FR2477953A1 - REDUCER FOR DOUBLE SCREW EXTRUDER - Google Patents

Abstract

DOUBLE SCREW EXTRUDER WITH A TORQUE DISTRIBUTOR REDUCER FOR DRIVING A SCREW MOTOR SHAFT AND INCLUDING FOUR INTERMEDIATE WHEELS MOUNTED TO ROTATE IN A SWIVEL FRAME, OF WHICH TWO WHEELS OF THE SAME SIZE IN RELATION GEAR WITH A PINION DRIVEN FROM THE SCREW MOTOR SHAFT, MOUNTED FOR ROTATION IN THE REDUCER HOUSING, OF WHICH THE TWO OTHER WHEELS OF THE SAME SIZE IN VIEW ENGAGE WITH A PINION DRIVING FROM A MOTOR SHAFT TRANSMITTING TORQUE, AND OF WHICH THE TWO WHEELS ARE ON THE SAME SIDE FROM THE RIGHT CONNECTING THE PINIONS ARE IN TAKEN. THE FRAME 9 IS PIVOTALLY MOUNTED IN THE REDUCER HOUSING, COAXIALLY WITH THE DRIVING GEAR 13. THE DRIVING GEAR 13 IS MOBILE RADIALLY IN THE CASING. APPLICATION TO THE DRIVING OF EXTRUDER SCREWS.

Description

The present invention relates to a reducer

for twin screw extruder.

  The distance between the screw shafts of an extruder

  double screw limit the diameter of the driven pinions,

  in the gearbox on the screw drive shafts. These cute leads can not be larger in any way than screw shafts. Even when the driven pinions of two screw motor shafts are offset axially relative to each other, 1C the high torques required make it difficult to obtain a sufficient life of the gearbox and loads

  allowable radial bearings fitted to the shafts

  Screw drivers. Principles of transmission of couples and forms of construction of reducers have consequently

  already been the subject of many different suggestions.

  The distribution of couples is the most important principle

  pandu for the training of screw motor shafts.

  This distribution of couples is preferably

  The experiment shows that the two meshes can not be uniform on the driven gear under consideration, due to manufacturing tolerances affecting the distances between the intermediate gears and the gears. conducted, as well as the tooth shapes of the wheels. With a view to uniform transmission of the partial pairs on the driven gear, suggestions have already been made to perform a self-tuning in

  gear reducer, allowing a game of meshing

  uniformly and consequently compensation for the inaccuracy

manufacturing processes.

  According to a known suggestion (German Democratic Republic Patent No. 111,971, FIG. 2), all the gear wheels of the gearbox used for the direct drive of a screw motor shaft and for compensation of the backlash and manufacturing inaccuracies. are arranged in a plane. Two intermediate gear wheels of the same size mesh with the driven pinion of the shaft

  screw motor, rotatably mounted in the housing of the

  ducer; they mesh each with one of two additional intermediate gears and the like

  cut. These two intermediate intermediate gears

  on opposite sides, with a driving pinion which transmits the driving torque and is

  same size as the driven pinion on the screw motor shaft.

  The primary shaft of the gearbox carrying the drive gear is also rotatably mounted in the gearbox housing. The four intermediate gears of

  same size are rotatably mounted in an oscillating frame

  which is freely mobile only in accordance with

  of the straight line connecting the leading and driven gears.

  Automatic adjustment of equal partial torques on the driven and driven gears is impossible with this gearbox as it would also require

  compensating movement of the intermediate gear wheels

  perpendicular to the plane of the gables. The only mobility parallel to the line connecting the gears ensures no adjustment of the meshing game. This results in high loads on the radial bearings of the screw drive shafts. Partial torque transmission on each driven gear is not uniform due to lack of full compensation

  manufacturing tolerances. This wheeled gearbox

  does not allow the desired uniform distribution of couples. The subject of the invention is a toothed gear reducer for driving a screw drive shaft and comprising four mounted intermediate gear wheels.

  rotating in a pivoting frame, two of which

  intermediate tees of the same size disposed opposite meshing with a driven pinion of the screw drive shaft, rotatably mounted in the gearbox housing, the two other intermediate gears of the same size arranged opposite meshing with a drive pinion of a motor shaft transmitting the torque, and the two intermediate gear wheels are on the same side of the line connecting the pinions are engaged, The reducer according to the invention allows in this case an automatic adjustment of the gear wheels to ensure a uniform distribution of couples by

always regular meshes.

  For this purpose, according to the invention, the frame

  pivoting arm is pivotally mounted in the housing of the

  driver, coaxially to the drive gear, and the pinion

  is radially movable in the crankcase

ducer.

