ASG, Fitting Spur Gear

Valve spur gears are primarily used to operate shut-off units such as sliders and valves. In order to move a valve or a slider out of the idle state in particular, increased torque is required. These gearboxes have a predetermined ratio of one-stage between 1:2.0 to 1:4.5 and two-stage between 1:2.75 to 1:12.0. This ratio increases the opening or closing force so that the gearbox can be operated using a handwheel or a flange rotary drive.

The installation position of the spur gear can be freely selected. However, the preferred installation position is with the drive shaft pointing downwards.

Spur gears ASG, structural design

Alternatively, the gearbox housing can be made of gray cast iron (quality EN-GJL-250) or nodular cast iron. The degree of protection of the gearbox is standard IP 65 according to EN 60 526. Due to the diverse use of the gearboxes in pipeline construction for supply lines, but also for shutting off lines in the chemical and petrochemical industries, there are a large number of connection flanges that are prescribed in the respective specialist area. Flanges according to DIN 3210 in sizes G1 to G7 are also available on the inlet side.

The application torques for the respective size are compiled as follows:

Fitting Spur Gear	Torque	Gear Input	Gear Output
Type	[Nm]	DIN 3210	DIN 3210
ASG 30	300	G0 ; G1/2	G1
ASG 60	600	G0 ; G1/2	G2
ASG 125	1250	G0 ; G1/2; G3	G3
ASG 250	2500	G1/2; G3; G4	G4
ASG 500	5000	G1/2; G3; G4	G5
ASG 1000	10000	G1/2; G3; G4	G6
ASG 2000	16000	G3; G4; G5	G7

Depending on the type and size of the gear ratio, the spur gear is designed in one or two stages. Standard gear ratios for all gearboxes are 2:1 / 3:1 / 4:1 / 6:1 / 8:1 / 12:1. The intermediate shaft that is always present means that the direction of rotation of the input shaft and output shaft is the same. The drive pinion and the idler wheels are made of wear-resistant tempered steel according to DIN 17200. These parts are stored using roller bearings. The drive wheel made of nodular cast iron (up to quality EN-GJS-600) according to DIN 1693 has plain bearings.

In a design of the spur gear with connection form “A” at the gear outlet, as shown in the picture above, the threaded bushing is made of high-quality special bronze. The axial forces that occur are absorbed by roller bearings. Spindle protection tubes of the required length can be installed to protect the through-feed spindles.

In order to enable the largest possible spindle for adjusting the actuator, the threaded bushing is also designed to be as large as possible to ensure sufficient passage. The (ASG) fittings spur gears are designed for short-term operation (not regular operation with constant operation) and are supplied ready for operation with adhesive grease.