Secondary brake for commercial vehicle using MR fluid

Patent metadata

Field	Value
Publication number	US-9810274-B2
Application number	US-201514933865-A
Country	US
Kind code	B2
Filing date	Nov 5, 2015
Priority date	Mar 31, 2015
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

A secondary brake for commercial vehicles using Magnetorheological (MR) fluid may include a rotor coupled to a transmission output shaft to be rotated together, a stator configured to be disposed between the rotor and a body of a transmission and having a cavity into which the MR fluid is filled and a portion of the rotor is received, and a stator coil provided in a portion of the stator and applying a magnetic field to the MR fluid so that braking torque is generated due to a shear resistance characteristic of the MR fluid.

First claim

What is claimed is:

1. A secondary brake for commercial vehicles using Magnetorheological (MR) fluid comprising:
a rotor coupled to a transmission output shaft to be rotated together;
a stator configured to be disposed between the rotor and a body of a transmission and having a cavity formed in the stator, wherein a portion of the rotor is received in the cavity;
a stator coil provided in a portion of the stator and applying a magnetic field to the MR fluid so that braking torque is generated due to a shear resistance characteristic of the MR fluid;
a circumferential hole formed in the cavity of the stator in a circumferential direction to receive the MR fluid inside of the circumferential hole;
through holes formed in the portion of the rotor to receive the MR fluid inside the through holes; and
flow holes formed in the portion of the rotor received in the cavity to provide a passage allowing the MR fluid in the through holes to flow into the circumferential hole,
wherein the MR fluid circulates via the through holes of the rotor, the flow holes of the rotor, and the circumferential hole of the stator.

2. The secondary brake of claim 1 , wherein a plurality of the through holes and a plurality of the flow holes are sequentially formed at regular intervals along a circumferential direction of the rotor.

3. A secondary brake for commercial vehicles using Magnetorheological (MR) fluid comprising:
a rotor coupled to a transmission output shaft to be rotated together;
a stator configured to be disposed between the rotor and a body of a transmission and having a cavity formed in the stator, wherein the MR fluid is filled in the cavity and a portion of the rotor is received in the cavity;
a stator coil provided in a portion of the stator and applying a magnetic field to the MR fluid so that braking torque is generated due to a shear resistance characteristic of the MR fluid;
a coil controller connected to the stator coil and configured to control magnetic force of the stator coil by increasing electric power in steps; and
a fluid supply which is interlocked with the coil controller and supplies MR fluid to the cavity,
wherein the rotor formed in the cavity of the stator having through holes and flow holes,
wherein a magnitude of the shear resistance of the MR fluid is configured to be adjusted by regulating amount of the MR fluid depending on pushed angles of a brake pedal manipulated by a driver or a number of operations of actuating switches, and
wherein the MR fluid circulates via the through holes of the rotor, the flow holes of the rotor, and the circumferential hole of the stator.

4. The secondary brake of claim 3 , wherein the fluid supply is provided with a solenoid valve which is opened and closed in steps by a plurality of actuating switches provided in the coil controller, and a fluid cylinder configured to supply the MR fluid to the cavity, wherein the fluid cylinder is actuated by receiving compressed air through the opening and closing of the solenoid valve.

Assignees

• Hyundai Motor Co Ltd

Inventors

• Jeong Jong Yun

Classifications

• B60T10/02

  with hydrodynamic brake · CPC title

• F16D57/002 Primary

  comprising a medium with electrically or magnetically controlled internal friction, e.g. electrorheological fluid, magnetic powder · CPC title