Grinding wheel, method for grinding a drive spindle, drive spindle, method for manufacturing a spindle pump stage and spindle pump stage

Abstract

The invention relates to a grinding wheel (6) for grinding a drive spindle (4) for a spindle pump stage, wherein the grinding wheel (6) comprises a grinding area (65) with a concave, continuously extending contour in a plane (51) in which the axis of rotation (61) of the grinding wheel (6) lies, the contour of the grinding area comprising at least one radius value. The invention further relates to a method for grinding a drive spindle (4), a drive spindle (4), a method for manufacturing a spindle pump stage (3), and a spindle pump stage (3).

Description

Technical FieldThe invention relates to a grinding wheel, a method for grinding a drive spindle, a drive spindle, a method for producing a spindle pump stage and spindle pump stage.Prior ArtThe document DE 101 29 341 A1 discloses a method for producing a spindle pump stage profile of a spindle.The publication DE 20 2014 010 877 U1 discloses a double spindle screw pump of single-flow construction.A particular disadvantage of the devices in the prior art is that sharp edges on the profile of a spindle of a spindle pump stage are subject to undesirably high wear during operation of the spindle pump stage. This leads to material particles which, due to the wear, become detached from the spindle and pass into the fluid to be conveyed. This can damage consumers or components of the fluid system to be supplied with the fluid, in addition to which the spindle pump stage belongs. In addition, grinding wheels for producing spindles are subject to high wear and must be reground regularly.Presentation of the Invention, Object, Solution, AdvantagesIt is the object of the present invention to provide an alternative grinding wheel which is distinguished in particular by its simplicity and its lower wear. Another object is to provide a method for grinding a drive spindle. Another object is to provide a drive spindle. Another object is to provide a method for manufacturing a spindle pump stage. Another object is to provide a spindle pump stage.The object with respect to the grinding wheel is achieved by a grinding wheel having the features of claim 1.An exemplary embodiment of the invention relates to a grinding wheel for grinding a drive spindle for a spindle pump stage, wherein the grinding wheel comprises a grinding region having a concave, continuously running contour in a plane in which the axis of rotation of the grinding wheel lies, wherein the contour of the grinding region comprises at least one radius value.It is particularly advantageous if the grinding wheel has a cross section in the plane in which the axis of rotation of the grinding wheel lies, which cross section comprises a grinding wheel head with two grinding wheel shoulders, wherein the transition from at least one of the grinding wheel shoulders to the grinding wheel head is formed by the grinding region which, in particular during a grinding process for producing or grinding a drive spindle, defines the contour of the drive spindle transition.The grinding wheel according to the invention is preferably a grinding wheel for producing a drive spindle.The contour of the grinding region preferably extends through 360° about the axis of rotation of the grinding wheel.Said plane runs in particular diametrically through the grinding wheel. Preferably, the grinding wheel shoulders and the grinding wheel head also form further grinding regions. In such a case, the grinding region formed by the transition from at least one of the grinding wheel shoulders to the grinding wheel head is the first grinding region and the other grinding regions relating to the grinding wheel shoulders and the grinding wheel head are the further grinding regions. It is expedient if the diameter of the grinding wheel is greater than the thickness of the wheel. The diameter of the disk is preferably measured transversely, in particular perpendicularly, to the axis of rotation of the grinding axis. The thickness of the disk is preferably measured in the direction of extension of the axis of rotation.A preferred exemplary embodiment is characterized in that the contour of the grinding region or of the first grinding region comprises at least one second radius value. In other words, the contour has a variable radius value. In this way, in a method for grinding a drive spindle for a spindle pump stage, different shapes of a contour of a drive spindle transition of the drive spindle can be formed by means of such a grinding wheel.A further preferred exemplary embodiment is characterized in that the smallest radius value of the contour of the grinding region or the at least one radius value of the contour of the grinding region corresponds to a multiple of a dressing radius of a dressing body with which the contour of the grinding region has been produced.The smaller the at least one radius value of the contour of the grinding region or the smallest radius value of the contour of the grinding region, the higher the wear of the grinding wheel. Therefore, a larger radius value results in