engage with a male splined structure of a respective axle, or vice versa. The output portions 28A, 28B may additionally, or alternatively, be configured to each be bolted to an axle to mechanically couple to the axle. The drive axis Y-Y corresponds to the axis about which the axles are driven as the output portions 28A, 28B rotate. In the present embodiment, the driveshaft 21A that connects the second gear 27A to the differential 28 also rotates about the drive axis Y-Y.

In alternative embodiments (not shown), the differential 28 may be omitted and instead the driveshaft 21A of the gearbox 21 is directly coupled to the front wheels 17. In one such embodiment (not shown), each of the front and/or rear wheels is driven by a respective drive apparatus. In a further embodiment (not shown), the driveshaft 21A is coupled to an intermediate shaft (not shown) that is coupled to the differential 28 or is coupled to the front wheels 17.

-6The output shaft 20 connects the rotor 24 of the electric motor 19 to the first gear 27A of the gearbox 21. The output shaft 20 is fixed relative to the rotor 24. Thus, when the electric motor 19 is operated, the rotor 24 is rotated which causes corresponding rotation of the first gear 27A to drive the second gear 27B. This results in rotation of the driveshaft 21A such that the first and second output portions 28A, 28B of the differential 28 are rotated to drive the front wheels 17 of the vehicle. Similarly, the second drive apparatus 13 comprises an output shaft (now shown) that connects a rotor of an electric motor (not shown) to a gearbox (not shown), the gearbox being connected to a driveshaft that rotates the rear wheels 18 of the vehicle via a differential (not shown).

The gearbox 21 provides a gear reduction, meaning that rotation of the first gear 27A at a first speed results in rotation of the second gear 27B at a slower second speed, whereas the torque is increased. In other words, when the electric motor 19 is powered to exert a first torque on the output shaft 20 to drive the first gear 27A, a second torque, greater than the first torque, is exerted on the driveshaft 21A by the second gear 27B. In one embodiment, the gearbox 21 has a gear ratio of at least 6:1 and, preferably, at least 9:1. In some embodiments, the gearbox 21 has a gear ratio in the range of 6:1 to 25:1 and, preferably, 9:1 to 19:1. However, it should be recognised that in alternative embodiments the gearbox 21 has a gear ratio outside of this range. In some preferred embodiments, the gearbox 21 has a gear ratio of about 9:1,14:1 or 19:1. The gearbox 21 may have a fixed gear ratio.

The electric motor 19 and gearbox 21 are connected together to form a drive unit. In the present embodiment, the outer casing 23 of the electric motor 19 is mounted to the outer casing 26 of the gearbox 21 such that the outer casing 23 of the electric motor 19 and outer casing 26 of the gearbox 21 together form an outer housing 29 of the first drive apparatus 12. In another embodiment (not shown), the outer casing 23 of the electric motor 19 and outer casing 26 of the gearbox 21 are integrally formed and together form the outer housing 29 of the first drive apparatus 12.

The output shaft 20 comprises opposite first and second ends 20A, 20B. The rotor 24 is connected to the output shaft 20 proximate to the first end 20A. The output shaft 20 extends through the gearbox 21 such that the first gear 27A is connected to the output shaft 20 at a location between the first and second ends 20A, 20B of the output shaft

-Ί20. The output shaft 20 projects from the outer casing 26 of the gearbox 21 such that the second end 20B is spaced from the gearbox 21.

The parking brake 22 comprises a first braking member 30, a pair of second braking 5 members 31 and an actuator 32. The first braking member 30 is in the form of a brake disc 30 and the second braking members 31 are in the form of a pair of brake pads 31.

The parking brake 22 further comprises a carrier 33 that connects the brake disc 30 to the output shaft 20. The carrier 33 comprises a shaft attachment portion 34 configured to connect to the output shaft 20 and a braking member attachment portion 35 configured to connect to the first braking member 30.

The shaft attachment portion 34 comprises first and second clamping members 36,37 that engage with the circumference of the output shaft 20 such that the output shaft 20 is located between the first and second clamping members 36, 37. In the present embodiment, the first and second clamping members 36, 37 are each curved such that the first and second clamping members 36,37 together form a tubular shape when they are connected to the output shaft 20.

