The Evolution Of Gauges: Taper Lock Hub Innovation

Gauges with screw-on taper lock hubs are used for measuring the accuracy and dimensions of parts that require high tolerances and precision, such as those used in the medical, automotive, oil/gas, and aerospace industries. The taper-lock design provides added holding strength for intermediate size ranges during gaging. For example, taper-lock plug gauges are used for conventional hole diameter inspections, while plug and ring gauges ensure proper contact between the taper of a hub and shaft to facilitate torque transmission. Taper-lock gauges are also used in conjunction with TAPER-LOCK bushings for the fast and simple attachment of fan wheels, cams, and similar parts on shafts, including in areas where welding is prohibited.

Taperlock plug gauges are used to check large diameters

Taperlock gauges are so-called because of their tapered shank, which locks into the tapered hole at the end of the handle. This design provides added holding strength, which is necessary for intermediate size ranges during gaging. Taperlock plug gauges are available with GO and NOGO members in Class XXX, XX, X, Y and Z, and are manufactured to American Gage Design (AGD) standards. They can be purchased in steel, chrome or carbide.

Taperlock gauges are manufactured per ANSI/ASME B47.1 AGD standard and ANSI/ASME B89.1.5 standards. They can be quickly changed by removing the old gage member and press-fitting a new one into the handle. Taperlock gauges are also available with a screw-down hub, which is used for the fast and simple attachment of fan wheels, cams and similar parts on shafts.

Taperlock gauges are used for conventional hole diameter inspection

Taperlock gauges are manufactured per ANSI/ASME B47.1 AGD standard and ANSI/ASME B89.1.5 standards. They are also manufactured to BS969 – 1982, with component hole tolerancing used as the basis for determining the gauge manufacturing tolerances. Gauges can also be supplied to DIN and ANSI standards.

Taperlock gauges are used to determine the fit of a hole. They can also be used as the gauge base for additional features, such as hexagonal holes, holes requiring a recess in the leading face of the gauge, and square and rectangular gauges. The gauge life and dimensional stability are guaranteed based on proven manufacturing processes and a robust quality management system.

The final inspection of taperlock gauges is completed in an environmentally controlled ISO 17025 laboratory. Gauges are ring lapped to size and hand-polished, providing superior accuracy and ensuring maximum gauge wearability.

Taperlock gauges are used in areas where welding is prohibited

Taperlock gauges are often used in conjunction with a TAPER-LOCK bushing for the fast and simple attachment of fan wheels, cams, and similar parts on shafts. They are inserted into a weld-on hub and can be directly accommodated into a pulley if the hub is not larger in size.

The key-way and thread on the taper lock bush are machined in compliance with ISO requirements. The term "tapered bush" is used to describe other variations of the standard taper lock bush. By tightening the cap screws, this bush fits over the tapered hub and creates a snug fit on the shaft.

Taperlock gauges are manufactured per ANSI/ASME B47.1 AGD standard and ANSI/ASME B89.1.5 standards. They are available in steel, chrome, or carbide in sizes from .105” to 1.150”. They are also manufactured to BS969 – 1982 standards and can be supplied to DIN and ANSI standards.

Taperlock gauges are used to check the accuracy and dimension of parts

Taperlock gauges are available in thread sizes of up to 1.5 inches in diameter. They are less expensive than reversible thread plug gauges and are considered the most popular style. The taperlock thread plug gauge allows for a quick and convenient replacement of the gauge member. A worn thread gauge can be easily removed, and a new replacement thread gauge can be inserted into the handle by press-fitting.

Taperlock gauges are manufactured to X tolerances in class 2B or 3B in inches and 6H in metric. All standard taperlock gauges are stocked with a chrome coating, which extends the wear life of the thread gauge by more than 100%. This provides dramatic savings in replacement costs.

Taperlock gauges are also used for conventional hole diameter inspection and as a gauge base for additional features such as hexagonal holes, holes requiring a recess in the leading face of the gauge, and square and rectangular gauges. The gauge life and dimensional stability of taperlock gauges are guaranteed based on well-proven manufacturing processes and a robust quality management system.

