EP4388225A1

EP4388225A1 - Gear, in particular gear rim

Info

Publication number: EP4388225A1
Application number: EP22750761.3A
Authority: EP
Inventors: Zili Wu
Original assignee: SEW Eurodrive GmbH and Co KG
Current assignee: SEW Eurodrive GmbH and Co KG
Priority date: 2021-08-20
Filing date: 2022-07-18
Publication date: 2024-06-26
Also published as: US20240344602A1; WO2023020711A1; DE102022002624A1

Abstract

The invention relates to a gear. The gear is composed of segments, each segment having a support region, a first flange region which is arranged at the front in the circumferential direction, and a second flange region which is arranged at the rear in the circumferential direction, wherein a surface region of the first flange region of each segment lies against the second surface region of the second flange region of the next adjacent segment of the respective segment, At least one screw which passes through the first flange region of the respective segment and the flange region of the respective next adjacent segment connects the segments, and a toothing is introduced into the support region of the segment, said toothing being designed as a helical toothing. The first surface region extends parallel to the tooth, which is next adjacent to the surface region, of the toothing of the respective segment.

Description

Gear, in particular ring gear

Description:

The invention relates to a gear wheel, in particular a toothed ring.

A gear composed of segments is known from WO 2013/020639 A1, which has helical gearing. As can be seen in FIGS. 3 and 4 there, the outermost tooth of the segment in the circumferential direction is not flush with the connecting surface with the reference number 42 there, but protrudes. Screws pass through the connecting surface.

A drum drive and a ring segment for this purpose are known from DE 10 2008 054 189 A1.

A gear wheel with helical teeth is known from DE 10 2016 010 084 A1.

DE 370560 A discloses a divided gear wheel.

The invention is therefore based on the object of developing a gear wheel in which a long service life should be achievable.

According to the invention, the object is achieved with the gear wheel according to the features specified in claim 1.

Important features of the invention in the gear wheel, in particular ring gear, are that the gear wheel is composed of segments arranged one behind the other in the circumferential direction in relation to the axis of rotation of the gear wheel, each segment having a support area, a first flange area arranged at the front in the circumferential direction and one at the rear in the circumferential direction arranged second flange area wherein the first flange area of a respective segment rests with a first surface area on the second surface area of the second flange area of a segment that is next adjacent to the respective segment, wherein at least one screw passing through the first flange area of the respective segment and the flange area of the respective next-adjacent segment connects the segments, gearing is introduced into the support area of the segment, the gearing being designed as helical gearing, i.e. in particular having a non-vanishing helix angle, i.e. in particular having a helix angle other than zero, the screw protruding through the first surface area, the first surface area being parallel to the surface area in each case next adjacent tooth of the toothing of the respective segment and / or wherein the first surface area parallel to the first surface area rich adjoining tooth of the toothing of the respective segment extends, in particular the surface area is flush with the tooth, so that the tooth does not protrude over the first surface area in the circumferential direction or is retracted.

The advantage here is that mechanical stresses can only build up to a lesser extent. Because the transition from the toothing to the surface area is designed without any overhang or recess. Thus, the surface area is flush with the toothing and the tension forces are distributed as evenly as possible. In addition, the service life is increased or a higher torque can be transmitted.

In an advantageous embodiment, the respective segment has a blade area and struts, with the support area and the blade area being connected via the struts and also via the first flange area, in particular with the first flange area being located radially between the support area and the blade area, in particular with the first flange portion is disposed on the front end portion of the segment in the circumferential direction. The advantage here is that a high degree of stability can be achieved with little material expenditure and thus a high torque can be transmitted with little material expenditure and a long service life can be achieved.

In contrast to the prior art, the screw protrudes through the first surface area. This is designed to extend in the direction of the helix. Thus, a flush connection of the next adjacent tooth to the first surface area along the entire axial extent of the tooth is made possible.

In an advantageous embodiment, the support area and the blade area are also connected via the second flange area, in particular with the second flange area being located radially between the support area and the blade area, in particular with the second flange area being arranged on the rear end area of the segment in the circumferential direction. The advantage here is that the segment is rigid and a high torque can be transmitted with little material expenditure.

In an advantageous embodiment, the struts are spaced apart from one another in the circumferential direction by means of continuous recesses in the axial direction, in particular wherein the recesses each have a clear width, measured in the circumferential direction, which increases with increasing radial distance, in particular in a radial distance area that exceeds at least 70% of the total radial distance area covered by the recesses. The advantage here is that a high level of stability can be achieved with low material costs.

