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Title:
WAVE SPRING WITH INTERMEDIATE LAYER
Document Type and Number:
WIPO Patent Application WO/2018/195158
Kind Code:
A1
Abstract:
The invention relates to a wave spring (20) made from a spring strip (100). The wave spring (20) comprises at least two layers (110, 120) which describe a corrugated line along the spring strip (100). The wave spring (20) additionally comprises an intermediate layer (140), which is configured substantially straight along the spring strip (100), and which in each case is between the at least two layers (110, 120).

Inventors:
HORNBACH JOHANNES (DE)
Application Number:
PCT/US2018/028100
Publication Date:
October 25, 2018
Filing Date:
April 18, 2018
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
BORGWARNER INC (US)
International Classes:
F16F1/32
Foreign References:
JPH0821471A1996-01-23
CH663256A51987-11-30
US2587016A1952-02-26
US1763146A1930-06-10
US20160298535A12016-10-13
US5639074A1997-06-17
US3674251A1972-07-04
Other References:
None
Attorney, Agent or Firm:
PENDORF, Stephan A. et al. (US)
Download PDF:
Claims:
Claims

1. A wave spring (20) made from a spring strip (100), characterized in that the wave spring (20) comprises at least two layers (110, 120) which each describe a corrugated line along the spring strip (100), and in that the wave spring (20) additionally comprises at least one intermediate layer (140), which is configured as substantially straight along the spring strip (100), between the at least two layers (110, 120).

The wave spring according to Claim 1, characterized in that the wave spring (20) comprises three or more layers (110, 120) which describe a corrugated line along the spring strip (100), and in that the wave spring (20) comprises at least one intermediate layer (140) in each case between two respectively adjacent layers (110, 120).

The wave spring according to Claim 1 or Claim 2, characterized in that the layers (110, 120), which describe a corrugated line, have shoulders (150), in particular wherein the shoulders (150) define maximums (152) and minimums (154) of the corrugated line(s).

The wave spring according to Claim 3, characterized in that the at least one intermediate layer (140) is positioned between respectively opposite shoulders (150) of two adjacent layers (110, 120) that describe a corrugated line along the spring strip (100), so that the intermediate layer(s) (140) contacts on its upper side (124) the first of the opposite shoulders (150) and contacts on its lower side (144) the second of the opposite shoulders (150).

5. The wave spring according to Claim 4, characterized in that the first or the first and second of the opposite shoulders (150) are fixedly connected to the intermediate layer(s) (140).

6. The wave spring according to any one of the preceding claims, characterized in that the corrugated lines encompass multiple periods per layer (110, 120). 7. The wave spring according to any one of the preceding claims, characterized in that the corrugated lines of the layers (110, 120) are sinusoidal and have an identical phase length.

8. The wave spring according to any one of the preceding claims, characterized in that two, three, or more intermediate layers (140) are provided between each two layers (110, 120) which describe a corrugated line along the spring strip (100).

9. The wave spring according to any one of the preceding claims, characterized in that the spring strip (100) additionally has at least one non-corrugated edge region (160, 162).

10. The wave spring according to any one of the preceding claims, characterized in that the spring strip (100) is arranged in a ring shape in such a way that the layers (110, 120), which describe a corrugated line along the spring strip (100), and the intermediate layer (140) each define a ring.

11. The wave spring according to any one of the Claims 1 through 9, characterized in that the spring strip is arranged linearly in such a way that the layers, which describe a corrugated line along the spring strip, and the intermediate layer(s) define a linear sandwich structure.

12. The use of wave springs (20) according to any one of the Claims 1 through 10 as an elastic compensating disc for a bearing in a charging device, in particular wherein the charging device is an electrically driven or electrically supported charging device.

13. A charging device, in particular an electrically driven charging device, comprising

a compressor (300) which has a compressor housing (310) and a compressor wheel (320), wherein the compressor wheel (320) is arranged on a shaft (400);

a bearing housing (200) comprising a bearing arrangement for bearing the shaft (400), wherein the bearing arrangement comprises two bearing components (210, 220),

characterized in that a wave spring (20) according to any one of the preceding claims is arranged between at least one of the bearing components (210, 220) and the bearing housing (200).

The charging device according to Claim 13, characterized in that the bearing components (210, 220) each comprise a roller bearing comprising in each case an inner bearing race (212), an outer bearing race (214), and rolling bodies (216) arranged therebetween, wherein the wave spring (20) is arranged between at least one of the outer bearing races (212) and the bearing housing (200).

