JPH0721296Y2 - Position adjustment mechanism of screw shaft in extruder - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention relates to an extruder screw speed reducer having both a speed reducing function for driving the screw rotation of the extruder by speed reduction and a function for adjusting the axial position of the screw. Regarding the machine.

(Prior Art) FIG. 2 shows a conventional speed reducer, in which a hollow shaft 22 is rotatably supported in a box-shaped frame 19 installed on a frame F via a thrust bear rig 20 and a bearing 21. , The hollow shaft
A main drive shaft 23 extending from the rear end of the screw 52 is fitted in the screw 22, and the drive shaft 23 is connected to the hollow shaft 22 by a slide key 24 so as not to be rotatable and slidably in the axial direction. There is. Reference numerals 25 and 26 denote speed change gears that are non-rotatably fitted to the hollow shaft 22 in the box-shaped frame 19, and the rotation is transmitted from a motor (not shown).

At the rear end of the frame 19, a support tube 27 has a flange.
28 is fixed by bolts 29, the supporting cylinder 27 is a cylindrical body having an external thread 30 formed on the outer peripheral surface thereof, and is positioned concentrically with the hollow shaft 22, and the adjusting screw is attached to the external thread 30. 31 is screwed and supported. The actuating cylinder 31 has an inner peripheral surface formed with a female screw 32 to be screwed into the male screw 30 and an inward flange at the rear end.
It is a cylindrical body in which 33 is fixed by bolts 34, and when it is rotated about its axis, it is slightly moved in the front-back direction. on the other hand,
The auxiliary drive shaft 35 is inserted into the inside of the operating cylinder 31 and the support cylinder 27 and the rear end portion of the hollow shaft 22, and the connecting screw rod 40 is vertically passed through the washer 41 into the auxiliary drive shaft 35 and the tip of the screw rod is inserted. The main drive shaft 23 is screwed to the rear end of the main drive shaft 23, thereby connecting the main drive shaft 23 and the sub drive shaft 35 to form a single drive shaft, and the front end of the sub drive shaft 35 is The slide key 36 is fitted to the rear end of the hollow shaft 22 so that it cannot rotate but can slide freely in the axial direction.
Further, the rear end portion thereof is provided with a thrust bearing 37 inserted in the front side of the flange 33 in the operating cylinder 31 and a bearing 39 inserted in the rear side of an annular projection 38 projecting on the inner circumference of the flange 33. Is engaged so as to be relatively immovable in the axial direction in a rotatable state.

As a means for rotationally driving the operating cylinder 31, a worm wheel 42 is concentrically formed on the outer peripheral surface of the operating cylinder 31, and the worm 43 is engaged with the worm wheel 42 to form a worm shaft.
Rotation is transmitted to a sprocket 45 fixed to 44 from an electric motor 46 with a forward / reverse rotation type speed reducer for adjustment through a chain 47. 48 is a support plate that supports the worm shaft 44, and is a flange
Installed on 28.

Next, the operation of the device will be described. When the rotation of the rotor is transmitted to the gear 25 or 26 and the hollow shaft 22 is rotated, the main and auxiliary drive shafts 23 and 35 are rotated to rotate a kneading screw (not shown), whereby molten synthetic resin is shown. The kneading and extruding is carried out by feeding it into the kneading and extruding passage which is a gap between the cylinder and the screw.

In order to process synthetic resin with low viscosity, it is necessary to increase the extrusion pressure by narrowing the width of the above passage, but in this case, when the adjusting motor 46 is started while the kneading screw is rotating, the chain 47 and sprocket 45 , The rotation is transmitted to the worm wheel 42 via the worm 43, which causes the adjustment operating cylinder.
31 rotates and makes a fine movement forward, and the forward movement of the operating cylinder 31 pushes the auxiliary drive shaft 35 and the main drive shaft 23 forward through the thrust bearing 37 to make a fine movement advance of the kneading screw, thereby gradually moving through the passage. I will sprinkle it. Here, the worker observes a continuous change in the degree of kneading of the synthetic resin due to the narrowing of the passage, and when the most desirable kneading is obtained, the adjusting motor 46 is stopped and the advance of the kneading screw is stopped.
The width of the passage at that time gives an optimum extrusion pressure for kneading the synthetic resin.

When returning the passage to a width suitable for a synthetic resin having a slightly higher viscosity than the above, when the adjusting motor 46 is rotated in the reverse direction while the kneading screw is being rotated, the operating cylinder 31 is reversely rotated and slightly moves backward, This movement of the operating cylinder 31 pulls the sub drive shaft 35 and the main drive shaft 23 rearward via the bearing 39 to move the kneading screw slightly backward, thereby gradually expanding the passage.

(Problems to be solved by the invention) In such a speed reducer, as described above, the screw shaft 52 is connected to the hollow shaft 22 via the slide key 24 so as not to be rotatable and appropriately slidable in the axial direction. The fitting sliding portion is in a non-lubricated state, and the disposition location of the slide key 24 is the inner peripheral portion of the hollow shaft 22, so that the following inconvenience occurs.

(1) The operation force for moving the screw shaft 52 in the axial direction is large.

(2) Due to the relative movement of the screw shaft 52 with the hollow shaft 22 and the slide key 24, wear of the fitting / sliding part is severe.

Therefore, an object of the present invention is to eliminate these disadvantages and to simplify the output structure of this type of speed reducer.