In particular, the axial direction is aligned parallel to the direction of the axis of rotation of the gear wheel.

In an advantageous embodiment, the support area, the blade area, the first flange area, the second flange area and the struts are made in one piece, in particular in one piece, so in particular the segment is made of one piece of steel. The advantage here is that the segment can be produced as a cast part, on which the toothing and the surface areas can be finely machined.

In an advantageous embodiment, the segment is made from ADI, in particular from a bainitic cast iron with nodular graphite, in particular from a heat-treated ductile nodular cast iron. The advantage here is that although a great deal of manufacturing effort is necessary, a high load-bearing capacity can be achieved and a high torque can therefore be transmitted.

In an advantageous embodiment, the first and/or second surface area is of planar design and/or is essentially planar. The advantage here is that the contact surface of the two segments can be provided with a sufficiently large size so that the two segments to be connected can be pressed onto one another with a high contact pressure.

In an advantageous embodiment, the normal direction of the first surface area has the helix angle to that tangential direction that belongs to the first surface area. The advantage here is that the surface area extends parallel to the toothing. The tooth root thus leads directly into the flat surface area over its entire axial length. In this way, an overhang or a retraction is avoided and the build-up of mechanical stresses is thus kept low. In an advantageous embodiment, a first stepped bore is made in the first surface area, through which the screw protrudes, in particular the drilling axis of the first stepped bore is not aligned parallel to the normal direction of the first surface area and/or has the helix angle to the normal direction of the first surface area. The advantage here is that the stepped bore is easy to produce and the screw can be protected from shearing forces of the segments by the area widened in front of the first step, ie the annular gap. By introducing forces further away, a lower shearing force can be built up within the screw.

In an advantageous embodiment, the minimum distance between the step of the first stepped bore and the first surface area can be changed in the circumferential direction around the drilling axis of the first stepped bore, in particular depending on the associated circumferential angle around the drilling axis. The advantage here is that the stepped bore is aligned inclined by the helix angle to the normal direction. Thus, although the stepped bore is aligned in the tangential direction, the flange area is designed parallel to the toothing. In this way, on the one hand, a long service life is achieved in that there is no overhang or the like and the mechanical stresses are reduced and run smoothly as a result. On the other hand, the screws are aligned in the tangential direction, that is, in the tangential direction perpendicular to the radial direction of the gear wheel at the contact surface.

In an advantageous embodiment, the clear inner diameter of the first stepped bore increases monotonically with increasing distance from the first surface area. The advantage here is that in the area where the two flange areas of the connected segments touch, an annular gap protects the screw from excessive shearing forces. In this way, the shearing forces can be redirected, thus reducing the load on the screw and increasing its service life.

In an advantageous embodiment, a second stepped bore is made in the second surface area, through which the screw protrudes. The advantage here is that in the other segment a tangentially directed stepped bore is also made in the surface area that is inclined by the helix angle relative to a radial surface. In an advantageous embodiment, the bore axis of the second stepped bore is not aligned parallel to the normal direction of the first surface area and/or has the angular amount of the helix angle to the normal direction of the first surface area. The advantage here is that the service life is increased, since protrusion of the toothing is avoided.

In an advantageous embodiment, the minimum distance between the step of the second stepped bore and the second surface area can be changed in the circumferential direction around the drilling axis of the second stepped bore, in particular depending on the associated circumferential angle around the drilling axis. The advantage here is that the screws are arranged in the tangential direction and the surface area is inclined by the helix angle. This prevents the toothing from protruding and increases the service life.

In an advantageous embodiment, the inside diameter of the second stepped bore increases monotonically with increasing distance from the second surface area. The advantage here is that an annular gap protecting the screw surrounds the screw in the contact area of the two flange areas.

In an advantageous embodiment, a threaded nut is screwed onto a threaded area of the screw, so that the flange areas of the respective segment and the segment next to it are pressed against one another between the nut and the screw head of the screw. The advantage here is that the segments can be connected easily and inexpensively.

In an advantageous embodiment, an annular gap surrounds the screw in an area seen in the direction of the screw axis, which is arranged between the contact area of the screw with the first flange area and the contact area of the screw with the second flange area. The advantage here is that the screw is protected against excessive shearing forces and thus the service life is increased.

In an advantageous embodiment, the annular gap includes the area covered by the contact area between the first and second surface area in the direction of the screw axis Area. The advantage here is that the screw is protected against excessive shearing forces and thus the service life is increased.