The charging device according to Claim 14, characterized in that the wave spring (20) is arranged, relative to the bearing housing (200), on the axially outer side of radially outer bearing race (214) of the roller bearing (210) farthest from the turbine (300) in the axial direction.

Description:
WAVE SPRING WITH INTERMEDIATE LAYER

Field of the Invention

[0001] The present invention relates to a wave spring, the use of wave springs in charging devices, and a charging device comprising a corresponding wave spring.

Background Information

[0002] Wave spring(s) are generally known and are used, for example, in the area of bearings to compensate for play. The use of wave springs thereby saves up to 50% in the installation height over classic, cylindrical springs. Known wave springs are manufactured from a flat wire and may be ring-shaped or have a linear configuration. Thus, problems may be solved by the use of wave springs that may not be solved using cylindrical helical springs or in which the installation space may be saved by using wave springs. A wave spring known from the prior art is depicted in Figure 1. [0003] In certain applications, the layers of the wave spring may slide into one another during operation due to high axial forces and manufacturing offsets of corrugated peaks to corrugated valleys. In cases of high vibrations, a skewing of the wave spring layers may occur due to reduced friction between the individual wave spring layers and influenced by temperature fluctuations and the resulting length extensions, until a transition point is reached and the wave spring layers fold in among themselves. As the axial forces of the spring are present in this case, the spring remains in this folded state.

[0004] It is thus the object of the present invention to provide a wave spring with higher stability and stiffness to avoid or to completely prevent layers from folding together or sliding into one another.

Brief Summary of the Invention [0005] The present invention relates to a wave spring according to Claim 1, a use of wave springs according to Claim 12, and a charging device according to Claim 13. [0006] The compressor according to the invention comprises a wave spring made from a spring strip. The wave spring comprises at least two layers which describe a corrugated line along the spring strip. The wave spring additionally comprises an intermediate layer, which is configured substantially straight along spring strip, and which in each case is between the at least two layers. Due to the intermediate layer(s), a sliding together or folding together of the corrugated layers of the wave spring is prevented. This leads to stabilization and increased stiffness of the wave spring. In addition, the absorption capacity for axial forces when outer torsional forces are simultaneously applied (for example, from an outer race of a ball bearing) remain higher in comparison to wave springs without intermediate layers.

[0007] In embodiments, the wave spring may comprise three or more layers which describe a corrugated line along the spring strip. The wave spring may comprise at least one intermediate layer in each case between two respectively adjacent layers.

[0008] In embodiments, which may be combined with all previously described embodiments, the layers, which describe a corrugated line, may have shoulders. In particular, the shoulders may define maximums and minimums. The at least one intermediate layer may be positioned between respectively opposite shoulders of two adjacent layers which describe a corrugated line along the spring strip, so that the intermediate layer(s) contacts on its upper side the first of the opposite shoulders and contacts on its lower side the second of the opposite shoulders. [0009] In particular, the first or the first and second of the opposite shoulders may be fixedly connected to the intermediate layer(s). The shoulders may be glued or welded to the intermediate layer(s) for this purpose. [0010] In embodiments, which may be combinable with all previously described embodiments, the spring strip may comprise spring steel. In particular, the spring strip may be manufactured completely from spring steel. [0011] In embodiments, which may be combined with all previously described embodiments, the corrugated lines may encompass multiple periods per layer.

[0012] In embodiments, which may be combined with all previously described embodiments, the corrugated lines of the layers may be sinusoidal and have an identical phase length.

[0013] In embodiments, which may be combined with all previously described embodiments, two, three, or more intermediate layers may be provided between two layers which respectively describe a corrugated line along the spring strip.

[0014] In embodiments, which may be combined with all previously described embodiments, all layers, which describe a corrugated line along the spring strip, and the intermediate layer, may be designed from a one-piece spring strip. [0015] In embodiments, which may be combined with all previously described embodiments, the spring strip may additionally have at least one non-corrugated edge region.

[0016] In embodiments, which may be combined with all previously described embodiments, the spring strip may be arranged in a ring shape in such a way that the layers, which describe a corrugated line along the spring strip, and the intermediate layer(s) each define a ring. Alternatively, the spring strip may be arranged linearly in such a way that the layers, which describe a corrugated line along the spring strip, and the intermediate layer(s) define a linear sandwich structure.

