Vapor Air Door Differential Motor Speed Adjustments

 

Description:

The Vapor door motor is an air-operated geared differential device with two horizontally opposed cylinders of different diameter size. A rack gear connects the pistons within the cylinders, the rack gear meshes with a rotary gear to convert straight line motion of the pistons into rotary motion. This rotary motion will rotate the teeter plate which moves the connecting rods to operate the doors.

Vapor, Doors, Assembly
Vapor Motor Door Assembly

 

 

 


 

 

Operation:

The Vapor differential motor operation:
1. To close the bus door, the large cylinder is charged with air thru an air solenoid, the large piston overcomes the air pressure in the small piston moving the rack gear to close the doors. The rate at which the door closes, depends on the closing speed adjustment and how air volume is allowed to the cylinder.

Vapor, door, differential
Door closing, large piston overcomes small piston to close door.

 

2. To open bus door, air to the large piston is shut off. The small piston being pressurized with air, will push towards the large piston. This will cause the air in the large piston to exhaust and cause the door to open. The rate of opening speed is controlled by the opening speed adjustment, by controlling the air exhaust rate.

Vapor, differential, motor
Door opening, air is exhausted from large piston side, this allows small piston to open door.

 

3. Cushioning effect, is used to control the doors from slamming when opening. As the large piston comes to end of it’s opening stroke, the remaining air will exhaust thru the cushioning orifice. How much cushioning depends on the cushioning adjustment.

Vapor, motor, differential
Cushioning adjustment controls the doors from slamming open.

 

 


 

Adjustment:

Door motor adjustments should be performed with a minimum of 90 psi. to get the proper adjustment speeds.
The required cycle time for opening or closing of doors is 2.5 to 3 seconds.
Always start with closing speed, since this affects the door opening speed.
All door hardware must be checked for wear or binding before motor adjustments are performed.
Wear eye protection.

Caution: Adjustment screws are not captive, and if they are unscrewed to far out with air pressure, they can become projectiles. 

 

Tools:

⇒ 5/32 Allen wrench
⇒ Flat blade screwdriver
⇒ 1/2 Wrench

Adjustments should be done in the following order:

Vapor, Closing speed, opening speed, cushion adjustment
Vapor differential motor adjustment order

1. Closing Speed: Loosen closing speed jam nut and use 5/32 Allen wrench to adjust closing speed.
Turning screw in (clockwise) will decrease closing speed.
Turning screw out (clockwise) will increase closing speed.
Closing speed should be approximately 2.5 – 3 seconds. After adjustment is done tighten jam nut, recheck closing speed.

 

2. Opening Speed: Loosen closing speed jam nut and use 5/32 Allen wrench to adjust opening speed.
Turning screw in (clockwise) will decrease closing speed.
Turning screw out (clockwise) will increase closing speed.
Opening speed should be approximately 2.5 – 3 seconds. After adjustment is done tighten jam nut, recheck opening speed. Disregard door slamming when opening, cushion adjustment will control this.

 

3. Cushion Adjustment: Loosen cushion adjustment jam nut and use flat blade screwdriver to adjust cushion speed to prevent door from slamming open.
Turning screw in (clockwise) will decrease dampening speed.
Turning screw out (clockwise) will increase dampening speed.
The cushioning adjustment is designed to affect the last quarter of the door travel on the opening cycle only. Opening speed may have to be readjusted to get the best combination of opening speed and cushion adjustment. Once adjustment is done, re-tighten cushion jam nut.

Recheck closing, opening and cushion adjustment. Check that all jam nuts are tight.

2 Comments on “Vapor Air Door Differential Motor Speed Adjustments

  1. Guys, this is an excellent service you are providing, I am proud to have had the pleasure to work with you in the past, you are a group of very professional, highly technical, well learned on the ways of training on bus systems and sub-systems, the simple idea that you requested my input, make me know that when we worked together, I did something right for you to consider my opinion on an already “Outstanding” write up on door adjustments.

    1. Luis, well I did learn from you how to do the door adjustments on the Vapor doors. Thanks for the teachings and knowledge!

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