In an advantageous embodiment, the first flange area has a continuous recess in the circumferential direction, the clear diameter, largest inner diameter and/or clear opening area of which decreases monotonically in the circumferential direction with increasing distance from the first surface area. It is advantageous that to connect the segments on the one hand a nut and on the other hand, a screw head of the screw presses the flange portion on the narrowed portion side of the recess. The recess is widened toward the contact area. Because there, a sufficiently large surface area acts as a contact area. The surface pressure is therefore kept sufficiently small. However, the nut and the screw head are pressed on in a very small area. In addition, not only one screw but several corresponding screws are provided and thus exert a high pressure. But since the recess is narrowed there, there is enough material to absorb the high pressing forces. However, widening the recess towards the contact area also saves material and thus weight.

In an advantageous embodiment, the second flange area has a continuous recess in the circumferential direction, the clear diameter, largest inner diameter and/or clear opening area of which decreases monotonically counter to the circumferential direction with increasing distance from the second surface area. The advantage here is that, to connect the segments, on the one hand a nut and on the other hand a screw head of the screw presses onto the flange area, specifically on the side of the narrowed area of the recess. The recess is widened toward the contact area. Because there, a sufficiently large surface area acts as a contact area. The surface pressure is therefore kept sufficiently small. However, the nut and the screw head are pressed on in a very small area. In addition, not only one screw but several corresponding screws are provided and thus exert a high pressure. But since the recess is narrowed there, there is enough material to absorb the high pressing forces. However, widening the recess towards the contact area also saves material and thus weight.

Further advantages result from the dependent claims. The invention is not limited to the combination of features of the claims. For the person skilled in the art, there are more meaningful combination possibilities of claims and/or individual claim features and/or features of the description and/or the figures, in particular from the task and/or the task arising from comparison with the prior art.

The invention will now be explained in more detail using schematic illustrations:

FIG. 1 shows one of the segments 1 from which a gear wheel according to the invention, in particular a ring gear, is composed.

FIG. 2 shows a plan view of segment 1, in particular from a radial direction.

A side view of two of the segments 1 connected with screws 30 is shown in FIG.

FIG. 4 shows the connection area of the two segments 1 in a sectional view.

In the figure 5, the segment 1 is shown in an oblique view.

The connection area of the two segments 1 around one of the screws 30 is sketched schematically in FIG. 6, in particular so that FIG. 6 corresponds to an enlarged section of FIG.

As shown in the figures, each segment 1 has a blade area 4, with which the segment is fastened by means of screws to a drum, in particular a cement drum, to be driven by the gear wheel, in particular the ring gear. Alternatively, a welded connection can also be used. The blade area 4 protrudes between two ring areas of the drum and is welded to these ring areas. In the embodiment with screws, the screws are each guided through the ring areas and also the blade area 4 in the axial direction.

As shown in the figures, the toothing 3 is introduced into a supporting area 7 on the radially outer circumference of the segment 1 of the gear wheel.

The gearing 3 is designed as a helical gearing with a helix angle of 20°. The carrying area 7 is connected via struts 6 arranged radially between the sword area 4 and the carrying area 7 . The struts are spaced apart from one another in the circumferential direction by means of recesses 2 that are continuous in the axial direction.

The axial direction is parallel to the direction of the axis of rotation of the gear.

Each of the recesses 2 is extended further in the circumferential direction as the radial distance from the axis of rotation of the gear wheel increases.

In addition, the support area 7 and the blade area 4 are also connected via a first flange area 5 , which is in particular located radially between the support area 7 and the blade area 4 . The first flange area 5 is arranged at the front end area of the segment 1 in the circumferential direction.

In addition, the support area 7 and the blade area 4 are also connected via a second flange area 5 , which is located radially between the support area 7 and the blade area 4 . The second flange area 5 is arranged at the rear end area of the segment 1 in the circumferential direction.

The preferably finely machined, in particular ground, front and rear face of the segment is a surface area of the first or second flange 5. These surface areas are used to connect the next adjacent segments 1. Thus, the contacting flanges 5 of two adjacent, interconnected segments 1 are precisely connected to each other adjustable. The surface areas thus function as alignment surfaces and/or centering surfaces.