Plug and ring gauges are used to ensure the taper of a hub and shaft have proper contact

Plug and ring gauges are often used to install a taper bore hub on a shaft. This is done to a specific pull-up distance that allows a taper bore hub to transmit torque. The pull-up distance refers to the predetermined axial movement of the hub relative to the shaft, which is made possible by dilation of the hub.

There are several steps to installing a taper bore hub on a shaft. Firstly, it is important to clean the parts, as the success of hydraulic mounting coupling hubs depends on the condition of the contact surfaces. The hub bore and shaft end must be free from burrs. Even the smallest particle trapped between the shaft and hub bore can distort the hub enough to make the fit unsuitable for use. Any nicks, scratches, and edges on mating surfaces must be polished smooth.

After cleaning and preparing the parts, the next step is to check for proper contact. According to the API Standard 671 4th Edition, "Tapered bores shall be checked by using the plug gauge from a matched plug and ring gauge set provided by the purchaser. A light coat of bluing shall be used for the check. Tapered bores for keyless, hydraulically fitted hubs shall have at least an 85% blued fit (surface contact) to the taper gauge." If less than 85% contact is found, and it is due to nicks and scratches, the damage can be lightly polished and then checked again with the ring and plug gauge set. If the minimum contact of 85% is still not achieved, the shaft and hub should be independently lapped using a ring and plug lapping tool set.

Once the tapers match with 85% or better contact, the next step is to set the Zero Start Position. This is done by putting the hub on the shaft with only hand pressure, pushing the hub onto the shaft until it stops advancing. This point is considered full engagement and is the initial position for starting the hub installation. It is critical to measure and record the distance between the hub and shaft end at this point, as this value will be needed for final use once the hub is fully installed.

The Zero Start Position is important because it serves as the reference point for the "pull-up" distance specified by the OEM. The pull-up distance is the amount by which the hub must be advanced up the shaft during installation. There are two popular methods for establishing this distance: the dial indicator method and the stop ring method. It is recommended to use both methods to set the pull-up accurately.

After determining the Zero Start Position and setting the pull-up distance, the hub can be removed, and the proper O-rings and back-up rings can be installed. It is important to keep these components clean and lubricated before installation, using the same hydraulic fluid that will be used to dilate the hub.

With the O-rings and back-up rings in place, the hub is replaced on the shaft. Advancing the hub up the shaft requires seating the rings, which can be done using a lead hammer or a pusher tool. The pusher tool is designed to match the shaft end threads and is threaded onto the shaft to apply pressure to the hub, re-establishing the Zero Start Position.

To perform the installation, two hydraulic pumps are required: a low-pressure pump and a high-pressure pump. The low-pressure pump connects to the pusher tool, while the high-pressure pump connects to the dilation port in the shaft end or through a radial passage in the hub. It is crucial not to mix up the connections to avoid equipment damage and personal injury.

Before beginning the installation, the Zero Start Position is rechecked, and then high pressure is slowly applied using the high-pressure pump to dilate the hub. Simultaneously, the low-pressure pump is used to develop sufficient force in the pusher tool to maintain the hub at its Zero Start Position. Some oil may bleed out between the hub and shaft joint during this process, which is normal. Continue applying pressure using both pumps until conditions are stable before advancing the hub up the shaft.

Once stabilized, the low-pressure pump is used to slowly advance the hub on the shaft while monitoring movement with a dial indicator. As the hub advances, the dilation pressure may rise without activating the pump. It is important to monitor this pressure and bleed off excess pressure if it exceeds the maximum limit. Always consult the OEM for the maximum dilation pressure, as it depends on the hub material and design.

Continue advancing the hub to the pull-up position while observing the high-pressure and low-pressure limits. If the low-pressure pump reaches its maximum limit, stop the installation and remove the hub to inspect for damage. Once the specified pull-up has been reached, the dilation pressure can be slowly relieved, and the hose disconnected. After allowing time for the hydraulic oil to drain, the pressure on the low-pressure pump can be slowly released while monitoring the dial indicator for any movement of the hub. Once all movement has ceased, the pusher tool and hoses can be disconnected, and a final measurement of the pull-up distance should be taken.

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