The carrier 33 comprises a fastener (not shown) that retains the first and second clamping members 36, 37 in engagement with the output shaft 20. In one embodiment, the fastener comprises a bolt that extends through recesses (not shown) in each of the first and second clamping members 36, 37 and a nut that engages with the bolt to lock the first and second clamping members 36, 37 together on the output shaft 20. In an alternative embodiment (not shown), the fastener comprises a clasp that connects the first and second clamping members 36, 37 together.

The first and second clamping members 36, 37 engage with the output shaft 20 such that the carrier 33 is fixed relative to the output shaft 20. Thus, rotation of the output shaft 20 results in corresponding rotation of the carrier 33. In the present embodiment, the first and second clamping members 36,37 clamp to the output shaft 20 to fix the carrier 33 relative to the output shaft 20. However, in alternative embodiments (not shown), the carrier 33 and/or output shaft 20 alternatively, or additionally, includes one or more surface features to rotationally fix the carrier 33 relative to the output shaft

20. For example, the output shaft 20 or the shaft attachment portion 34 comprises one or more recesses (not shown) and the other of the output shaft 20 or the shaft

-8attachment portion 34 comprises one or more protrusions (not shown) that engage with the recesses to rotationally fix the carrier 33 relative to the output shaft 20. The first and second gripping members 36, 37 may comprise the protrusions or recesses of the shaft attachment portion 34. In one embodiment (not shown), the output shaft 20 or the shaft attachment portion 34 comprises one or more grooves (not shown) and the other of the output shaft 20 or the shaft attachment portion 34 comprises one or more splines (not shown) that engage with the grooves (not shown).

The braking member attachment portion 35 comprises first and second connecting 10 members 38, 39 that extend radially outwardly from the shaft attachment portion 34.

The first connecting member 38 extends from the first clamping member 36 and the second connecting member 39 extends from the second clamping member 37. Therefore, when the first and second clamping members 36, 37 are connected together and fixed relative to the output shaft 20 by the fastener, the first and second connecting members 38,39 are also connected together and fixed relative to the output shaft 20. The first and second connecting members 38, 39 may be integrally formed with the first and second clamping members 36, 37 respectively.

In the present embodiment, the first and second connecting members 38,39 each comprise a plate and together form an annular shape when the first and second clamping members 36,37 are connected together. The first and second connecting members 38,39 may together form a flange that extends radially outwardly from the shaft attachment portion 34.

The first and second connecting members 38, 39 each comprise a recess 40, 41 at an end of the first and second connecting members 38, 39 that is distal to the shaft attachment portion 34. Each recess 40,41 is configured to receive a portion of the brake disc 30. Each of the first and second connecting members 38,39 comprises one or more bolt holes 38A, 39A in the portion of the first and second connecting members

38,39 at the recess 40, 41.

The brake disc 30 is generally annular. The brake disc 30 comprises an annular recess 42 that extends from an edge of the brake disc 30 such that the brake disc 30 has a portion of reduced thickness that forms an engagement portion 43. The engagement portion 43 comprises one or more bolt holes 43A. The engagement portion 43 is configured to be received in the recesses 40,41 of the first and second connecting

-9members 38,39 of the braking member attachment portion 35 such that the bolt holes 43A of the brake disc 30 align with the bolt holes 38A, 39A of the braking member attachment portion 35. The brake disc 30 is secured to the braking member attachment portion 35 by a plurality of bolts (not shown) such that rotation of the output shaft 20 results in corresponding rotation of the carrier 33 and brake disc 30.

The output shaft 20, rotor 24, first gear 27A, brake disc 30 and carrier 33 are fixed relative to each other and rotate together about the first axis X-X. This causes rotation of the second gear 27B, driveshaft 21A, and the first and second output portions 28A,

28B of the differential 28 about the second axis Y-Y to drive the front wheels 17 of the vehicle. The brake disc 30 maybe arranged coaxially with the output shaft 20. The brake disc 30 may be arranged concentrically with the output shaft 20.

The actuator 32 comprises an electric motor 44 and a calliper 45. The brake pads 31 are mounted to the calliper 45. The electric motor 44 is configured to drive the calliper 45 to control the position of the brake pads 31 relative to the brake disc 30. The arrangement of the calliper 45 will be apparent to a skilled person and so a detailed description has not been included herein. For example, the calliper 45 may include a gear assembly (not shown), for example, a rack and pinion gear, configured to convert rotational motion of the electric motor 44 into linear movement of the brake pads 31 relative to the brake disc 30.

