Double-screw extruder gear box with adjustable center distance

Abstract

A spline is arranged at the left end of a spline connecting shaft, the spline connecting shaft is connected with an inner spline shaft through a pull rod, drum-shaped outer teeth are arranged at the right end of the spline connecting shaft, and the drum-shaped outer teeth are inserted into a straight tooth inner gear ring at the left end of an inner gear sleeve transmission shaft; straight tooth inner gear rings are arranged at the left and right ends of the inner gear sleeve transmission shaft, and outer circle parts at the left and right ends are respectively arranged in bearing inner rings of the spherical roller bearing M and the spherical roller bearing N; drum-shaped outer teeth are arranged at the left end of the short main shaft and are inserted into a straight tooth inner gear ring at the right end of the inner gear sleeve transmission shaft; the replaceable bearing seat is mounted on the spherical roller bearing N; the drum-shaped outer teeth swing on the axis of the straight tooth inner gear ring, and the spherical roller bearing M and the spherical roller bearing N can be automatically aligned. The center distance of the gear box is changed by replacing the bearing seat in front of the box body, the gear boxes with similar center distance specifications share the same gear box, production organization is facilitated, and the supply cycle is shortened.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gearboxes, in particular to a center distance adjustable double screw extruder gearbox. BACKGROUND

[0002] The prior art co-rotating double screw extruder gearbox works, the input gear shaft transmits torque to gear A, and at the same time completes the speed reduction transmission. The pull rod connects the main shaft and the inner spline shaft into one body, and the main shaft and gear A rotate at the same speed. Gear A and gear B are fixed on the inner spline shaft by means of a flat key (same speed). Gear B completes the power distribution (torque is transmitted to gear C) - speed reduction transmission, gear C rotates at the same speed as gear D through the transmission shaft, and gear D transmits torque to gear E (secondary shaft) - speed up transmission. After two-stage transmission, the secondary shaft rotates in the same direction as the main shaft (same direction).

[0003] The number of teeth Z1 (gear B): the number of teeth Z2 (gear C) = the number of teeth Z4 (gear E): the number of teeth Z3 (gear D), the secondary shaft and the main shaft rotate at the same speed. Under the condition of meeting the same direction and the same speed, the main parameters of the gearbox: the center distance of the output shaft, that is, the center distance Z of the main shaft and the secondary shaft = (gear B / gear C center distance) X - (gear D / gear E center distance) Y.

[0004] The output shaft center distance specification of the double screw extruder gearbox is a result of convention, after the leading enterprise puts forward this specification, in order to the universality of the matching parts, the center distance specification of small and medium-sized enterprises also increases. Some enterprises often do some individualization treatment in order to the after market (the demand for gearbox parts after several years), which has several millimeter difference with the commonly used specification. The small range adjustment of the center distance usually changes the gear height displacement (positive displacement or negative displacement) of the gear C with more teeth, so that the center distance X increases or decreases, and finally the center distance Z = X-Y increases or decreases.

[0005] The center distance adjustment changes the position of the hole system (bearing U, bearing V, bearing W) of the main shaft on the gearbox body, the gearbox body is reprocessed, and the bearing seat in front of the gearbox body also needs to be replaced. For similar specifications of the gearbox, one center distance corresponds to one set of gearbox and one bearing seat, which is very unfavorable for production organization and delivery cycle.

[0006] Therefore, it is necessary to develop a center distance adjustable double screw extruder gearbox to overcome the above problems. SUMMARY

[0007] The purpose of the present application is to overcome the deficiencies and shortcomings of the prior art, and to provide a center distance adjustable double screw extruder gearbox, which changes the center distance of the gearbox by replacing the bearing seat in front of the gearbox, and the gearboxes with similar center distance specifications share the same type of gearbox, which is convenient for production organization and shortens the delivery cycle.

