An air-cooled heat exchanger has a frame assembly, a plenum supported by the frame assembly, an engine and a fan assembly. The engine includes a drive shaft and the fan assembly includes a fan connected to a fan shaft. The fan assembly is configured to move air through the plenum. The air-cooled heat exchanger also includes a drive assembly connected between the engine and the fan assembly. The drive assembly has a fan shaft sheave connected to the fan shaft, a driver sheave connected to the drive shaft, an idler pulley, and a drive belt in contact with the fan shaft sheave, driver sheave and idler pulley. The air-cooled heat exchanger has an idler bearing adjustment mechanism that is configured to adjust tension on the drive belt by adjusting the position of the idler pulley relative to the drive belt.

A chain tensioner is formed with internal threads each including a push-in-side flank, a protruding-side flank, and a thread top face. The push-in-side flank has a flank angle which is larger than a flank angle of the protruding-side flank. The push-in-side flank and the protruding-side flank are rolled surfaces formed by rolling, and have a surface roughness smaller than Ra 1.0 μm. Each internal thread further includes, at a position at which the protruding-side flank intersects with the thread top face, a chamfer configured to receive a bulge resulting from excess materials pushed out from the protruding-side flank during formation of the internal thread by rolling.

A belt tensioning device for a crusher or a screening machine for tensioning at least one circulating drive belt which is deflected about a belt pulley of a drive and has a load strand and an empty strand. The drive can be driven with a crushing assembly, a screening unit, a generator, or the like of the crusher by the drive belt. The vibrational stress acting on the machine chassis can be significantly reduced in that the belt tensioning device has two tensioning rollers each of which is rotatably mounted on a holder of a tensioning part. One tensioning roller is paired with the empty strand and the other is paired with the load strand. Additionally, the two tensioning parts can be adjusted relative to each other between an open position and a tensioning position, in which the tensioning parts are held against each other at least opposite the tensioning direction. In particular the tensioning parts can be blocked against each other, and the complete closed system can be freely moved linearly using adjustment guides according to the load situation.

A chain tensioner is formed with internal threads each including a push-in-side flank, a protruding-side flank , and a thread top face. The push-in-side flank has a flank angle larger than the flank angle of the protruding-side flank. The push-in-side flank and the protruding-side flank are rolled surfaces formed by rolling, and have a surface roughness smaller than Ra 1.0 μm. Each internal thread further includes, at its position at which the protruding-side flank intersects with the thread top face, a chamfer configured to receive a bulge moving from the protruding-side flank during rolling.

A belt-driven linear module includes a tensioning assembly and a drive belt. The tensioning assembly includes a support shaft and a bearing. The support shaft is configured to be installed at a driven end of the linear module. The bearing includes an inner ring and an outer ring. The inner ring is positioned on the support shaft, and the outer ring is configured to be wrapped by the drive belt of the linear module so as to tension the drive belt of the linear module.

A chain tensioner includes an oil supply passage for supplying hydraulic oil into a pressure chamber defined by a cylinder and a plunger, and a check valve provided at the end of the oil supply passage. A leak gap is defined between the sliding surfaces of the cylinder and the plunger. The plunger is biased by a return spring in the direction in which the plunger protrudes out of the cylinder. A plug is press-fitted in a cylindrical inner periphery of a through hole formed in the plunger to extend from a protruding end surface of the plunger to the pressure chamber to define an air vent passage. It is possible to change the hydraulic damper force simply by replacing the plug with another different type of plug to define a different air vent passage.

The invention relates to a belt tensioning device for a crusher or a screening machine for tensioning at least one circulating drive belt (20) which is deflected about a belt pulley (12) of a drive (10) and has a load strand (21) and an empty strand (22). The drive (10) can be driven with a crushing assembly, a screening unit, a generator, or the like of the crusher by means of the drive belt (20). The vibrational stress acting on the machine chassis can be significantly reduced in that the belt tensioning device has two tensioning rollers (47), each of which is rotatably mounted on a holder (41, 51) of a tensioning part (40, 50). One tensioning roller (47) is paired with the empty strand (22) and the other is paired with the load strand (21). Additionally, the two tensioning parts (40, 50) can be adjusted relative to each other between an open position and a tensioning position, in which the tensioning parts are held against each other at least opposite the tensioning direction, in particular the tensioning parts can be blocked against each other, and the complete closed system can be freely moved linearly using actuators (44.2) according to the load situation.

A belt-driven linear module includes a tensioning assembly and a drive belt. The tensioning assembly includes a support shaft and a bearing. The support shaft is configured to be installed at a driven end of the linear module. The bearing includes an inner ring and an outer ring. The inner ring is positioned on the support shaft, and the outer ring is configured to be wrapped by the drive belt of the linear module so as to tension the drive belt of the linear module.

A chain tensioner includes an oil supply passage for supplying hydraulic oil into a pressure chamber defined by a cylinder and a plunger, and a check valve provided at the end of the oil supply passage. A leak gap is defined between the sliding surfaces of the cylinder and the plunger. The plunger is biased by a return spring in the direction in which the plunger protrudes out of the cylinder. A plug is press-fitted in a cylindrical inner periphery of a through hole formed in the plunger to extend from a protruding end surface of the plunger to the pressure chamber to define an air vent passage. It is possible to change the hydraulic damper force simply by replacing the plug with another different kind of plug to define a different air vent passage.

An internal combustion engine includes a cam chain chamber accommodating a cam chain and a chain guide guiding the cam chain. The engine also includes a chain tensioner including a case main body, a plunger sliding in the case main body, a coil spring biasing the chain guide against the cam chain via the plunger, interlocking teeth located on a surface of the plunger, and an engaging portion engaged with the interlocking teeth and configured to inhibit the plunger from moving in a direction away from the chain guide. The engine also includes oil supply passages in an inner wall of the cylinder head and an inner wall of the cylinder body and configured to supply oil to the chain tensioner.