1. Characteristics and applications of diamond rollers

Diamond roller is a newly developed dressing tool. Compared with single particle diamond pen dressing grinding wheels, it has a much shorter dressing time for non linear dressing and is easy to shape various complex surfaces. The methods for dressing grinding wheels with diamond rollers can be divided into two types: cutting wheel dressing and swinging wheel dressing. Due to the simpler structure of the cutting wheel dressing device compared to the swinging wheel dressing device, it is more commonly used in practical production. In the cutting in roller dressing, similar to the outer circle cutting in grinding workpiece, the roller is driven by an electric motor to rotate and perform cutting motion relative to the grinding wheel, thereby performing grinding wheel dressing. The main parameters that characterize roller cutting in type trimming include: trimming speed ratio qd, trimming feed rate, and number of light trimming revolutions. The following is an introduction to the application of the cut in diamond ferry trimmer in HSQB885.4 channel grinding.

HSQB885.4 is a large four point contact ball bearing with peach shaped grooves. The existing TM1500 floor grinder is used to replace the vertical grinder in grinding its grooves, and a TM1500 diamond roller trimmer is designed.

The bracket is fixed at the front of the machine tool bed, and the base is installed on the bracket and can be adjusted in both longitudinal and transverse directions. The ferry shaft is a sleeve type main shaft, which adopts a two support shaft system structure composed of two sets of angular contact ball bearings. The main shaft is driven by a multi wedge belt, which is stable and reliable. The driving motor is a lightweight aluminum shell wireless speed control motor, and a stepless speed control motor is used to ensure that the ratio qd of the linear speed between the roller and the grinding wheel is kept within a certain range. Because as the grinding wheel consumes, its linear speed decreases, it is necessary to adjust the speed of the roller appropriately to achieve the best dressing effect. Change the cutting feed for trimming to grinding wheel feed. During trimming, the grinding wheel does not move. Use the original hand crank mechanism for grinding wheel feed to manually feed to achieve the cutting motion for trimming.

It is also possible to use the method of grinding wheel not moving and ferry feeding for dressing. At this time, the structure of the dressing device is more complex, such as using linear guide rails, ball screws, stepper motors, etc. The roller dressing action can be designed as a simple CNC system, with the action program designed as: fast forward (cannot touch the grinding wheel) - slow forward (feed according to the required cutting speed) ->optical dressing ->exit.

2. Precautions

Due to the characteristics of short repair time, the ability to repair various complex surfaces, good surface accuracy, and convenient repair operations, the diamond roller forming and repair method has gradually been recognized and widely used in production. However, in the design, manufacturing, and use of rollers, the following points should be noted:

The particle size of diamond should be one size coarser than that of the repaired grinding wheel, and diamond particles with similar sizes and spherical shapes should be selected. The commonly used particle sizes are 36 # -100 #. Usually, the linear velocity direction at the contact point between the roller and the grinding wheel is in the same direction, and the ratio of the linear velocity of the roller to the linear velocity of the grinding wheel (qd value) should be taken as+0.3-+0.7, which should not exceed+1; The appropriate amount of roller cutting during dressing is 0.5-1um per revolution of the grinding wheel, and the total amount of each dressing of the grinding wheel should be 0.02-0.04mm; Try to compress the light repair time as much as possible.

The manufacturing error of diamond rollers should be less than about 1/2 of the workpiece tolerance, and the clearance between the roller hole and the installation fit should be 2-4um. Natural or artificial diamonds can be used, and artificial diamonds must use high-strength grade diamonds, such as steel grinding specific diamond SCD or high-strength diamond SMD.

When manufacturing rollers, general precision rollers can be manufactured using external plating and sintering methods, while high-precision and complex surface rollers can be manufactured using internal plating methods while undergoing grinding and trimming. When repairing the grinding wheel with a diamond roller, it is necessary to follow the action program of fast forward (not touching the grinding wheel) → slow forward (feeding at the required cutting speed) → light repair → exit, and do not make mistakes, otherwise the service life of the roller will be difficult to guarantee.

2024 July 2nd Week JFZ Product Recommendation:

Tapered Roller Bearing:

The inner and outer ring raceways are segments of cones and the rollers are tapered so that the conical surfaces of the raceways, and the roller axes, if projected, would all meet at a common point on the main axis of the bearing. This geometry makes the motion of the cones remain coaxial, with no sliding motion between the raceways and the outside diameter of the rollers.

This conical geometry creates a linear contact patch which permits greater loads to be carried than with spherical (ball) bearings, which have point contact. The geometry means that the tangential speeds of the surfaces of each of the rollers are the same as their raceways along the whole length of the contact patch and no differential scrubbing occurs.

The rollers are stabilized and restrained by a flange on the inner ring, against which their large end slides, which stops the rollers from popping out due to the "pumpkin seed effect" of their conical shape.

The larger the half angles of these cones the larger the axial force that the bearing can sustain.

Tapered roller bearings are separable into a cone assembly and a cup. The non-separable cone assembly consists of the inner ring, the rollers, and a cage that retains and evenly spaces the rollers. The cup is simply the outer ring. Internal clearance is established during mounting by the axial position of the cone relative to the cup, although preloaded installations without clearance are common.

https://www.jfz-bearing.com/products/Tapered-Roller-Bearing/155.html