  The frame pivoting about the center of the driving gear, on the reducing side, allows the adjustment of a uniform meshing between the driven gear and the two corresponding intermediate gear wheels, with

  which it meshes with two opposite sides. Lemon-

  onion floor leading with radial mobility allows division of engine torque into two partial pairs

  equal on this sprocket. Intermediate gears

  Both the driven gear and the drive gear are always adjusted for uniform torque distribution. The same gear pressure is obtained on the two meshing points of the driven gear and the

  two meshing points of the drive gear, independently

  manufacturing tolerances for gears and center distances. The radial bearing of the motor shaft of

  screw is thus not subject to any significant load.

  According to another advantageous characteristic of the invention, the driving pinion comprises in the gear reducer a radial shoulder provided with a curved toothing and surrounded by a coupling sleeve, the other end of which surrounds a curved toothed end

  an axially aligned motor shaft.

  The invention makes it possible to transmit the efforts

  today's high motors needed in

  double screwdrivers, without a large arrow in the shaft

  screw motor and consequently without premature deterioration

  radial bearings. Whatever the charge of

  the screw shaft, an even distribution divides the neck

  high to be transmitted in two equal partial pairs, then transmits them. It is possible to reduce the cost

  bearings of the drive shafts.

  Other features and benefits of

  the invention will be better understood with the aid of

  detailed description below of an example of

  annexed drawings in which:

  FIG. 1 is a schematic side elevation

  toothed gear reducer for driving a screw motor shaft; Figure 2 is the section of the gearwheel gear along the line II-II of Figure 1; and Figure 3 is the section of the wheeled gearbox

  toothed along the line III-III of Figure 1.

  The drive shafts of screws 4 and 5 of an extrusion

  double screws are parallel and have a

  ble gap. The gear reducer is used to

  the driving of the screw drive shaft 5, rotatably mounted

  in the housing 10 of the gearbox, and which comprises a

  6. The latter meshes with two wheels

  intermediate tees 7 and 8 arranged opposite and rotatably mounted in a pivoting frame 9. A wheel

  additional intermediate tooth of the same size

  11 or 12, is engaged with each wheel den-

  intermediate head, 7 or 8 respectively.

  13, which transmits the engine torque, meshes on two sides with the intermediate gear wheels 11 and 12 facing each other. The pivoting frame 11 is pivotally mounted in the housing 10 of the gearbox, coaxially with the drive pinion 13, on a hub 15 provided with a bearing 14. The driving pinion 13 comprises a coaxial shoulder 16 of smaller diameter and provided with a curved toothing . The gear 16 with curved teeth is surrounded by a coupling sleeve 17 with internal teeth, the other end of which surrounds the curved end 20 of an axially aligned motor shaft 18. The driving shaft 18 is rotatably mounted in the casing 10 of the gear unit and carries a driving wheel 19 which is integral in rotation.

  and that a motor drives through a re-engineered

  appropriate driver, not shown.

  The drive motor shaft 5, rotatably mounted in the housing 10 of the gearbox, passes through the latter and bears in an axial stop 21 at its end.

away from the screw shaft.

  The driving wheel 19 transmits the driving torque

  to the gear reducer shown. When this

  deny is loaded, the driving pinion 13, radially movable,

  is adjusted to divide the engine torque into two sections

  even partial pleas. The radial mobility of the driving pinion 13 is ensured by the curved toothed coupling 16, 17, 20 produced by the sleeve 17. The partial torques 23 are transmitted by the intermediate wheels 11 and 12 to the intermediate gears 7 and 8, then by these on both sides to the driven gear 6 of the drive shaft 5, rotatably mounted in the housing of the gearbox. In the case of different meshes, the pivoting of the frame 9 makes it possible to adjust the intermediate gear wheels 7 and

  8 so as to produce a uniform transmission of ef-

  strong on the two meshing points of the driven gear 6.

  The uniform distribution of couples thus obtained

  to transmit high torque to a small tree

  Screw driver, arranged parallel and at a short distance

  of a second screw motor shaft, and to reduce the

  technical rearrangement of gear reducer.

  Of course, various modifications may be made by those skilled in the art to the principle and devices which have just been described by way of non-limiting examples, without departing from the scope of the invention.

Claims (2)

  1 - Double screw extruder with a   torque-splined gear motor for driving a screw drive shaft and comprising four intermediate gearwheels rotatably mounted in a pivoting frame, whose two intermediate gearwheels of the same size arranged opposite meshing with a driven gear of the screw motor shaft rotatably mounted in the gearbox housing, both of which   other intermediate gear wheels of the same size   placed opposite to meshing with a pinion driving a torque transmitting motor shaft, and whose two intermediate gear wheels are on the same side of the straight line connecting the pinions are engaged, said extruder being characterized in that the frame pivoting member (9) is pivotally mounted in the gearbox housing (10) coaxially with the drive gear (13) and the drive gear (13) is radially movable in the housing (10) of the gearbox.   2 - Twin screw extruder with reducer   with toothed wheels torque distributor according to the   1, characterized in that the driving gear (13) comprises   carries in the gearwheel, a radial shoulder (16) provided with a curved toothing and surrounded by a coupling piece (17), the other end of which surrounds a curved end (20) of a shaft engine (18) aligned axially.