CN113700800B - Metering pump worm gear transmission mechanism with bidirectional overload protection - Google Patents

Abstract

The invention relates to a metering pump worm and gear transmission mechanism with bidirectional overload protection. The novel worm spindle is characterized by comprising a worm spindle, a bearing left side, a nut left side, a compression spring left side, a worm, a compression spring right side, a nut right side, a bearing right side and a worm wheel, wherein the worm spindle sequentially penetrates through the bearing left side, the nut left side, the compression spring left side, the worm, the compression spring right side, the nut right side and the bearing right side, the nut left side and the nut right side are respectively in threaded fit with external threads arranged on the worm spindle, and the pretightening force of the compression spring left side and the compression spring right side is adjusted through the threaded fit of the nut left side and the nut right side and the external threads of the worm spindle. The transmission mechanism skillfully utilizes the pretightening force of the nut and the spring to realize the transmission of the worm mandrel and the worm in clearance fit, when the worm mechanism bears a larger load, the worm and the worm mandrel slip, can be automatically disconnected with the power mechanism, and can perform audible and visual alarm and cut off the power supply of the motor at the same time, thereby realizing overload protection.

Description

A worm gear transmission mechanism for a metering pump with bidirectional overload protection

Technical Field

The invention relates to a worm gear transmission mechanism of a metering pump with bidirectional overload protection.

Background Art

Worm gear mechanisms are often used to transmit motion and power between two staggered axes. They can achieve a large transmission ratio and are more compact than staggered helical gear mechanisms. This mechanism is currently widely used in the market.

The meshing tooth surfaces of the two wheels are in line contact, and its load-bearing capacity is much higher than that of the staggered axis helical gear mechanism. Worm transmission is equivalent to spiral transmission, which is a multi-tooth meshing transmission, so the transmission is smooth, the noise is very small, and it has self-locking properties. When the lead angle of the worm is less than the equivalent friction angle between the meshing gear teeth, the mechanism has self-locking properties and can achieve reverse self-locking, that is, only the worm can drive the worm wheel, but the worm wheel cannot drive the worm. For example, the self-locking worm mechanism used in lifting machinery can play a safety protection role in its reverse self-locking property. However, the transmission efficiency is low and the wear is serious. When the worm gear is meshing, the relative sliding speed between the meshing gear teeth is large, so the friction loss is large and the efficiency is low. On the other hand, the large relative sliding speed causes serious wear and heat generation on the tooth surface. In order to dissipate heat and reduce wear, more expensive materials with good friction reduction and wear resistance and good lubrication devices are often used, so the cost is high and the axial force of the worm is large. When the worm gear mechanism is subjected to a large load, the meshing gear teeth will be severely worn. If the worm gear mechanism is overloaded for a long time, it may cause damage to the device at the least, or even cause loss of life and property in serious cases. Therefore, the market is in urgent need of a low-cost worm gear transmission with two-way overload protection and alarm output.

Summary of the invention

In view of the problems existing in the prior art, the object of the present invention is to provide a technical solution for a worm gear transmission mechanism of a metering pump with bidirectional overload protection.

The worm gear transmission mechanism of a metering pump with bidirectional overload protection is characterized in that it includes a worm core shaft, a left bearing, a left nut, a left compression spring, a worm, a right compression spring, a right nut, a right bearing and a worm wheel. The worm core shaft passes through the left bearing, the left nut, the left compression spring, the worm, the right compression spring, the right nut and the right bearing in sequence. The left nut and the right nut are respectively threadedly matched with the external thread set on the worm core shaft. The left compression spring is set between the left nut and the worm, and the right compression spring is set between the worm and the right nut. The pre-tightening force of the left and right compression springs is connected to the worm core shaft through the left nut and the right nut. The external thread of the shaft is adjusted; the worm and the worm core shaft are matched with each other in clearance, and the worm can mesh with the external worm wheel; a conical groove is arranged on the worm, and the conical groove cooperates with the conical teeth arranged at the lower end of the rotating pointer, and the rotating pointer cooperates with the limit block through a pin key, and the rotating pointer can rotate freely around the pin key; a circular boss is arranged on the upper end of the rotating pointer, and the circular boss can be contacted and matched with the left and right travel switches arranged on both sides of the circular boss, and the rotational torque of the worm core shaft and the left and right springs can be changed by adjusting the relative distance between the left and right travel switches and the circular boss at the upper end of the rotating pointer.