[0017] The invention additionally comprises a use of wave springs according to any one of the preceding embodiments as an elastic compensating element or biasing element in a charging device, in particular as an annular elastic compensating disk for a bearing in a charging device. The charging device may, for example, be an electrically driven charging device or an electrically supported charging device (e.g., an electrically supported exhaust gas turbocharger). [0018] The invention additionally comprises a charging device, in particular an electrically driven charging device comprising a compressor which has a compressor housing and a compressor wheel, wherein the compressor wheel is arranged on a shaft. The charging device additionally comprises a bearing housing comprising a bearing arrangement for bearing the shaft, wherein the bearing arrangement comprises two bearing components. A wave spring according to any one of the preceding embodiments is arranged between at least one of the bearing components and the bearing housing.

[0019] In embodiments of the charging device, the bearing components may respectively comprise a roller bearing comprising in each case an inner bearing race, an outer bearing race, and rolling bodies arranged therebetween, wherein the wave spring is arranged between at least one of the outer bearing races and the bearing housing. The wave spring is arranged, for example, relative to the bearing housing, on the axially outer side of the radially outer bearing race of the roller bearing farthest from the turbine in the axial direction. In particular, the wave spring may be arranged between the roller bearing and a cover of the bearing housing.

[0020] Additional details and features of the invention are subsequently described by way of the figures.

Brief Description of the Drawings

Figure 1 shows a side view of a wave spring from the prior art; Figure 2 shows a cutaway view of a first embodiment of the wave spring according to the invention; Figure 3 shows a cutaway view of an embodiment of the charging device according to the invention.

Detailed Description of the Invention

[0021] In the following, embodiments of the wave spring according to the invention and the use of the wave spring according to the invention, and the charging device according to the invention will be described based on the figures. The same reference numerals are hereby used for the same parts.

[0022] Figure 1 shows a side view of a wave spring 10 as is known in the prior art. Wave springs 10 of this type are constructed from one or multiple layers 110, 120, 130 of a spring band 100 and act primarily axially. Spring strip 100 is designed with a wave shape. In wave springs 10 with multiple layers 1 10, 120, 130, as shown, for example, in the case of the wave spring shown with three layers 110, 120, 130, corresponding shoulders 150 of the wave springs directly contact one another and define maximums 152 and minimums 154.

[0023] Figure 2 shows a cutaway view of a wave spring 20 according to the invention. Wave spring 20 is likewise formed from a spring strip 100. Wave spring 20 comprises at least two layers 110, 120 that describe a corrugated line along spring strip 100. Wave spring 20 additionally comprises an intermediate layer 140, which is configured substantially straight along spring strip 100, and which in each case is between two of the layers 110, 120. The term "straight" is to be understood here as relative to the corrugated layers 110, 120, and encompasses not only intermediate layers 140, which are completely flat and level along spring strip 100, but also encompasses slight deviations from a completely flat and level course of spring strip 100 along intermediate layer 140. [0024] Figure 2 shows an embodiment with multiple corrugated layers. In other embodiments of the wave spring according to the invention, only two, three, or more than the number of corrugated layers shown may also be provided, and only one intermediate layer 140 or also multiple intermediate layers 140 may be provided. In the case of more than two corrugated layers 110, 120, an intermediate layer 140 may be provided between each two corrugated layers (as shown in Figure 2) or more than one, thus two, three, or more intermediate layers 140 may be provided between each two layers. Due to intermediate layer(s) 140, a sliding inside of one another or folding together of corrugated layers 110, 120 of wave spring 20 is prevented. This leads to stabilization and increased stiffness of wave spring 20. In addition, the absorption capacity for axial forces when outer torsional forces are simultaneously applied (for example, from an outer race of a ball bearing) remain higher in comparison to wave springs without intermediate layers.

[0025] Spring strip 100 may, for example, comprise spring steel. In particular, spring strip 100 may be manufactured completely from spring steel. The entire wave spring 20, thus all layers 110, 120 which describe a corrugated line along spring strip 100, and all intermediate layers 140 may also be designed from a correspondingly formed, one-piece spring strip 100.

