Grinding wheel, in particular for machining teeth preferably for the production of a gear

Abstract

The invention relates to a grinding wheel, in particular for machining teeth preferably for the production of a gear, said grinding wheel comprising a clamping unit (1, 21) and at least two partial grinding wheels (2, 3, 22, 23) which can be fastened next to one another on said clamping unit and extend coaxially to one another. The first partial grinding wheel (2, 22) is used preferably for quickly grinding a predefined profile of gear teeth to be machined, and the second partial grinding wheel (3, 23) is used for subsequently polishing the profile. Said first partial grinding wheel (2, 22) can be fastened independently of the second partial grinding wheel (3, 23) on the clamping unit (1, 21) between two stop surfaces (6, 10, 26, 30) of the clamping unit. Advantageously, the second partial grinding wheel (3, 23) has a larger inner diameter (D3) than that of the first partial grinding wheel (2, 23). This design results in a very solid hold of the grinding wheel in the machine tool.

Description

[0001]

[0002] Grinding wheel, especially for machining gears, preferably for the production of a gear

[0003] The invention relates to a grinding wheel, in particular for machining gear teeth, preferably for producing a gear, comprising a clamping unit, at least two partial grinding wheels arranged next to one another on the latter, which run coaxially to one another, of which the first partial grinding wheel preferably serves for quickly grinding a predetermined profile of a toothing of a gear or the like to be machined and the second partial grinding wheel preferably serves for subsequently polishing the same.

[0004] An abrasive body of this type is disclosed in US 2021 / 0299818 A1, in which abrasive round bodies of an abrasive product are assembled with a sleeve body and at least one inner sleeve part, which inner sleeve part can also be made of an abrasive material. The sleeve bodies, for example, have the same inner diameter and are firmly bonded to the inner part or are otherwise integrated into it. These sleeve bodies can be made of different abrasive materials.

[0005] The invention is based on the object of creating a grinding wheel of the type mentioned at the outset which enables rapid grinding as roughing and subsequent polishing of a given profile of a gear with high efficiency and precision and which is relatively easy to manufacture despite the use of at least two partial grinding wheels.

[0006] This object is achieved according to the invention by the features of claim 1.

[0007] When using two partial grinding wheels on the clamping unit, according to the invention the first partial grinding wheel can be clamped on both sides between two stop surfaces of the clamping unit independently of the second partial grinding wheel.

[0008] This design provides the significant advantage of ensuring that the first partial grinding wheel is firmly clamped in the machine tool for the solid mounting of the grinding wheel. This partial grinding wheel is made of a harder material than the second partial grinding wheel for higher grinding performance, thus ensuring a permanently rigid fixation of the grinding wheel in the tool holder of the gear cutting machine.

[0009] The grinding wheel is therefore mounted by clamping the first partial grinding wheel between stop surfaces of the clamping unit and positioning the second partial grinding wheel on the clamping unit, which can preferably be connected to the first partial grinding wheel adjacent to it.

[0010] This ensures optimal clamping of the partial grinding wheels, taking into account their grinding performance, and also enables easy handling when assembling and disassembling the grinding wheel with these partial grinding wheels, where the clamping unit can be reused when the partial grinding wheels are worn out and need to be replaced with new ones.

[0011] It is very advantageous to dimension the second partial grinding wheel with a larger inner diameter than that of the first partial grinding wheel, creating a shoulder within the second partial grinding wheel, within which the clamping unit extends, and one lateral stop surface for the first partial grinding wheel is preferably aligned flush with the lateral contact surfaces of the partial grinding wheels. This enables a relatively simple design of the clamping unit and, at the same time, the stable attachment of the first partial grinding wheel.

[0012] The invention provides that the clamping unit has a metallic support sleeve, the outer shell of which is provided with a shoulder forming a stop surface for holding the second partial grinding wheel.

[0013] To clamp or position the partial grinding wheels, the clamping unit is equipped with an annular clamping element on the front side. This element can be adjusted in the direction of the grinding wheel's rotational axis, preferably by means of clamping screws screwed into the clamping unit. It is advantageous if the annular clamping element is guided coaxially to the rotational axis with a protruding flange on the support sleeve. Despite this simple design of the clamping unit, the partial grinding wheels can be clamped quickly and with extreme precision.

[0014] The invention also provides that the annular clamping element accommodates the second partial grinding wheel entirely or partially the first partial grinding wheel. This allows the overall length of the grinding wheel or the clamping unit to be kept short.

[0015] In order to clamp the grinding wheel in the tool holder of the gear cutting machine, the invention provides that the support sleeve is provided on the inside with fastening and / or centering holes.