less wear.It is particularly advantageous if the at least one radius value of the contour of the grinding region or the smallest radius value of the contour of the grinding region is a maximum of 2 mm. Alternatively, it is conceivable that the at least one radius value of the contour of the grinding region or the smallest radius value of the contour of the grinding region has a maximum of 1.5 mm, 1.2 mm, 1.0 mm, 0.8 mm, 0.5 mm, 0.3 mm, 0.2 mm, 0.1 mm, 0.05 mm or 0.02 mm. Furthermore, it is preferred if the at least one radius value of the contour of the grinding region or the smallest radius value of the contour of the grinding region corresponds to at least 0.01 mm, 0.04 mm, 0.09 mm, 0.19 mm, 0.25 mm, 0.4 mm, 0.6 mm, 0.9 mm, 1.0 mm, 1.3 mm or 1.5 mm. The higher the at least one radius value of the contour of the grinding region or the smallest radius value of the contour of the grinding region, the lower the wear that occurs at this location of the grinding wheel.Preferably, the contour of the grinding region has only a constant radius value. However, this can result in a drive spindle transition with more than one radius value in a plane transverse to the direction of extension of the spindle tooth of the drive spindle.It is particularly preferred if the smallest radius value of the contour of the grinding region or the at least one radius value of the contour of the grinding region corresponds to at least 1.5 times, twice, three times, four or five times the dressing radius of the dressing body.The dressing body is preferably a tool with a higher hardness than the grinding wheel. Furthermore, it is preferable if the dressing body is used after wear or during the production of the grinding wheel. In this case, it is preferred if the dressing body forms the grinding wheel head, the grinding wheel shoulders and / or the grinding region by a grinding process.Furthermore, it is preferred if the dressing radius of the dressing body corresponds to the radius value of the contour of the grinding region that can be minimally produced by means of a grinding process with the dressing body.The object with respect to the method for grinding a drive spindle for a spindle pump stage is achieved by a method for grinding a drive spindle for a spindle pump stage, wherein the drive spindle has at least one helically extending drive spindle tooth, wherein the at least one drive spindle tooth comprises a driven flank, a drive spindle transition and a drive spindle tooth tip surface, wherein the drive spindle transition forms a transition from the driven flank to the drive spindle tooth tip surface, comprising at least the step of grinding a contour of the drive spindle transition, which contour extends convexly in a plane transversely to the direction of extent of the at least one drive spindle tooth, by means of the grinding region of the grinding wheel, wherein the drive spindle transition has at least one drive spindle transition radius value.The grinding wheel is in particular the grinding wheel according to the invention.The output flank is in particular a flank of the at least one drive spindle tooth which is or can be brought into drive-transmitting contact with a drive flank of a running spindle. During operation, the torque of the driving drive spindle is transmitted by means of the drive flank of the drive spindle to the driven flank of the running spindle and thus to the running spindle.The drive spindle tooth head surface is in particular a surface of the at least one drive spindle tooth which is arranged radially on the outside, at a distance from a or the drive spindle rotation axis of the drive spindle and remote from the drive spindle rotation axis.It is also preferable if the contour of the drive spindle transition has at least two drive spindle transition radius values.In addition, it is advantageous if the plane in which the contour of the drive spindle transition extends extends extends perpendicular to the direction of extension of the at least one drive spindle tooth.It is particularly advantageous if the drive spindle has one, two or three drive spindle teeth, in particular running parallel to one another. In all these cases, each of the drive spindle teeth has the configuration with the drive spindle transition radius.It is preferred if the at least one helically extending drive spindle tooth has a constant pitch. In other words, the spiral course of the at least one drive spindle tooth has a constant pitch.The fluid to be conveyed with the drive spindle is preferably a liquid, in particular oil, coolant, fuel or a cleaning agent. It is therefore preferred if the drive spindle is designed to be resistant to the respective liquid for the conveyance of which it is designed.The object with respect to the drive spindle is achieved in that a drive spindle for a spindle pump stage, produced according to the method according to the invention for grinding a drive spindle for a spindle pump stage, is provided.It is also preferable for the drive spindle to consist of a metal, preferably a steel, in particular a stainless steel. This ensures a particular longevity. It is particularly preferred if one