Abstract
A synchronization unit of a switchable gear changing transmission for a vehicle. The synchronization unit includes a friction ring having an outer installation surface and a synchronizer ring having an inner installation surface. The outer installation surface of the friction ring is shaped as a first geometrically structured profile. The inner installation surface of the synchronizer ring is shaped as a corresponding second geometrically structured profile. The first profile of the friction ring is configured to engage with the second profile of the synchronizer ring in such a manner that the friction ring is secured in the radial direction to the axis and in the circumferential direction at the synchronizer ring.
Claims
1. A synchronization unit for a gear changing transmission of a vehicle, said unit comprising: a friction ring having an outer installation surface; the outer installation surface having a first geometrically structured profile extending in a circumferential direction around an axial axis of the friction ring and extending at a predetermined installation angle relative to the axial axis; a synchronizer ring having an inner installation surface; the inner installation surface having a second geometrically structured profile extending in a circumferential direction around an axial axis of the synchronizer ring and extending at a predetermined installation angle relative to the axial axis; and said axial axis of the friction ring being coaxial with said axial axis of the synchronizer ring, wherein, in an installed state, first segments of said first profile radially and circumferentially engage with second segments of said second profile.
2. The unit of claim 1, wherein segments of the first profile comprise at least one of: straight segments; outwardly curved segments; convex segments; inwardly curved segments; or concave segments.
3. The unit of claim 1, wherein segments of the first profile comprise at least one of: straight segments; outwardly curved segments; convex segments; inwardly curved segments; or concave segments.
4. The unit of claim 1, wherein said first profile is polygonal.
5. The unit of claim 1, wherein said second profile is polygonal.
6. The unit of claim 1, wherein the first segments of said first profile comprises adjacent straight segments arranged at an angle () of between 120 and 160.
7. The unit of claim 1, wherein the second segments of said second profile comprises adjacent straight segments arranged at an angle () of between 120 and 160.
8. The unit of claim 1, wherein the first segments of said first profile and segments of said second profile have a same shape.
9. The unit of claim 1, wherein alternating segments of said first profile and alternating segments of said second profile have a same shape.
10. The unit of claim 1, wherein the first segments of said first profile comprise at least two adjacent segments having different shapes.
11. The unit of claim 1, wherein the second segments of said second profile comprise at least two adjacent segments having different shapes.
12. The unit of claim 1, wherein the friction ring is at least one of: a split ring; a ring with spaced-apart ends; and a ring that can expand or contract radially and circumferentially.
13. The unit of claim 1, wherein at least one of: the outer installation surface comprises one of: a coating; and a friction reducing coating; and the inner installation surface comprises one of: a coating; and a friction reducing coating.
14. The unit of claim 1, wherein the friction ring is one of: a sheet metal part; a sintered steel part; a forged steel part; or a forged brass part.
15. The unit of claim 1, wherein the synchronizer ring is one of: a sheet metal part; a sintered steel part; a forged steel part; or a forged brass part.
16. A gear changing transmission for a vehicle or a passenger vehicle, comprising: a transmission; and a synchronization unit in accordance with claim 1.
17. A friction ring for a synchronization unit, said friction ring comprising: an outer installation surface that has a first geometrically structured profile extending in a circumferential direction around an axial axis and is segmented and extends at a predetermined installation angle relative to an axial axis of the synchronization unit; and the outer installation surface being configured to engage with an inner installation surface having a correspondingly shaped second geometrically structured profile of a synchronizer ring, wherein, in an installed state, segments of said first profile are configured to radially and circumferentially engage with segments of said second profile.
18. The ring of claim 17, wherein segments of the first profile comprise at least one of: straight segments; outwardly curved or convex segments; and inwardly curved or concave segments.
19. A synchronizer ring for a synchronization unit, said synchronizer ring comprising: an inner installation surface that has a first geometrically structured profile extending in a circumferential direction around an axial axis and extends at a predetermined installation angle relative to an axial axis of the synchronization unit; and the inner installation surface being configured to engage with an outer installation surface having a correspondingly shaped second geometrically structured profile of a friction ring, wherein, in an installed state, segments of said first profile are configured to radially and circumferentially engage with segments of said second profile.
20. The ring of claim 19, wherein segments of the first profile comprise at least one of: straight segments; outwardly curved segments; convex segments; inwardly curved segments; or concave segments.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:
[0053] FIG. 1 shows a synchronization unit known in the prior art;
[0054] FIG. 2a shows a first embodiment of a known segmented friction ring having axial securing means against rotation in an expanded configuration for a synchronization unit according to FIG. 1;
[0055] FIG. 2b shows the friction ring according to FIG. 2a in a compressed configuration;
[0056] FIG. 2c shows a section along the line I-I according to FIG. 2a;
[0057] FIG. 2d shows a section of the friction ring according to FIGS. 2a or 2b in a perspective view;
[0058] FIG. 3a shows a second embodiment of a known segmented friction ring having radial securing means against rotation;
[0059] FIG. 3b shows a section of the friction ring according to FIG. 3a in perspective view;
[0060] FIG. 4a shows a perspective view of an embodiment of a synchronization unit according to the invention;
[0061] FIG. 4b shows a perspective view of a synchronizer ring according to the invention for a synchronization unit according to FIG. 4a;
[0062] FIG. 4c shows a perspective view of a friction ring according to the invention for a synchronization unit according to FIG. 4a;
[0063] FIG. 4d shows a schematic view of the profile of the friction ring according to FIG. 4c;
[0064] FIG. 4e shows a cross-section of the unit shown in FIG. 4a using a sectioning plane passing through the unit and perpendicular to the center axis;
[0065] FIG. 4f shows a perspective cross-section of the unit shown in FIG. 4a;
[0066] FIG. 5a shows a schematic view of a profile of a second embodiment of a friction ring according to the invention;
[0067] FIG. 5b shows a schematic view of a profile of a third embodiment of a friction ring according to the invention;
[0068] FIG. 5c shows a schematic view of a profile of a fourth embodiment of a friction ring according to the invention; and
[0069] FIG. 5d shows a schematic view of a profile of a fifth embodiment of a friction ring according to the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0070] The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice.
