A self-protecting coupling for a turbo-powder feeder

Abstract

The utility model discloses a kind of self-protection couplings of impeller powder feeder, it is related to the field of coupling, including worm side half coupling and motor side half coupling, the adjacent surface of worm side half coupling and motor side half coupling is plane, the outer circle of worm side half coupling and motor side half coupling is processed with four pin holes, coupling driving pin is inserted in pin hole, coupling driving pin is stepped, the diameter of coupling driving pin near worm side half coupling one end is less than the diameter of coupling driving pin near motor side half coupling one end, coupling driving pin near worm side half coupling one end is connected with nut. Advantageous effect lies in: when powder feeder appears overload, coupling driving pin will break from step position, play the role of mechanical protection, ensure that motor and transmission mechanism do not damage. Coupling driving pin used simultaneously can reduce wear and tear between coupling, so as to ensure that equipment long-period operation.

Description

Technical Field

[0001] This utility model relates to the field of couplings, and in particular to a self-protecting coupling for an impeller powder feeder. Background Technology

[0002] The impeller feeder is the main pulverized coal feeding equipment in the boiler pulverized coal feeding system of a thermal power plant. Pulverized coal from the coal bunker falls under gravity into the toothed grooves of the rotating feed impeller, rotating 180° with it before falling into the next stage measuring impeller. The pulverized coal continues its 180° circular motion with the measuring impeller until it reaches the outlet. At this point, it falls under gravity into the outlet and enters the pulverized coal conveying pipeline. Because the impeller toothed grooves are evenly distributed around the circumference, the feeding motion is continuous and the feed rate is uniform, preventing pulverized coal from flowing back into the coal bunker during shutdown and preventing primary air from returning to the pulverized coal bunker. The feed rate is adjusted by regulating the impeller speed, thereby controlling boiler temperature and pressure and ensuring boiler production capacity.

[0003] However, in actual use, the failure frequency of the coupling is relatively high. Currently, domestic couplings typically use pin couplings. Since the impeller feeder adjusts the feed rate by adjusting the impeller speed, wear on the pins and coupling is unavoidable. After long-term operation, the pin holes of the coupling exhibit different wear patterns, and the frequency of pin replacement gradually increases.

[0004] In addition, foreign objects often appear inside the pulverized coal, causing overload during equipment operation. Although motor overload protection can protect the equipment in time, frequent shutdowns can still damage the motor. Utility Model Content

[0005] The purpose of this invention is to provide a self-protecting coupling for an impeller feeder in order to solve the above-mentioned problems.

[0006] This utility model achieves the above objectives through the following technical solutions: A self-protecting coupling for an impeller powder feeder includes a worm gear side half coupling and a motor side half coupling. The adjacent surfaces of the worm gear side half coupling and the motor side half coupling are both planes. The outer circumference of both the worm gear side half coupling and the motor side half coupling is machined with four pin holes. A coupling drive pin is inserted into the pin holes. The coupling drive pin is stepped. The diameter of the end of the coupling drive pin near the worm gear side half coupling is smaller than the diameter of the end near the motor side half coupling. A nut is connected to the end of the coupling drive pin near the worm gear side half coupling.

[0007] Preferably, a bushing is fitted into the pin hole of the motor-side half coupling, and the bushing wraps around the coupling drive pin.

[0008] Preferably, the coupling drive pin is transitionally fitted with the pin hole and bushing of the worm gear side half coupling, and a cotter pin hole is opened at one end of the coupling drive pin near the worm gear side half coupling, and a cotter pin is installed in the cotter pin hole.

[0009] Preferably, there is a gap between the nut on the coupling drive pin and the end face of the worm gear side half coupling.

[0010] The beneficial effects are as follows: when the powder feeder is overloaded, the coupling drive pin will break off at the stepped position, providing mechanical protection and ensuring that the motor and transmission mechanism are not damaged. At the same time, the use of a coupling drive pin reduces wear between the drive pin and the coupling, thus ensuring long-term operation of the equipment.

[0011] The additional technical features and advantages of this utility model will become more apparent from the following description, or may be learned through specific practice of this utility model. Attached Figure Description

[0012] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the following detailed description to explain the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of a self-protecting coupling for an impeller feeder according to the present invention; Figure 2 This is a schematic diagram of the worm gear side half coupling of a self-protecting coupling for an impeller powder feeder according to the present invention; Figure 3 This is a schematic diagram of the motor side half coupling of the self-protecting coupling of the impeller powder feeder described in this utility model.

[0013] The reference numerals in the attached diagram are explained as follows: 1. Worm side half coupling; 2. Worm side locking screw; 3. Nut; 4. Cotter pin; 5. Bushing; 6. Coupling drive pin; 7. Motor side locking screw; 8. Motor side half coupling. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0015] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0016] The present invention will be further described below with reference to the accompanying drawings: like Figures 1-3 As shown, a self-protecting coupling for an impeller feeder includes a worm-side half coupling 1 and a motor-side half coupling 8. The adjacent surfaces of the worm-side half coupling 1 and the motor-side half coupling 8 are both planes. The outer circumference of both the worm-side half coupling 1 and the motor-side half coupling 8 is machined with four pin holes, and a coupling drive pin 6 is inserted into the pin holes. Screw holes are machined at corresponding positions of the keyways of the worm-side half coupling 1 and the motor-side half coupling 8 for installing worm-side locking screws 2 and motor-side locking screws 7.