of the aforementioned materials is a material which is corrosion-resistant to fuels.The object relating to the method for producing a spindle pump stage is achieved by a method for producing a spindle pump stage, wherein the spindle pump stage comprises a spindle pump stage housing, a drive spindle and a drive spindle, wherein the drive spindle is produced according to the method according to the invention for grinding a drive spindle for a spindle pump stage, wherein the shape or the course of the contour of the drive spindle transition is formed by grinding the drive spindle transition by means of the grinding wheel such that a bypass channel cross section of a bypass channel of the spindle pump stage, which bypass channel runs transversely to the direction of extent of the bypass channel through the spindle pump stage housing, the drive spindle and the drive spindle transition, is minimal. Alternatively, the bypass channel cross section can be 30% greater, 20%, 10%, 5%, 1% greater than the bypass channel cross section that can be minimally produced by means of this grinding disk. The power loss of the spindle pump stage is thus reduced, since the smaller the bypass channel cross section, the lower the delivery loss capacity of the spindle pump stage.In addition, it is advantageous if the plane in which the bypass channel cross section of the bypass channel of the spindle pump stage lies runs perpendicular to the direction of extent of the bypass channel or perpendicular flow direction of a bypass flow that can flow through the bypass channel.The bypass channel cross section described here is likewise known in technical circles as a blow hole.Preferably, the shape or the course of the contour of the drive spindle transition is formed by grinding the drive spindle transition by means of the grinding wheel in such a way that the bypass channel cross section is or becomes minimal at a predefined dressing radius of the dressing body. Alternatively, the bypass channel cross section can be 30% greater, 20%, 10%, 5%, 1% greater than the bypass channel cross section that can be minimally produced by means of this grinding disk.It is also preferable for the bypass channel cross section to be at most 0.1 mm 2, 0,025 mm 2, 0,01 mm 2, 0,005 mm 2 or 0.002 mm 2. This limits the delivery loss capacity of the spindle pump stage.The object with respect to the spindle pump stage is achieved by a spindle pump stage, produced according to the method according to the invention for producing a spindle pump stage.Preferably, a conveying device has such a spindle pump stage. Depending on the field of application and application, this can be a fuel delivery device, oil delivery device, coolant delivery device or a cleaning agent device.If, within the scope of the disclosure, a plane is described which runs transversely to a direction or an axis, then it is preferred if this plane runs perpendicular to said plane or axis.It is particularly preferred if a motor vehicle has such a spindle pump stage or such a conveying device.Brief Description of the DrawingsThe invention is explained in detail below on the basis of exemplary embodiments with reference to the drawings. In the drawings, there are shown: FIG. 1 shows a motor vehicle, FIG. 2a shows a method for producing a drive spindle, FIG. 2 bshows a sectional view A-A from FIG. 2 a, FIG. 2c shows different driving spindle transition radii, FIG. 3a shows a spindle pump stage, FIG. 3 b shows detail-A of the spindle pump stage from FIG. 3 a, FIG. 4a shows a grinding wheel, and FIG. 4 b shows detail-B of the grinding wheel from FIG. 4 a.Preferred Embodiment of the InventionFIG. 1 shows a motor vehicle 1, comprising a fuel delivery device 2, with which fuel can be delivered from a fuel tank 21 to an internal combustion engine 22. The fuel delivery device 2 has a spindle pump stage 3 according to the invention with a drive spindle 4 according to the invention.FIG. 2 ashows the inventive drive spindle 4, which is arranged here in the X-Y plane 51. The drive spindle rotation axis 45, a driven flank 41, a drive spindle tooth head surface 43 and a driven rear flank 44 of the drive spindle tooth 46 can be seen. This drive spindle transition 42, in particular its contour, prevents undesired wear during operation of the drive spindle 4 in a spindle pump stage in comparison with a sharp edge arranged at this point. In this embodiment, three drive spindle teeth 46 all run spirally and parallel to one another about the drive spindle rotation axis 45 in the X direction. The drive spindle 4 is partially shown as a sectional illustration in the X-Y plane 51. Moreover, a grinding wheel 6 according to the invention is shown in a highly simplified form with its axis of rotation 61 and its direction of grinding wheel movement 62 during the production process of the drive spindle 4. In the method according to the invention for producing the inventive drive spindle 4 or the inventive spindle pump stage, the grinding wheel 6 rotates about its rotational axis 61, wherein the drive spindle 4 rotates about its drive spindle rotational axis 45 and wherein the grinding wheel 6 is moved relative to the