Gear reduction box

Abstract

A sleeve shaft is used within a gear reduction box to reduce the package size and weight. A sleeve mounts around a shaft for independent rotation relative to the shaft. The independently rotating sleeve allows for two power paths through the gear box. A first power path passes either the sleeve only or the shaft only. The second power path passes separately through both the sleeve and the shaft. The sleeve may be disposed around an input shaft or an intermediate shaft. A second sleeve can be disposed around an output shaft or another intermediate shaft.

Description

Attorney Docket No. 15720.1147WOU1GEAR REDUCTION BOXCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of Indian Provisional Application No. 202411073686, filed September 30, 2024, titled “GEAR REDUCTION BOX,” the disclosure of which is hereby incorporated herein by reference in its entirety.BACKGROUND

[0002] Vehicle transmissions decrease an input speed and increase torque between a prime mover and a wheel axle. A differential or other gear box is mounted to the wheel axle to apply a modified torque from the prime mover. Conventional transmissions use intermediate shafts between an input shaft and a differential shaft to achieve a required gear ratio. These intermediate shafts increase the package size and weight of the gear box.SUMMARY

[0003] In accordance with some aspects of the disclosure, a gear reduction box includes a first shaft and a second shaft; a first shaft sleeve mounted about the first shaft; and a second shaft sleeve mounted about the second shaft. The first shaft sleeve is configured to rotate independent of the first shaft. The second shaft sleeve is selectively configured to rotate independent of the second shaft. A first gear set connects the first shaft and the second shaft sleeve. A second gear set connects the second shaft sleeve and the first shaft sleeve. A third gear set connects the first shaft sleeve and the second shaft.

[0004] In accordance with other aspects of the disclosure, a gear reduction box provides two different torque transfer paths between the input shaft and the output shaft. The transfer paths use different gear sets having different gear ratios. Accordingly, the first transfer path has a different torque conversion from the second transfer path.

[0005] For example, in certain implementations, a gear reduction box includes a plurality of shafts; and a plurality of shaft sleeves. The shafts include an input shaft and an output shaft. Each shaft sleeve is mounted to one of the shafts and is configurable for independent rotation relative to the respective shaft. The shaft sleeves include a first shaft sleeve and a second shaft sleeve. A first gear set includes a gear carried by the first shaft sleeve. A second gear set includes a gear carried by the second shaft sleeve. The second gear set has a different gear ratio from the first gear set. A first torque transfer path between the input shaft and the outputAttorney Docket No. 15720.1147WOU1 shaft passes through the first of the shaft sleeves. A second torque transfer path between the input shaft and the output shaft passes through the second of the shaft sleeves.

[0006] In some examples, the first and second sleeves are disposed on different ones of the shafts. In other examples, the first and second sleeves are disposed on a common one of the shafts.

[0007] A variety of additional inventive aspects will be set forth in the description that follows. The inventive aspects can relate to individual features and to combinations of features. It is to be understood that both the forgoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The accompanying drawings, which are incorporated in and constitute a part of the description, illustrate several aspects of the present disclosure. A brief description of the drawings is as follows:

[0009] FIG. 1 schematically shows an example gear box including an input shaft and an output shaft connected by gear sets, the input and output shafts supporting independently rotatable sleeves.

[0010] FIG. 2 shows the power transfer path amongst the shafts and sleeves of FIG. 1.

[0011] FIG. 3 schematically shows another example gear box including an input shaft, an intermediate shaft, and an output shaft, at least one of the shafts supporting an independently rotatable sleeve.

[0012] FIG. 4 shows a first power transfer path through the gear box of FIG. 3.

[0013] FIG. 5 shows a second power transfer path through the gear box of FIG. 3.

[0014] FIG. 6 schematically shows another example gear box including an input shaft, multiple intermediate shafts, and an output shaft, where multiple of the shafts support respective independently rotatable sleeves.

[0015] FIG. 7 shows a first power transfer path through the gear box of FIG. 6.

