Non-linear stiffness actuator for vehicle suspension

Patent metadata

Field	Value
Publication number	US-10457108-B2
Application number	US-201715790595-A
Country	US
Kind code	B2
Filing date	Oct 23, 2017
Priority date	Oct 23, 2017
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

A non-linear stiffness actuator for a suspension corner employed in a vehicle includes an actuator housing and an actuator shaft configured to transmit an actuator force to the road wheel. The actuator also includes a primary elastic member assembly arranged between the actuator housing and the actuator shaft and configured to exert a primary elastic member force along the actuator shaft. The actuator additionally includes a secondary elastic member assembly configured to exert a variable secondary elastic member force acting between the actuator housing and the actuator shaft. The variable secondary elastic member force is configured to selectively contribute to and subtract from the primary elastic member force to thereby facilitate the non-linear stiffness of the actuator. A vehicle having such a non-linear stiffness actuator is also provided.

First claim

What is claimed is:

1. A non-linear stiffness actuator for a suspension corner employed in a vehicle having a vehicle body and a road wheel, the non-linear stiffness actuator comprising:
an actuator housing;
an actuator shaft configured to transmit an actuator force to the road wheel;
a primary elastic member assembly arranged between the actuator housing and the actuator shaft and configured to exert a primary elastic member force along the actuator shaft; and
a secondary elastic member assembly configured to exert a variable secondary elastic member force acting between the actuator housing and the actuator shaft, wherein the variable secondary elastic member force is configured to selectively contribute to and subtract from the primary elastic member force to thereby facilitate the non-linear stiffness of the actuator.

2. The non-linear stiffness actuator according to claim 1 , wherein the primary elastic member assembly includes a mechanism configured to adjust the primary elastic member force.

3. The non-linear stiffness actuator according to claim 2 , wherein the vehicle includes an anti-roll bar, wherein the actuator shaft is fixed to the anti-roll bar, and wherein the primary elastic member assembly includes a plurality of torsion springs connecting the adjustment mechanism to the anti-roll bar, the secondary elastic member assembly is fixed to the actuator housing, the anti-roll bar includes a ramp element configured to compress the secondary elastic member assembly when the anti-roll bar is twisted to generate the variable secondary elastic member force acting between the actuator housing and the actuator shaft and thereby generate the non-linear stiffness of the actuator.

4. The non-linear stiffness actuator according to claim 2 , wherein the adjustment mechanism includes a motor configured as at least one of an electric motor, a pneumatic servomechanism, a hydraulic servomechanism, and a transfer gear set configured to adjust the primary elastic member force.

5. The non-linear stiffness actuator according to claim 4 , wherein the primary elastic member assembly includes a first spring seat connected to the motor, a second spring seat, and a compression spring arranged between the first and second spring seats.

6. The non-linear stiffness actuator according to claim 5 , wherein:
the compression spring is compressed between the first spring seat and the second spring seat under a weight of the vehicle body;
the secondary elastic member assembly is mounted to the second spring seat; and
the second spring seat is configured to shift relative to the actuator housing in response to an input force from the road wheel.

7. The non-linear stiffness actuator according to claim 6 , wherein the secondary elastic member assembly includes a plurality of secondary springs and rollers, and wherein each secondary spring is in operative connection with a respective one of the rollers and each roller is in operative contact with the actuator housing.

8. The non-linear stiffness actuator according to claim 7 , wherein the actuator housing is characterized by an interior surface arranged along a first axis and defining a contour configured to guide the rollers; and wherein each of the plurality of secondary springs is configured to extend the respective one of the rollers along a second axis that is orthogonal to the first axis into contact with the contour of the interior surface to follow the contour of the interior surface upon translation of the second spring seat and thereby define the non-linear stiffness of the actuator.

9. The non-linear stiffness actuator according to claim 1 , wherein the suspension corner includes a damper assembly, and wherein the actuator shaft is configured to compress the damper assembly.

10. The non-linear stiffness actuator according to claim 1 , wherein the variable force of the secondary elastic member assembly is configured to progressively change over a stroke of the actuator shaft to thereby selectively complement and detract from the primary elastic member force and modify the actuator force.

11. A vehicle comprising:
a vehicle body;
a road wheel configured to maintain contact with a road surface; and
a suspension corner connecting the road wheel to the vehicle body, configured to maintain contact between the road wheel and the road surface, and including a non-linear stiffness actuator having:
an actuator housing;
an actuator shaft configured to transmit an actuator force;
a primary elastic member assembly arranged between the actuator housing and the actuator shaft and configured to exert an elastic member force along the actuator shaft to the road wheel; and
a secondary elastic member assembly configured to exert a variable secondary elastic member force acting between the actuator housing and the actuator shaft, wherein the variable secondary elastic member force is configured to selectively contribute to and subtract from the primary elastic member force to thereby facilitate the non-linear stiffness of the actuator.

12. The vehicle according to claim 11 , wherein the primary elastic member assembly includes a mechanism configured to adjust the primary elastic member force.

13. The vehicle according to claim 12 , further comprising an anti-roll bar, wherein the actuator shaft is fixed to the anti-roll bar, and wherein the primary elastic member assembly includes a plurality of torsion springs connecting the adjustment mechanism to the anti-roll bar, the secondary elastic member assembly is fixed to the actuator housing, the anti-roll bar includes a ramp element configured to compress the secondary elastic member assembly when the anti-roll bar is twisted to generate the variable secondary elastic member force acting between the actuator housing and the actuator shaft and thereby generate the non-linear stiffness of the actuator.

14. The vehicle according to claim 12 , wherein the adjustment mechanism includes a motor configured as at least one of an electric motor, a pneumatic servomechanism, a hydraulic servomechanism, and a transfer gear set configured to adjust the primary elastic member force.

15. The vehicle according to claim 14 , wherein the primary elastic member assembly includes a first spring seat connected to the motor, a second spring seat, and a compression spring arranged between the first and second spring seats.

16. The vehicle according to claim 15 , wherein:
the compression spring is compressed between the first spring seat and the second spring seat under a weight of the vehicle body;
the secondary elastic member assembly is mounted to the second spring seat; and
the second spring seat is configured to shift relative to the actuator housing in response to an input force from the road wheel.

17. The vehicle according to claim 16 , wherein the secondary elastic member assembly includes a plurality of secondary springs and rollers, and wherein each secondary spring is in operative connection with a respective one of the rollers and each roller is in operative contact with the actuator housing.

18. The vehicle according to claim 17 , wherein the actuator housing is characterized by an interior surface arranged along a first axis and defining a contour configured to guide the rollers; and wherein each of the plurality of secondary springs is configured to extend the respective one of the rollers along a second axis that is orthogonal to the first axis into contact with the contour of the interior surface to follow the contour of the interior surface upon translation of the second spring seat and th

Assignees

• Gm Global Tech Operations Llc

Inventors

• Suplin Vladimir
• Suissa Avshalom
• Trangbaek Klaus

Classifications

• F16F2230/0064

  using a cam · CPC title

• F16F2228/066

  Variable stiffness · CPC title

• F16F3/04

  composed only of wound springs · CPC title

• F16F1/00

  Springs (working with fluid F16F5/00, F16F9/00) · CPC title

• B60G15/04

  and mechanical damper {or dynamic damper} · CPC title