SEMI-INDEPENDENT SUSPENSION SYSTEM FOR A LOW-FLOOR VEHICLE

• US 20150191070A1
• Filed: 06/11/2013
• Published: 07/09/2015
• Est. Priority Date: 07/03/2012
• Status: Active Grant

• Current Assignee: Pantero Technologies Inc.
• Original Assignee: Pantero Technologies Inc.
• Inventors: Raymond, Jean
• Granted Patent: US 9,527,368 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60G 21/051 Trailing arm twist beam axles
• CPC Class Codes: B60G 21/052 Mounting means therefor
• CPC Class Codes: B60G 2200/21 Trailing arms connected by a torsional beam, i.e. twist-beam axles
• CPC Class Codes: B60G 2200/341 Panhard rod
• CPC Class Codes: B60G 2200/44 steerable
• CPC Class Codes: B60G 2204/148 on the unsprung part of the vehicle, e.g. wheel knuckle or rigid axle
• CPC Class Codes: B60G 2206/014 with reinforcing nerves or branches
• CPC Class Codes: B60G 2206/20 Constructional features of semi-rigid axles, e.g. twist beam type axles
• CPC Class Codes: B60G 2206/50 Constructional features of wheel supports or knuckles, e.g. steering knuckles, spindle attachments
• CPC Class Codes: B60G 2206/82 Joining
• CPC Class Codes: B60G 2300/02 Trucks; Load vehicles
• CPC Class Codes: B60G 2300/38 Low or lowerable bed vehicles
• CPC Class Codes: B60G 3/14 the arm being rigid

Abstract

A semi-independent suspension system adapted for a rear or front drive and optionally steerable axle system of a low-floor heavy vehicle, comprising a twist beam axle assembly (1), a Panhard rod (8), and a pair of spring and shock absorber systems (9). The twist beam axle assembly (1) comprises a pair of rigid longitudinal trailing arms (3), a pair of wheel mounting members to lower the cross-beam relative to the wheel axis (2) and a straight cross-beam (7). The cross-beam is set in the right and left trailing arms and the wheel mounting members by an interference fit technique. The cross-beam (7) has an open-section and is rigid in bending but flexible in torsion. The shape of the cross-section is specifically tailored to increase and control each of the vertical and horizontal bending stiffness (7). The cross-section is characterized by having horizontal and vertical lines of symmetry, but with asymmetric horizontal and vertical geometries. The combination of features of the twist beam axle assembly (1) provides for a full flat floor without slope or extra height over the axle.

Claims

1. A rear suspension system for a low-floor vehicle, the vehicle having a chassis frame, spaced apart right and left wheels defining a wheel axis;

the rear suspension system comprising;

a twist beam axle assembly, a Panhard rod, and a pair of spring and shock absorber systems, said twist beam axle assembly forming a drop beam axle comprising right and left rigid longitudinal trailing arms, right and left wheel mounting members and a straight cross-beam, each of said right and left wheel mounting members forming a vertical member to lower said cross-beam relative to the wheel axis, said wheel mounting members being shaped on their upper portion to be mounted to a wheel support assembly and having on their lower portion an axle locating portion, said axle locating portion shaped for matingly receiving a corresponding end portion of said cross-beam, said right and left trailing arms having at one end an axle locating portion shaped for matingly receiving the corresponding end portion of said cross-beam, said cross-beam having an open cross-section and being rigid in bending but flexible in torsion, the open cross-section of said cross-beam having horizontal and vertical lines of symmetry, but asymmetric horizontal and vertical geometries, wherein said cross-beam is set in the axle locating portions of said right and left trailing arms and wheel mounting members with an interference fit, wherein said right and left trailing arms are adapted to be joined to the chassis frame of the vehicle, each of said right and left trailing arms also comprising a mounting base for attachment to an associated one of said spring and shock absorber systems, said spring and shock absorber systems being adapted to be joined to the chassis frame of the vehicle, and wherein said Panhard rod is adapted to be joined at one end thereof to the chassis frame of the vehicle and at another end thereof to one of the right and left wheel mounting members.

2. A rear suspension system according to claim 1, wherein said cross-beam has a section in the shape of an asymmetric cross potent.

3. A rear suspension system, according to claim 1, wherein each of said axle locating portions of said right and left wheel mounting members and trailing arms has an orifice in the negative shape of the open cross-section of said cross-beam.

