Abstract: A linear actuator having a free fall function. The linear actuator moves a piston-rod member back and forth using torque of a rotary motor. Here, the piston-rod member is disposed within a portion of a cylinder body to be movable back and forth. In the event of jamming in which the piston-rod member is stopped due to sticking between an operating nut and a screw member, the piston-rod member is caused to freely fall in a direction in which load is applied. This can consequently obtain the maximum stretched length of the piston-rod member, thereby providing safety in an emergency.

Abstract: A linear actuator having a free fall function. The linear actuator moves a piston-rod member back and forth using torque of a rotary motor. Here, the piston-rod member is disposed within a portion of a cylinder body to be movable back and forth. In the event of jamming in which the piston-rod member is stopped due to sticking between an operating nut and a screw member, the piston-rod member is caused to freely fall in a direction in which load is applied. This can consequently obtain the maximum stretched length of the piston-rod member, thereby providing safety in an emergency.

Abstract: An active suspension apparatus for a vehicle according to one embodiment of the present invention includes a pump configured to control movement of a fluid, an actuator connected with a coil spring, which is connected with a wheel of the vehicle, and configured to receive the fluid from the pump and to compensate for a displacement of the coil spring, a fluid path configured to connect the pump with the actuator, and a valve configured to control a flow of the fluid in the fluid path, wherein, when the actuator is controlled to receive the fluid from the pump, the valve is configured to prevent the fluid from flowing from the actuator to the pump by a pressure of the fluid accommodated in the actuator.

Abstract: An active suspension apparatus for a vehicle includes a pump configured to adjust movements of a fluid and actuators configured to receive the fluid from the pump and to compensate displacements of coil springs connected to wheels of the vehicle, in which the pump supplies the fluid contained in a cylinder to one of the actuators of left wheels of the vehicle and the actuators of right wheels of the vehicle based on the driving of a motor.

Abstract: An active suspension apparatus for a vehicle includes actuators configured to compensate displacements of coil springs connected to wheels of the vehicle, a first pump configured to supply a fluid to one of the actuators on left and right front wheels of the vehicle among the actuators, and a second pump configured to supply a fluid to one of the actuators on left and right rear wheels of the vehicle among the actuators, in which the fluid contained in one of cylinders of the first pump and the second pump is supplied to at least one of the actuators based on driving of a motor.

Abstract: An active suspension apparatus for a vehicle according to one embodiment of the present invention includes a pump configured to control movement of a fluid, an actuator connected with a coil spring, which is connected with a wheel of the vehicle, and configured to receive the fluid from the pump and to compensate for a displacement of the coil spring, a fluid path configured to connect the pump with the actuator, and a valve configured to control a flow of the fluid in the fluid path, wherein, when the actuator is controlled to receive the fluid from the pump, the valve is configured to prevent the fluid from flowing from the actuator to the pump by a pressure of the fluid accommodated in the actuator.

Abstract: A frequency sensitive type shock absorber is provided. A housing has a bypass hole formed such that an upper portion of a chamber part is opened to connect to the opening, and a lower portion of the chamber part communicates with the compression chamber. A spool is formed within the chamber part and is elevated by a fluid flowing into the chamber part. A pair of partition members partitions the chamber part into upper and lower chambers and provides a restoring force to the spool. A guide member is formed between the pair of the partition members, has a elastic force, and guides the partition members to maintain positions thereof. A pair of elastic members is formed in the upper and lower chambers to prevent a fluid from penetrating between the pair of the partition members and the side of the chamber part, and assist a restoration of the partition members by elasticity.

Abstract: A piston valve assembly for a shock absorber is disclosed. In a high-frequency mode, a damping force control is achieved through an open passage that is always opened. In a low-frequency mode, a guide assembly moves downward due to an increase in a pressure of a first pressure chamber by a fluid moved through an inlet hole of the first pressure chamber. At this time, the guide assembly blocks the open passage and the damping force control is achieved through only a rebound passage. Consequently, it is possible to solve a fluid bottle neck through a passage formation. A disk is installed on the inlet hole to prevent a continuous increase in the pressure of the first pressure chamber, thereby effectively preventing the reduction of the damping force.

Abstract: An active suspension apparatus for a vehicle includes actuators configured to compensate displacements of coil springs connected to wheels of the vehicle, a first pump configured to supply a fluid to one of the actuators on left and right front wheels of the vehicle among the actuators, and a second pump configured to supply a fluid to one of the actuators on left and right rear wheels of the vehicle among the actuators, in which the fluid contained in one of cylinders of the first pump and the second pump is supplied to at least one of the actuators based on driving of a motor.

Abstract: An active suspension apparatus for a vehicle includes a pump configured to adjust movements of a fluid and actuators configured to receive the fluid from the pump and to compensate displacements of coil springs connected to wheels of the vehicle, in which the pump supplies the fluid contained in a cylinder to one of the actuators of left wheels of the vehicle and the actuators of right wheels of the vehicle based on the driving of a motor.

Abstract: In a high-frequency mode (a small-amplitude mode), a shock absorber opens a guide member to reduce a damping force. In a low-frequency mode (a large-amplitude mode), the shock absorber prevents the guide member from being opened by increasing a pressure of a second pressure chamber formed between a second piston (lower piston) and a pilot valve through a groove (passage) formed in an outer periphery of a piston rod. A main damping force is generated through the second pressure chamber and a disk valve assembly. Therefore, it is possible to provide a round ride comfort having a damping feeling and ensure a steering stability through a linear vehicle control.

