Abstract: An embodiment provides a damper a damper including: a housing; a rotor; and a sealing member. The housing includes outer and inner cylinder portions to define a filling space portion therebetween for filling with a viscose fluid. The rotor includes a head portion and a cylinder portion extended downwardly therefrom so as to be inserted into the filling space portion. The sealing member seals the filling space portion. The rotor further includes axially-extending first and second groove portions provided on outer and inner peripheral surfaces of the cylinder portion near the bottom portion thereof. At least one of the first groove portions includes a communicating portion which communicates the inside and the outside of the rotor, and the second groove portion is apart from the communicating portion in a circumferential direction.

Abstract: A rotational speed reduction device 1 for a truck tailgate includes a housing 5, a rotor 8 disposed inside the housing 5, a viscous fluid 14a accommodated in an inner space 13a, passages 15a and 16a provided in the rotor 8, a one-way valve 19 disposed in the passage 15a, and a one-way valve 20a disposed in the passage 16a.

Abstract: A rotational damper 10 comprising: a casing 13 provided therein with a partition wall portion 12 provided with a flow path 11; a rotation body 16 rotatably disposed within the casing and provided with a pair of rotary vanes 14, 15 for partitioning the inside of the casing into two chambers R1, R2, in corporation with the casing; a viscous fluid L contained within the casing; lip seals 17 mounted to the pair of rotary vanes in such a manner that, only when the rotation body rotates and moves in one direction, the lip seals 17 expand in the direction perpendicular to the vertical direction to prevent the viscous fluid from flowing between the two chambers; and a lid body 18 for closing the opening of the casing.

Abstract: The present invention provides a rotary damper in which both yields and braking characteristics can be enhanced. The rotary damper of the invention includes a valve mechanism which comprises an operating chamber 7 through which fluid can pass, a valve body 8 which forwardly moves from a natural state position when the valve body 8 receives fluid pressure and which can forwardly moves in the operating chamber 7, and a first spring 9 capable of giving a resistance to the forward movement of the valve body 8. The valve mechanism can reduce a flow rate of fluid which passes through the operating chamber 7 by a flow path 14 formed between the valve body 8 and a peripheral wall 7a of the operating chamber 7. A reducing amount of fluid can be increased as a moving distance of the valve body 8 which forwardly moves in the operating chamber 7 is increased.

Abstract: A snubber for a mining shovel including a dipper body and a dipper door rotatably coupled to the dipper body. The snubber includes a housing having an internal wall defining a fluid-filled chamber, a shaft rotatably coupled to the housing and including a portion positioned within the chamber, a paddle positioned within the chamber, a dam positioned within the chamber, a first valve, and a second valve. Rotation of the dipper door relative to the dipper body causes rotation of the shaft relative to the housing. The paddle is coupled to the shaft such that the paddle rotates with the shaft. The dam and paddle substantially partition the internal chamber into a first portion and a second portion. The first valve controls fluid flow from the first chamber to the second chamber, and the second valve controls fluid flow from the second chamber to the first chamber.

Abstract: The present invention provides a rotary damper in which both yields and braking characteristics can be enhanced. The rotary damper of the invention includes a valve mechanism which comprises an operating chamber 7 through which fluid can pass, a valve body 8 which forwardly moves from a natural state position when the valve body 8 receives fluid pressure and which can forwardly moves in the operating chamber 7, and a first spring 9 capable of giving a resistance to the forward movement of the valve body 8. The valve mechanism can reduce a flow rate of fluid which passes through the operating chamber 7 by a flow path 14 formed between the valve body 8 and a peripheral wall 7a of the operating chamber 7. A reducing amount of fluid can be increased as a moving distance of the valve body 8 which forwardly moves in the operating chamber 7 is increased.

Abstract: A torsional vibration damper having a stator and a rotor provided with stator vanes and rotor wanes, respectively, which are arranged so as to form a plurality of work chambers fillable with damping medium and alternately changing their volumes during oscillation of the rotor. A damping device is provided in the rotor and has a compensation space in flow communication with the work chambers. The damping device has a throttle point configured so as to allow the compensation space to be pressurized by a relatively low pressure.

Abstract: In a rotary damper, an outer lid is attached to an outer side surface of a casing. A first oil passage and a second oil passage are in respective communication. A first oil chamber and a second oil chamber are provided in parallel between the outer side surface of the casing and the inner side surface of the outer lid. A first check valve is provided in the first oil passage, a second check valve is provided in the second oil passage, and an orifice plate is movably provided so as to face both the first oil passage and the second oil passage.

Abstract: A damper device includes a casing, a rotor partly housed in the casing, a viscous fluid filled in the casing around the rotor, and a torque generator for generating a torque during a rotating stroke of the rotor. The torque generator includes a fluid torque adjuster for producing a relatively large torque in at least a terminal range of the rotating strokes in normal and reverse directions of the rotor.

Abstract: A rotary vibration damper having a housing, a stator having stator vanes and a rotor having vanes. The stator and the rotor are arranged in the housing so as to form at least two work chambers fillable with damping medium, which work chambers alternately change their volumes during the vibrational movement. At least one damping device is connected to at least one of the work chambers. At least one radial flow connection is arranged to connect the work chamber to the damping device. The at least one radial flow connection is arranged outside of the rotor vane and the stator vane.

Abstract: A rotary damper for stabilization of a damping and temperature characteristic without impairing a temperature compensation function and facilitates a lubricating operation. The damper includes a bore for a damping force generating mechanism as a single communication flowpassage and a bore for a temperature compensation mechanism arranged in a line in a casing. The damping force generating mechanism is divided into two sets of damping elements with damping valves and return valves, arranged in series in the communication flowpassage with back surfaces of the damping valves and are oppositely positioned. A portion of the communication flowpassage between the damping valves is communicated with an oil chamber of a temperature compensation mechanism by an oil passage. A side panel is provided with a lubricating port toward the oil chamber of the temperature compensation mechanism.

Abstract: A fluid-filled bushing with variable damping forces includes an inner tube, an outer tube, an elastomeric body joining the inner and outer tubes, a plurality of fluid chambers defined by the elastomeric body between the inner and outer tubes in circumferentially spaced relationship, a fluid passage for providing communication between the fluid chambers, a valve disposed in the inner tube for controlling fluid flow through the fluid passage, and a valve actuator for actuating the valve. The fluid passage includes a plurality of first passages defined in the inner tube and each communicating with one of the fluid chambers, and a plurality of second passages defined in the valve and communicable with the first fluid passages, respectively, the second fluid passages cooperating with the first fluid passages in varying cross-sectional areas thereof.

Abstract: A dampener for a clapper valve wherein a rotor member having radially outwardly extending vanes which subdivide each of two fluid cavities defined in a housing into first and second fluid volumes is characterized by radially extending, first and second passages axially spaced within the rotor which respectively communicate each of the first volumes and the corresponding second volume. The increase in pressure within either of the volumes generated by the motion of the vanes (which move with the clapper) is accommodated by the fluid in one passage venting to the other passage through an axially movable valve. The valve piston presents equal surface areas to each passage, to thereby fluid balance the damper in both the opening and closing directions of the clapper. A bypass channel is provided through which one of the fluid volumes in the first cavity with one of the volumes in the second cavity.