The surface areas are preferably designed as flat surfaces

These surface areas are aligned parallel to the course of the tooth root of the tooth of the segment 1 which is in each case closest to the flange 5 . Because the gearing is designed as helical gearing, the surface area is also designed with a helix angle to a plane that contains the axis of rotation of the gear wheel and is preferably tangentially in contact with the tooth root profile at one point of the tooth root profile. The root of the tooth means that surface point of a tooth of the toothing 3 which lies on the root circle of the toothing, in particular at an axial position. The tooth root has the distance of the root circle radius to the axis of rotation of the gear.

The course of the tooth root means that line which is formed from the tooth roots of all axial positions.

Since the surface areas of the respective flange area 5 extend parallel to the adjacent tooth, i.e. in particular the tooth next to the surface area, the surface area is flush with the tooth, so that the tooth does not protrude or retract in the circumferential direction. Smooth stress curves can thus advantageously be achieved and predetermined breaking points avoided.

The axial width of the flange areas 5 is greater than the axial width of the sword area 4.

As shown in FIG. 4 and FIG. 6, the respective screw 30 protrudes through the contacting flange areas 5 of the segments 1 that are in each case closest to one another. For this purpose, the screw 30 is cylindrical in an area arranged between the screw head of the screw 30 and a threaded area of the screw 30 . With the cylindrically designed area, the screw 30 rests against that borehole of the flange area 5 through which the screw 30 protrudes.

In this way, the two segments can be centered relative to one another.

A nut is screwed onto the threaded area of the screw 30 so that the nut and the screw head press the two flange areas 5 onto one another.

However, in the plane receiving the contact surface of the segments 1, the boreholes are widened, so in particular they have a step.

This widening of the boreholes creates an annular gap 62 that winds around the screw 30 . Shear forces 61 acting in the contact plane are thus deflected and the screw 30 is protected from high peak stress curves. In this way, the service life, in particular of the screw and the connection of the two segments 1 brought about by the screw, is increased.

The two aligned boreholes are each designed as a stepped borehole in the respective flange area 5, with the two boreholes resting against one another with their wider inside diameter.

The two boreholes are drilled into the respective surface area. Thus, the drilling axis is not parallel to the normal direction of the respective surface area. However, the normal directions of the two surface areas are aligned parallel to one another.

The step of the respective borehole therefore has a non-constant and/or variable distance from the flat surface area. The distance of the step from the planar surface area depends on the circumferential angle in the circumferential direction around the drilling axis.

The clear inside diameter of the respective borehole decreases monotonously with increasing distance from the respective other segment 1 or borehole, in particular it monotonically decreases with increasing distance from the surface area of the flange area 5 .

The threaded area of the screw 30 protrudes from the flange area 5, so that a threaded nut is screwed onto the threaded area.

Since the screw 30 rests against the narrower area of the bores, in particular with a precise fit, the segments 1 are centered with respect to one another.

In further exemplary embodiments according to the invention, instead of designing the boreholes as stepped boreholes for receiving the screw 30, the course of the clear inside diameter of the respective borehole is not stepped, ie not or less abruptly. In this way, the shear forces do not act directly from the step, but slowly build up with increasing distance to the surface area. On in this way, the screw 30 is subjected to fewer stress variations and the screw 30 thus has an increased service life. Preferably, the clear inside diameter decreases with increasing distance from the respective surface area, smoothly and/or continuously differentiable to the contact area between screw 30 and borehole, ie in particular flange area 5, subsequent function.

Reference List

1 segment

2 recess

3 teeth

4 sword area

5 flange area

6 strut

7 carrying area

20 helix angles

30 screw

40 window opening, in particular stepped window opening

50 borehole

60 touch area

61 shear force

62 annular gap

Claims

Patent Claims:

1. Gear wheel, in particular ring gear, wherein the gear wheel is composed of segments arranged one behind the other in the circumferential direction in relation to the axis of rotation of the gear wheel, each segment having a support area, a first flange area arranged at the front in the circumferential direction and a second flange area arranged at the rear in the circumferential direction, wherein the first flange area of a respective segment rests with a first surface area on the second surface area of the second flange area of a segment that is next adjacent to the respective segment, with at least one screw running through the first flange area of the respective segment and the flange area of the respective next-adjacent segment connecting the segments, with the A gearing is introduced in the supporting area of the segment, the gearing being designed as helical gearing, ie in particular having a non-vanishing helix angle, ie in particular one has a non-zero helix angle, characterized in that the screw protrudes through the first surface area, wherein the first surface area extends parallel to the tooth of the toothing of the respective segment that is next to the first surface area and/or that the first surface area extends parallel to the tooth of the toothing of the respective segment that is adjacent to the first surface area, i.e. in particular the surface area is flush with the tooth connects, so that the tooth is not projected or retracted over the first surface region in the circumferential direction.