[0008] Technical solution: The center distance adjustable double screw extruder gear box of the application is characterized by comprising a spline connecting shaft, an inner tooth sleeve transmission shaft, a short main shaft and a replaceable bearing seat; the left end of the spline connecting shaft is a spline, the spline connecting shaft is connected with the inner spline shaft through a pull rod, the right end of the spline connecting shaft is a drum-shaped external gear, and the drum-shaped external gear is inserted into the straight-toothed inner gear ring at the left end of the inner tooth sleeve transmission shaft; the left and right ends of the inner tooth sleeve transmission shaft are straight-toothed inner gear rings, and the outer circle parts of the left and right ends are respectively installed into the bearing inner rings of spherical roller bearings M and N; the left end of the short main shaft is a drum-shaped external gear, and the drum-shaped external gear is inserted into the straight-toothed inner gear ring at the right end of the inner tooth sleeve transmission shaft; the replaceable bearing seat is installed on the spherical roller bearing N; the drum-shaped external gear oscillates on the axis of the straight-toothed inner gear ring, and the spherical roller bearings M and N can be automatically aligned.

[0009] Among them, the oscillation angle of the drum-shaped external gear on the axis of the straight-toothed inner gear ring is 1.5°-3°.

[0010] Among them, the spherical roller bearings M and N can be automatically aligned, and the angle error between the inner ring and the outer ring is 1.5°-3.5°.

[0011] Among them, the spherical roller bearings M and N are provided with two rows of rollers, the outer ring is a common spherical raceway, and the inner ring is two raceways.

[0012] Among them, the spherical roller bearing M is installed at a position before the bearing W.

[0013] Among them, the pull rod passes through the inner spline shaft, and the inner spline shaft is sequentially provided with a bearing U, a bearing V, a gear A, a gear B and a bearing W.

[0014] Among them, the gear B is connected with the gear C, the gear C is connected with the gear D through a transmission shaft, and the gear D is connected with the gear E.

[0015] Among them, the gear D is connected with the gear E, the gear E is connected with the countershaft, and the gear E and the countershaft are integrated parts.

[0016] Among them, the right end of the spline connecting shaft and the left end of the short main shaft are machined into convex spherical surfaces; the bottoms of the two ends of the inner tooth sleeve transmission shaft are machined into concave spherical surfaces of the same specifications; the axial thrust of the short main shaft is transmitted to the bearing U, i.e. the aligning roller thrust bearing, through two spherical pairs and then the inner spline shaft.

[0017] Beneficial effects: compared with the prior art, the present application has the following remarkable advantages: the present application divides the main shaft into three parts, the spline connecting shaft, the inner tooth sleeve transmission shaft and the short main shaft. This structure makes the center distance change not affect the main shaft box body structure. Two spherical roller bearings are used in pairs, which still ensure long-term stable operation under the condition of slight angular deviation of the bearing inner and outer rings, making the gear box center distance slight adjustment simple and reliable. The combination of the drum-shaped external teeth and the straight-tooth inner tooth ring used in pairs makes the meshing transmission contact good, and the transmission is stable and reliable under the condition that the spline connecting shaft, the inner tooth sleeve transmission shaft and the short main shaft have a certain inclination angle. The spherical pair between the spline connecting shaft, the inner tooth sleeve transmission shaft and the short main shaft makes the three accurately transmit the axial thrust at the front end of the short main shaft to the bearing U (thrust bearing) at the rear end under the condition of a certain inclination angle. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a structure schematic diagram of the prior art co-rotating twin-screw extruder gear box;

[0019] Figure 2 It is a structure schematic diagram of the present application;

[0020] In the figure, 1 is the spline connecting shaft; 2 is the inner tooth sleeve transmission shaft; 3 is the short main shaft; 4 is the spherical roller bearing M; 5 is the spherical roller bearing N; 6 is the replaceable bearing seat. DETAILED DESCRIPTION

[0021] The technical solutions of the present application will be further described below in combination with the drawings and specific embodiments.