[0016] FIG. 8 shows a second power transfer path through the gear box of FIG. 6.DETAILED DESCRIPTION

[0017] Reference will now be made in detail to exemplary aspects of the present disclosure that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.Attorney Docket No. 15720.1147WOU1

[0018] Referring to the figures in general, a gear box 100 includes multiple shafts 102 operationally connected by gear sets 120. Each shaft 102 is configured to rotate about a respective longitudinal axis L. Bearings 104 (e.g., roller bearings) may support the shafts 102 to enable rotation of the shafts 102. The gear sets 120 transfer torque between the shafts 102. Each gear set 120 includes a first gear and a second gear that mesh together to transfer rotational motion therebetween. In certain examples, the gear sets 120 are configured to change (e.g., increase or reduce) the torque and / or rotation speed between shafts 102.

[0019] The shafts 102 include at least an input shaft 106 and an output shaft 108. The input shaft 106 receives torque from a prime mover (e.g., an EV motor, an internal combustion engine, etc.) to rotate the input shaft 106 about the longitudinal axis L of the input shaft 106. The output shaft 108 is coupled to one or more wheels 112 of a vehicle. In certain implementations, the output shaft 108 includes a differential housing 105 (e.g., for a locking differential assembly). In some implementations, the gear reduction box 100 includes only the input and output shafts 106, 108 (e.g., see FIGS. 1-2). In other implementations, however, one or more intermediate shafts 110 enable further changes to torque and / or speed between the input and output shafts 106, 108 as will be discussed in further detail herein.

[0020] In accordance with certain aspects of the disclosure, independently rotatable sleeves 130 may be disposed about two or more of the shafts 102. For example, a first sleeve 132 may be disposed around the input shaft 106 and a second sleeve 134 may be disposed around the output shaft 108. In certain examples, the second sleeve 134 is disposed about the differential housing 105. Each sleeve 130, 132, 134 is supported by a respective bearing arrangement 136 (e.g., needle bearings) to enable the sleeve 130, 132, 134 to rotate about the supporting shaft 102, 106, 108 independent of the rotation of the supporting shaft 102, 106, 108. In certain implementations, the sleeves 130, 132, 134 may carry portions of gears sets 120. In certain examples, the sleeves 130 may be at least partially offset from each other along the shafts 102 to accommodate multiple gear sets 120 to be disposed in series along the longitudinal axes L of the shafts 102.

[0021] Referring to FIGS. 1-2, a first 121 of the gear sets 120 connects the input shaft 106 to the second sleeve 134 disposed about the output shaft 108; a second 122 of the gear sets 120 connects the second sleeve 134 to the first sleeve 132 disposed about the input shaft 106; and a third 123 of the gear sets 120 connects the first sleeve 132 to the output shaft 108. Accordingly, torque from the input shaft 106 is first transferred to the second sleeve 134 via the first gear set 121. Torque from the second sleeve 134 is then transferred to the first sleeveAttorney Docket No. 15720.1147WOU1132 via the second gear set 122. Torque from the first sleeve 132 is transferred to the output shaft 108 via the third gear set 123.

[0022] In certain examples, each of the gear sets 121, 122, 123 converts (e.g., increases or decreases) the torque and / or rotational speed between the respective components. For example, the first gear set 121 includes a first gear 140 and a second gear 142. The first gear 140 is mounted about the input shaft 106 and configured to rotate in unison with the input shaft 106. The second gear 142 is mounted about the second sleeve 134 and configured to rotate in unison with the second sleeve 134. A gear ratio between the first and second gears 140, 142 provides a first torque conversion Cl between the input shaft 106 and the second sleeve 134. The second gear set 122 includes a third gear 144 and a fourth gear 146. The third gear 144 is mounted about the second sleeve 134 and configured to rotate in unison with the second sleeve 134. The fourth gear 146 is mounted about the first sleeve 132 and configured to rotate in unison with the first sleeve 132. A gear ratio between the third and fourth gears 144, 146 provides a second conversion C2 between the second sleeve 134 and the first sleeve 132. The third gear set 123 includes a fifth gear 148 and a sixth gear 150. The fifth gear 148 is mounted about the first sleeve 132 and configured to rotate in unison with the first sleeve 132. The sixth gear 150 is mounted about the output shaft 108 and configured to rotate in unison with the output shaft 108. A gear ratio between the fifth and sixth gears 148, 150 provides a third conversion C3 between the first sleeve 132 and the output shaft 108. Accordingly, multiple torque / speed conversions can be made within a package sized to hold only two shafts 102.