4. A rear suspension system according to claim 1, wherein each of said right and left wheel mounting members is shaped to be attached to a steering knuckle by a split king pin.

5. A rear suspension system according to claim 1, wherein each of said right and left wheel mounting members is shaped like a ring with circumferentially disposed bores to be connected to a wheel hub assembly.

6. A rear-wheel axle unit with single tires comprising a rear suspension system according to claim 1, wherein right and left wheels are driven by two short drive half-shafts with constant velocity joints and connected to right and left wheel hub and spindle assemblies.

7. A rear-wheel axle unit with single tires comprising a rear suspension system according to claim 4, wherein right and left wheels are steerable.

8. A rear-wheel axle unit according to claim 7, wherein right and left wheels are driven by two short drive half-shafts with constant velocity joints and connected to right and left wheel hub and spindle assemblies.

9. A tandem of rear axles comprising two rear-wheel axle units with single tires according to claim 6.

16. A low-floor vehicle comprising at least one axle unit according to claim 6.

10. A front suspension system for a low-floor vehicle, the vehicle having a chassis frame, spaced apart right and left wheels defining a wheel axis, and a steering system;

the front suspension system comprising;

a twist beam axle assembly, a Panhard rod, and a pair of spring and shock absorber systems, said twist beam axle assembly forming a drop beam axle comprising right and left rigid longitudinal leading arms, right and left wheel mounting members and a straight cross-beam, each of said right and left wheel mounting members forming a vertical member to lower said cross-beam relative to the wheel axis, said wheel mounting members being shaped on their upper portion to be mounted to a steering knuckle by a split king pin and having on their lower portion an axle locating portion, said axle locating portion for matingly receiving an end portion of said cross-beam, said right and left leading arms having at one end an axle locating portion for matingly receiving the end portion of said cross-beam, said cross-beam having an open cross-section and being rigid in bending but flexible in torsion, the open cross-section of said cross-beam having horizontal and vertical lines of symmetry, but asymmetric horizontal and vertical geometries, said wherein the cross-beam is set in the axle locating portions of said right and left leading arms and wheel mounting members with an interference fit, said right and left leading arms being adapted to be joined to the chassis frame of the vehicle, each of said leading arms also comprising a mounting base for attachment to a associated one of said spring and shock absorber systems, wherein said spring and shock absorber systems are adapted to be joined to the chassis frame of the vehicle, and wherein said Panhard rod are adapted to be joined at one end thereof to the chassis frame of the vehicle and at another end thereof to one of the right and left wheel mounting members.

11. A front suspension system according to claim 10, wherein said cross-beam has a section in the shape of an asymmetric cross potent.

12. A front suspension system according to claim 10, wherein each of said axle locating portions of said right and left wheel mounting members and leading arms has an orifice in the negative shape of the open cross-section of said cross-beam.

13. A front-wheel axle unit with single tires comprising a front suspension system according to claim 10.

14. A front-wheel axle unit with single tires according to claim 13, wherein right and left wheels are driven by two short drive half-shafts with constant velocity joints and connected to right and left wheel hub and spindle assemblies.

15. A tandem of front axles comprising two front-wheel axle units with single tires according to claim 13.

17. A twist beam axle assembly suited for use as a drop beam axle, comprising a straight cross-beam, right and left rigid longitudinal arms mounted at opposed ends of the cross-beam, and right and left wheel mounting members also mounted at said opposed ends of the cross-beam, each of said right and left wheel mounting members having a vertical member extending upwardly relative to the cross-beam, said wheel mounting members being shaped on their upper portion to be mounted to a wheel support assembly and having on their lower portion an axle locating portion, said axle locating portion matingly receiving a corresponding end portion of said cross-beam, said right and left arms having at one end an axle locating portion matingly receiving the corresponding end portion of said cross-beam, said cross-beam having an open cross-section and being rigid in bending but flexible in torsion, the open cross-section of said cross-beam having horizontal and vertical lines of symmetry, but asymmetric horizontal and vertical geometries, wherein said cross-beam is set in the axle locating portions of said right and left arms and wheel mounting members with an interference fit, wherein said right and left arms are adapted to be joined to the chassis frame of the vehicle.

18. The twist beam axle assembly defined in claim 17, wherein each of said right and left arms also comprises a mounting base for attachment to a spring and shock absorber system.