8 Maintenance of Tracks & Skirt Panels

8 Maintenance of Tracks & Skirt Panels Tracks – Tangential Tracks, Relieving Curves – Q 409 619

Foggy Bottom Station Operation & Maintenance Manual 8-1 Washington Metropolitan Area Transit Authority Schindler 9700™ Escalators

8 Maintenance of Tracks & Skirt Panels

8.1 Tracks – Tangential Tracks, Relieving Curves – Q 409 619

1 Description and Mode of Operation

The track system consists of three blocks:

Drive station track block (1)

consisting of the side plates (2) with the tracks for the chain rollers (3) and the tracks for the step rollers (4)

as well as the handrail drive shaft (5).

The step chains are supported by relieving curves (6) and (7) both in the transition curve of the advance

track and in the transition curve of the return track.

In addition, the step chains are supported by tangential tracks (10) at the nip points of the main shaft's (9)

sprockets (8).

Fig. 619-01

1) Track block

2) Side plates

3) Chain roller tracks

4) Step roller tracks

5) Handrail drive shaft

6) Relieving curve, drive station/top

7) Relieving curve, drive station/bottom

8) Step chain sprocket

9) Main shaft



Detail X:

Middle section

The sectional steel tracks (11) are mounted on ribs (25) which are positioned during installation by means

of jigs.

Fig. 619-02

8) Step chain sprocket

10) Tangential track

11) Tracks

25) Ribs



Tension station track block (12)

has the same structure as the drive station track block; in addition, containing the tension carriage (13) for

tensioning the step chains.

Step chains of all sizes are supported by relieving curves in the transition curve of the advance track (14),

whereas only step chains of the sizes 2 and 3 are supported by relieving curves in the transition curve of

the return track (15).

In addition, the step chains are supported by tangential tracks (10) at the nip points of the tension carriage's

(13) newel chain sprockets (16) (see Detail X, Fig. 619-01).

Fig. 619-03

12) Track block

13) Tension carriage

14) Relieving curve, tension station/top

15) Relieving curve, tension station/bottom

(not applicable)

16) Newel chain sprocket



2 Maintenance

2.1 Cleaning

Clean the step roller advance track (17) over its entire length (by means of a spatula).

Warning: "Bouncing" steps!

Undulating accumulations of oil and dust on the tracks cause unloaded steps to "bounce"

noise.

Hint!

Do not lubricate the tracks.

Check whether the step roller return track (18) is soiled and clean it, if necessary.

Fig. 619-04

In the Track Block Area In the Middle Section

17) Advance track

18) Return track



2.2 Checking the Setting of the Tangential Tracks

2.2.1 Tangential Track in the Advance Track

Fig. 619-05

Center of the step chain sprocket (8) (newel chain sprocket (16))

3) Chain roller track

10) Tangential track

19) Chain roller

20) Clamping screws

22) Step chain

A) Location holes

With the chain roller (19) positioned at the center of the step chain sprocket (8) (or the newel chain

sprocket (16)), it should have a distance of 0.4 to 0.7 mm from the chain roller track (3).

With the chain roller (19) positioned at a distance of approx. 50 to 60 mm from the tangential track's (10)

rear edge, it should abut the track (3) or have a distance of max. 0.2 mm from the track (3).

Readjustment:

– Loosen the clamping screws (20).

– Insert eccentrics (21) (preferably 2 pcs.) into the location holes (A).

– With the chain roller (19) positioned at the center of the step chain sprocket (8):

Turn the eccentrics in the location holes (A) until the tangential track (10) abuts the step chain

sidebars (22) with light pressure; tighten the front clamping screw (20) by hand.

– With the chain roller (19) positioned at a distance of approx. 50 to 60 mm from the tangential

track's (10) rear edge:

Turn the eccentric in the second location hole (A) to adjust the tangential track (10) so that the chain

roller (19) abuts the track (3) or has a distance of max. 0.2 mm from the track (3).

– Tighten all clamping screws (20).

Fig. 619-06 Eccentric (Drawing Z 552 485, ID no. SDZ 393 759)



2.2.2 Tangential Track in the Return Track

Fig. 619-07

23) Return track

With the chain roller (19) positioned at the center of the step chain sprocket (8) (or the newel chain

sprocket (16)), it should have a distance of 0.4 to 0.7 mm from the track (3) as well as from the return

track (23).

With the chain roller (19) positioned at a distance of approx. 50 to 60 mm from the tangential track's (10)

rear edge, it should abut the return track (23) or have a distance of max. 0.2 mm from the return track (23).