[0023] Referring to FIGS. 3-11, the gear box 100 can include one or more intermediate shafts 110 through which torque is transferred between the input shaft 106 and the output shaft 108. In certain examples, one or more sleeves 130 may be mounted about the intermediate shaft 110 to rotate independent of the intermediate shaft 110. Each of the sleeves 130 may carry a gear set 120. The inclusion of the intermediate shaft 110 provides an extra opportunity for gear ratio conversions between the input and output shafts 106, 108.

[0024] In accordance with certain aspects of the disclosure, the sleeves 130 enable multiple torque transfer pathways to be formed between the shafts 102. For example, multiple sleeves 130 may be mounted to a common shaft 102. A clutch arrangement 170 (e.g., a dog clutch) also may be mounted at the common shaft 102. The clutch arrangement 170 is configurable (e.g., axially movable) between a first state and a second state. When in the first state, the clutch 170 rotationally fixes a first of the sleeves 130 to the common shaft 102 to rotate in unison with the common shaft 102 while a second of the sleeves 130 remains rotationally independent of the common shaft 102. When in the second state, the clutch 170Attorney Docket No. 15720.1147WOU1 rotationally fixes the second sleeve 130 to the common shaft 102 while the first sleeve remains rotationally independent. Accordingly, the state of the clutch 170 determines through which gear set 120 the torque will transfer as will be discussed in more detail herein.

[0025] FIGS. 3-5 illustrate a second example implementation of a gear box 200 that includes an input shaft 106, an output shaft 108, and an intermediate shaft 110. Each of the shafts 106, 108, 110 is supported by bearings 104 and is configured to rotate about its longitudinal axis L. A first sleeve 132 is mounted to the input shaft 106, a second sleeve 134 is mounted to the intermediate shaft 110, and a third sleeve 136 also is mounted to the intermediate shaft 110. A clutch 170 also is disposed on the intermediate shaft 110. The clutch 170 selectively connects either the second sleeve 134 or the third sleeve 136 to the intermediate shaft 110 to rotate in unison therewith.

[0026] A first gear set 121 connects the input shaft 106 to the second sleeve 134 disposed about the intermediate shaft 110. Torque from the input shaft 106 is first transferred to the second sleeve 134 via the first gear set 121. A second gear set 122 connects the second sleeve 134 to the first sleeve 132 disposed about the input shaft 106 and a third gear set 123 connects the first sleeve 132 to the third sleeve 136. The gear ratio of the third gear set 123 is different than the gear ratio of the second gear set 122.

[0027] When in a first state, the clutch 170 allows the second sleeve 134 to rotate independent of the intermediate shaft 110 (e.g., see FIG. 4). In certain examples, the clutch 170 connects the third sleeve 136 to the intermediate shaft 110 to rotate therewith when the clutch 170 is configured in the first state. Accordingly, torque transfers from the second sleeve 134 to the first sleeve 132 via the second gear set 122 and then from the first sleeve 132 to the third sleeve 136 via the third gear set 123 (e.g., see FIG. 4). The clutch 170 causes the intermediate shaft 110 to rotate with the third sleeve 136. The fourth gear set 124 transfers torque from the intermediate shaft 110 to the output shaft 108. Accordingly, when the clutch 170 is disposed in the first state, the torque transfers through four sets of gear ratio conversions — a first conversion Cl at the first gear set 121, a second conversion C2 at the second gear set 121, a third conversion C3 at the third gear set 123, and a fourth conversion C4 at the fourth gear set 124 (e.g., see FIG. 4).

[0028] When in a second state, however, the clutch 170 connects the second sleeve 134 to the intermediate shaft 110 to rotate therewith (e.g., see FIG. 5). Torque from the second sleeve 134 transfers directly to the intermediate shaft 110, thereby bypassing the torque transmission path through the first sleeve 132 (and through the second and third gear sets 122, 123). The torque transfers through only two sets of gear ratio conversions — the conversion Cl at the firstAttorney Docket No. 15720.1147WOU1 gear set 121 and the conversion C4 at the fourth gear set 124. Accordingly, the gear box 200 is configured to selectively provide two different torque conversions between the input shaft 106 and the output shaft 108.