The worm gear transmission mechanism of a metering pump with bidirectional overload protection is characterized in that stepped shafts are arranged at both ends of the worm core shaft, and the stepped shafts can limit the maximum tightening length of the left nut and the right nut and thus limit the maximum compression preload of the left compression spring and the right compression spring.

The worm gear transmission mechanism of a metering pump with bidirectional overload protection is characterized in that a left spring washer is arranged between the left compression spring and the left nut, and a right spring washer is arranged between the right compression spring and the right nut.

The worm gear transmission mechanism of a metering pump with bidirectional overload protection is characterized in that the left spring washer and the right spring washer are in the shape of circular ring columns, and the outer diameters of the left spring washer and the right spring washer are larger than the outer diameter of the compression spring.

The worm gear transmission mechanism of the metering pump with bidirectional overload protection is characterized in that the left end of the worm core shaft cooperates with the motor, and the motor transmits the electric power rotation torque to the worm core shaft.

The worm gear transmission mechanism of a metering pump with bidirectional overload protection is characterized in that the worm changes its rotation direction by changing the rotation direction of the motor.

The worm gear transmission mechanism of a metering pump with bidirectional overload protection is characterized in that the rotation directions of the left nut and the right nut are opposite, and the rotation directions of the left spring and the right spring are also opposite.

The transmission method of the worm gear transmission mechanism of a metering pump with bidirectional overload protection is characterized in that:

When the motor rotates clockwise, the motor rotational power is transmitted to the worm through the mechanism composed of the worm core shaft, the left nut, the left spring washer, the left compression spring, the right compression spring, the right spring washer and the right nut through the pre-tightening friction force of the left and right compression springs, and finally the power is transmitted to the worm wheel; when the rotational resistance of the worm wheel exceeds the pre-tightening friction force set by the worm and the left and right compression springs, since the left and right compression springs rotate in opposite directions, the left compression spring becomes longer and the right compression spring becomes shorter, the worm is moved to the right by a certain distance, the conical groove set in the worm contacts the conical teeth set at the lower end of the rotating pointer, the rotating pointer is rotated around the limit block as the center by a certain angle, the circular boss set at the upper end of the rotating pointer contacts the left travel switch, and at the same time, the pre-tightening friction force of the left and right compression springs is less than the torque required by the worm wheel, causing the worm and the worm core shaft to slip, and the left travel switch outputs a switching signal to the control system, which gives an audible and visual alarm and cuts off the power supply of the motor to achieve overload protection;

When the motor rotates counterclockwise, the motor's rotating power is transmitted to the worm through the mechanism composed of the worm core shaft, nut left, spring washer left, compression spring left, compression spring right, spring washer right and nut right, through the pre-tightening friction force of the compression spring left and compression spring right, and finally the power is transmitted to the worm wheel; when the rotation resistance of the worm wheel exceeds the pre-tightening friction force set between the worm and the compression spring left and compression spring right, due to the opposite rotation directions of the compression spring left and compression spring right, the compression spring left becomes shorter and the compression spring right becomes longer, moving the worm to the left by a certain distance, and the conical groove set in the worm contacts the conical tooth set at the lower end of the rotating pointer, rotating the rotating pointer around the limit block as the center by a certain angle, so that the circular boss set at the upper end of the rotating pointer contacts the right travel switch, and at the same time, the pre-tightening friction force of the compression spring left and compression spring right is less than the torque required by the worm wheel, causing the worm and the worm core shaft to slip, and the travel switch right outputs a switching signal to the control system, which gives an audible and visual alarm and cuts off the power supply of the motor to achieve overload protection.

