| 摘要 |
A rotary damper capable of stabilizing a temperature characteristic while allowing a leakage of operating oil from a clearance between a basic portion of a rotor and a bearing end on the casing side for supporting said rotor with relative rotational motion between the casing and the rotor. Two sets of operating oil chambers (17a, 17b) and operating oil chambers (18a, 18b) which repeat contraction and expansion alternately with rotational displacement of a casing (1) and a rotor (9) are communicated with each other by an interconnecting flowpassage (54) provided on the housing (2), a damping force generating mechanism (44) composed of two sets of damping elements (43a, 43b) having damping valves (55, 56) and return valves (61, 62) and damping force regulating mechanisms(72, 73) arranged in combination with the damping elements (43a, 43b) are arranged on the midway of the interconnecting flowpassage (54), and a flow resistance of operating oil passing through the interconnecting flowpassage (54) is imparted by the damping force generating mechanism (44) and the damping force regulating mechanisms (72, 73) to generate a predetermined damping force corresponding to the operating direction of the rotary damper. On the other hand, an independent bypass flowpassage (31) which immediately short-circuits the operating oil chambers (17a, 17b) and the operating oil chambers (18a, 18b) is provided in parallel with the interconnecting flowpassage (54), a variable throttle mechanism (21) for automatically and continuously regulating a throttle degree to a high or low level with the change in temperature is disposed on the bypass flowpassage (31), and an amount of change in a leakage amount leaked from a clearance between bearings (11a, 11b) on the casing (1) side and the rotor (9) with the change in temperature is offset by a control flow of operating oil leaking through the variable throttle mechanism (21) to maintain small the change amount of the leakage amount of operating oil irrespective of the temperature change to enhance the temperature characteristic of the rotary damper. <IMAGE>
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