Denso Corporation

Kabushiki Kaisha Toyoda Jidoshokki Seisakusho

Desno Corporation

Michiyasu Nosaka

Yasuo Tabuchi

Yoshiki Tada

Motohiko Ueda

Takayuki Suzuki

Mitsuhiro Tanabe

Kiyoshi Kurohata

Hiroshi Nagae

Masahiro Yamashita

Kouji Kida

Keiji Ishikawa

Takushi Kamiya

Masahiro Kawaguchi

Ken Suitou

Tetsuhiko Fukanuma

Ryo Matsubara

Hiroshi Kubo

Kazuhito Miyagawa

Shintaro Miura

Mutsumi Yoshino

Shinya Miura

Shozo Tatematsu

Koichi Hashinaga

Yoshihiro Nakata

Masatoshi Hiramatsu

A power transmission device includes a pulleyand a hubhaving an inner hub, a rubber damperand an outer hub. A hub side engagement portionformed of an elastic material and arranged at either one, or both, of an inner peripheral surface and an outer peripheral surface of the outer hub engages with a pulley side engagement portion, which is arranged at a position corresponding to the outer hub, of the pulley in a concavo-convex fitting to thereby constitute a torque transmission structure between the hub and the pulley. The hub side engagement portion and the pulley side engagement portion have a concavo-convex outer shape and mesh with each other. A ring-like dust invasion prevention portioncovers a front surface of said concavo-convex fitting.

Power transmission device

A hub for use in a power transmission apparatus comprises cylindrical portionand outer ringincluding a plurality of tongue-like reinforcing portionseach protruded radially inward from the peripheral end of the corresponding one of the plurality of protrusions. When the distance from point C where the rear-side end surface of the cylindrical portionand hub-side engaging portionare connected with each other, to rear-side end surface D of reinforcing portionsis given a, and the distance from rear-side end surface D of reinforcing portionsto radially innermost front-side portion E is given b, distance b is less than one half of distance a.

Hub for power transmission apparatus

A power transmission device includes a pulleyand a hubhaving an inner hub, a rubber damperand an outer hub. A hub side engagement portionformed of an elastic material and arranged either one, or both, of inner peripheral surface and outer peripheral surface of the outer hub engages with a pulley side engagement portion, arranged at a position corresponding to the outer hub, of the pulley in concavo-convex fitting to thereby constitute a torque transmission structure between the hub and the pulley. The hub side engagement portion and the pulley side engagement portion have a concavo-convex outer shape and mesh with each other.

A power transmission apparatus includes a pulleyhaving a belt attached thereto to transmit the rotating drive force, a hubwhich connects the pulley to a rotating shaft of a driven device, a bearingwhich rotatably supports the pulley, and a sleeve ringwhich is fitted and secured to the pulley and attaches the bearing to the pulley to prevent it relatively moving. The sleeve ring is provided, on its first end opposite to the driven device, with a bent portionagainst which the bearing abuts to restrict further movement of the bearing. An annular retaineris provided on the portion of the bearing adjacent to the drive device. The bearing is secured to the sleeve ring through the annular retainer by calking a second endof the sleeve ring opposite to the first end. The sleeve ring is provided with a projectionwhich projects in the axial direction from the rear surface of the pulley and a casingis provided with an annular groovewhich at least partly receives therein the projection.

Power transmission apparatus

A power transmission system including an integrally molded hub and elastic member, where stress is inhibited from concentrating at the gate marks remaining after integral molding. In a pulley driven by a belt, a plastic pulley side relief sectionprovided at a pocket section of the pulley and a plastic hub side relief section provided on an iron outer ring of the hub engaged at the pocket section whereby power is transmitted from the pulley to the shaft. The hub side relief section and outer ring forming parts of the hub, the iron inner hub to be fastened to the shaft, and the plastic cylindrical part are integrally molded so that the gate mark for plastic injection is formed near to or further to the outer circumference of the outer ring.

Power transmission system

A power transmission apparatus comprises a pulley mounted rotatably on a casing of a rotary device, a hub coupled to the pulley by fitting between depressions and protrusions, a power shutoff member for preventing excessive torque between a rotary shaft and the hub, and an engaging device for engaging the hub and the pulley each other. The engaging device includes a first stepped portion formed radially on the outer periphery of the hub and a second stepped portion formed radially on the inner peripheral wall of a rim of the pulley in such a manner as to engage the first stepped portion in the axial direction.

A power transmission device includes: a pulleyrotatably attached to a casing; a hubconnected to the pulleyby an engagement of protrusions with recesses; and a power shutoff memberinterposed between the huband a rotary shaft. The power shutoff member and the rotary shaftare joined to each other by means of screwing. When a water intrusion path formed between a hub side seating face of the hub and a shaft side seating faceof the rotary shaft is formed into a labyrinth structure, water is prevented from entering the seating face. An engagement portionon the power shutoff member side is engaged with a hub side engagement portionso that it can be accommodated in the hub side engagement portion, and the power shutoff member can be rotated together when the hub is rotated. An engagement gap formed between a power shutoff member side engagement portion and a hub side engagement portion in the radial direction perpendicular to an axis of the rotary shaft is in a range from 0.001 mm to 15% of a diameter of a circumscribed circle of the power shutoff member side engagement portion.