drive spindle 4 in the grinding wheel movement direction 62. In this case, the contour of the drive spindle teeth 46, in particular of the drive spindle transition 42, is ground by means of the grinding wheel 6. In addition, FIG. 2 ashows a cutting course A-A through a drive spindle tooth 46 of the illustrated drive spindle 4, wherein the cutting course extends to the extension direction of the drive spindle tooth 46.FIG. 2 bshows the sectional view A-A of the sectional profile A-A from FIG. 2 a. This is a sectional view through one of the drive spindle teeth 46 of the drive spindle from FIG. 2 a. The driven flank 41 can be seen, which merges into the driving spindle tooth head surface 43 by means of the driving spindle transition 42. The drive spindle tooth head surface 43 is a surface of the drive spindle tooth 46 that faces away from the drive spindle rotation axis or, as shown here, the X-Y plane 51. In addition, the drive spindle tooth tip surface 43 is radially spaced apart from the drive spindle rotation axis, i.e. as illustrated here, in the Z direction.FIG. 2 cshows a detailed view of the contour of the drive spindle transition 42, which is shown here as a continuous line. Furthermore, for comparison, the contours of two alternative drive spindle transitions 42 are shown in dashed lines, each having a different shape. All three contours of the drive spindle transitions 42 each have the same smallest radius value and have been produced with grinding wheels which have been produced with the same dressing body. It can be seen that the shape of the contour of the drive spindle transition 42 determines the cross section of the bypass channel to a decisive extent given the same smallest radius value of the contour of the drive spindle transition 42.FIG. 3 ashows in a greatly simplified manner a spindle pump stage according to the invention, which comprises a drive spindle 4 according to the invention and a running spindle 7. The drive spindle 4 and the running spindle 7 are rotatably mounted in a spindle pump stage housing, which is not illustrated in FIG. 3 a for the sake of simplicity. The view of FIG. 3 ais a sectional view in the Y-Z plane 52 The spindle teeth 76 of the spindle 7 and the spindle teeth 46 of the spindle 4 can be seen. The detail-A shows a driving contact between a driving flank of a lead screw tooth 76 and a driven flank of a lead screw tooth 46, whereby the torque of the lead screw 7 is transmitted to the lead screw 4 by means of hydraulic coupling.FIG. 3 bshows the location of detail-A from FIG. 3 ain a greatly simplified manner, however, in a different opposite view and in a different rotational position of the running spindle and the driving spindle with respect to one another. In contrast to FIG. 3 a, the spindle pump stage housing 8 is shown in dashed lines. A bypass channel 478 can be seen, which is bounded by the spindle pump stage housing 8, the running spindle tooth 76 and the driving spindle tooth 46 in the Y-Z plane 52 shown. This bypass channel 478 reduces the delivery capacity of the spindle pump stage. The larger the cross section of the bypass channel 478, the greater the reduction in the delivery capacity of the spindle pump stage. At the same time, the cross section of the bypass channel 478 is dependent on the drive spindle transition 42, in particular on the shape or the course of the contour of the drive spindle transition 42.FIG. 4 ashows a detailed view of the grinding wheel 6 from FIG. 2 ain a section which runs diametrically through the grinding wheel 6. The axis of rotation 61 with respect to which the grinding wheel 6 is designed to be rotationally symmetrical can be seen. Radially on the outside, in the region identified as detail-B, a grinding wheel head 64 is formed, to which two grinding wheel shoulders 63 are each axially adjacent. The grinding wheel shoulders 63 are used to grind the drive spindle tooth tip surfaces during the production process of the drive spindle.FIG. 4 bshows the detail-B of the grinding wheel 6 from FIG. 4 a. At the transitions from the grinding wheel shoulders 63 to the grinding wheel head 64, a grinding region 65 having a concave contour is formed in each case. The grinding region 65 determines the lead screw transition.The different features of the individual exemplary embodiments can also be combined with one another. The exemplary embodiments of FIGS. 1 to 4b have in particular no limiting character and serve to clarify the concept of the invention.List of reference characters1 Motor vehicle 2 Fuel delivery device 21 Fuel tank 22 Internal combustion engine 3 Spindle pump stage 4 Drive spindle 41 Driven flank 42 Drive spindle transition 43 Drive spindle tooth head surface 44 Driven rear flank 45 Drive spindle rotation axis 46 Drive spindle tooth 478 Bypass channel 51 X-Y plane 52 Y-Z plane 53 Drive spindle rotation direction 6 Grinding wheel 61 Grinding wheel rotation axis 62 Grinding wheel movement direction 63 Grinding wheel shoulder 64 Grinding wheel head 65 Grinding region 7 Running spindle 76 Running spindle tooth 8 Spindle pump stage housingReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 101 29 341 A1

