Rotary shafts – gudgeons – housings – and flexible couplings for ro – Overload release coupling – Torque transmitted via frangible element
Reexamination Certificate
2000-06-19
2001-12-25
Browne, Lynne H. (Department: 3629)
Rotary shafts, gudgeons, housings, and flexible couplings for ro
Overload release coupling
Torque transmitted via frangible element
C464S032000, C417S319000, C403S011000, C403S041000
Reexamination Certificate
active
06332842
ABSTRACT:
CROSS REFERENCE TO RELATED APPLICATION
This application is based on Japanese Patent Application Nos. Hei. 11-174437 filed on Jun. 21, 1999, Hei. 11-213407 filed on Jul. 28, 1999, Hei. 11-273614 filed on Sep. 28, 1999, and Hei. 11-358430 filed on Dec. 17, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rotation transmitter suitable for use in a compressor of an automotive air conditioning system.
2. Description of Related Art
An automotive air conditioning system, having a compressor which has a variable refrigerant discharge capacity from 0% through 100%, dispenses with an electromagnetic clutch to drive the compressor. However, in the clutch-less compressor, when the compressor shaft locks because the compressor seizes and excess load torque (shock torque) arises, the pulley driving the compressor shaft stops rotating. Thus, a V-belt driven by the engine slides against the pulley, thereby breaking the V-belt.
For solving this problem, a rotation transmitter including a torque limiting mechanism is used for interrupting the rotation transmission from the engine to the compressor when excess load torque arises due to compressor shaft lock. Here, excess load torque means that the torque difference between the pulley and the compressor shaft exceeds a threshold.
The rotation transmitter includes a pulley, an outer hub, a flange, an inner hub, and a plurality of friction plates. The pulley rotates by receiving rotation force from the engine through the V-Belt. The outer hub is connected to the pulley, and the flange is connected to the outer hub through a rubber damper. The inner hub is connected to the compressor shaft, and the plurality of friction plates are provided between the flange and the inner hub. When the compressor shaft is locked to create the excess load torque, the rotation transmission from the flange to the inner hub is interrupted. The pulley, outer hub, flange, inner hub, and friction plates are made of metal such as iron.
However, the number of parts for the torque limiting mechanism is large, thereby increasing the cost of the product. The friction plates are provided in the axial direction, thereby enlarging the axial dimension of the torque limiting mechanism. Further, most of the parts of the rotation transmitter are made of metal such as iron, thereby increasing the weight of the entire rotation transmitter.
JP-A-10-47244 discloses another conventional rotation transmitter. The rotation transmitter also includes a torque limiting mechanism interrupting rotation transmission when the compressor shaft is locked. The torque limiting mechanism includes an intermediate member having an elastically transforming portion made of thermoplastic resin. The intermediate member is connected to one of the pulley and the hub, and press-connected to the other to rotate therewith. When the compressor operates normally, the elastically transforming portion absorbs torque pulsations from the compressor shaft. When excess load torque arises (when the shaft is locked), friction heat caused by slide friction at the press-connection surface melts the elastically transforming portion, thereby interrupting the excess load torque transmission from the shaft to the pulley.
However, this conventional rotation transmitter requires a large number of parts, and a space where the intermediate member is provided in front of a bearing supporting the pulley, thereby enlarging an entire size of the rotation transmitter.
SUMMARY OF THE INVENTION
An object of the present invention is to reduce the size, weight, and production cost of a rotation transmitter including torque limiting mechanism.
According to a first aspect of the present invention, a torque limiting mechanism is disposed within an axial dimension of a driving side rotary member (cylindrical wall of a pulley). Thus, the axial dimension of the rotation transmitter can be reduced in comparison with a conventional rotation transmitter, thereby reducing the entire size of the rotation transmitter having the torque limiting mechanism.
According to a second aspect of the present invention, a torque limiting mechanism includes an axial space formed in the pulley, and a pin protruding and extending from a discharge disc. The pin is inserted into the axial space, and is broken when an excess torque arises between the pulley and the discharge disc. That is, since the torque limiting mechanism is integrally provided within the pulley and the discharge disc, the torque limiting mechanism can be attained without plural friction plates. Thus, the number of parts and assembly process for the torque limiting mechanism are reduced, thereby reducing the price of the product. Further, the discharge disc is made of resin which is lighter and cheaper than metal material such as iron, thereby reducing the weight and the manufacturing cost of the entire rotation transmitter.
According to a third aspect of the present invention, a hub connected to a rotating shaft of rotary machine includes a torque limiting mechanism. That is, a break portion, which is broken when the excess load torque arises between the pulley and the hub, is provided in the hub. Thus, the torque limiting mechanism is simplified, and the number of parts and assembly process for the torque limiting mechanism are reduced, thereby reducing the cost of the product.
According to a fourth aspect of the present invention, a rotation transmitter includes a first hub and a second hub. The first hub rotates by receiving rotation force from a pulley. The second hub is connected to a rotating shaft of rotary machine and rotates by receiving rotation force from the first hub. When excess load torque arises between the first and second hubs, a connection portion therebetween is broken because at least one of these hubs is made of resin or sintered metal. That is, the torque limiting mechanism is attained without adding supplemental parts. Thus, the torque limiting mechanism is simplified, and the number of parts therefor is reduced, thereby reducing the size of the rotation transmitter having the torque limiting mechanism.
According to a fifth aspect of the present invention, a rotation transmitter includes a hub made of resin or sintered metal. The hub rotates by receiving a rotation force from a pulley. The hub is connected to a rotating shaft of rotary machine. When excess load torque arises between the hub and the rotating shaft, a connection portion therebetween is broken because the hub is made of resin or sintered metal. That is, the torque limiting mechanism is attained without adding supplemental parts. Thus, the torque limiting mechanism is simplified, and the number of parts therefor is reduced, thereby reducing the size of the rotation transmitter having the torque limiting mechanism.
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patent: 6068452 (2000-05-01), Okada et al.
patent: 10-47244 (1998-02-01), None
Aoki Yuuichi
Hayashi Toshihiro
Ohguchi Junichi
Saiki Manabu
Sakai Takuo
Browne Lynne H.
Denso Corporation
Dunwoody Aaron
Pillsbury & Winthrop LLP
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