A bearing according to the present invention includes a cylindrical member formed on and around an outer member of a usual bearing. To firmly connect the cylindrical member to the outer member, grooves having an inclination relative to the axial direction of the bearing are formed so that the grooves do not cross one another on the outer surface of the outer member. The cylindrical member is made of a resin material by molding, and the resin, which is melted by heat in the molding process, enters into and adheres to the grooves. In this manner, the cylindrical member is firmly connected to the outer member so that movement in both of the rotational and axial directions of the bearing is prevented. The grooves formed on the outer surface of the outer member may be grouped, and their inclination relative to the axial direction may be alternately reversed group by group.

Bearing having cylindrical member connected to outer member of bearing

A power transmission device () comprises a rotatable rotary part () to which a rotational drive force is transmitted from a drive source and a power transmission shut-off member () that shuts off transmission of an excessive torque between the rotary part and a rotating shaft () of a device to be driven. The power transmission shut-off member is threadedly coupled to the rotating shaft and can rotate with the rotating shaft. The rotary part is installed so as to be sandwiched between the power transmission shut-off member and the rotating shaft. A disc spring (), installed between the power transmission shut-off member and the rotary part, is further provided. A caulked part () for preventing a part of the power transmission shut-off member from dropping is provided on the front end side of the rotating shaft.

A power transmission apparatus () includes a rotary portion () to which turning driving force from a driving source is transmitted and which can rotate, a power cutoff member () mechanically connected to the rotary portion () and one of the ends of a rotary shaft () of a driven apparatus and cutting off transmission of excessive torque between them, and a cap () connected to the end of the rotary shaft () on one hand and fastened by screw meshing to the power cutoff member () on the other hand, and transmitting power from the power cutoff member () to the rotary shaft (). The rotary portion (), the power cutoff member (), the cap () and the rotary shaft () all rotate integrally with one another. The cap () has a flange portion () protruding in a radial direction with respect to an axis of the rotary shaft () and supporting an axial force.

A plate (()), the outer diameter side of which is fixed to be integral with a plate section (), and which is provided with an engagement part () to be engaged with a shoulder () formed on the inner diameter side of a boss section (), is integral with a center hub (). Thereby, even if a bridge section () is broken and the plate section () moves in the detachment direction of the center hub (), the engagement part () of the plate () is engaged with the shoulder () of the boss section (), whereby the plate section () and the boss section (13a) are engaged and coupled with each other while interrupting the torque transmission. Accordingly, even if the bridge section () is broken, the boss section () as well as the plate section () side are prevented from being detached from a pulley ().

Torque transmission device

In the power transmission device having a torque limiting function for shutting off the transmission of an excessively high torque between the pulleyand the rotary shaft, the huband the rotary shaftare connected to each other by means of screw engagement between the female screw portion, which is formed on the inner circumferential face of the hub, and the male screw portionwhich is formed on the outer circumferential face of the forward end portionof the rotary shaft, and the seal meansfor sealing between the hub and the rotary shaft is provided adjacent to the front face or the front and rear faces of the screw engaging portion. The torque limiting function may be provided on the rotary shaft side or the hub side.

A screw engagement portion between a pulley and a shaft is provided with a thread in a direction to increase the tightening torque when the pulley is driven. A breakable part broken by the axial tension produced when the tightening torque acting on the screw engagement portion is above a predetermined value, is also provided. The stress to break the breakable part is mainly a tensile stress. The tensile stress is substantially uniformly distributed in a cross section and, hence, the stress distribution of the breakable part can be relatively precisely predicted and analyzed. Consequently, the necessity of determining aspects of the breakable part, such as dimension, material, and the like, by trial and error is reduced. The breakable part can be broken without being subject to fatigue fracture.

Rotating apparatus with a torque limiter function

When a first damper contacts both of a protruding portion of a pulley body and a protruding portion of a center hub, a second damper is disposed as being apart from the protruding portion of the center hub with a gap. Even when the pulley body is rotated in a reverse direction, no reverse torque is thereby transmitted to the center hub as long as the gap exists, or before the second damper contacts the protruding portion of the center hub. As a result, torque fluctuation is sufficiently absorbed. This prevents the following: a reverse torque is transmitted to the center hub; a torque limiter wrongly acts; a fastening part between a shaft and the center hub loosens; or abnormal noise or aversive vibration takes place.

Torque transmission system

A power transmission device which interrupts torque transmission when the torque exceeds a predetermined torque. A torque limiter includes projections formed on a center hub and a pulley. The center hub includes bridges that transmit torque by a pulling force. When a preset torque limit is reached, the projections on the center hub make contact with and move along slanted faces so as to move the center hub in an axial direction relative to the pulley. The bridges are thereby subjected to a bending moment in addition to the pulling force when the torque exceeds the preset torque level, so that the bridges break precisely above the preset torque level due to the reduced fatigue limit.

Growing community of inventors

Anjo, Japan

Michiyasu Nosaka