The electric motor 44 of the actuator 32 may comprise, for example, a servo motor or stepper motor.

The brake pads 31 are moveable relative to the brake disc 30 between a disengaged position and an engaged position. When the brake pads 31 are in the disengaged position the brake pads 31 are spaced from the brake disc 30. The electric motor 44 is operable to drive the calliper 45 such that the brake pads 31 are moved to the engaged position wherein the brake pads 31 are urged against the brake disc 30. Thus, when the brake pads 31 are in the engaged position the friction between the brake pads 31 and brake disc 30 resists rotation of the brake disc 30. The brake disc 30 is coupled to the output shaft 20 and therefore said friction between the brake pads 31 and brake disc 30 also resists rotation of the output shaft 20. Moreover, since the output shaft 20 is coupled to the front wheels 17 of the vehicle via the gearbox 21, the front wheels 17 are

- 10 resisted from rotating when the brake pads 31 are in the engaged position. Therefore, the driver is able to operate the parking brake 22 to prevent the vehicle from moving.

The front drive apparatus 12 thus comprises an integrated electric motor 19 and 5 parking brake 22. It is therefore not necessary to provide a separate parking brake system that applies a braking force individually to each of the front wheels 17 or rear wheels 18 of the vehicle. Furthermore, the amount of braking force applied to park the vehicle is scalable by adding further drive apparatus to the vehicle, wherein each drive apparatus includes a parking brake coupled to a corresponding output shaft. For instance, a relatively light vehicle may only require a single drive apparatus, for example, a front or rear drive apparatus 12,13, to power the vehicle and the braking force provided by the parking brake of the single drive apparatus will be sufficient to retain the vehicle in position even when parked on a steep gradient. A heavier vehicle may comprise multiple drive apparatus, for example, multiple front and/or rear drive apparatus 12,13, in order to provide sufficient power to power the vehicle. Together, the parking brake 22 of each drive apparatus 12,13 will provide sufficient braking force to retain the heavier vehicle in position. However, it should be recognised that in embodiments comprising multiple drive apparatus 12,13, some of the drive apparatus 12,13 may be provided without a parking brake 22.

The parking brake 22 being configured to act on the output shaft 20 increases the braking torque of the parking brake 22. This is because the parking brake 22 is coupled to the front wheels 17 via the gearbox 21. As discussed above, the gearbox 21 has a reduction ratio, meaning that torque transmitted through the gearbox 21 from the first gear 27A to the second gear 27B is increased. Therefore, if a given braking torque is applied to the output shaft 20 by the parking brake 22, a significantly higher torque would need to be exerted on the front wheels 17 of the vehicle to overcome the given braking torque and rotate the front wheels 17 to move the vehicle. The greater the reduction ratio of the gearbox 21, the larger the torque that must be exerted on the front wheels 17 to overcome the braking torque of the parking brake 22 to rotate the front wheels 17. Therefore, the power consumption of the actuator 32 and the size and weight of the parking brake 22 can be reduced.

In the above described embodiment, the parking brake 22 has a first braking member

30 comprising a brake disc 30 and a pair of second braking members 31 comprising brake pads 31. However, it should be recognised that one of the second braking

- 11 members 31 maybe omitted. For example, in one embodiment (not shown) the parking brake 22 instead comprises a single brake pad 31 that is urged against the brake disc 30 to control braking of the vehicle. In yet further embodiments (not shown), the parking brake 22 comprises a different type of first braking member 30 and/or second braking member 31. For instance, the first braking member 30 may comprise a brake drum (not shown) that is coupled to the output shaft 20 and the second braking member 31 may comprise a brake shoe (not shown) that is urged against the brake drum to resist rotation of the output shaft 20.

In the above described embodiment, the actuator 32 comprises an electric motor 44. However, in alternative embodiments (not shown), a different type of actuator is provided to move the brake pads 31 relative to the brake disc 30. In one such embodiment (not shown), the actuator comprises a hydraulic or pneumatic system that controls movement of the brake pads 31 using fluid pressure. For example, the brake calliper 45 may be connected to a first piston that is fluidly connected to a second piston via a fluid line. When the user applies the parking brake, the second piston is moved, for example, by a lever coupled to the second piston, to adjust the pressure of the fluid, resulting in movement of the first piston to control movement of the brake pads 31. In yet another embodiment (not shown), the actuator comprises a cable that is connected to the calliper 45. When the user applies the parking brake, the tension of the cable is adjusted, for example, by a lever and/or pulley, to control movement of the brake pads 31.