[0026] As is clear in Figure 2, corrugated layers 110, 120 have shoulders 150. Shoulders 150 define maximums 152 and minimums 154 of the corrugated lines. Intermediate layers 140 are arranged in each case between opposite shoulders 150 of two adjacent corrugated layers 110, 120, so that intermediate layer 140 may contact on its upper side 142 with the first of opposite shoulders 150, and may contact on its lower side 144 with the second of opposite shoulders 150. This means that, unlike known wave springs 10, in which shoulders 150 directly contact corresponding maximums 152 and minimums 154, a part of intermediate layer 140 is arranged in each case between opposite maximums 152 and minimums 154, so that shoulders 150 do not directly contact in wave spring 20 according to the invention. If more than one intermediate layer 140 is provided between two respectively adjacent corrugated layers 110, 120, then shoulders 150 of corresponding minimums 154 contact upper side 142 of the top intermediate layer and shoulders 150 of corresponding maximums 152 contact lower side 144 of the bottom intermediate layer. In the embodiments, corrugated layers 110, 120 and intermediate layers 140 are not fixedly connected to one another at the corresponding contact points. In alternative embodiments, one or more of shoulders 150 may be fixedly connected to intermediate layers 140 either only on upper sides 142 of intermediate layers 140, or only on lower sides 144 of intermediate layers 140, or on upper sides 142 and lower sides 144. If multiple intermediate layers 140 are provided, these may or may not be fixedly connected to one another. In case they are fixedly connected to one another, then the connecting points may be provided on the corresponding contact areas with shoulders 150 of corrugated layers 110, 120. Shoulders 150 may, for example, be glued, soldered, or welded to intermediate layer(s) 140 or the intermediate layers may themselves be glued, solder, or welded to one another. [0027] As is clear in Figure 2, the corrugated line encompasses multiple periods per corrugated layer 110, 120. The corrugated line may be designed according to application and desired spring effect. It is also possible, for example, that the corrugated shape of the corrugated line changes along a layer, in order to implement, for example, a changing spring characteristic curve. For example, the corrugated lines of corrugated layers 110, 120 may also have a sinusoidal shape and an identical phase length.

[0028] Spring strip 100 may additionally have at least one non-corrugated edge region 160, 162. Edge regions 160, 162 may be designed both on the upper side and also on the underside of wave spring 20 (as is represented in Figure 2) and may be formed correspondingly from intermediate layer 140. The straight edge regions may function, for example, as contact surface(s) and ensure a better bearing surface of the wave spring in use. In alternative embodiments, only one non-corrugated edge region or no non-corrugated edge regions may be provided.

[0029] Figure 2 shows an embodiment of wave spring 20 according to the invention in which spring strip 100 is arranged as an annular shape. These types of wave springs are also designated as annular wave springs. Spring strip 100 is thereby formed in such a way that layers 110, 120, which describe a corrugated line along spring strip 100, and intermediate layers 140 each define a ring, wherein the rings are not each closed in themselves, but in each case transition directly into a new corrugated layer 110, 120 or intermediate layer 140. The rings of layers 110, 120 and intermediate layers 140 are arranged concentric to one another in the example shown in Figure 2. In addition, all rings have the same diameter. In alternative embodiments, the rings may have different diameters and, for example, may define a conical body.

[0030] Alternatively to wave spring 20 shown in Figure 2, the spring strip may also be arranged linearly. In wave spring of this type, the spring strip is formed in such a way that the layers, which describe a corrugated line along the spring strip, and the intermediate layer(s) define a linear sandwich structure. Wave springs of this type may be used, for example, in linearly-extending components to bias the same and/or to compensate for play.

[0031] The invention additionally comprises a use of wave springs described herein as elastic compensating elements or biasing elements in a charging device. In particular, an annular wave spring, as is shown in Figure 2 in an embodiment comprising multiple corrugated layers 110, 120 and in each case an intermediate layer 140 between two corrugated layers 110, 120, may be used as an elastic compensating disk for a bearing in a charging device. The charging device may, for example, be an electrically driven charging device or an electrically supported charging device (e.g., an electrically supported exhaust gas turbocharger). [0032] The invention additionally comprises a charging device, in particular an electrically driven charging device. A charging device of this type is shown in Figure 3. The charging device comprises a compressor 300 which has a compressor housing 310 and a compressor wheel 320, wherein the compressor wheel 320 is arranged on a shaft 400. The charging device additionally comprises a bearing housing 200 with a bearing arrangement for bearing shaft 400. The bearing arrangement comprises two bearing components 210, 220. A previously described wave spring 20 is provided as a compensating or biasing element between at least one of bearing components 210, 220 and bearing housing 200. Bearing components 210, 220 each have a roller bearing with in each case an inner bearing race 212, and outer bearing race 214, and rolling bodies 216 arranged therebetween. In the example shown in Figure 3, wave spring 20 is arranged, relative to bearing housing 200, on the axially outer side of radially outer bearing race 214 of roller bearing 210 farthest from turbine 300 in the axial direction. Wave spring 20 is thereby arranged between roller bearing 210 and a cover 230 of bearing housing 200. Alternatively, a wave spring may also be arranged only between roller bearing 220 situated closer to turbine 300 in the axial direction and bearing housing 200, or a wave spring may be arranged between both roller bearings 220 and bearing housing 200 or cover 230 of bearing housing 200.

