Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to a bending-roll
machine having a single mo-tor drive mechanism for a pair of
feed rollers for use in the manufacture of helical seam pipes.
A drive of the above-described type may employ a
direct current control Oc the motor and operates through a
distributor and reduction gearing having spur gears and pivotal
shafts on a lower feed roll and on an upper feed roll, which
is adjustable in height~ A uniform power distribution to
the two rolls, the diameters of which are not always exactly
equal, and rotation of the two rolls at the same speed are
not sufficiently accurately achieved with the prior art drive
mechanisms.
It is accordingly an object of the present invention
to mitigate this disadvantage.
According to the presen-t invention, there is provided
a roll drive mechanism for a bending-roll machine for use
in the manufac-ture of helical seam pipes, the machine comprising
an upper fead roll and a lower feed roll co-operating therewith
and the mechanism being a single motor drive mechanism comprising
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a drive motor for rotationally driving the feed rolls; differ-
ential distributor gear means for -transmitting drive from
the drive motor to both of the feed rolls so as to rotate
the feed rolls at substantially equal speeds of rotation;
and planetary gearing means which are adjus-table for corres-
pondingly adjusting the speeds of rotation of the feed rolls.
Preferably, the planetary gearing means comprise
a pair of variable planetary gearings respectively associated
with the feed rolls for transmitting drive thereto from -the
drive motor.
3~ The drive transmitting means may comprise differential
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distributor gear means connected to an output shaft of the
drive motor, the distributor gear means heing connected to
the planetary gearings for distributing power thereto from
~; the drive motor output shaf-t.
The diEferential distributor gear means effects
uniform power distribution to the fe~d rolls, and the
planetary gearings enable the circumferential speeds of the
;~ feed rolls to be adjusted in addition to the speed regulation
which can be eEfected by means of the motor. The drive mechanism ;
according to the invention operates accurately and is furthermore
':, economical.
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~` In a development of the invention, the drive trans-
mitting means includes a pivotal shaft allowing the position
of one of the feed rolls to be adjusted.
However, instead of the pivotal shaft, a spiral-
toothed bevel gear coupling may be provided.
The planetary gearings may, furthermore, be slip-
,~ on gearings adapted to be mounted directly on shafts of the
feed rolls. The high torque which can be expected is, with
such sIip-on gea~ings, suitably transmitted to the feed roll
` shafts through shrink~fitted discs.
~he invention will be more readily understood from
the following description of two embodiments thereoE, given
by way of example, with reference to the accompanying drawings,
in which:
Figures 1 and 2 show broken away views, in side
elevation in the direction of strip feed and in plan view,
respectively, a drlve mechanism having a planetary differential
distributor gearing and embodying the invention; and
Figures 3 and 4 show corresponding views of a modified
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drive mechanism having a bevel gear differen-tial distributor
gearing.
In the embodimen-t of the invention illustrated in
Figures 1 and 2, a motor 1 has its output shaft 1' connected
- -through a differential gearing 2, a power take-off shaft 2'
and a planetary reduction gearing S to a lower roll 6 for
driving the latter. Through spur gears 31 to 33, a pivotal
shaft 4 and a power take off shaft 2a' and through a planetary
` gearing Sa, the motor 1 also drives an upper roll 6a, which
1~ is adjustable in height. The gears 31 to 33 rotate about
parallel axes and are a simple gear train, the gear 33 beir~g
mounted on the motor and output shaft 1' and the gear 31 being
. mounted on a hollow rotatable shaft 4' connected to the pivotal
shaft 4. The planetary gearings 5 and 5a are varia~le by
means of a joint speed control (not shown) and are secured
by means of shrink~fitted discs 5' and 5a' on stub shafts
or journals 6' and 6a' of the lower roll 6 and the upper roll
6a, respecti.vely.
In this embodiment, the differential distributo.r
gearing 2 is in the form o:E a reversing gear.
In the embodiment of the invention illus-trated in
Figures 3 and ~, ].ike reference numerals indicate the same
parts as in Figures 1 and 2. However, a bevel gear diEferential
distributor gearing 20 is provided for distribu-ting power from
the motor 1 to -the :Eeed shafts 6 and 6a, without -the gears
31 to 3~, and is provided with toothed couplings 7 and 7a,
of which the upper toothed coupl~ng 7a allows axial displace-
ment, whereby the height adjustment of the upper roll 6a is
possible. Further, gearings indicated by reference numerals
8 and 8a compensate for the larger height of the bevel gear
differential distributor gearing 20 and the couplings 7 and
7a relative to the spacing of the axes of the roll 6 and 6a.
The hatched parts i.llustrate the mounting of the
drive mechanism on a machine frame, which is not illustrated.
In operation of the above-described embodiments,
power from the motor 1 is dis-tributed to the two feed rolls
6 and 6a and the speed of the rolls 6 and 6a can be varied
by adjusting the speed of the motor. In addition to the speed
control by the motor, the speeds of the feed rolls 6 and 6a
can be addi.tionally adjusted by adjustment of the planetary
gearings 5 and 5a to provide greater accuracy of the feed
roll speeds of rotation.
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