[0016] In order to enable precise assembly of the partial grinding wheels, the invention provides that the inner diameters of the partial grinding wheels and the outer diameters of the outer casing of the support sleeve or the clamping element are manufactured with high precision at least in the hundredths of a millimeter range, and that they can be slipped onto one another with almost no play without any aids.

[0017] With regard to the composition of the partial grinding wheels, it is particularly advantageous if they are made of different materials due to their working functions.

[0018] The first part of the grinding wheel is advantageously manufactured as a vitrified bonded grinding wheel with abrasive grains of 25-70 vol%, a glass or ceramic bond of 5-40 vol% and pores of 10-80 vol% with an E-modulus range of 5-50 GPa.

[0019] In contrast, the second part of the grinding wheel is preferably made as a resin-bonded grinding wheel made of a soft material with a certain percentage of abrasive grains and a polymer bond, with an elastic modulus range of 1-10 GPa.

[0020] The invention and further advantages thereof are explained in more detail below using exemplary embodiments with reference to the drawings. They show:

[0021] Fig. 1 shows a half longitudinal section of a grinding wheel according to the invention; and

[0022] Fig. 2 shows a half longitudinal section of a variant of a grinding wheel according to the invention.

[0023] The grinding wheel shown in Fig. 1 is a grinding worm as a profiled grinding wheel with a rotation axis 13. It consists of a metallic clamping unit 1 and two joined-together partial grinding wheels 2, 3, which are sleeve-shaped and are made of an abrasive material at least in the outer processing area.

[0024] This grinding wheel is particularly intended for polishing the teeth of a gear or the like, with machining being carried out in a known manner by means of continuous generating grinding, partial generating grinding, discontinuous or continuous profile grinding of workpieces. The first partial grinding wheel 2 is used for rapid grinding, also called rough grinding, of a given profile, and the second partial grinding wheel 3 is used for subsequent polishing of the profile. Both partial grinding wheels are arranged side by side in the clamping unit 1 and are firmly connected to one another at their mutually touching contact surface 4, preferably by gluing. However, they could also be simply pressed together without any connection.These partial grinding wheels 2, 3 are provided with the same outer diameter and their toothings are designed at the contact surface 4 with a continuous transition from one wheel to the other so that the toothing of a workpiece can be produced in one operation.

[0025] In principle, the grinding wheel could also be designed for coarse and fine polishing or for coarse and fine machining of a workpiece, which can primarily be influenced by the choice of the material composition of the abrasive materials, at least in the outer machining area of ​​the partial grinding wheels 2, 3. The clamping unit 1 comprises a metallic support sleeve 8 and an annular clamping element 12. The latter is adjustably guided in the direction of the rotation axis 13 by a clamping means in the support sleeve 8, wherein this clamping means can be implemented, for example, as illustrated, as one or more clamping screws 14. By means of this clamping element 12, the first partial grinding wheel 2 is fastened and, at the same time, the second partial grinding wheel 3 is positioned or fixed. According to the invention, the clamping unit 1 is designed such that the first partial grinding wheel 2 is clamped on both sides between two stop surfaces 6,

[0026] 10 of the clamping unit 1 can be clamped independently of the second partial grinding wheel 3. This achieves a permanently rigid fixation of the grinding wheel in the tool holder of a gear cutting machine.

[0027] For this purpose, the second partial grinding wheel 3 has a larger inner diameter D3 than the inner diameter D2 of the first partial grinding wheel 2. As a result, a shoulder 5 is formed within the second partial grinding wheel 3, into which the clamping unit 1 extends and thereby forms this lateral stop surface 6 for the first partial grinding wheel 2, which is preferably arranged flush with the contact surface 4. In addition, the clamping unit 1 is provided with shoulders 11, 18, of which one shoulder 11 with the stop surface 10 is formed by an end flange 9 on the support sleeve 8 and, opposite, the shoulders 5, 18 on the clamping element 12.

[0028] The inner diameters D2, D3 of the partial grinding wheels 2, 3 and the outer diameter(s) of the outer casing 8' of the support sleeve 8 or the clamping element 12 are dimensioned with high precision, such that they can be slipped onto the support sleeve or the clamping element with virtually no play. When mounting the grinding wheel, first the partial grinding wheel 2 is slipped onto the support sleeve 8 and the partial grinding wheel 3 onto the clamping element 12. The latter is then screwed tight to the side of the support sleeve 8 using screws 14, so that the partial grinding wheel 2 is advantageously secured in the clamping unit 1 with a predetermined clamping force.

