Power transmission device

#This application is a U.S. National Phase Application under 35 U.S.C. 371 of International Application No. PCT/JP2014/001842 filed on Mar. 28, 2014 and published in Japanese as WO 2014/162710 A1 on Oct. 9, 2014. This application is based on and claims the benefit of priority from Japanese Patent Application No. 2013-079424 filed on Apr. 5, 2013. The entire disclosures of all of the above applications are incorporated herein by reference.

#The present disclosure relates to a power transmission device that transmits a rotation driving power.

#Conventionally, a power transmission device that transmits a rotation driving power, outputted from a driving source, to a driving target device is known. This kind of power transmission device is required to have a function to block transmission of a rotation driving power quickly in order to prevent the driving source from being subjected to an undue load when the driving target device is locked by burning or the like.

#FIG. 1 is a partially sectional diagram illustrating a power transmission device according to a first embodiment of the present disclosure.

#FIG. 2 is a side view illustrating the power transmission device according to the first embodiment.

#FIG. 3 is a sectional diagram illustrating the power transmission device when a shim is fixed to a pulley according to the first embodiment.

#Hereinafter, multiple embodiments for implementing the present disclosure will be described referring to drawings. In the respective embodiments, a part that corresponds to a matter described in a preceding embodiment may be assigned the same reference numeral, and redundant explanation for the part may be omitted. When only a part of a configuration is described in an embodiment, another preceding embodiment may be applied to the other parts of the configuration. The parts may be combined even if it is not explicitly described that the parts can be combined. The embodiments may be partially combined even if it is not explicitly described that the embodiments can be combined, provided there is no harm in the combination.

#A first embodiment of the present disclosure will be described referring to FIGS. 1 to 4. A power transmission device 20 according to the present embodiment is adopted for transmitting a rotation driving power outputted from a vehicle-traveling engine to a compressor 10 of a vehicular refrigeration cycle. Therefore, in the present embodiment, the engine is used as an example of a driving source that outputs rotation driving power. The compressor 10 is used as an example of a driving target device to which the rotation driving power outputted from the driving source is transmitted. The vehicular refrigeration cycle according to the present embodiment is applied to an air conditioning device for a vehicle and functions to cool an air blown to a vehicle interior.

#Moreover, in this vehicular refrigeration cycle, a swash-plate type and variable capacity compressor is adopted as the compressor 10 compressing a refrigerant. In such variable capacity compressor, when a discharge capacity is reduced to approximately 0 percent, the compressor 10 can be made into an operation stop state where the compressor 10 virtually does not show refrigerant discharge capability. Therefore, in the present embodiment, a crutch-less device in which the engine and the compressor are connected at all times is adopted as the power transmission device 20.