In the above described embodiment, the gearbox 21 is a single-speed gearbox.

However, it should be recognised that in alternative embodiments the gearbox 21 is a multi-speed gearbox.

In the above described embodiment, the brake disc 30 is mounted to the circumference of the output shaft 20. More specifically, the carrier 33 engages with the circumferential surface of the output shaft 20 to retain the brake disc 30 in position relative to the output shaft 20. However, in an alternative embodiment (not shown), the brake disc 30 maybe mounted to either end surface of the output shaft 20. The end surfaces of the output shaft 20 may be generally flat and face in opposite directions. In one such embodiment (not shown), the carrier 33 is mounted to either of the end surfaces of the output shaft 20, for example, by bolts or screws, or is welded to either of the end surfaces.

- 12 In the above described embodiment, the brake disc 30 is mounted to the output shaft 20 at a location at, or proximate to, the second end 20B of the output shaft 20 such that the gearbox 21 is located between the electric motor 19 and the brake disc 30.

Therefore, it is relatively easy to replace the brake disc 30 if the brake disc 30 becomes worn without having to disassemble the electric motor 19 or gearbox 21. However, in an alternative embodiment (not shown), the brake disc 30 may be mounted to the output shaft 20 at a location between the electric motor 19 and gearbox 21.

In some embodiments (not shown), the first braking member 30 and/or carrier 33 comprises one or more recesses to reduce the weight of the first braking member 30 and/or carrier 33.

In the above described embodiment, the output shaft 20 is the motor output shaft, meaning that the output shaft is connected directly to the rotor 24 of the electric motor 19. However, it should be recognised that in alternative embodiments (not shown) the output shaft 20 is a separate shaft to the motor output shaft and is connected to the motor output shaft such that it is fixed relative to the motor output shaft. For example, the motor output shaft may be connected directly to the rotor 24 and extends from the electric motor 19, wherein the output shaft 20 is connected to the motor output shaft by a coupling.

In the above described embodiment, the carrier 33 comprises first and second clamping members 36, 37 that couple the carrier 33 to the output shaft 20. However, in alternative embodiments (not shown), the carrier 33 may comprise a single component that couples to the output shaft 20. In one such embodiment (not shown), the carrier comprises an annular member with a recess, wherein the carrier is slid over an end of the output shaft 20 such that the output shaft 20 is received in the recess. In one embodiment (not shown), the braking member attachment portion 35 comprises one or more arms that extend radially outwardly from the shaft attachment portion 34, wherein the brake disc 30 is connected to said one or more arms.

In the above described embodiment, the carrier 33 is a separate component to the output shaft 20 and clamps to the output shaft 20. However, in an alternative embodiment (not shown), the carrier 33 is integrally formed with the output shaft 20.

In another embodiment (not shown), the carrier 33 is omitted and instead the first

-13braking member 30 is coupled directly to the output shaft 20. The first braking member 30 maybe bolted or welded directly to the output shaft 20. In one such embodiment (not shown), the first braking member 30 comprises a flat plate that is bolted or welded to an end surface of the output shaft 20. In some embodiments (not shown), the first braking member 30 is integrally formed with the output shaft 20.

In some embodiments, the actuator 32 of the parking brake 22 is connected to a controller (not shown) that is configured to control operation of the parking brake 22. The controller may comprise a memory for storing instructions and a processor for performing said instructions. In one such embodiment, the controller is connected to a user input device, for example, a button or switch, which controls operation of the parking brake 22. The user input device sends a signal to the controller to operate the actuator 32 such that the brake pads 31 are engaged or disengaged with the brake disc 30 to prevent or allow movement of the vehicle. In embodiments wherein multiple drive apparatus 12,13 are provided, the controller may be configured to control the operation of the actuator 32 of each drive apparatus 12,13.