Readjustment:

Proceed as described under Section 2.2.1, Tangential Track in the Advance Track.



2.3 Checking the Relieving Curve, Drive Station/Top

2.3.1 Setting Check

Fig. 619-08

Hint!

The starting points (RA) and the center of the radius (RM) are marked on the side plate (2) by

w-shaped symbols.

The gap between the chain roller (19) and the track (3) shall measure:

– 0.2 to 0.7 mm at both starting points of the radius (RA)

– 0.8 to 1.3 mm at the center of the radius (RM)

Hint!

As soon as the minimum permissible gap of 0.2 mm at the starting point of the radius or 0.8 mm

at the center of the radius is reached, the relieving curve must be readjusted.

Warning: Damage to plastic tire!

If the chain rollers exert pressure on the track in the area of the radius, uncontrolled forces will

act on the plastic tire and destroy it within a relatively short time.

2) Side plate



19) Chain roller

22) Step chain

RA: Starting points of radius

RM: Center of radius



Readjustment:

Fig. 619-09

– Loosen the nuts of the clamping screws (24).

Hint!

The heads of the clamping screws are welded to the support plate of the relieving curve.

– Loosen the clamping nuts of the eccentrics (25).

Hint!

With Schindler 9700-20, only 2 eccentrics; with Schindler 9700-30, 3 eccentrics

– Turn the eccentrics (25) to lift the relieving curve (6) until the gap between the chain roller (19) and the

track (3) measures

approx. 0.5 to 0.7 mm at the starting points of the radius (RA) and

approx. 1.1 to 1.3 mm at the center of the radius (RM)

(see Fig. 619-08).

Hint!

Tighten the clamping nuts immediately after lifting the relieving curve by means of the eccentrics

to prevent it from falling back.

– Tighten the nuts of the clamping screws (24).


24) Clamping screws

25) Eccentrics



Design of the eccentrics (25)

With projecting hex nose,

wrench size 19 mm

Fig. 619-10

2.3.2 Checking the Condition of the Wearing Band

Fig. 619-11

Thickness D of a new wearing band: 4.0 mm

Minimum permissible thickness D: 1.5 mm


24) Wearing band



2.4 Checking the Relieving Curve, Drive Station/Bottom

2.4.1 Setting Check

Fig. 619-12

Hint!

The two outer ribs (25) are located exactly at the starting points of the radius (RA), the central

rib (25) at the center of the radius (RM).

The gap between the chain roller (19) and the return track (23) shall measure:



Hint!

If the gap at the starting points of the radius equals or falls short of 0.2 mm or the gap at the

center of the radius equals or falls short of 0.9 mm, the relieving curve must be readjusted.

7) Relieving curve, drive station/bottom

19) Chain rollers

23) Return track

25) Ribs



Readjustment:

Fig. 619-13

– Unscrew the fastening screw (27) by a couple of millimeters.

– Lift the relieving curve (7).

– Insert a sheet-metal strip of the corresponding thickness (0.5 or 0.6 mm) between the relieving curve (7)

and the rib (25).

– Tighten the fastening screw (27).

2.4.2 Condition Check

Hint!

Relieving curves are equipped with plastic profiles as standard. Optionally, they are also

available with wearing bands.

Fig. 619-14

Standard Option

Standard design with plastic profile (28)

– New: H = 15 mm

– Minimum permissible height: H = 12 mm

Optional design with wearing band (24)

– Thickness D of a new wearing band: 4.0 mm

– Minimum permissible thickness D: 1.5 mm

26) Threaded plate

27) Fastening screw

24) Wearing band

28) Plastic profile



2.5 Checking the Relieving Curve, Tension Station/Top

Hint!

For this relieving curve only a setting check is required, since it is only subjected to the step

chain tension stress which virtually rules out wear and tear.

Fig. 619-15

Hint!

The starting points (RA) and the center of the radius (RM) are marked on the side plate (2) by

w-shaped symbols.

The gap between the chain roller (19) and the track (3) shall measure:



Hint!

If the gap equals or exceeds 1.0 mm, the relieving curve must be readjusted.

2) Side plate


14) Relieving curve, tension station/top

19) Chain roller



Readjustment:

Fig. 619-16

– Loosen the clamping nut (30) of the eccentric screw (29).

– Turn the eccentric screw (29) to lower the tangential track until the gap between the chain roller (19)

and the track (3) measures 0.5 to 0.8 mm at the points (RA) and (RM).

– Tighten the clamping nut (30).

29) Eccentric screw

30) Clamping nut

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8 Maintenance of Tracks & Skirt Panels