Abstract: An image forming apparatus includes: a photoconductor; an exposure portion that exposes the photoconductor; a fan that generates an airflow for cooling the exposure portion; a duct portion that communicates with the fan; and an elevating duct that relatively moves with respect to the duct portion integrally with the exposure portion, in which the elevating duct includes a rib protruding in a direction away from the exposure portion in a vertical direction, the duct portion includes a sealing member surrounding an opening portion that communicates with the elevating duct, when the elevating duct is located at an exposure position, a surface of the rib intersecting a rotation axis of the photoconductor is in contact with the sealing member, and when the elevating duct is located at a retracted position, a surface of the rib intersecting with the rotation axis of the photoconductor is in contact with the sealing member.

Abstract: An image forming apparatus having front and rear surfaces, a photoreceptor having a rotation axis extending in a first direction, an exposure unit, and a cooling unit. The exposure unit includes a substrate having a longitudinal axis extending in the first direction, a first surface and a second surface. A plurality of light emitting elements that emit light toward the photoreceptor are mounted on the first surface of the substrate. The cooling unit includes an intake port that sucks air from outside of the image forming apparatus The intake port is disposed at an intake port distance in the first direction to the rear surface. The intake port distance is shorter than a distance in the first direction of a center of the substrate to the rear surface. The cooling unit cools the substrate by blowing air sucked by the intake port onto the second surface of the substrate.

Abstract: A hydraulic auto-tensioner includes a sleeve having its bottom end press-fitted in a sleeve fitting hole in the bottom surface of a cylinder, a rod having its bottom end slidably fitted in the sleeve, and a return spring mounted between a spring support at the upper portion of the rod and the bottom surface of the cylinder. A pressure chamber communicates with a reservoir chamber through a passage formed between fitting surfaces of the sleeve fitting hole and the sleeve. The passage has a check valve. The rod has a valve fitting hole and a communication passage through which the valve fitting hole communicates with the reservoir chamber. The valve fitting hole has a relief valve. An orifice is formed between a valve hole formed in a valve seat of the relief valve and a valve body to prevent a sharp drop in pressure in the pressure chamber.

Abstract: A tensioner assembly includes a pulley arm pivotable about a pivot shaft, and a tension pulley mounted on the pulley arm at its end remote from the pivot shaft and pressed against a belt to keep the tension of the belt. The tension pulley is rotatably mounted around a base portion of the pulley arm through a rolling bearing with the inner surface and axial rear end surface of the bearing inner race in contact with the outer peripheral surface of the base portion and an end surface of a shoulder of the base portion, respectively. The base portion has an axial through hole formed with an internal thread on its inner surface. A support bolt is threaded into the through hole from the axial front end to press the rolling bearing against the end surface of the shoulder. The internal thread has an axial front end located in the vicinity of, or axially rearwardly of, the end surface of the shoulder.

Abstract: In a fulcrum bearing device for a pulley arm, a sleeve is inserted in a shaft hole formed in a boss portion of a pulley arm, washers are fitted on the outer peripheries of small diameter tube portions formed at the respective end portions of the sleeve, and the sleeve is fixed to an engine block by means of a bolt inserted through the sleeve and tightened, so that the pulley arm is pivotally supported. The shaft hole is formed at its respective end portions with seal receiving recesses having large diameters. Each seal member includes a cylindrical portion provided on its outer peripheral portion and press-fitted in the seal receiving recess, and a radial lip extending obliquely inwardly and provided on the inner periphery of the seal member. The distal end portions of the radial lips are kept in elastic contact with the outer diameter surface of the sleeve.

Abstract: A tensioner assembly includes a pulley arm pivotable about a pivot shaft, and a tension pulley mounted on the pulley arm at its end remote from the pivot shaft and pressed against a belt to keep the tension of the belt. The tension pulley is rotatably mounted around a base portion of the pulley arm through a rolling bearing with the inner surface and axial rear end surface of the bearing inner race in contact with the outer peripheral surface of the base portion and an end surface of a shoulder of the base portion, respectively. The base portion has an axial through hole formed with an internal thread on its inner surface. A support bolt is threaded into the through hole from the axial front end to press the rolling bearing against the end surface of the shoulder. The internal thread has an axial front end located in the vicinity of, or axially rearwardly of, the end surface of the shoulder.