The transmission mechanism of the present invention cleverly utilizes the pre-tightening force of the nut and the spring to realize the transmission between the worm core shaft and the worm with clearance fit. When the worm mechanism is subjected to a large load, the worm and the worm core shaft slip and can be automatically disconnected from the power mechanism, giving an audible and visual alarm while cutting off the power supply of the motor, thereby realizing overload protection.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic diagram of the structure of the present invention;

FIG2 is a schematic cross-sectional view of the present invention;

FIG3 is a schematic diagram of a worm gear transmission mechanism in a normal state;

FIG4 is a schematic diagram of the worm gear transmission mechanism when the motor rotates clockwise in an overload state;

FIG5 is a schematic diagram of the worm gear transmission mechanism when the motor rotates counterclockwise in an overload state;

In the figure: 1. worm shaft; 2. left bearing; 3. left nut; 4. left spring washer; 5. left compression spring; 6. worm; 7. left travel switch; 8. rotating pointer; 9. right travel switch; 10. right compression spring; 11. right spring washer; 12. right nut; 13. right bearing; 14. worm wheel.

DETAILED DESCRIPTION

The present invention will be further described below in conjunction with the accompanying drawings:

The worm gear transmission mechanism with bidirectional overload protection and alarm of the present invention can automatically disconnect from the power mechanism when the worm mechanism is subjected to a large load, and simultaneously output a signal to the control system to give an audible and visual alarm and cut off the power supply of the motor, thereby realizing overload protection.

A metering pump worm gear transmission mechanism with bidirectional overload protection comprises a worm core shaft 1, a left bearing 2, a left nut 3, a left compression spring 5, a worm 6, a right compression spring 10, a right nut 12, a right bearing 13 and a worm wheel 14. The worm core shaft passes through the left bearing, the left nut, the left compression spring, the worm, the right compression spring, the right nut and the right bearing in sequence. The left nut and the right nut are respectively screwed with the external thread arranged on the worm core shaft. The left compression spring is arranged between the left nut and the worm, and the right compression spring is arranged between the worm and the right nut. The preload force of the left compression spring and the right compression spring is transmitted through the left nut and the nut. The right external thread of the worm core shaft cooperates with the external thread of the worm core shaft to adjust the clearance between the worm and the worm core shaft, and the worm can mesh with the external worm wheel; a conical groove is arranged on the worm, and the conical groove cooperates with the conical teeth arranged at the lower end of the rotating pointer, and the rotating pointer cooperates with the limit block A through the pin key, and the rotating pointer can rotate freely around the pin key; a circular boss is arranged on the upper end of the rotating pointer, and the circular boss can be contacted and cooperated with the left and right travel switches arranged on both sides of the circular boss, and the rotational torque of the worm core shaft and the left and right springs can be changed by adjusting the relative distance between the left and right travel switches 7 and 9 and the circular boss at the upper end of the rotating pointer.

Stepped shafts are arranged at both ends of the worm shaft, and the stepped shafts can limit the maximum tightening length of the left nut and the right nut, thereby limiting the maximum compression preload of the left compression spring and the right compression spring.

In order to ensure reliability, the left spring washer 4 and the right spring washer 11 are in the shape of circular ring columns, and the outer diameters of the left spring washer and the right spring washer are greater than the outer diameter of the compression spring.

The left end of the worm shaft of the present invention cooperates with the motor, and the motor transmits the electric power rotation torque to the worm shaft, and the worm changes its rotation direction by changing the rotation direction of the motor.

The left and right rotation directions of the nut of the present invention are opposite, and the left and right rotation directions of the spring are also opposite.