[0029] This clamping element 12 accommodates the second partial grinding wheel 3 on its outer circumference and the shoulder 18, and its front stop surface 6 presses laterally against the partial grinding wheel 2 in the assembled state to clamp it firmly. The thickness b of the partial grinding wheel 3 and the groove length from the stop surface 6 to the shoulder 18 of the clamping element 12 are preferably of equal length, so that no clamping force acts on this partial grinding wheel 3 from the clamping element 12, but advantageously there is also no play between them. The thickness b of the partial grinding wheel 3 to the thickness of the partial grinding wheel 2 is shown in a ratio of approximately 1:3. This ratio can be adapted and specifically optimized depending on the requirements of the machining of a workpiece. In any case, this ratio can be adjusted practically arbitrarily due to the inventive design of the grinding wheel.

[0030] The support sleeve 8 is provided on its end face with an annular projection 15, on which the annular clamping element 12 is guided coaxially to the rotational axis 13. It also has fastening and / or centering bores 16 on its inside, which can accommodate corresponding means for fastening the grinding wheel to the drive spindle of the machine tool. The grinding wheel according to Fig. 2 is shown as a raw grinding wheel, in which no worm gearing or the like is machined on the outer circumference of its partial grinding wheels 22, 23. Certain details of the grinding wheel correspond to those according to Fig. 1. Therefore, not all details are explained again below, and some of the same reference numerals are used. This also applies to the function and operation of the grinding wheel explained below.

[0031] It differs from the grinding wheel shown in Fig. 1 primarily in that the arrangement of the partial grinding wheels is reversed. Accordingly, the first partial grinding wheel 22 is received in its end region in a recess 17 of the clamping element 32, which is formed with a stop surface 30, and opposite it is received in a recess 25 with a stop surface 26.

[0032] According to the invention, the first partial grinding wheel 22 is thus fastened independently of the second partial grinding wheel 23 on the clamping unit 21 between the two formed stop surfaces 26, 30. In contrast, the second partial grinding wheel 23 is fixed to the support sleeve 28 of the clamping unit 21.

[0033] The second partial grinding wheel 23 is dimensioned with the larger inner diameter D3 than the inner diameter D2 of the first partial grinding wheel 22 and thus a shoulder 25 is present within the second partial grinding wheel 23 into which the clamping unit 21 extends and thereby forms this lateral stop surface 26 for the first partial grinding wheel 22.

[0034] The partial grinding wheels 22, 23 are again advantageously aligned with their lateral contact surfaces 24 flush with this stop surface 26 of the shoulder 25. Theoretically, however, the partial grinding wheel 23 could, for example, engage in a lateral annular recess of the partial grinding wheel 22, and thus the contact surfaces 24 would be offset from the stop surface 26.

[0035] The first partial grinding wheel 2, 22 of the grinding wheel according to the invention shown in Fig. 1 and Fig. 2 is preferably composed of a hard material consisting of a vitrified bonded grinding wheel with abrasive grains of 25-70 volume percent (vol%), a glass and / or ceramic bond of 5-40 vol%, and a pore content of 10-80 vol%, with an elastic modulus in the range of 5-50 GPa. The abrasive grains of this first partial grinding wheel 2, 22 are corundum, silicon carbide, boron nitride, diamond, and / or similar materials. The average abrasive grain diameter of the abrasive grains is preferably between 30 and 300 micrometers.

[0036] The second grinding wheel component 3, 23 of the grinding wheel according to the invention is preferably composed of a softer material, a resin-bonded grinding wheel with abrasive grains, a polymer bond, and pores, and has a modulus of elasticity in the range of 1-10 GPa. The abrasive grains of this second grinding wheel component 3, 23 are advantageously also corundum, silicon carbide, boron nitride, diamond, and / or similar materials, while polyurethane, epoxy resin, or the like are used for the polymer bond. The average abrasive grain diameter of the abrasive grains is preferably between 3 and 40 micrometers.

[0037] The invention is sufficiently illustrated by the above embodiment. However, it could be further explained by further variants.

[0038] The second partial grinding wheel could at least be secured in the clamping unit by an additional clamping device.

[0039] For example, more than two partial grinding wheels could be arranged next to each other to preferably allow a further gradation between roughing and polishing.

[0040] The grinding wheel can be mounted on the drive spindle of the machine tool, which is rotated by a motor, in such a way that either the second partial grinding wheel or the first partial grinding wheel is advantageously placed on the motor side.