In some embodiments, the controller is configured to operate as a hill-start assist system, operating the parking brake 22 to prevent the vehicle from rolling backwards when the vehicle is on an incline, for instance, if the driver is waiting at traffic lights or a junction. In some embodiments, the controller is connected to a sensor that inputs a signal to the controller based on information indicative of a condition of the vehicle, for instance, whether the vehicle is on an incline and/or whether the vehicle is rolling backwards. In one embodiment, the sensor detects whether the vehicle is on an incline and may comprise, for example, an inclinometer. If the sensor detects that the vehicle is on an incline, the controller operates the parking brake 22 to retain the vehicle in position until the electric motor 19 is operated to move the vehicle forwards. In another embodiment, the sensor detects backwards motion of the vehicle and the controller is configured to operate the parking brake 22 if backwards motion of the vehicle is detected and the vehicle is not in a reverse gear.

In order to address various issues and advance the art, the entirety of this disclosure shows by way of illustration various embodiments in which the claimed invention(s) maybe practiced and provide for a superior parking brake assembly, drive apparatus and vehicle. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are

-14presented only to assist in understanding and teach the claimed features. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope and/or spirit of the disclosure. Various embodiments may suitably comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. In addition, the disclosure includes other inventions not presently claimed, but which may be claimed in future.

Claims

Claims

1. A parking brake assembly for a vehicle comprising an electric motor that has a rotor, wherein the parking brake assembly comprises:

5 an output shaft configured to be fixed relative to said rotor such that said electric motor is operable to rotate the output shaft; a first braking member coupled to the output shaft; and, a second braking member configured to act on the first braking member to resist rotation of the output shaft.

io
2. A parking brake assembly according to claim l, wherein the first braking member is located proximate to an end of the output shaft that is distal to the electric motor.

15
3· A parking brake assembly according to claim l or claim 2, wherein the first braking member is configured to couple to the output shaft such that the first braking member extends about the rotational axis of the output shaft.
4. A parking brake assembly according to any of claims l to 3, wherein the first

20 braking member comprises a brake disc.
5. A parking brake assembly according to any of claims 1 to 4, further comprising a carrier that is configured to couple the first braking member to the output shaft.

25
6. A parking brake assembly according to claim 5, wherein the carrier comprises a shaft attachment portion configured to connect to the output shaft and a braking member attachment portion configured to connect to the first braking member.
7. A parking brake assembly according to claim 6, wherein the shaft attachment

30 portion comprises first and second gripping members configured to engage with a circumferential surface of the output shaft.
8. A parking brake assembly according to claim 6 or claim 7, wherein the braking member attachment portion extends radially outwardly from the shaft attachment

35 portion.

-ι69. A parking brake assembly according to any of claims 6 to 8, wherein the braking member attachment portion comprises first and second connecting members and, preferably, the first and second connecting members each comprise a plate.

5 10. A parking brake assembly according to any of claims 1 to
9, wherein the second braking member comprises a brake pad.

11. A parking brake assembly according to any of claims 1 to 10, further comprising an actuator configured to move the second braking member relative to the first braking
10 member to act on the first braking member.
12. A parking brake assembly according to claim 11, wherein the actuator comprises a parking brake motor.
15 13. A drive apparatus comprising a parking brake assembly according to any of claim 1 to 12 and an electric motor having a rotor, wherein the output shaft is fixed relative to the rotor of the electric motor such that the electric motor is operable to drive the output shaft.

20 14. A drive apparatus according to claim 13, further comprising a gearbox that is coupled to the output shaft.

15. A drive apparatus according to claim 14, wherein the gearbox is coupled to the output shaft at a location between the electric motor and the first braking member.
16. A drive apparatus according to claim 14 or claim 15, wherein the output shaft extends through the gearbox.
17. A drive apparatus according to any of claims 14 to 16, wherein the gearbox is

30 mounted to the electric motor.
18. A drive apparatus according to any of claims 14 to 17, further comprising a housing that contains the gearbox and the electric motor.

-1719- A drive apparatus according to any of claims 14 to 18, wherein the gearbox has a gear ratio of at least 9:1 and, preferably, has a gear ratio in the range of about 9:1 to
19:1.

5
20. A vehicle comprising a drive apparatus according to any of claims 13 to 19.
21. A vehicle according to claim 20, wherein the vehicle further comprises a further drive apparatus according to any of claims 13 to 19.

Intellectual

Property

Office

Application No: GB1702859.8 Examiner: Jason Clee