Therefore, according to the present invention, one end of a hollow shaft, in which the extruder screw is fixed in the axial direction and the speed change gear in the box-shaped frame is fixed to the outer periphery, is provided in the box-shaped frame. Is rotatably supported by a bearing, and is movably supported in the axial direction through a sleeve that supports the inside of the bearing. The other end of the hollow shaft is rotated through the thrust bearing in the adjusting cylinder and is axially supported. Movably supported by the adjusting cylinder, the male screw on the outer peripheral portion is screwed into the female screw provided on the box-shaped frame, and the hollow shaft is movable in the axial direction as the adjusting cylinder rotates. Further, the bearing and the thrust bearing are arranged in the lubricating oil in the same box type frame, and this is used as a means for solving the above problems.

(Operation) The screw connecting member in the speed reducer is arranged in the lubrication portion to eliminate wear of the rotary sliding portion of the member, and
Structurally, the rotary sliding portion is arranged away from the rotary shaft core to reduce the sliding resistance and reduce the external operating force for sliding.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a speed reducer output section according to the present invention.
One of the hollow shafts 4 is rotatably supported via bearings 2 and 3 in the box-shaped frame 1 arranged on the frame F,
On the other hand, a female screw portion 6 of a thrust housing 7 as a sub-box type frame fixed to the box-shaped frame 1 with bolts 5
Is supported rotatably and axially fixedly via a thrust bearing 10 arranged in an adjusting cylinder 9 screwed with a male screw portion 8.

In addition, the bearings 2, which are arranged in the box-shaped frame 1,
The outer ring of 3 is fixed to the same frame 1, but the sleeves 2 ', 3'as inner rings of the bearings 2, 3 are configured to move in conjunction with the axial movement of the hollow shaft 4, so that The axial length of the sleeves 2'and 3'is larger than that of the outer ring.

Reference numeral 11 denotes a speed-changing gear which is fixed to the outer peripheral portion of the hollow shaft 4 in the box-shaped frame 1 and rotates integrally with the hollow shaft 4, and the rotation is transmitted from a gear (not shown) meshing with the gear.

Next, the operation of this device will be described. The screw shaft (not shown) meshes with the hollow hole 12 of the hollow shaft 4 and is non-rotatably fixed to the hollow shaft 4 by a rotary fastening element such as a key 13. Now, the screw shaft (not shown) is rotationally driven through the hollow shaft 4 by the rotational drive of the speed change gear 11, but in this state, one end 14 of the adjusting cylinder 9 is used to adjust the axial movement of the screw shaft. When rotated by appropriate power including manual operation, the adjusting cylinder 9 is moved back and forth by a required distance ε by screwing the male screw portion 8 formed on the same cylinder and the female screw portion 6 formed on the thrust housing 7.

On the other hand, the thrust bearing 10 is sandwiched in the space formed by the hollow hole of the adjusting cylinder 9 and the bearing cover 15, and the inner ring 16 of the bearing 10 is hollow with the space cylinder 17 whose axial movement is controlled by the snap ring 18. It is sandwiched between the step portion of the shaft 4 and fixed in the axial direction of the hollow shaft 4. Therefore, the axial movement of the screw shaft (not shown) due to the rotation of the adjusting cylinder 9 causes the thrust bearing 10 and the hollow shaft 4 to move. Is transmitted to the screw shaft (not shown) via the shaft, and the axial movement is possible even when the coaxial shaft is in a rotationally driven state.

The bearing and the thrust bearing are lubricated by a lubricating oil held in the box frame.

(Effect of the Invention) As described in detail above, according to the present invention, one end of the hollow shaft having the extruder screw fixed in the axial direction is rotated by the bearing and moved in the axial direction through the inner ring of the bearing. The other end of the hollow shaft is rotatably and axially movably supported via a thrust bearing, and the male screw of the adjusting cylinder and the female screw of the box frame are screwed together. Yes, when the adjusting cylinder is rotated by the rotating means of the adjusting cylinder, the adjusting cylinder moves in the axial direction and the hollow shaft also moves in the axial direction. It is possible to reduce the capacity of an operation drive source such as a motor) and to reduce the size of the reduction mechanism in the box-shaped frame.

Therefore, according to the present invention, the axial movement of the hollow shaft can be dealt with by a manual operation without using a hydraulic power source, so that the structure is simple and the cost can be reduced. Further, since the piston is not used, the width can be made compact. Further, since the sliding portion is rolling, the operating force can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of an extruder screw speed reducer according to a typical embodiment of the present invention, and FIG. 2 is a sectional view of a conventional extruder screw speed reducer. Description of the main parts of the figure 1 …… Box-shaped frame 2, 3 …… Bearing 4 …… Hollow shaft 7 …… Thrust housing 9 …… Adjusting cylinder 10 …… Thrust bearing

Claims (1)

[Scope of utility model registration request] 1. A hollow shaft having an extruder screw fixed in the axial direction and a transmission gear in a box-shaped frame fixed to the outer periphery of the box-shaped frame is rotated by a bearing in the box-shaped frame, and the inside of the bearing is rotated. The hollow shaft is movably supported in the axial direction through a sleeve, and the other end of the hollow shaft is rotatably and axially movably supported inside the adjusting cylinder through a thrust bearing. Is a male screw on the outer peripheral portion screwed into a female screw provided on the box-shaped hellem, the hollow shaft is movable in the axial direction with the rotation of the adjusting cylinder, and the bearing and thrust bearing are of the same box type. A screw shaft position adjusting mechanism in an extruder, which is arranged in lubricating oil in a frame.