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US 7,066,819 B2Granted
Coupling device
AssigneeDenso Corporation
InventorsMotohiko Ueda, Yasuo Tabuchi
Life of this patent
Estimating the term…
Abstract
A coupling device has a pulley that receives rotational torque from an engine. The torque is transmitted to a shaft through a hub and a one-way clutch. A torque limiter is screwed on the shaft to fasten the inner ring of the one-way clutch onto the shaft. The torque limiter has a breakable portion. The torque is directly transmitted from the inner ring to the shaft when the torque is normal. If the torque exceeds the tightening torque of the torque limiter, the inner ring begins to slide and rotate, and drives the torque limiter in a tightening direction. As the torque limiter is tightened additionally, the tensile stress on the breakable portion is increased. Then, the breakable portion breaks and is separated in axial direction so that the coupling device disconnects torque transmission.
Claims17
A coupling device comprising:
- a driving member and a driven member, the driven member including a threaded member having a first thread,
- a threaded portion on the driving member having a second thread corresponding to the first thread formed on the threaded member of the driven member;
- a planar thrust contact portion provided between the driving member and the threaded portion, the planar thrust contact portion being formed so as to remain stationary with respect to an axial direction when the threaded portion is tightened onto the threaded member of the driven member;
- and
- a breakable portion provided between a part of the threaded portion and the planar thrust contact portion having a tensile strength that breaks at a predetermined level of the thrust force, wherein
- the first and second threads are formed in a direction to generate a thrust force on the breakable portion when one of the first and second threads are rotated with respect to the other of the first and second threads in the same direction as a direction of a torque transmitted from the driving member to the driven member;
- and
- the threaded portion and the breakable portion are provided in a cylindrical portion, the breakable portion being thinner in a radial direction than the threaded portion.
5 more elements
A coupling device comprising:
- a driving member and a driven member, the driven member including a threaded member having a first thread,
- a threaded portion on the driving member having a second thread corresponding to the first thread formed on the threaded member of the driven member;
- an annular planar thrust contact portion provided between the driving member and the threaded portion, the annular planar thrust contact portion being formed so as to come in contact with one of the driving member and the driven member with respect to an axial direction when the threaded portion is tightened onto the threaded member of the driven member;
- and
- a breakable portion provided between a part of the threaded portion and the planar thrust contact portion having a tensile strength that breaks at a predetermined level of the thrust force, wherein
- the first and second threads are formed in a direction to generate a thrust force on the breakable portion when one of the first and second threads are rotated with respect to the other of the first and second threads in the same direction as a direction of a torque transmitted from the driving member to the driven member;
- and
- the threaded portion and the breakable portion are provided in a cylindrical portion, the breakable portion being thinner in a radial direction than the threaded portion.
5 more elements
A coupling device comprising:
- a driving member and a driven member, the driven member including a threaded member having a first thread,
- a planar contact surface disposed on the driving member adapted to contact the driven member in an axial direction;
- a second thread provided on the driving member to generate a thrust force in a contacting direction for press-contacting one of the driving member and the driven member and the planar contact surface, when the second thread is rotated with respect to the first thread in the same direction as a direction of torque transmitted from the driving member to the driven member;
- and
- a breakable portion disposed between a part of the second thread and the contact surface such that the thrust force generated by the second thread is applied to the contact surface via the breakable portion, wherein
- the first and second threads are formed in a direction to generate the thrust force on the breakable portion when one of the first and second threads are rotated with respect to the other of the first and second threads in the same direction as a direction of a torque transmitted from the driving member to the driven member
- the breakable portion breaks when the torque is larger than a predetermined value;
- and
- the threaded portion and the breakable portion are provided in a cylindrical portion, the breakable portion being thinner in a radial direction than the threaded portion.
6 more elements
Dependencies are inferred from the claim text.