[0029] In certain examples, the third sleeve 136 is offset along the longitudinal axis L of the intermediate shaft from the second sleeve 134. In certain implementations, the clutch 170 is disposed between the second and third sleeves 134, 136. In certain examples, the clutch 170 moves along the longitudinal axis L of the intermediate shaft 110 to selectively contact the second and third sleeves 134, 136 when transitioning between the first and second states, respectively. In certain examples, the second and third sleeve 134, 136 are coaxial with each other. In certain examples, the third sleeve 136 rotates independent of the intermediate shaft 110 when the clutch 170 is configured in the second state.

[0030] FIGS. 6-8 illustrate a third example implementation of a gear box 300 configured to selectively provide two different torque conversions between the input shaft 106 and the output shaft 108. The third gearbox 300 includes an input shaft 106, an output shaft 108, and multiple intermediate shafts 110. In the example shown, the gear box 300 includes a main intermediate shaft 110A and a counter intermediate shaft HOB. Each of the shafts 106, 108, 110A, 110B is supported by bearings 104 and is configured to rotate about its longitudinal axis L.

[0031] In the gear box 300, the first sleeve 132 is coupled to the counter shaft HOB instead of to the input shaft 106. The second and third sleeves 134, 136 are coupled to the main shaft 110A. The clutch 170 also is mounted to the main shaft 110A to selectively rotationally fix either the second sleeve 134 or the third sleeve 136 to the main shaft 110A. A first gear set 121 transfers torque from the input shaft 106 to the first sleeve 132, which rotates independent of the counter shaft 110B. A second gear set 122 transfers torque from the first sleeve 132 to the second sleeve 134.

[0032] When the clutch 170 is configured in the first state, the second sleeve 134 rotates independent of the main intermediate shaft 110A. A third gear set 123 transfers torque from the second sleeve 134 to the counter shaft 110B, which applies the torque to the third sleeve 136 via a fourth gear set 124. The third sleeve 136 is rotationally fixed to the main shaft 110A via the clutch 170 and, therefore, transfers torque to the main shaft 110A. A fifth gear set 125 applies the torque from the main shaft 110A to the output shaft 108. Accordingly, the torque undergoes five conversions Cl, C2, C3, C4, C5 between the input shaft 106 and the output shaft 108 (e.g., see FIG. 7).Attorney Docket No. 15720.1147WOU1

[0033] When the clutch 170 is configured in the second state, however, the second sleeve 134 is rotationally fixed to the main shaft 110A. Accordingly, torque from the first sleeve 132 is transferred to the main shaft 110A through the second sleeve 134 and the clutch 170. The fifth gear set 125 applies the torque from the main shaft 110A to the output shaft 108. Accordingly, the torque undergoes only three conversions Cl, C2, C5 between the input shaft 106 and the output shaft 108 (e.g., see FIG. 8).

[0034] Some example sleeve shaft configurations suitable for a gear box reduction configured in accordance with the principles of the present disclosure are disclosed in the following aspects:

[0035] Aspect 1. A gear reduction box comprising:

[0036] a plurality of shafts including an input shaft and an output shaft;

[0037] a plurality of shaft sleeves, each shaft sleeve being mounted to one of the shafts and being configurable for independent rotation relative to the respective shaft, the plurality of shaft sleeves including a first shaft sleeve and a second shaft sleeve;

[0038] a first gear set including a gear carried by the first shaft sleeve;

[0039] a second gear set including a gear carried by the second shaft sleeve, the second gear set having a different gear ratio from the first gear set;

[0040] a first torque transfer path between the input shaft and the output shaft, the first torque transfer path passing through the first of the shaft sleeves; and

[0041] a second torque transfer path between the input shaft and the output shaft, the second torque transfer path passing through the second of the shaft sleeves.

[0042] Aspect 2. The gear reduction box of aspect 1, wherein the first and second sleeves are disposed on different ones of the shafts.

[0043] Aspect 3. The gear reduction box of aspect 1, wherein the first and second sleeves are disposed on a common one of the shafts.