Abstract: A shock absorber is provided. A first piston, a pilot valve, a second piston, and a rebound retainer are sequentially connected to a piston rod reciprocating within a cylinder. An upper portion of the second piston is provided inside the first piston. Due to a first compression chamber formed in the first piston, a second compression chamber formed in the second piston, a third compression chamber formed between the first piston and the second piston, and a fourth compression chamber formed in the rebound retainer, it is possible to improve a ride comfort by reducing a damping force over periods from an ultra-low-speed period to a high-speed period and it is possible to achieve the compact configuration and the cost reduction by reducing the overall length of the processing portion.

Abstract: A valve assembly of a shock absorber can achieve both an effect of varying an attenuation force according to a frequency region of vibration or shock transferred to the shock absorber during the driving of an automobile and an effect of varying an attenuation force according to an additional pressure and can increase the attenuation force in response to an instantaneous input of a large amplitude behavior. The valve assembly includes: a valve housing coupled to a piston rod having an orifice hole and a space formed therein, the space having an open lower end to communicate with the orifice hole; a frequency sensitive valve unit including a free piston configured to vertically partition the space; and a sub-valve unit coupled to the lower end of the space, wherein operation of the sub-valve unit is controlled by ascending and descending of the free piston.

Abstract: Disclosed herein is a piston assembly of a shock absorber which ensures easy and prompt connection of components in the correct positions in assembling the piston assembly of a shock absorber by forming a seating unit between a piston body and a compression retainer and between the piston body and a tension retainer.

Abstract: In a high-frequency mode (a small-amplitude mode), a shock absorber opens a guide member to reduce a damping force. In a low-frequency mode (a large-amplitude mode), the shock absorber prevents the guide member from being opened by increasing a pressure of a second pressure chamber formed between a second piston (lower piston) and a pilot valve through a groove (passage) formed in an outer periphery of a piston rod. A main damping force is generated through the second pressure chamber and a disk valve assembly. Therefore, it is possible to provide a round ride comfort having a damping feeling and ensure a steering stability through a linear vehicle control.

Abstract: A piston valve assembly for a shock absorber is disclosed. In a high-frequency mode, a damping force control is achieved through an open passage that is always opened. In a low-frequency mode, a guide assembly moves downward due to an increase in a pressure of a first pressure chamber by a fluid moved through an inlet hole of the first pressure chamber. At this time, the guide assembly blocks the open passage and the damping force control is achieved through only a rebound passage. Consequently, it is possible to solve a fluid bottle neck through a passage formation. A disk is installed on the inlet hole to prevent a continuous increase in the pressure of the first pressure chamber, thereby effectively preventing the reduction of the damping force.

Abstract: A frequency/pressure sensitive shock absorber for generating a damping force varying according to a frequency and a pressure-includes: a cylinder filled with a working fluid; a piston rod having one end located inside the cylinder and the other end extending outward from the cylinder; a main piston valve assembly installed at one end of the piston rod and configured to operate in a state that the inside of the cylinder is divided into an upper chamber and a lower chamber, and generate a damping force varying according to a moving speed; and a sensitive unit installed at one end of the piston rod under the main piston valve assembly and configured to generate a damping force varying according to a frequency and a pressure.

Abstract: A frequency sensitive type shock absorber is provided. A housing has a bypass hole formed such that an upper portion of a chamber part is opened to connect to the opening, and a lower portion of the chamber part communicates with the compression chamber. A spool is formed within the chamber part and is elevated by a fluid flowing into the chamber part. A pair of partition members partitions the chamber part into upper and lower chambers and provides a restoring force to the spool. A guide member is formed between the pair of the partition members, has a elastic force, and guides the partition members to maintain positions thereof. A pair of elastic members is formed in the upper and lower chambers to prevent a fluid from penetrating between the pair of the partition members and the side of the chamber part, and assist a restoration of the partition members by elasticity.

Abstract: A shock absorber is provided. A first piston, a pilot valve, a second piston, and a rebound retainer are sequentially connected to a piston rod reciprocating within a cylinder. An upper portion of the second piston is provided inside the first piston. Due to a first compression chamber formed in the first piston, a second compression chamber formed in the second piston, a third compression chamber formed between the first piston and the second piston, and a fourth compression chamber formed in the rebound retainer, it is possible to improve a ride comfort by reducing a damping force over periods from an ultra-low-speed period to a high-speed period and it is possible to achieve the compact configuration and the cost reduction by reducing the overall length of the processing portion.

Abstract: A valve assembly of a shock absorber can achieve both an effect of varying an attenuation force according to a frequency region of vibration or shock transferred to the shock absorber during the driving of an automobile and an effect of varying an attenuation force according to an additional pressure and can increase the attenuation force in response to an instantaneous input of a large amplitude behavior. The valve assembly includes: a valve housing coupled to a piston rod having an orifice hole and a space formed therein, the space having an open lower end to communicate with the orifice hole; a frequency sensitive valve unit including a free piston configured to vertically partition the space; and a sub-valve unit coupled to the lower end of the space, wherein operation of the sub-valve unit is controlled by ascending and descending of the free piston.