When in use, the left and right bearings fix the worm on a box. When the motor rotates, it transmits power to the worm shaft. The worm shaft and the worm are clearance-fitted and have a smooth surface. They can rotate and move freely around the worm shaft, but cannot directly transmit power to the worm. The preload friction of the left and right compression springs is adjusted by the left and right nuts. The worm shaft is a stepped shaft, which limits the maximum tightening length of the left and right nuts, thereby limiting the maximum compression preload of the spring, preventing the preload force of the spring from being too large due to the self-spin of the left and right nuts during work, which makes the overload protection mechanism ineffective. Changing the preload friction of the left and right springs can also be changed by changing the thickness of the left and right spring washers.

When the motor rotates clockwise, the motor rotational power is transmitted to the worm through the mechanism composed of the worm core shaft, the left nut, the left spring washer, the left compression spring, the right compression spring, the right spring washer and the right nut through the pre-tightening friction force of the left compression spring and the right compression spring, and finally the power is transmitted to the worm wheel; when the rotational resistance of the worm wheel exceeds the pre-tightening friction force set by the worm and the left and right compression springs, since the left and right compression springs rotate in opposite directions, the left compression spring becomes longer and the right compression spring becomes shorter, the worm is moved to the right by a certain distance, the conical groove set in the worm contacts the conical teeth set at the lower end of the rotating pointer, the rotating pointer is rotated around the limit block A as the center by a certain angle, the circular boss set at the upper end of the rotating pointer contacts the left travel switch, and at the same time, the pre-tightening friction force of the left compression spring and the right compression spring is less than the torque required by the worm wheel, causing the worm and the worm core shaft to slip, and the left travel switch outputs a switching signal to the control system, which gives an audible and visual alarm and cuts off the power supply of the motor to achieve overload protection;

When the motor rotates counterclockwise, the motor's rotating power is transmitted to the worm through the mechanism composed of the worm core shaft, nut left, spring washer left, compression spring left, compression spring right, spring washer right and nut right through the pre-tightening friction force of the compression spring left and compression spring right, and finally the power is transmitted to the worm wheel; when the rotation resistance of the worm wheel exceeds the pre-tightening friction force set between the worm and the compression spring left and compression spring right, since the compression spring left and compression spring right rotate in opposite directions, the compression spring left becomes shorter and the compression spring right becomes longer, moving the worm to the left by a certain distance, and the conical groove set in the worm contacts the conical tooth set at the lower end of the rotating pointer, rotating the rotating pointer around the limit block A as the center by a certain angle, so that the circular boss set at the upper end of the rotating pointer contacts the right travel switch, and at the same time, the pre-tightening friction force of the compression spring left and compression spring right is less than the torque required by the worm wheel, causing the worm and the worm core shaft to slip, and the travel switch right outputs a switching signal to the control system, which gives an audible and visual alarm and cuts off the power supply of the motor to achieve overload protection.

Since the left and right nuts have opposite rotation directions when adjusting the preload of the compression spring, the left and right springs also have opposite rotation directions. As a result of this design, the nut will never loosen when the mechanism is running, thereby ensuring the set preload of the left and right springs of the mechanism.

The user can adjust the relative distance between the circular boss on the upper end of the rotating pointer and the left and right travel switches as needed, thereby changing the rotational torque of the worm shaft, the left spring and the right spring. The left and right travel switches can transmit switch signals to the control system via wire or wireless.

This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims (6)