[0022] The center distance adjustable twin-screw extruder gear box of the present application comprises the spline connecting shaft 1, the inner tooth sleeve transmission shaft 2, the short main shaft 3 and the replaceable bearing seat 6; the left end of the spline connecting shaft 1 is a spline, the spline connecting shaft 1 is connected with the inner spline shaft through a pull rod, the right end of the spline connecting shaft 1 is a drum-shaped external tooth, which is inserted into the straight-tooth inner tooth ring at the left end of the inner tooth sleeve transmission shaft 2; the left and right ends of the inner tooth sleeve transmission shaft 2 are straight-tooth inner tooth rings, and the outer circle parts of the left and right ends are respectively fitted into the bearing inner rings of the spherical roller bearing M 4 and the spherical roller bearing N 5; the left end of the short main shaft 3 is a drum-shaped external tooth, which is inserted into the straight-tooth inner tooth ring at the right end of the inner tooth sleeve transmission shaft 2; the replaceable bearing seat 6 is installed on the spherical roller bearing N 5, the drum-shaped external tooth oscillates on the axis of the straight-tooth inner tooth ring, and the spherical roller bearing M 4 and the spherical roller bearing N 5 can automatically align.

[0023] The drum type outer gear of the application swings 1.5-3° on the axis of the straight tooth inner gear ring. The spherical roller bearing M4 and the spherical roller bearing N5 can automatically align, allowing the angle error between the inner ring and the outer ring to be 1.5-3.5°. The spherical roller bearing M4 and the spherical roller bearing N5 are provided with two rows of rollers, the outer ring is a common spherical raceway, and the inner ring is two raceways. The spherical roller bearing M4 is installed in the position before the bearing W. The pull rod passes through the inner spline shaft, and the inner spline shaft is sequentially provided with the bearing U, the bearing V, the gear A, the gear B, and the bearing W. The gear B is connected with the gear C, and the gear C is connected with the gear D through a transmission shaft. The gear D is connected with the gear E, and the gear E is connected with the auxiliary shaft, and the gear E and the auxiliary shaft are integrated parts.

[0024] The right end of the spline connection shaft 1 and the left end of the short spindle 3 are machined into convex spherical surfaces; the two ends of the inner tooth sleeve transmission shaft 2 are machined into concave spherical surfaces of the same specification; the axial thrust of the short spindle 3 is transmitted to the rear bearing U, i.e. the self-aligning roller thrust bearing, through two spherical pairs and finally through the inner spline shaft. (The shaft is inclined at an angle, and in order to ensure the contact surface and transmit the axial thrust, the spherical surface contact pair must be machined).

[0025] The spherical roller bearing has two rows of rollers, the outer ring has a common spherical raceway, and the inner ring has two raceways at a certain angle with the vertical axis of the bearing. The spherical roller bearing can automatically align, so it can withstand a larger alignment error. The spherical roller bearing allows the maximum angle error between the inner ring and the outer ring to be 1.5-3.5° (depending on the different bearing specifications), and the axis works within the allowable angle range without affecting the performance of the bearing.

[0026] The drum type outer gear and the straight tooth inner gear ring are combined together, and the torque is transmitted by the meshing of the inner and outer teeth. The drum type outer gear swings (called angular displacement, the swing does not exceed 1.5-3°) on the axis of the straight tooth inner gear ring, which can be used to compensate for the relative offset of the two transmission axes. Due to the drum length direction, the meshing transmission contact is good, and the transmission is stable and reliable.

[0027] The present application comprehensively utilizes the principle characteristics of the spherical roller bearing (one of the necessary conditions for realizing the adjustable center distance function) and the drum type tooth coupling (the second necessary condition for realizing the adjustable center distance function). The variable of the "adjustable center distance" is:

[0028] L*tanα (L is the center distance between the two spherical roller bearings), taking a gear box center distance of Z=100mm as an example, L=458, α takes +0.5° / -0.5°, and the adjustable center distance K=Z±458*tan0.5=104mm / 96mm.