Although the present invention has been described and is defined in the attached claims, it should be understood that the invention may also be alternatively defined according to the following embodiments: 1. A wave spring (20) made from a spring strip (100), characterized in that the wave spring (20) comprises at least two layers (110, 120) which each describe a corrugated line along the spring strip (100), and in that the wave spring (20) additionally comprises at least one intermediate layer (140), which is configured as substantially straight along the spring strip (100), between the at least two layers (110, 120).

2. The wave spring according to Embodiment 1, characterized in that the wave spring (20) comprises three or more layers (110, 120) which describe a corrugated line along the spring strip (100), and in that the wave spring (20) comprises at least one intermediate layer (140) in each case between two respectively adjacent layers (110, 120).

3. The wave spring according to Embodiment 1 or Embodiment 2, characterized in that the layers (110, 120), which describe a corrugated line, have shoulders (150), in particular wherein the shoulders (150) define maximums (152) and minimums (154) of the corrugated line(s).

4. The wave spring according to Embodiment 3, characterized in that the at least one intermediate layer (140) is positioned between respectively opposite shoulders (150) of two adjacent layers (110, 120) that describe a corrugated line along the spring strip (100), so that the intermediate layer(s) (140) contacts on its upper side (124) the first of the opposite shoulders (150) and contacts on its lower side (144) the second of the opposite shoulders (150).

5. The wave spring according to Embodiment 4, characterized in that the first or the first and second of the opposite shoulders (150) are fixedly connected to the intermediate layer(s) (140). The wave spring according to Embodiment 5, characterized in that the shoulders (150) are glued or welded to the intermediate layer(s) (140). The wave spring according to any one of the preceding embodiments, characterized in that the spring strip (100) comprises spring steel, in particular wherein the spring strip (100) is produced entirely from spring steel. The wave spring according to any one of the preceding embodiments, characterized in that the corrugated lines encompass multiple periods per layer (110, 120). The wave spring according to any one of the preceding embodiments, characterized in that the corrugated lines of the layers (110, 120) are sinusoidal and have an identical phase length. The wave spring according to any one of the preceding embodiments, characterized in that two, three, or more intermediate layers (140) are provided between each two layers (110, 120) that describe a corrugated line along the spring strip (100). The wave spring according to any one of the preceding embodiments, characterized in that all layers (110, 120), which describe a corrugated line along the spring strip (100), and the intermediate layer (140) are formed from a one-piece spring strip (100).

The wave spring according to any one of the preceding embodiments, characterized in that the spring strip (100) additionally has at least one non-corrugated edge region (160, 162). The wave spring according to any one of the preceding embodiments, characterized in that the spring strip (100) is arranged in a ring shape, in such a way that the layers (110, 120), which describe a corrugated line along the spring strip (100), and the intermediate layer (140) each define a ring.

The wave spring according to any one of the Embodiments 1 through 12, characterized in that the spring strip is arranged linearly in such a way that the layers, which describe a corrugated line along the spring strip, and the intermediate layer(s) define a linear sandwich structure.

The use of wave springs (20) according to any one of the Embodiments 1 through 13 as an elastic compensating disc for a bearing in a charging device, in particular wherein the charging device is an electrically driven or electrically supported charging device.

A charging device, in particular an electrically driven charging device, comprising

a compressor (300) which has a compressor housing (310) and a compressor wheel (320), wherein the compressor wheel (320) is arranged on a shaft (400);

a bearing housing (200) comprising a bearing arrangement for bearing the shaft (400), wherein the bearing arrangement comprises two bearing components (210, 220),

characterized in that a wave spring (20) according to any one of the preceding embodiments is arranged between at least one of the bearing components (210, 220) and the bearing housing (200).

The charging device according to Embodiment 16, characterized in that the bearing components (210, 220) each comprise a roller bearing comprising in each case an inner bearing race (212), an outer bearing race (214), and rolling bodies (216) arranged therebetween, wherein the wave spring (20) is arranged between at least one of the outer bearing races (212) and the bearing housing (200). A charging device according to Embodiment 17, characterized in that the wave spring (20) is arranged, relative to the bearing housing (200), on the axially outer side of radially outer bearing race (214) of the roller bearing (210) farthest from the turbine in the axial direction.

19. The charging device according to Embodiment 18, characterized in that the wave spring (20) is arranged between the roller bearing (210) and a cover (230) of the bearing housing (200).