Active tractor suspension system
First Claim
1. An active suspension system for isolating an operator cab from a frame of a tractor, said active suspension system comprising:
- at least one vibration isolator including first and second mounts adapted to attach said vibration isolator between the operator cab and the frame, a spring connected between the first and second mounts, a linear actuator connected to the first mount, and an elastomeric vibration isolator connected between said linear actuator and the second mount which is attached to the operator cab;
a sensor which detects movement of the operator cab said sensor being located adjacent to said linear actuator to detect movement at a point that is between said linear actuator and said elastomeric vibration isolator and producing an electrical signal in response to detected movement; and
a controller operably connected to the linear actuator and responsive to the electrical signal by producing a control signal which selectively causes the linear actuator to expand and contract between the first and second mounts thereby changing the spacing therebetween, so as to attenuate transmission of movement of the operator cab and the frame.
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Accused Products
Abstract
An active vehicle suspension employs a multi-point support system between a vehicle'"'"'s chassis and cab. Each support point has an isolator which includes a linear hydraulic actuator that is connected at its quiet end to the payload by a passive vibration isolator and is connected at its vibrating end to the chassis. Each isolator also has a support spring to off-load the majority of the weight of the cab from the hydraulic actuator. An accelerometer is mounted to sense movement at a point between the linear hydraulic actuator and the passive vibration isolator. An electrical signal produce by the accelerometer is processed to operate a hydraulic valve that controls movements of the hydraulic actuator so that transmission of vibrations from the chassis to the cab is attenuated.
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Citations
13 Claims
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1. An active suspension system for isolating an operator cab from a frame of a tractor, said active suspension system comprising:
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at least one vibration isolator including first and second mounts adapted to attach said vibration isolator between the operator cab and the frame, a spring connected between the first and second mounts, a linear actuator connected to the first mount, and an elastomeric vibration isolator connected between said linear actuator and the second mount which is attached to the operator cab; a sensor which detects movement of the operator cab said sensor being located adjacent to said linear actuator to detect movement at a point that is between said linear actuator and said elastomeric vibration isolator and producing an electrical signal in response to detected movement; and a controller operably connected to the linear actuator and responsive to the electrical signal by producing a control signal which selectively causes the linear actuator to expand and contract between the first and second mounts thereby changing the spacing therebetween, so as to attenuate transmission of movement of the operator cab and the frame. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An active suspension system for isolating an operator cab from a frame of a tractor, said active suspension system comprising:
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at least one vibration isolator including first and second mounts adapted to attach said vibration isolator between the operator cab and the frame, a hydraulic actuator having a piston moveable with respect to a cylinder, and a passive isolator connected in series with the hydraulic actuator between the first and second mounts; a valve operable to selectively supply a flow of pressurized hydraulic fluid from an external source to said actuator and to selectively relieve pressurized hydraulic fluid from said actuator so as to cause the piston to move in a given direction relative to the cylinder; a sensor mechanism which produces a signal indicative of the absolute velocity of a point between the hydraulic actuator and the passive isolator; and a controller which responds to the signal from said sensor by producing a valve control signal for operating said valve to produce movement of the piston relative to the cylinder, so as to attenuate transmission of movement of the operator cab with respect to the frame. - View Dependent Claims (10, 11, 12, 13)
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Specification