US 5,855,518 AGranted

Damper device for rotary motion

AssigneeNsk Ltd.

InventorsHirohisa Tanaka, Satoshi Dairokuno

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Abstract

A damper device for rotary motion is disclosed which is small in size, has an excellent durability and can optionally change damping characteristics from the outside. Rotation of an input shaft is transmitted to a cylinder tube through a rotation transmitting device of loading cam type, thereby rotating an output shaft engaged with the cylinder tube through splines. When the rotational speed and torque of power to be transmitted is fluctuated, the cylinder tube is displaced against the resiliency of a conical plate spring and the volume of a pressure chamber is reduced. A viscous liquid in the pressure chamber is then discharged to the outside through a throttle hole. A relative displacement between the input and output shafts absorbs vibrations in terms of energy corresponding to the product of the mass and changes in the angular speed of members which are displaced in synch with the input shaft.

A damper device for rotary motion comprising:

a first shaft,
an outwardly flanged piston end plate having an outer peripheral edge concentrically with said first shaft and fixed to an end of said first shaft,
a cylinder tube having an inner peripheral surface positioned at least one of close to and in sliding contact with the outer peripheral edge of said piston end plate,
an inwardly flanged cylinder end plate having an inner peripheral edge positioned at least one of close to and in sliding contact with an outer peripheral surface of said first shaft in an intermediate portion,
a first cam surface formed as a circumferentially undulated surface in an outer side of said cylinder end plate,
a cam plate supported on the intermediate portion of said first shaft in such a manner that said cam plate is prohibited from displacement in a direction away from said first cam surface, and from rotating relative to said first shaft,
a second cam surface formed as a circumferentially undulated surface in one side of said cam plate,
a rolling member arranged rollably between said second cam surface and said first cam surface,
an elastic member and a thrust bearing arranged in series in the axial direction between an inner surface of said piston end plate and an inner surface of said cylinder end plate,
a second shaft arranged concentrically with said first shaft and engaging said cylinder tube to be displaceable only in the axial direction,
a pressure chamber defined by an inner surface of said piston end plate, an inner surface of said cylinder end plate, the outer peripheral surface of said first shaft and the inner peripheral surface of said cylinder tube,
a throttle passage for communicating said pressure chamber with the outside,
a supply passage for supplying a viscous liquid to said pressure chamber, and
backflow preventing means disposed adjacent to and midway a downstream opening of said supply passage for supplying the viscous fluid only in a direction toward said pressure chamber.

11 more elements

Facts

Application

08/680,917Filed 11 Jul 1996

Priority

JP 7-18029017 Jul 1995

Granted

5 Jan 1999

Term ends

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Classification9 codes

F16D 3/66
Comprising elastic elements arranged between substantially-radial walls of both coupling parts: the elements being metallic, e.g. in the form of coils
F16F 9/145
Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect: involving only rotary movement…
F16F 15/10
Suppression of vibrations in systems ; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion: suppression of…
F16F 15/123
Using springs as elastic members, e.g. metallic springs: wound springs

Abstract

Claims9