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US-12624754-B2 - Geartrain anti-backlash linkage

US12624754B2US 12624754 B2US12624754 B2US 12624754B2US-12624754-B2

Abstract

A geartrain assembly includes a first gear, a second gear, and a third gear. A linkage connects the first gear and the second gear, and defines an assembly location of the third gear to connect the third gear to the first and second gears in a manner that minimizes a backlash in the geartrain assembly.

Inventors

  • Bradley S. Adriaansen

Assignees

  • CUMMINS INC.

Dates

Publication Date
20260512
Application Date
20230531

Claims (15)

  1. 1 . A geartrain assembly, comprising: a first gear; a second gear; a third gear positionable between the first gear and the second gear; and a linkage including a first link member connected to the first gear and a second link member connected to the second gear, the first link member and the second link member each including at least one free end that engage one another to define a mounting location of the third gear to connect the third gear to the first gear and to the second gear, wherein: the first link member includes a first circular flange at one end thereof that is positioned around an idler shaft of the first gear, the first link member including a first locating member at the other end thereof opposite the first circular flange; the second link member includes a second circular flange at one end thereof that is positioned around an idler shaft of the second gear, the second link member includes a second locating member at the other end thereof opposite the second circular flange; the first and second locating members are interlocked with one another to define the mounting location for the third gear; and each of the first and second locating members includes a ring-shaped plate, and one of the first and second locating members includes a lip projecting outwardly from the ring-shaped plate thereof that is captured in the ring-shaped plate of the other of the first and second locating members.
  2. 2 . A geartrain assembly, comprising: a first gear; a second gear; a third gear positionable between the first gear and the second gear; and a linkage connecting the first gear and the second gear that defines a mounting location of the third gear to connect the third gear to the first gear and to the second gear, wherein the third gear includes: an idler shaft including at least one hole for receiving a fastener; a retainer engaged to the idler shaft to retain the third gear on the idler shaft, the retainer including at least one hole for receiving the fastener; and a load plate engaged to the retainer with the fastener, wherein the at least one hole in each of the idler shaft and the retainer are over-sized relative to the fastener to allow for alignment of the third gear with respect to the mounting location.
  3. 3 . The geartrain assembly of claim 2 , wherein the third gear includes: a first thrust bearing between the retainer and a first face of a gear wheel of the third gear; and a second thrust bearing between a radially extending lip of the idler shaft and a second face of the gear wheel of the third gear that is opposite the first face.
  4. 4 . The geartrain assembly of claim 2 , wherein the third gear includes a bushing around the idler shaft.
  5. 5 . The geartrain assembly of claim 2 , wherein the idler shaft includes a radially extending lip around its circumference that is positioned against the linkage at the mounting location.
  6. 6 . The geartrain assembly of claim 2 , wherein the linkage includes a first link member connected to the first gear and a second link member connected to the second gear, the first link member extending from the first gear and the second link member extending from second gear to corresponding free ends of the first and second link members, wherein the free ends engage one another to define the mounting location for the third gear.
  7. 7 . The gear train assembly of claim 6 , wherein: the first link member includes a first circular flange at one end thereof that is positioned around an idler shaft of the first gear; and the second link member includes a second circular flange at one end thereof that is positioned around an idler shaft of the second gear.
  8. 8 . The geartrain assembly of claim 7 , wherein: the first link member includes a first locating member at the other end thereof opposite the first circular flange; the second link member includes a second locating member at the other end thereof opposite the second circular flange; and the first and second locating members are interlocked with one another to define the mounting location for the third gear.
  9. 9 . The geartrain assembly of claim 8 , wherein each of the first and second locating members includes a ring-shaped plate, and one of the first and second locating members includes a lip projecting outwardly from the ring-shaped plate thereof that is captured in the ring-shaped plate of the other of the first and second locating members.
  10. 10 . A geartrain assembly, comprising: a first gear; a second gear; a third gear positionable between the first gear and the second gear; and a linkage connecting the first gear and the second gear that defines a mounting location of the third gear to connect the third gear to the first gear and to the second gear, wherein each of the first gear and second gear includes: an idler shaft including at least one hole for receiving a fastener; a retainer engaged to the idler shaft to retain the corresponding one of the first gear and the second gear on the idler shaft, the retainer including at least one hole for receiving the fastener; and a bushing around the idler shaft about which the corresponding one of the first gear and the second gear rotates.
  11. 11 . The geartrain assembly of claim 10 , wherein the idler shaft includes a radially extending lip around its circumference and the linkage is positioned between the radially extending lip and a rearward face of a gear wheel of the corresponding one of the first gear and the second gear.