[0002] DE 20 2014 010 877 U1

[0003]

Claims

Grinding wheel (6) for grinding a drive spindle (4) for a spindle pump stage, wherein the grinding wheel (6) comprises, in a plane (51) in which the axis of rotation (61) of the grinding wheel (6) lies, a grinding region (65) having a concave, continuously running contour, wherein the contour of the grinding region comprises at least one radius value.The grinding wheel of claim 1, wherein the contour of the grinding region comprises at least a second radius value.Grinding wheel according to one of the preceding claims, wherein the smallest radius value of the contour of the grinding region or the at least one radius value of the contour of the grinding region corresponds to a multiple of a dressing radius of a dressing body with which the contour of the grinding region has been produced.Method for grinding a drive spindle (4) for a spindle pump stage, wherein the drive spindle (4) has at least one helically running drive spindle tooth (46), wherein the at least one drive spindle tooth (46) comprises an output flank (41), a drive spindle transition (42) and a drive spindle tooth tip surface (43), wherein the drive spindle transition (42) forms a transition from the output flank (41) to the drive spindle tooth tip surface (43), comprising at least the step: - grinding a continuously running contour of the drive spindle transition (42), which contour is convex in a plane transverse to the direction of extent of the at least one drive spindle tooth (46), by means of the grinding region (65) of the grinding wheel (6) according to one of the preceding claims, wherein the contour of the drive spindle transition (42) has at least one drive spindle transition radius value.A drive spindle (4) for a spindle pump stage, manufactured according to the method of claim 4.Method for producing a spindle pump stage (3), wherein the spindle pump stage comprises a spindle pump stage housing (8), a running spindle (7) and a driving spindle (4), wherein the driving spindle (4) is produced according to the method according to claim 4, wherein the shape of the contour of the driving spindle transition (42) is formed by grinding the driving spindle transition (42) by means of the grinding wheel (6) in such a way that a bypass channel cross section of a bypass channel (478) of the spindle pump stage, which bypass channel runs transversely to the direction of extent of the bypass channel (478), is bounded by the spindle pump stage housing (8), the running spindle (7) and the driving spindle transition (42), becomes minimal.A spindle pump stage (3) produced by the method according to claim 6.

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