[0044] Aspect 4. The gear reduction box of aspect 1, further comprising a clutch disposed on the common one of the shafts, the clutch rotationally fixing the first sleeve to the common one of the shafts when the clutch is configured in a first state, and the clutch rotationally fixing the second sleeve to the common one of the shafts when the clutch is configured in a second state.

[0045] Aspect 5. The gear reduction box of aspect 1, wherein the first sleeve is disposed on the input shaft.

[0046] Aspect 6. The gear reduction box of aspect 1, wherein the second sleeve is disposed on the output shaft.Attorney Docket No. 15720.1147WOU1

[0047] Aspect 7. The gear reduction box of aspect 1, wherein the output shaft includes a differential housing.

[0048] Aspect 8. A gear reduction box having a torque input and a torque output, the gear reduction box comprising:

[0049] a shaft (106, HOB);

[0050] a sleeve (132) mounted to the shaft (106, HOB), the sleeve (132) being configured for independent rotation relative to the shaft;

[0051] a first torque transfer path passing from the torque input to the torque output, the first torque transfer path passing through only one of the shaft (106, 110B) and the sleeve (132), and; and

[0052] a second torque transfer path passing from the torque input to the torque output, the second torque transfer path passing separately through both the shaft (106, 110B) and the sleeve (132).

[0053] Aspect 9. The gear reduction box of aspect 8, wherein the shaft is a first shaft (106, HOB) and the sleeve (132) is a first sleeve; wherein a second sleeve (134) is mounted to a second shaft (110, 110A) and configured for independent rotation relative to the second shaft; and wherein both the first and second torque transfer paths pass through the second sleeve (134) and the second shaft (110, 110A) to reach the torque output.

[0054] Aspect 10. The gear reduction box of aspect 9, wherein the second torque transfer path passes from the torque input, through the first shaft (106), to the second sleeve (134), to the first sleeve (132), to the second shaft (110).

[0055] Aspect 11. The gear reduction box of aspect 9, wherein the second torque transfer path passes from the torque input, through the first sleeve (132), to the second sleeve (134), to the first shaft (HOB), to the second shaft (110A).

[0056] Aspect 12. The gear reduction box of any of aspects 9-11, further comprising a clutch disposed on the second shaft (110, 110A), the clutch being selectively transitionable between first and second states, the clutch coupling the second sleeve (134) to the second shaft (110, 110B) when configured in the first state to form the first torque transfer path, and the clutch coupling the second sleeve (134) to the first sleeve (132) when configured in the second state to form the second torque transfer path.

[0057] Aspect 13. The gear reduction box of aspect 9, wherein the torque output includes an output shaft.

[0058] Aspect 14. The gear reduction box of aspect 9, wherein the torque output includes a differential housing.Attorney Docket No. 15720.1147WOU1

[0059] Aspect 15. A gear reduction box comprising:

[0060] a plurality of shafts including a first shaft and a second shaft;

[0061] a first shaft sleeve mounted about the first shaft, the first shaft sleeve being configured to rotate independent of the first shaft;

[0062] a second shaft sleeve mounted about the second shaft, the second shaft sleeve being selectively configured to rotate independent of the second shaft;

[0063] a first gear set connecting the first shaft and the second shaft sleeve;

[0064] a second gear set connecting the second shaft sleeve and the first shaft sleeve; and

[0065] a third gear set connecting the first shaft sleeve and the second shaft.

[0066] Aspect 16. The gear reduction box of aspect 15, wherein the first sleeve is disposed on an input shaft extending from a prime mover.

[0067] Aspect 17. The gear reduction box of aspect 15, wherein the second sleeve is disposed on the output shaft.

[0068] Aspect 18. The gear reduction box of aspect 17, wherein the second sleeve is disposed around a differential housing.

[0069] Aspect 19. The gear reduction box of aspect 15, wherein the plurality of shafts includes an output shaft; and wherein the second shaft is an intermediate shaft.

[0070] Aspect 20. The gear reduction box of aspect 19, wherein the intermediate shaft couples directly to the output shaft.

[0071] Having described the preferred aspects and implementations of the present disclosure, modifications and equivalents of the disclosed concepts may readily occur to one skilled in the art. However, it is intended that such modifications and equivalents be included within the scope of the claims which are appended hereto.

