System for predicting auger failure in a tire injection filling mixing machine

Abstract

A method of performing preventative maintenance on an auger in a tire filling mixing machine, by: (a) mixing a polyurethane isocyanate and a catalyst in a first mixer to form a virgin polyurethane; (b) grinding polyurethane core bits in a grinder, the grinder having an auger and a motor; (c) mixing the virgin polyurethane and the ground core bits in a second mixer thereby forming a mixed flatproofing material; (d) injecting the mixed flatproofing material into a tire; (e) measuring vibration of the auger; and (f) comparing the measured vibration of the auger to a predefined maximum vibration; and (g) removing the auger from the grinder if the measured vibration exceeds the pre-defined maximum vibration for a predefined period of time, or removing the auger from the grinder if the measured temperature of the auger exceeds the pre-defined maximum temperature for a predefined period of time.

Claims

1. A tire filling mixing machine, comprising: a first mixer for mixing a polyurethane isocyanate and a catalyst to form a virgin polyurethane; a grinder comprising an auger and a motor for grinding core bits; a second mixer for mixing the virgin polyurethane and the ground core bits to form a mixed flatproofing material; a sensor that measures vibration of the auger; a vibration measuring system configured to compare measured vibration of the auger to a predefined maximum vibration; and a warning system to alert an operator to remove the auger from the grinder if the measured vibration exceeds the pre-defined maximum vibration for a predefined period of time.

2. The tire filling mixing machine of claim 1, further comprising: a temperature measuring system for measuring the temperature of the auger and comparing the measured temperature of the auger to a pre-defined maximum temperature; and a warning system to alert an operator to remove the auger from the grinder if the measured temperature of the auger exceeds the pre-defined maximum temperature for a predefined period of time.

3. The tire filling mixing machine of claim 1, wherein the vibration and temperature of the auger are measured with sensors positioned on auger bearings and on the grinder motor.

4. The tire filling mixing machine of claim 1, further comprising: a measuring system for measuring performance of the motor in the grinder, wherein measuring the performance of the motor comprises measuring at least one of: amperage of the motor, speed of the motor, vibration of the motor, temperature of the motor, a magnetic field of the motor, and sounds emanating from the motor; and a warning system for alerting an operator to stop the motor if the measured performance of the motor remains outside a pre-defined performance range for a pre-defined period of time.

5. The tire filling mixing machine of claim 1, further comprising: a measuring system for measuring the level of core bits in the grinder; and a control system for automatically shutting down the grinder and the first and second mixers if the detected level of core bits in the grinder falls below a pre-determined minimum level.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 is a flow schematic of the present system, explaining its operation.

(2) FIG. 2A is a perspective view of the present system.

(3) FIG. 2B is a side elevation view of the present system.

(4) FIG. 2C is a top plan view of the present system.

(5) FIG. 2D is a front elevation view of the present system.

(6) FIG. 3A is an illustration of an exemplary auger for use with the present system.

(7) FIG. 3B is a close-up illustration of the exemplary auger of FIG. 3A (showing further details of the auger).

DETAILED DESCRIPTION OF THE FIGURES

(8) FIG. 1 is a flow schematic of the present system, explaining its operation, as follows. Tire filling system 10 comprises a first mixer 20 which receives an isocyanate into an inlet 22 and a catalyst into inlet 24. First mixer 20 mixes the isocyanate and catalyst to form a virgin polyurethane.

(9) A grinder 30 grinds rubber core bits therein. These rubber core bits preferably come from pre-used tires. An exemplary auger 32 (FIGS. 3A and 3B) is disposed within grinder 30 for grinding the core bits down to a preferred small size. In preferred aspects, the ground core bits may have a diameter of inch or less. This small dimension can be achieved by passing the ground rubber bits through the auger 32 and then passing through a screen having inch holes. In preferred aspects, grinder 30 has an upper hopper 31 into which large pieces of rubber are inserted.

(10) The ground polyurethane core bits from grinder 30 and the virgin material from first mixer 20 are than mixed together in second mixer 40 to form a tire flatproofing material that is then passed through an injector 50 into a tire 60. Tire 60 may be either a tubed or tubeless tire. Injector 50 may be a screw-type injector. A pump will also accompany injector 50.