  12. 12 . The geartrain assembly of claim 10 , wherein the linkage includes a first link member connected to the first gear and a second link member connected to the second gear, the first link member extending from the first gear and the second link member extending from second gear to corresponding free ends of the first and second link members, wherein the free ends engage one another to define the mounting location for the third gear.
  13. 13 . The gear train assembly of claim 12 , wherein: the first link member includes a first circular flange at one end thereof that is positioned around an idler shaft of the first gear; and the second link member includes a second circular flange at one end thereof that is positioned around an idler shaft of the second gear.
  14. 14 . The geartrain assembly of claim 13 , wherein: the first link member includes a first locating member at the other end thereof opposite the first circular flange; the second link member includes a second locating member at the other end thereof opposite the second circular flange; and the first and second locating members are interlocked with one another to define the mounting location for the third gear.
  15. 15 . The geartrain assembly of claim 14 , wherein each of the first and second locating members includes a ring-shaped plate, and one of the first and second locating members includes a lip projecting outwardly from the ring-shaped plate thereof that is captured in the ring-shaped plate of the other of the first and second locating members.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation of International PCT Application No. PCT/US21/72026 filed on Oct. 26, 2021, which claims the benefit of the filing date of, U.S. Provisional Application Ser. No. 63/120,950 filed on Dec. 3, 2020, which is incorporated herein by reference. TECHNICAL FIELD The present application relates generally to a geartrain assembly, and more particularly to an anti-backlash linkage for assembly of the geartrain. BACKGROUND Geartrain assemblies for internal combustion engines and other applications are well known in the industry and often used for driving cam shafts, balancer shafts, fuel injection pumps and other components. The geartrain assembly may include a start gear, an end gear, and a middle gear positioned between and connecting the start gear and the end gear. In certain installations, such as when spanning a casting joint or in long gear stackups, the location of the middle gear(s) may have to be manually set and therefore may not be precisely controlled relative to the start and end gears. As a result, backlash between the gears can occur which creates noise, vibration, and/or harshness (NVH) issues that must then be attenuated, to the extent possible, by other components, increasing the cost of the assembly. Therefore, further contributions in this area of technology are needed to improve a geartrain assembly. Therefore, there remains a significant need for the apparatuses, methods and systems disclosed herein. SUMMARY An anti-backlash linkage is disclosed that automatically locates, for example, a middle gear between start and end gears. The linkage creates a shorter tolerance stackup loop which allows for fixed mounting methods to be used for mounting the middle gear rather than manually adjustable methods. In one embodiment, the linkage is employed in geartrains that span across multiple engine components that create long tolerance stackup chains, such as when spanning a cylinder block to cylinder head interface. In one embodiment, the linkage remains as a permanent fixture and part of the geartrain assembly after installation. In another embodiment, the linkage is an assembly aide that is removed post-installation of the geartrain assembly. The linkage provides improved backlash for the geartrain across high-variation joints, such as between the head and block, but is not limited to such applications. The improved backlash reduces NVH, improves engine operation, reduces mechanical noise response from the engine during operation, and provides more consistent NVH from engine to engine. This summary is provided to introduce a selection of concepts that are further described below in the illustrative embodiments. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS The concepts described herein are illustrative by way of example and not by way of limitation in the accompanying figures. For simplicity and clarity of illustration, elements illustrated in the figures are not necessarily drawn to scale. Where considered appropriate, references labels have been repeated among the figures to indicate corresponding or analogous elements. FIG. 1 is a perspective view of a geartrain assembly of the present disclosure. FIG. 2 is a partial sectional view of the start and end gears of the geartrain assembly of FIG. 1. FIG. 3 is a partial sectional view of the middle gear of the geartrain assembly of FIG. 1. FIG. 4 is a diagram showing how the linkage can be used to precisely locate the middle gear during installation of the geartrain assembly. FIGS. 5A-5C show various steps in a geartrain assembly procedure. DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, any alterations and further modifications in the illustrated embodiments, and any further applications of the principles of the invention as illustrated therein as would normally occur to one skilled in the art to which the invention relates are contemplated herein. FIGS. 1-3 show a geartrain assembly 10 along with a start or first gear 20, an end or second gear 30, and a middle or third gear 50 that connects the first and second gears 20, 30. In one embodiment, the geartrain assembly 10 span a joint 12, such as a casting joint between a block 14 and a head 16 of an internal combustion engine. However, the present disclosure also has application in gear train assemblie