Claims

PATENT CLAIMS 1. Grinding wheel, in particular for machining gear teeth, preferably for producing a gear, comprising a clamping unit (1, 21), at least two partial grinding wheels (2, 3, 22, 23) which can be fastened next to one another on the latter and which run coaxially to one another, of which the first partial grinding wheel (2, 22) is preferably used for quickly grinding a predetermined profile of a toothing of a gear or the like to be machined and the second partial grinding wheel (3, 23) is preferably used for subsequently polishing the profile, characterized in that the first partial grinding wheel (2, 22) can be fastened on the clamping unit (1, 21) between two stop surfaces (6, 10, 26, 30) of the latter, independently of the second partial grinding wheel (3, 23).

2. Grinding wheel according to claim 1, characterized in that the second partial grinding wheel (3, 23) is dimensioned with a larger inner diameter (D3) than the inner diameter (D2) of the first partial grinding wheel (2, 23) and as a result a shoulder (5, 25) is formed within the second partial grinding wheel (3, 23), into which shoulder the clamping unit (1, 21) extends and thereby forms one lateral stop surface (6, 26) for the first partial grinding wheel (2, 22), preferably flush with the lateral contact surfaces (4, 24) of the partial grinding wheels (2, 3, 22, 23).

3. Grinding wheel according to claim 1 or 2, characterized in that the clamping unit (1, 21) is provided on the end face with an annular clamping element (12, 32) for clamping the first partial grinding wheel (2, 22) and positioning the second partial grinding wheel (3, 23), wherein this clamping element (12, 32) is adjustable in the direction of a rotation axis (13) by clamping means, preferably clamping screws (14).

4. Grinding wheel according to claim 3, characterized in that the clamping unit (1, 21) has a metallic support sleeve (8, 28) which is provided at the end with a flange (9, 29) through which the one stop surface (10, 27) for the first or for holding the second partial grinding wheel (2, 3, 22, 23) is formed.

5. Grinding wheel according to claim 4, characterized in that the annular clamping element (12) is guided coaxially to the rotation axis (13) at a projection (15) of the support sleeve (8, 28).

6. Grinding wheel according to claim 4 or 5, characterized in that the second partial grinding wheel (3) is mounted on the inside of the annular clamping element (12).

7. Grinding wheel according to claim 6, characterized in that the thickness (b) of the partial grinding wheel (3) and the groove length from the stop surface (6) to the shoulder (18) of the clamping element (12) are approximately the same length, so that no clamping force acts on this partial grinding wheel (2) from the clamping element (12).

8. Grinding wheel according to claim 4 or 5, characterized in that the first partial grinding wheel (22) is partially mounted on the annular clamping element (32).

9. Grinding wheel according to one of claims 1 to 8, characterized in that the inner diameters (D2, D3) of the partial grinding wheels (2, 3, 22, 23) and the outer diameter(s) of the outer casing (9) of the support sleeve (8) or of the clamping element (32) are provided with high-precision dimensions are dimensioned in such a way that they can be slipped onto the support sleeve or the clamping element with almost no play.

10. Grinding wheel according to one of claims 1 to 9, characterized in that the partial grinding wheels (2, 3, 22, 23) on the clamping unit (1, 21) are arranged abutting against one another at the lateral contact surface (4, 24) and are firmly connected to one another.

11. Grinding wheel according to one of claims 1 to 10, characterized in that the first partial grinding wheel (2, 22) is composed as a ceramically bonded grinding wheel with abrasive grains of 25-70 vol%, at least one glass or ceramic bond of 5-40 vol% and with pores of 10-80 vol% and has an E-modulus in the range of 5-50 GPa.

12. Grinding wheel according to claim 11, characterized in that the abrasive grains of the first partial grinding wheel (2, 22) are corundum, silicon carbide, boron nitride, diamond and / or similar materials.

13. Grinding wheel according to claim 11 or 12, characterized in that the average abrasive grain diameter of the abrasive grains is preferably between 30 and 300 micrometers.

14. Grinding wheel according to one of claims 1 to 13, characterized in that the second partial grinding wheel (3, 23) is manufactured as a resin-bonded grinding wheel with abrasive grains, at least one polymer bond, for example polyurethane, epoxy resin or the like, and with pores and has an E-modulus in the range of 1-10 GPa.

15. Grinding wheel according to claim 14, characterized in that the abrasive grains of the second partial grinding wheel (3, 23) are corundum, silicon carbide, boron nitride, diamond and / or similar materials.

16. Grinding wheel according to claim 14 or 15, characterized in that the average abrasive grain diameter of the abrasive grains is preferably between 3 and 40 micrometers.

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