(11) FIGS. 2A to 2D illustrate further views of the present system 10 in which a control system and method of controlling operation of tire filling mixing machine 10 is provided. This method first comprises: (a) mixing a polyurethane isocyanate and catalyst in first mixer 20 to form a virgin polyurethane; (b) grinding polyurethane core bits in grinder 20; (c) mixing the virgin polyurethane and the ground core bits in second mixer 40 thereby forming a mixed flatproofing material; (d) injecting the mixed flatproofing material into tire 60.

(12) It is to be understood that a cured polyurethane core bit as used herein is understood to refer to herein any of a cured virgin polyurethane, a cured virgin polyurethane and a used polyurethane either in chunks or in granules, a cured virgin polyurethane blended with crumb rubber particles, or a blend of any of these.

(13) FIGS. 3A and 3B are illustrations of an exemplary auger for use with the present system. Preferably, such measurements are taken at the opposite ends of the auger; however, additional sensor locations at the auger motor and/or gearbox are also contemplated within the scope of the present system.

(14) In preferred aspects, the present system operates by performing preventative maintenance on an auger in a tire filling mixing machine, by:

(15) (a) mixing a polyurethane isocyanate and a catalyst in a first mixer 20 to form a virgin polyurethane;

(16) (b) grinding polyurethane core bits in a grinder 30, grinder 30 having an auger 32 and a motor;

(17) (c) mixing the virgin polyurethane and the ground polyurethane core bits in a second mixer 40 thereby forming a mixed flatproofing material;

(18) (d) injecting the mixed flatproofing material into a tire 60; and

(19) (e) measuring at least one of vibration or temperature of the auger; and then performing one or both of: (i) comparing the measured vibration of the auger to a pre-defined maximum vibration and removing the auger from the grinder if the measured vibration exceeds the pre-defined maximum vibration range for a predefined period of time; or (ii) comparing the measured temperature of the auger to a pre-defined temperature range and removing the auger from the grinder if the measured temperature remains outside the pre-defined vibration range for a predefined period of time.

(20) As such, the vibration is measured by an accelerometer and the temperature by a thermocouple. The accelerometer and thermocouple may optionally be housed together in a single sensor body.

(21) Should an excessive level of vibration continue for a predefined period of time, then the present system will automatically shut down grinder 30, stopping the movement of auger 32. Similarly, should the temperature of the auger exceed its preferred maximum temperature for a predefined period of time, then the present system will automatically shut down grinder 30, stopping the movement of auger 32. The present inventors have experimentally determined that if the auger bearing vibration exceeds 0.14 gRMS and a 160 degree Fahrenheit temperature or the discharge bearing exceeds 0.14 gRMS and a temperature greater than 200 degrees Fahrenheit, or the gearbox exceeds 0.10 gRMS and a 150 degree Fahrenheit temperature, a warning should be sent. Accordingly, should these conditions develop, the present system then automatically notifies technical support staff regarding the current condition.

(22) In other preferred aspects, the present system also performs preventative maintenance on the auger by:

(23) (i) measuring performance of the motor in the grinder, wherein measuring the performance of the motor comprises measuring at least one of: amperage of the motor, speed of the motor, vibration of the motor, temperature of the motor, a magnetic field of the motor, and sounds emanating from the motor; and

(24) (ii) stopping the motor if the measured performance of the motor remains outside a pre-defined performance range for a pre-defined period of time.

(25) In preferred aspects, the present system independently monitors the overall grinder performance based on speed, torque, and calculated temperature. As such, the present control system can automatically stop the motor prior to a damaging conditions. This independent system compliments the trending and preventative maintenance system.

(26) Optionally as well, the present system may also (a) measure the level of rubber core bits in the grinder, and (b) automatically shut down the grinder and the first and second mixers if the detected level of core bits in the grinder falls below a pre-determined minimum level. In addition to simply using a minimum level, the present system can use a combination of current ratio, weight, crumb level, and speed when determining whether to shut down the grinder.

(27) In addition, sensors (such as an ultrasound sensor) can be added to the hopper 31 to detect the level of rubber crumb in the hopper. Should the level drop too far, the sensor(s) can be used to automatically shut down the system operation. This has the beneficial effect of preventing virgin material from being wasted when the recycled rubber crumb supply drops in the machine. Since rubber crumb is loaded into hopper 31 in bulk lots, this also ensures that the ratio of ground rubber crumb to virgin rubber material remains consistent.