1. A worm gear transmission mechanism for a metering pump with bidirectional overload protection, characterized in that it includes a worm core shaft, a left bearing, a left nut, a left compression spring, a worm, a right compression spring, a right nut, a right bearing and a worm wheel, the worm core shaft sequentially passes through the left bearing, the left nut, the left compression spring, the worm, the right compression spring, the right nut and the right bearing, the left nut and the right nut are respectively threadedly engaged with the external thread set on the worm core shaft, the left compression spring is set between the left nut and the worm, the right compression spring is set between the worm and the right nut, and the preload force of the left compression spring and the right compression spring is connected to the worm core shaft through the left nut and the right nut The external thread of the shaft is adjusted; the worm and the worm core shaft are matched with each other in clearance, and the worm can mesh with the external worm wheel; a conical groove is arranged on the worm, and the conical groove cooperates with the conical teeth arranged at the lower end of the rotating pointer, and the rotating pointer cooperates with the limit block through a pin key, and the rotating pointer can rotate freely around the pin key; a circular boss is arranged on the upper end of the rotating pointer, and the circular boss can be contacted and matched with the left and right travel switches arranged on both sides of the circular boss, and the rotation torque of the worm core shaft and the left and right springs can be changed by adjusting the relative distance between the left and right travel switches and the circular boss at the upper end of the rotating pointer; Both ends of the worm shaft are provided with stepped shafts, which can limit the maximum tightening length of the left nut and the right nut and thus limit the maximum compression preload of the left compression spring and the right compression spring; A left spring washer is arranged between the left compression spring and the left nut, and a right spring washer is arranged between the right compression spring and the right nut. 2. A metering pump worm gear transmission mechanism with bidirectional overload protection according to claim 1, characterized in that the left spring washer and the right spring washer are annular and cylindrical, and the outer diameters of the left spring washer and the spring washer are larger than the outer diameter of the compression spring. 3. A metering pump worm gear transmission mechanism with bidirectional overload protection according to claim 1, characterized in that the left end of the worm core shaft cooperates with the motor, and the motor transmits the electric power rotation torque to the worm core shaft. 4. A metering pump worm gear transmission mechanism with bidirectional overload protection according to claim 3, characterized in that the worm changes its rotation direction by changing the rotation direction of the motor. 5. A metering pump worm gear transmission mechanism with bidirectional overload protection according to claim 1, characterized in that the rotation directions of the left nut and the right nut are opposite, and the rotation directions of the left spring and the right spring are also opposite. 6. A transmission method of a worm gear transmission mechanism of a metering pump with bidirectional overload protection as claimed in claim 1, characterized in that: When the motor rotates clockwise, the motor rotational power is transmitted to the worm through the mechanism composed of the worm core shaft, the left nut, the left spring washer, the left compression spring, the right compression spring, the right spring washer and the right nut through the pre-tightening friction force of the left and right compression springs, and finally the power is transmitted to the worm wheel; when the rotational resistance of the worm wheel exceeds the pre-tightening friction force set by the worm and the left and right compression springs, since the left and right compression springs rotate in opposite directions, the left compression spring becomes longer and the right compression spring becomes shorter, the worm is moved to the right by a certain distance, the conical groove set in the worm contacts the conical teeth set at the lower end of the rotating pointer, the rotating pointer is rotated around the limit block as the center by a certain angle, the circular boss set at the upper end of the rotating pointer contacts the left travel switch, and at the same time, the pre-tightening friction force of the left and right compression springs is less than the torque required by the worm wheel, causing the worm and the worm core shaft to slip, and the left travel switch outputs a switching signal to the control system, which gives an audible and visual alarm and cuts off the power supply of the motor to achieve overload protection; When the motor rotates counterclockwise, the motor's rotating power is transmitted to the worm through the mechanism composed of the worm core shaft, nut left, spring washer left, compression spring left, compression spring right, spring washer right and nut right, through the pre-tightening friction force of the compression spring left and compression spring right, and finally the power is transmitted to the worm wheel; when the rotation resistance of the worm wheel exceeds the pre-tightening friction force set between the worm and the compression spring left and compression spring right, due to the opposite rotation directions of the compression spring left and compression spring right, the compression spring left becomes shorter and the compression spring right becomes longer, moving the worm to the left by a certain distance, and the conical groove set in the worm contacts the conical tooth set at the lower end of the rotating pointer, rotating the rotating pointer around the limit block as the center by a certain angle, so that the circular boss set at the upper end of the rotating pointer contacts the right travel switch, and at the same time, the pre-tightening friction force of the compression spring left and compression spring right is less than the torque required by the worm wheel, causing the worm and the worm core shaft to slip, and the travel switch right outputs a switching signal to the control system, which gives an audible and visual alarm and cuts off the power supply of the motor to achieve overload protection.