Claims

Attorney Docket No. 15720.1147WOU1What is claimed is:

1. A gear reduction box comprising: a plurality of shafts including an input shaft and an output shaft; a plurality of shaft sleeves, each shaft sleeve being mounted to one of the shafts and being configurable for independent rotation relative to the respective shaft, the plurality of shaft sleeves including a first shaft sleeve and a second shaft sleeve; a first gear set including a gear carried by the first shaft sleeve; a second gear set including a gear carried by the second shaft sleeve, the second gear set having a different gear ratio from the first gear set; a first torque transfer path between the input shaft and the output shaft, the first torque transfer path passing through the first of the shaft sleeves; and a second torque transfer path between the input shaft and the output shaft, the second torque transfer path passing through the second of the shaft sleeves.

2. The gear reduction box of claim 1, wherein the first and second sleeves are disposed on different ones of the shafts.

3. The gear reduction box of claim 1, wherein the first and second sleeves are disposed on a common one of the shafts.

4. The gear reduction box of claim 1, further comprising a clutch disposed on the common one of the shafts, the clutch rotationally fixing the first sleeve to the common one of the shafts when the clutch is configured in a first state, and the clutch rotationally fixing the second sleeve to the common one of the shafts when the clutch is configured in a second state.

5. The gear reduction box of claim 1, wherein the first sleeve is disposed on the input shaft.

6. The gear reduction box of claim 1, wherein the second sleeve is disposed on the output shaft.Attorney Docket No. 15720.1147WOU17. The gear reduction box of claim 1, wherein the output shaft includes a differential housing.

8. A gear reduction box having a torque input and a torque output, the gear reduction box comprising: a shaft; a sleeve mounted to the shaft, the sleeve being configured for independent rotation relative to the shaft; a first torque transfer path passing from the torque input to the torque output, the first torque transfer path passing through only one of the shaft and the sleeve, and; and a second torque transfer path passing from the torque input to the torque output, the second torque transfer path passing separately through both the shaft and the sleeve.

9. The gear reduction box of claim 8, wherein the shaft is a first shaft and the sleeve is a first sleeve; wherein a second sleeve is mounted to a second shaft and configured for independent rotation relative to the second shaft; and wherein both the first and second torque transfer paths pass through the second sleeve and the second shaft to reach the torque output.

10. The gear reduction box of claim 9, wherein the second torque transfer path passes from the torque input, through the first shaft, to the second sleeve, to the first sleeve, to the second shaft.

11. The gear reduction box of claim 9, wherein the second torque transfer path passes from the torque input, through the first sleeve, to the second sleeve, to the first shaft, to the second shaft.

12. The gear reduction box of any of claims 9-11, further comprising a clutch disposed on the second shaft, the clutch being selectively transitionable between first and second states, the clutch coupling the second sleeve to the second shaft when configured in the first state to form the first torque transfer path, and the clutch coupling the second sleeve to the first sleeve when configured in the second state to form the second torque transfer path.Attorney Docket No. 15720.1147WOU113. The gear reduction box of claim 9, wherein the torque output includes an output shaft.

14. The gear reduction box of claim 9, wherein the torque output includes a differential housing.

15. A gear reduction box comprising: a plurality of shafts including a first shaft and a second shaft; a first shaft sleeve mounted about the first shaft, the first shaft sleeve being configured to rotate independent of the first shaft; a second shaft sleeve mounted about the second shaft, the second shaft sleeve being selectively configured to rotate independent of the second shaft; a first gear set connecting the first shaft and the second shaft sleeve; a second gear set connecting the second shaft sleeve and the first shaft sleeve; and a third gear set connecting the first shaft sleeve and the second shaft.

16. The gear reduction box of claim 15, wherein the first sleeve is disposed on an input shaft extending from a prime mover.

17. The gear reduction box of claim 15, wherein the second sleeve is disposed on the output shaft.

18. The gear reduction box of claim 17, wherein the second sleeve is disposed around a differential housing.

19. The gear reduction box of claim 15, wherein the plurality of shafts includes an output shaft; and wherein the second shaft is an intermediate shaft.

20. The gear reduction box of claim 19, wherein the intermediate shaft couples directly to the output shaft.

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