[0017] A nut 3 is connected to one end of the coupling drive pin 6 near the worm gear side half coupling 1. A cotter pin hole is opened at the end of the coupling drive pin 6 near the worm gear side half coupling 1, and a cotter pin 4 is installed in the cotter pin hole. The cotter pin 4 is used to position the nut 3.

[0018] There is a gap between the nut 3 on the coupling drive pin 6 and the end face of the worm-side half coupling 1. This gap prevents the coupling drive pin 6 from moving axially towards the motor side when it wears out during long-term operation. It also facilitates the removal of the coupling drive pin 6 on the worm side if it breaks, saving replacement time. A bushing 5 is fitted inside the pin hole of the motor-side half coupling 8. The bushing 5 wraps around the coupling drive pin 6. The bushing 5 mainly serves to reduce vibration and buffer, and at the same time avoids misalignment caused by factors such as slight changes in the position of the motor, which could lead to a rigid connection and increase the risk of shaft breakage.

[0019] The coupling drive pin 6 is fitted with the pin hole and bushing 5 of the worm gear side half coupling 1 to ensure that the coupling drive pin 6 does not rotate relative to the worm gear side half coupling 1 and bushing 5, thus avoiding wear.

[0020] The coupling drive pin 6 is stepped. The diameter of the end of the coupling drive pin 6 near the worm gear side half 1 is smaller than the diameter of the end near the motor side half 8. Under overload, the drive pin 6 will break at the stepped position, providing mechanical protection. The diameter of the end of the coupling drive pin 6 near the worm gear side half 1 can be calculated using a formula, as follows: (1) Calculate the torque T transmitted by the coupling: In the formula: P represents the power of the motor, measured in kW. n represents the motor's rotational speed, measured in rpm.

[0021] (2) Calculate the shear force on the pin: Therefore In the formula: T represents the torque transmitted by the coupling, expressed in N·mm. F is the total shear force on the pin, in N; R is the lever arm of the shear force, r = D / 2; D is the pitch circle diameter of the pin hole, in mm.

[0022] (3) Calculate the pin diameter: Formula for calculating bending normal stress: In the formula: σ—bending normal stress, in MPa; M is the bending moment experienced by the cantilever beam, in N·mm; In the formula: G represents the distance the force acts on the cantilever beam, measured in mm. W represents the section modulus of bending, in mm. 3 ; In the formula: d is the diameter of the transmission pin (worm side), in mm; but: Based on the above formula, the diameter d of the coupling drive pin (worm side) should be: In the formula: This represents the allowable stress corresponding to the pin material, expressed in MPa.

[0023] Working principle: Install the worm-side half coupling 1 onto the worm and install the worm-side locking screw 2. Install the motor-side half coupling 8 onto the motor shaft and install the motor-side locking screw 7. Install the bushing 5 into the coupling hole of the motor-side half coupling 8, and then install the entire motor onto the frame. Insert the coupling drive pin 6 through the pin hole on the motor-side half coupling 8, and adjust the alignment value according to the requirements until it meets the standard. Tighten the nut 3 to the installation position and insert the cotter pin 4 for fixation. When overloaded, the coupling drive pin 6 will break at the stepped position, providing mechanical protection.

[0024] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. A self-protecting coupling for an impeller feeder, characterized in that: The coupling includes a worm gear side half coupling (1) and a motor side half coupling (8). The adjacent surfaces of the worm gear side half coupling (1) and the motor side half coupling (8) are both planes. The outer circles of the worm gear side half coupling (1) and the motor side half coupling (8) are all machined with four pin holes. A coupling drive pin (6) is inserted into the pin hole. The coupling drive pin (6) is stepped. The diameter of the coupling drive pin (6) near the end of the worm gear side half coupling (1) is smaller than the diameter of the end near the end of the motor side half coupling (8). A nut (3) is connected to the end of the coupling drive pin (6) near the worm gear side half coupling (1).

2. The self-protecting coupling for an impeller feeder according to claim 1, characterized in that: The motor-side half coupling (8) has a bushing (5) fitted into the pin hole, and the bushing (5) wraps around the coupling drive pin (6).

3. The self-protecting coupling for an impeller feeder according to claim 2, characterized in that: The coupling drive pin (6) is transitionally fitted with the pin hole of the worm gear side half coupling (1) and the bushing (5). The end of the coupling drive pin (6) near the worm gear side half coupling (1) is provided with a cotter pin hole, and a cotter pin (4) is installed in the cotter pin hole.

4. The self-protecting coupling for an impeller feeder according to claim 1, characterized in that: There is a gap between the nut (3) on the drive pin (6) of the coupling and the end face of the worm gear side half coupling (1).

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