The Rowland Company - DBA Brakes

Model DBA brakes are spring applied, pressure released, disc style brakes. They develop equal torque in either direction of rotation. Their torque and thermal capacities allow them to be used in the most demanding applications.

Brake construction and operation is shown in the figure. Pressurizing the brake compresses the brake springs and withdraws the clamping plates from the brake discs. Standard brakes are furnished with either one or two discs, which are free to move axially.

Model DBA uses a rubber diaphragm to form the releasing pressure chamber and to serve as the releasing piston. Brake friction material is attached to stationary components. Brake discs are either solid or ventilated. The disc type is indicated by an S for solid, or V, for ventilated, in the brake model designation. Solid discs are used in applications requiring a heat sink and/or where engagement is infrequent. Ventilated discs are recommended for cyclic applications.

Torque ratings listed are for brakes with a standard compliment of springs. The quantity of springs can be varied to customize the torque of the brake to suit a particular application. Consult the factory for brake torque of units with nonstandard spring configurations.

Brake sizes are indicated by the number of brake discs and the disc diameter in inches. For instance, size 229DBA has two discs 29 inches in diameter.

Unit of Measure

Items	146148 DBA Brakes	146152 DBA Brakes	146145 DBA Brakes	146151 DBA Brakes	146162 DBA Brakes
Features	N/A Large friction area. Allows brakes to absorb and dissipate high energy loads associated with high cyclic and high inertia stops. Minimal adjustment required for lining wear. Single disc units require no wear adjustment and dual disc units require only one wear adjustment during the long life of the friction material.
Where Used	N/A Can making machines Draglines Power shovels Conveyors Power presses
Model	N/A 117DBAV	N/A 217DBAV	N/A 121DBAV	N/A 221DBAV	N/A 129DBAV
Dimension D₂₅	N/A 2.00 in51 mm	N/A 2.00 in51 mm	N/A 2.00 in51 mm	N/A 2.00 in51 mm	N/A 2.75 in70 mm
Dimension H	N/A 21.000 in533 mm	N/A 21.000 in533 mm	N/A 3.000 in584 mm	N/A 3.000 in584 mm	N/A 31.000 in787 mm
Dimension H₁₁	N/A 17.25 in438 mm	N/A 17.25 in438 mm	N/A 21.00 in533 mm	N/A 21.00 in533 mm	N/A 28.00 in711 mm
Dimension H₁₃	N/A 10.00 in254 mm	N/A 10.00 in254 mm	N/A 12.12 in308 mm	N/A 12.12 in308 mm	N/A 14.75 in375 mm
Dimension H₁₆	N/A 5.38 in137 mm	N/A 5.38 in137 mm	N/A 7.62 in194 mm	N/A 7.62 in194 mm	N/A 10.25 in260 mm
Dimension G¹	N/A 24.998 in634.9 mm	N/A 24.998 in634.9 mm	N/A 26.498 in673.9 mm	N/A 26.498 in673.9 mm	N/A 33.998 in863.5 mm
Dimension L	N/A 0.78 in20 mm	N/A 0.78 in20 mm	N/A 1.06 in27 mm	N/A 1.06 in27 mm	N/A 1.06 in27 mm
Dimension O₂	N/A 1/2-14 NPT	N/A 1/2-14 NPT	N/A 1-11 1/2 NPT	N/A 1-11 1/2 NPT	N/A 1-11 1/2 NPT
Minimum Bore	N/A 2.50 in64 mm	N/A 3.25 in79 mm	N/A 2.88 in73 mm	N/A 3.88 in98 mm	N/A 3.94 in105 mm
Maximum Bore	N/A 4.25 in108 mm	N/A 4.25 in108 mm	N/A 5.75 in146 mm	N/A 5.88 in149 mm	N/A 7.38 in187 mm
Dimension D	N/A 12.55 in319 mm	N/A 15.77 in401 mm	N/A 13.19 in335 mm	N/A 16.47 in418 mm	N/A 15.51 in394 mm
Dimension D₁	N/A 11.19 in284 mm	N/A 14.41 in366 mm	N/A 11.33 in287 mm	N/A 14.61 in371 mm	N/A 13.75 in349 mm
Dimension D₇	N/A 4.88 in124 mm	N/A 6.50 in165 mm	N/A 2.50 in64 mm	N/A 5.63 in143 mm	N/A 3.50 in89 mm
Dimension D₂₉	N/A 1.00 in25 mm	N/A 1.88 in48 mm	N/A 2.12 in54 mm	N/A 2.12 in54 mm	N/A 2.25 in57 mm
Dynamic Torque Rating²	N/A 20500 lb·in2320 Nm	N/A 38000 lb·in4290 Nm	N/A 52500 lb·in5930 Nm	N/A 96000 lb·in10800 Nm	N/A 113000 lb·in12800 Nm
Disc & Gear (Inertia)	N/A 10 lb·ft²0.42 kg·m²	N/A 20 lb·ft²0.84 kg·m²	N/A 30 lb·ft²1.26 kg·m²	N/A 60 lb·ft²2.52 kg·m²	N/A 97 lb·ft²4.07 kg·m²
Disc & Gear (Weight)	N/A 70 lb32 kg	N/A 112 lb51 kg	N/A 105 lb48 kg	N/A 210 lb95 kg	N/A 185 lb84 kg
Housing (Weight)	N/A 320 lb145 kg	N/A 363 lb164 kg	N/A 480 lb217 kg	N/A 565 lb256 kg	N/A 970 lb439 kg
Minimum Releasing Pressure	N/A 60 psi4.1 bar
Maximum Speed	N/A 1300 rpm	N/A 1300 rpm	N/A 1000 rpm	N/A 1000 rpm	N/A 900 rpm
Manufacturer	N/A Eaton-Airflex
Actuation	N/A Spring Applied, Air Release
General Description	N/A Model DBA brakes are spring applied, pressure released, disc style brakes. They develop equal torque in either direction of rotation. Their torque and thermal capacities allow them to be used in the most demanding applications. Brake construction and operation is shown in the figure. Pressurizing the brake compresses the brake springs and withdraws the clamping plates from the brake discs. Standard brakes are furnished with either one or two discs, which are free to move axially. Model DBA uses a rubber diaphragm to form the releasing pressure chamber and to serve as the releasing piston. Brake friction material is attached to stationary components. Brake discs are either solid or ventilated. The disc type is indicated by an S for solid, or V, for ventilated, in the brake model designation. Solid discs are used in applications requiring a heat sink and/or where engagement is infrequent. Ventilated discs are recommended for cyclic applications. Torque ratings listed are for brakes with a standard compliment of springs. The quantity of springs can be varied to customize the torque of the brake to suit a particular application. Consult the factory for brake torque of units with nonstandard spring configurations. Brake sizes are indicated by the number of brake discs and the disc diameter in inches. For instance, size 229DBA has two discs 29 inches in diameter.
¹ Tolerance +0.000/-0.003 in (+0,00/-0,08 mm) ² Dynamic torque shown. Static torque approximately 1.15 greater. Torque values are for new linings. Torque decreases with lining wear. At the worn out condition, torque is approximately 0.66 of values shown.