Lift axle drag reduction system and method

• US 10,450,016 B2
• Filed: 05/05/2017
• Issued: 10/22/2019
• Est. Priority Date: 05/05/2017
• Status: Active Grant

• Current Assignee: PACCAR Incorporated
• Original Assignee: PACCAR Incorporated
• Inventors: Smith, Jeffrey P.
• Primary Examiner(s): Fleming, Faye M
• Application Number:
  US15/588,050
• Publication Number:
  US 20180319451A1
• Time in Patent Office: 900 Days
• Field of Search: 280 865
• CPC Class Codes: B60G 17/0155 pneumatic unit
• CPC Class Codes: B60G 17/016 characterised by their responsiveness, when the vehicle is travelling, to specific motion, a specific condition, or driver input B60G17/017 takes precedence
• CPC Class Codes: B60G 2204/4702 pneumatically
• CPC Class Codes: B60G 2204/62 Adjustable continuously, e.g. during driving
• CPC Class Codes: B60G 2300/0262 Multi-axle trucks
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/39 Brake pedal position
• CPC Class Codes: B62D 61/12 with variable number of ground engaging wheels, e.g. with some wheels arranged higher than others, or with retractable wheels for manoeuvring purposes only B60S

Abstract

A disclosed lift axle is suitable for a vehicle that has a first wheel for supporting the vehicle on a road surface. The lift axle system includes a lift mechanism that is coupled to the vehicle and is configured to reciprocate an axle between a stowed position and deployed position. The lift axle system further includes a second wheel coupled to the axle. The second wheel engages the road surface when the lift mechanism is in the deployed position, and the second wheel is disengaged from the road surface when the lift mechanism is in the stowed position. The second wheel has a lower rolling resistance than the first wheel.

Claims

1. A lift axle system for a vehicle having a first axle, a first wheel, and a tire for supporting the vehicle on a road surface, the lift axle system comprising:

(a) a lift mechanism coupled to the vehicle, the lift mechanism being positioned adjacent to the first axle and configured to reciprocate a second axle between a stowed position and a deployed position;

(b) a second wheel coupled to the second axle, the second wheel comprising a solid wear ring for engaging the road surface when the lift mechanism is in the deployed position, the solid wear ring being disengaged from the road surface when the lift mechanism is in the stowed position, and

(c) a controller configured to cause the lift mechanism to selectively move the second axle between the deployed position and the stowed position,

wherein the controller is configured to cause the lift mechanism to move the second axle from the deployed position to the stowed position based on receipt of a service brake signal indicative of a service brake engaged condition, and wherein the solid wear ring has a lower rolling resistance than the tire of the first wheel.

2. The lift axle system of claim 1, wherein the tire is filled with a compressed gas.

3. The lift axle system of claim 1, wherein the lift mechanism comprises a beam rotatably coupled to the vehicle, one end of the beam supporting the second axle.

4. The lift axle system of claim 3, wherein the lift mechanism further comprises an actuator operably coupled to the beam, the actuator selectively rotating the beam between a first position and a second position, wherein the lift mechanism is in the stowed position when the beam is in the first position, and the lift mechanism is in the deployed position when the beam is in the second position.

5. The lift axle system of claim 4, wherein the actuator comprises a pneumatic spring.

6. The lift axle system of claim 4, wherein the actuator is one of an electric actuator and a hydraulic actuator.

7. The lift axle system of claim 1, further comprising a vehicle speed sensor operatively coupled to the controller, wherein the controller is configured to cause the lift mechanism to move the second axle from the stowed position to the deployed position based on receipt of a vehicle speed signal indicative of a condition that the vehicle speed has exceeded a predetermined threshold speed.

8. The lift axle system of claim 1, further comprising a service brake sensor operatively coupled to the controller and configured to generate the service brake signal.

9. The lift axle system of claim 1, further comprising an operator input device operatively coupled to the controller, wherein the controller is programmed to stow and to deploy the lift mechanism in response to operator input from the operator input device.

17. The lift axle system of claim 7, wherein the controller is further configured to cause the lift mechanism to move the second axle from the deployed position to the stowed position based on receipt of a vehicle speed signal indicative of a condition that the vehicle speed has fallen below a predetermined threshold speed.

18. The lift axle system of claim 17, wherein the predetermined threshold speed is 45 mph.

10. A lift axle system for a vehicle having a first axle, a first wheel, and a tire for supporting the vehicle on a road surface, the lift axle system comprising:

(a) a beam positioned adjacent to the first axle and rotatably coupled to the vehicle;

(b) a second axle coupled to the beam;

(c) an actuator operably coupled to the beam to selectively rotate the beam between a stowed position and a deployed position;

(d) a second wheel coupled to the second axle, the second wheel comprising a solid wear ring for engaging the road surface when the beam is in the deployed position, the solid wear ring being disengaged from the road surface when the beam is in the stowed position; and

(e) a controller configured to cause the actuator to selectively rotate the beam between the stowed position and the deployed position,

wherein the controller is configured to cause the actuator to move the beam from the deployed position to the stowed position based on receipt of a vehicle speed signal indicative of a condition that the vehicle speed has fallen below a predetermined threshold speed, and wherein the solid wear ring has a lower rolling resistance than the tire of the first wheel.

11. The lift axle system of claim 10, wherein the actuator is a first air spring engaging a first end of the beam to bias the beam toward the stowed position.

12. The lift axle system of claim 11, further comprising a second air spring engaging a second end of the beam to bias the beam toward the deployed position.

13. The lift axle system of claim 10, wherein the tire is filled with a compressed gas.

14. The lift axle system of claim 10, wherein the controller is configured to cause the actuator to move the beam from the stowed position to the deployed position based on receipt of a vehicle speed signal indicative of a condition that the vehicle speed has exceeded a predetermined threshold speed.

15. The lift axle system of claim 10, further comprising a service brake sensor operatively coupled to the controller, wherein the controller is configured to cause the actuator to move the beam from the deployed position to the stowed position based on receipt of a service brake signal indicative of a service brake engaged condition.

16. The lift axle system of claim 10, further comprising an operator input device operatively coupled to the controller, wherein the controller is programmed to stow and to deploy the beam in response to operator input from the operator input device.

19. A method for controlling a lift axle system for a vehicle having a first axle, a first wheel, and a tire for supporting the vehicle on a road surface, the lift axle system having a lift mechanism positioned adjacent to the first axle, a second wheel coupled to the second axle and comprising a solid wear ring for engagement with the road surface, and a controller, the method comprising:

receiving, by the controller, a service brake signal indicative of a service brake engaged condition; and

based on receipt of the service brake signal by the controller, causing the lift mechanism to move the second axle from a deployed position, wherein the solid wear ring of the second wheel engages the road surface, to a stowed position, wherein the solid wear ring disengages from the road surface.