OBRABOTKAMETALLOV MATERIAL SCIENCE Том 23 № 3 2021 EQUIPMEN . INSTRUM TS Vol. 6 No. 1 2024 Introduction Gear honing is an operation of fi nal processing of tooth profi les of heat-treated cylindrical wheels made of alloyed structural steels with hardness of HRC 50–68 [1, 2, 3]. Gear hone (abrasive shaver) is a gear wheel, the functional rim of which is made of a composite material based on a bond and abrasive materials. The hone hub is usually made of steel or aluminum alloy. The material of the gear hone rim consists of bonding and cutting elements, i.e. abrasive powders of a certain grain size made of various abrasive materials. The use of hones helps to increase the wheel load capacity by 15–20 %, and durability by 1.5– 2.5 times. The most widespread gear hones were obtained when processing hardened gear wheels of 7–9 accuracy degrees. The structural and mechanical characteristics of the composite material of gear hones largely determine its performance [4, 5, 6]. The values of these indicators (tensile and bending strength, toughness, elastic modulus, hardness) depend on the bond material, process methods of hone manufacturing, material and granularity of grinding powders. Abrasive gear hones are made by free casting or injection molding. Epoxy resins and acrylic plastics with various plasticizers and modifi ers are used as binders of abrasive polymer compositions. In addition to hones on rigid bonds with elastic modulus of 3,000–6,000 MPa, elastic hones on polyurethane, acrylicpolyurethane and hydroxyurethane bonds are used, the elastic modulus of which is 1,100–1,200 MPa. Polyurethane SKU-PFL and other urethane-based copolymers give increased elasticity to the hone material [7, 8]. Based on the requirements for processing gears of 7–9 accuracy degrees, the hones are made of various abrasive materials, for example, white electrocorundum with a grain size of F 60–F 90. To ensure the necessary density and strength of the hone material, up to 20 % of grinding powders with a grain size of F 150–F 180 are additionally introduced. Such a tool reduces gear errors, primarily by redistributing its values, for example, fl uctuations in the measuring center-to-center distance, profi le errors, improving the quality of the side surfaces of the teeth, reducing noise in the engagement of machined wheels [3, 9]. In addition to gear hones, which have grinding powders made of classical abrasive materials as cutting elements, diamond gear hones are used for tooth honing. The diamond-bearing layer is made on metal and polymer rubber bonds [4, 10]. The diamond-free base of the hones may be metallic (based on non-ferrous alloys) and rubber (elastic hones). Diamond powders with a main-fraction grain size of 28–20 μm are used for polishing gears of 5–6 accuracy degrees [11, 12]. Diamond tools are widely used in metalworking in roughing [12], fi nishing and precision grinding [13–15]. Certain types of diamond tools provide roughness at the level of polishing operations [16–19]. In the manufacture of automobiles, machine tools, aviation and space engineering, special diamond and abrasive tools have become widely used in the fi nishing operations of high-precision gear wheels [20–22]. For example, imported elastic hones are used to polish tooth surfaces after grinding [8]. The sanctions policy of the Western countries has signifi cantly limited the access of Russian manufacturers to imported tools, and it is impossible to obtain individual items of such tools. These tools include diamond hones for polishing special-purpose gear wheels. The purpose of work is to develop a formulation, technological equipment and technology of manufacturing of elastic diamond gear hones instead of imported ones for teeth honing of gear wheels of special purpose. To achieve this goal, it is necessary to address the following objectives. 1. To determine the intended materials of the abrasive layer and the geared rim based on the results of the literature review, studies of the mechanical properties, morphology and chemical composition of the analyzed hone. 2. To develop and manufacture tooling for molding laboratory specimens of the gear hone. 3. To develop a formulation and manufacturing technology for elastic gear hones for honing the teeth of special-purpose gears based on the results of laboratory studies.
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