Abstract: A tensioner assembly includes a pulley arm pivotable about a pivot shaft, and a tension pulley mounted on the pulley arm at its end remote from the pivot shaft and pressed against a belt to keep the tension of the belt. The tension pulley is rotatably mounted around a base portion of the pulley arm through a rolling bearing with the inner surface and axial rear end surface of the bearing inner race in contact with the outer peripheral surface of the base portion and an end surface of a shoulder of the base portion, respectively. The base portion has an axial through hole formed with an internal thread on its inner surface. A support bolt is threaded into the through hole from the axial front end to press the rolling bearing against the end surface of the shoulder. The internal thread has an axial front end located in the vicinity of, or axially rearwardly of, the end surface of the shoulder.

Abstract: In a fulcrum bearing device for a pulley arm, a sleeve is inserted in a shaft hole formed in a boss portion of a pulley arm, washers are fitted on the outer peripheries of small diameter tube portions formed at the respective end portions of the sleeve, and the sleeve is fixed to an engine block by means of a bolt inserted through the sleeve and tightened, so that the pulley arm is pivotally supported. The shaft hole is formed at its respective end portions with seal receiving recesses having large diameters. Each seal member includes a cylindrical portion provided on its outer peripheral portion and press-fitted in the seal receiving recess, and a radial lip extending obliquely inwardly and provided on the inner periphery of the seal member. The distal end portions of the radial lips are kept in elastic contact with the outer diameter surface of the sleeve.

Abstract: A hydraulic auto-tensioner includes a sleeve having its bottom end press-fitted in a sleeve fitting hole in the bottom surface of a cylinder, a rod having its bottom end slidably fitted in the sleeve, and a return spring mounted between a spring support at the upper portion of the rod and the bottom surface of the cylinder. A pressure chamber communicates with a reservoir chamber through a passage formed between fitting surfaces of the sleeve fitting hole and the sleeve. The passage has a check valve. The rod has a valve fitting hole and a communication passage through which the valve fitting hole communicates with the reservoir chamber. The valve fitting hole has a relief valve. An orifice is formed between a valve hole formed in a valve seat of the relief valve and a valve body to prevent a sharp drop in pressure in the pressure chamber.

Abstract: A tensioner assembly includes a pulley arm pivotable about a pivot shaft, and a tension pulley mounted on the pulley arm at its end remote from the pivot shaft and pressed against a belt to keep the tension of the belt. The tension pulley is rotatably mounted around a base portion of the pulley arm through a rolling bearing with the inner surface and axial rear end surface of the bearing inner race in contact with the outer peripheral surface of the base portion and an end surface of a shoulder of the base portion, respectively. The base portion has an axial through hole formed with an internal thread on its inner surface. A support bolt is threaded into the through hole from the axial front end to press the rolling bearing against the end surface of the shoulder. The internal thread has an axial front end located in the vicinity of, or axially rearwardly of, the end surface of the shoulder.

Abstract: A developing apparatus includes a guide member for guiding toner toward an image bearing member bearing an electrostatic image thereon, the guide member having a first end and a second end, a vibration generating device for applying an ultrasonic oscillation to the guide member proximate one of the first end and the second end of the guide member, and a vibration absorbing device for absorbing the ultrasonic oscillation in the guide member at the other one of the first end and the second end, wherein toner is conveyed on the guide member in a direction from the absorbing device to the vibration applying device. In one aspect, the toner is a magnetic toner, and a magnetic field is generated on the guide member at a position opposite a surface for guiding the toner.

Abstract: An ultrasonic oscillation is applied in the neighborhood of one end of a guide member for supporting and guiding a powder, so that a transverse proceeding wave is generated in the guide member. The powder moves from the other end of the guide member toward a position of the applied ultrasonic oscillation under the action of this proceeding wave.