[0029] The present application adjusts the center distance, and can be realized by only replacing the replaceable bearing seat, and other parts and bearings are universal. The main shaft and the auxiliary shaft of the double screw extruder bear a large axial thrust. The main shaft of the original structure transmits the axial thrust to the rear bearing U (a self-aligning roller thrust bearing) through an inner spline shaft. The right end of the spline connecting shaft and the left end of the short main shaft of the present application are machined into convex spherical surfaces. The bottom of both ends of the inner toothed sleeve transmission shaft is machined into concave spherical surfaces of the same specification. The axial thrust of the short main shaft is transmitted to the rear bearing U (a self-aligning roller thrust bearing) through two spherical pairs and finally through the inner spline shaft.

Claims

1. A central distance adjustable twin screw extruder gearbox characterized by: It includes spline connection shaft (1), inner tooth sleeve transmission shaft (2), short main shaft (3) and replaceable bearing seat (6); the left end of spline connection shaft (1) is spline, spline connection shaft (1) is connected with inner spline shaft through drawbar, the right end of spline connection shaft (1) is drum-shaped external gear, and drum-shaped external gear is inserted into straight tooth inner gear ring at the left end of inner tooth sleeve transmission shaft (2); the left and right ends of inner tooth sleeve transmission shaft (2) are straight tooth inner gear rings, and the outer circle parts of the left and right ends are respectively installed into bearing inner rings of spherical roller bearing M (4) and spherical roller bearing N (5); the left end of short main shaft (3) is drum-shaped external gear, and drum-shaped external gear is inserted into straight tooth inner gear ring at the right end of inner tooth sleeve transmission shaft (2); replaceable bearing seat (6) is installed on spherical roller bearing N (5); drum-shaped external gear oscillates on the axis of straight tooth inner gear ring, and spherical roller bearing M (4) and spherical roller bearing N (5) can automatically align.

2. A center distance adjustable twin screw extruder gearbox according to claim 1, characterized in that: The oscillation angle of drum-shaped external gear on the axis of straight tooth inner gear ring is 1.5°-3°.

3. The variable center distance twin screw extruder gear box of claim 1, wherein: Spherical roller bearing M (4) and spherical roller bearing N (5) can automatically align, and the angle error between inner ring and outer ring is 1.5°-3.5°.

4. A center distance adjustable twin screw extruder gearbox according to claim 3, characterized in that: Spherical roller bearing M (4) and spherical roller bearing N (5) are provided with two rows of rollers, the outer ring is a common spherical raceway, and the inner ring is two raceways.

5. The variable center distance twin screw extruder gear box of claim 1, wherein: Spherical roller bearing M (4) is installed at the position before bearing W.

6. The variable center distance twin screw extruder gearbox of claim 1, wherein: The drawbar passes through inner spline shaft, and bearing U, bearing V, gear A, gear B and bearing W are sequentially installed on inner spline shaft.

7. A center distance adjustable twin screw extruder gearbox according to claim 6, characterized in that: Gear B is connected with gear C, gear C is connected with gear D through transmission shaft.

8. A center distance adjustable twin screw extruder gearbox according to claim 7, characterized in that: Gear D is connected with gear E, gear E is connected with auxiliary shaft, and gear E and auxiliary shaft are integrated parts.

9. A center distance adjustable twin screw extruder gearbox according to any of claims 1-8, characterized in that: The right end of spline connection shaft (1) and the left end of short main shaft (3) are processed into convex spherical surfaces; the bottoms of the two ends of inner tooth sleeve transmission shaft (2) are processed into concave spherical surfaces with the same specifications; the axial thrust of short main shaft (3) is transmitted to bearing U, i.e. aligning roller thrust bearing, through two spherical pairs and then through inner spline shaft.

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