2. Gear wheel according to Claim 1, characterized in that the respective segment has a blade area and struts, the support area and the blade area being connected via the struts and also via the first flange area, in particular the first flange area being located radially between the support area and the The blade area is located, in particular wherein the first flange area is arranged on the front end area of the segment in the circumferential direction.

3. Gear wheel according to one of the preceding claims, characterized in that the support area and the blade area are also connected via the second flange area, in particular wherein the second flange area is located radially between the support area and the blade area, in particular wherein the second flange area is at the rear in the circumferential direction Forehead area of the segment is arranged.

4. Toothed wheel according to one of the preceding claims, characterized in that the struts are spaced apart from one another in the circumferential direction by means of continuous recesses in the axial direction, in particular with the recesses each having a clear width measured in the circumferential direction, which increases with increasing radial distance, in particular in a radial distance region , which exceeds at least 70% of the total radial spacing area covered by the recesses.

5. Gear according to one of the preceding claims, characterized in that the axial direction is aligned parallel to the direction of the axis of rotation of the gear.

6. Gear according to one of the preceding claims, characterized in that the support area, the sword area, the first flange area, the second flange area and the struts are made in one piece, in particular in one piece, so in particular the segment is made of one piece of steel.

7. Gear wheel according to one of the preceding claims, characterized in that the segment is made from ADI, in particular from a bainitic cast iron with nodular graphite, in particular from a heat-treated ductile nodular iron.

8. Toothed wheel according to one of the preceding claims, characterized in that the first and/or second surface region is planar and/or is essentially planar.

9. Gear according to one of the preceding claims, characterized in that the normal direction of the first surface area has the helix angle to that tangential direction that belongs to the first surface area, and/or that the first surface area is aligned parallel to the first flange area.

10. Gear wheel according to one of the preceding claims, characterized in that a first stepped bore is made in the first surface area, through which the screw protrudes, in particular wherein the bore axis of the first stepped bore is not aligned parallel to the normal direction of the first surface area and/or the helix angle to the normal direction of the first surface region.

11. Gear wheel according to one of the preceding claims, characterized in that the minimum distance between the step of the first stepped bore and the first surface area can be changed in the circumferential direction around the drilling axis of the first stepped bore, in particular depending on the associated circumferential angle around the drilling axis, and/ or that the clear internal diameter of the first stepped bore increases monotonically with increasing distance from the first surface area.

12. Gear wheel according to one of the preceding claims, characterized in that a second stepped bore is made in the second surface area, through which the screw protrudes, in particular wherein the bore axis of the second stepped bore is not aligned parallel to the normal direction of the first surface area and/or the angle amount of the helix angle to the normal direction of the first surface region.

13. Gear wheel according to one of the preceding claims, characterized in that the minimum distance between the step of the second stepped bore and the second surface area can be changed in the circumferential direction around the drilling axis of the second stepped bore, in particular depending on the associated circumferential angle around the drilling axis, and/ or that the inside diameter of the second stepped bore increases monotonically with increasing distance from the second surface area.

14. Gear wheel according to one of the preceding claims, characterized in that a threaded nut is screwed onto a threaded area of the screw, so that the flange areas of the respective segment and the segment next to it are pressed against one another between the nut and the screw head of the screw.

15. Gear wheel according to one of the preceding claims, characterized in that an annular gap surrounds the screw in an area seen in the direction of the screw axis, which is arranged between the contact area of the screw with the first flange area and the contact area of the screw with the second flange area , and/or that the annular gap comprises the area covered by the contact area between the first and second surface area in the direction of the screw axis.

16. Gear wheel according to one of the preceding claims, characterized in that the first flange area has a continuous recess in the circumferential direction, the clear diameter, largest inner diameter and/or clear opening area of which decreases monotonically in the circumferential direction with increasing distance from the first surface area and/or that the second The flange area has a continuous recess in the circumferential direction, the inside diameter of which, the largest inside diameter and/or the inside opening area decreases monotonically counter to the circumferential direction as the distance from the second surface area increases.

17. Gear wheel according to one of the preceding claims, characterized in that the clear inner diameter of the respective stepped bore increases with increasing distance from the respective surface area according to a decreasing, smoothly and/or continuously differentiable function that follows the contact area between the screw and the wall of the stepped bore, in particular the flange area runs.