[0071] As mentioned above, FIGS. 1 to 3b show a prior art unit which has already been explained in detail so that any further discussion may not be considered necessary. It is emphasized, however, that the friction ring shown in FIGS. 3a and 3b includes distinct projections 6 on the outer installation surface and these projections 6 non-rotatably engage with distinct comparably shaped recesses in the synchronizer ring (not shown in FIGS. 3a and 3b). As will be evident from the below description, the invention uses a geometrically shaped profile for the installation surfaces (outer installation surface in the case of the friction ring and inner installation surface in the case of the synchronizer ring) which does not utilize distinct projections of the type shown in FIGS. 3a and 3b.
[0072] FIG. 4a shows in a perspective view a first embodiment of a synchronization unit according to the invention which is designated with reference numeral 1. The reference numerals used in FIG. 4a to FIG. 5d have no apostrophe and refer to embodiments of the present invention. As already mentioned above, reference numerals used in FIG. 1 to FIG. 3b have an apostrophe, because they refer to embodiments known in the art.
[0073] The synchronization unit 1 comprises in a manner known per se a generally cone-shaped friction ring 2 and a generally cone-shaped synchronizer ring 3 which can be assembled or connected to each other in an interlocking manner. The friction ring 2 can have a conical inner surface 401 and has a conical outer installation surface 402. The synchronizer ring 3 has a conical outer surface and a conical inner installation surface 301. The outer installation surface 402 and the inner installation surface 301 extend at a predefinable installation angle conically along an axial axis 12 of the synchronization unit 1. The outer installation surface 402 of the friction ring 2 is shaped (e.g., bent or deformed) so as to have a first geometrically structured profile 7 extending in a circumferential direction U around the axis 12, and the inner installation surface 301 of the synchronizer ring 3 is similarly shaped with a corresponding second geometrically structured profile 8 in the circumferential direction U. In the installed state (or assembled state shown in FIG. 4a) the first profile 7 of the friction ring 2 engages with or into the second profile 8 of the synchronizer ring 3 in such a manner that the friction ring 2 is secured in the radial direction relative to the axis 12 and in the circumferential direction U at the synchronizer ring 3. According to the invention, the first profile 7 and the second profile 8 are shaped each in the form of a segmented trace 13 in the circumferential direction U. The segmented trace 13 is made up of a plurality of profile segments 14 arranged directly adjacent to one another. These segments 14 are shaped to as to correspond to an imaginary circle or cone coaxial with the axis 12 and in contact with outermost portions of the respective installation surface 301 and 402. The friction ring 2 can have a slit in this embodiment to allow for radial and/or circumferential expansion/contraction. The segmented curve trace 13 with form segments 14 can otherwise constitute a continuous closed surface 15 over a part of the circumference of the friction ring 2, i.e., the continuous closed surface 15 can be almost entirely continuous or only interrupted in the area of the slit. This is different in the case of the synchronizer ring 3, which lacks a slit, such that where the segmented curve trace 13 with form segments 14 constitutes a continuous closed surface 15 over the whole circumference of the synchronizer ring 3. The friction ring 2 and the synchronizer ring 3 are thus essentially connected non-rotatably by the segmented curve trace 13 with form segments 14 of the first profile 7 and the segmented curve trace 13 with form segments 14 of the second profile 8, i.e., apart from little angular deflections in the circumferential direction U, the friction ring 2 is non-rotatably connected to and/or non-rotatably assembled to the synchronizer ring 3.
[0074] FIG. 4b and FIG. 4c show separately in a perspective view the synchronizer ring 3 and the friction ring 2 of the synchronization unit 1 according to the invention illustrated in FIG. 4a. As should be apparent, the friction ring 2 can have a conical inner surface 401 which does not have a shaped profile like that of the outer installation surface 402. On the other hand, the synchronizer ring 3 can have an outer installation surface that has a shaped profile like that of the inner installation surface 301. When assembled as shown in FIG. 4a, the profiled outer installation surface 402 can be said to be tapered and irregularly shaped and is configured to nest with and frictionally engage with the tapered and correspondingly irregularly shaped profiled inner installation surface 301. The correspondingly irregularly shaped profiles 7 and 8 can this prevent relative rotation between the ring 2 and ring 3 when these are assembled together. In the nested configuration shown in FIG. 4a, the ring 2 can be forced to move axially in one direction relative to the ring 3 until the slit is closed (the ends of ring 2 defining the slit contact one another) and also move back to an original or relaxed position with the slit assuming a predefined separated position such as that shown in FIG. 4a.
[0075] As shown in FIG. 4c, the friction ring 2 is a generally conical friction ring body 4 having an inner friction surface 401 and an outer installation surface 402, which each bound the friction ring body 4 in a radial direction extending perpendicular to an axial friction ring axis 5. The inner friction surface 401 extends at a predetermined friction angle and the outer installation surface 402 extends at a predetermined installation angle conically along the friction ring axis 5. The outer installation surface 402 of the friction ring 2 is shaped so as to have a first geometrically structured profile 7 extending in a circumferential direction U around the friction ring axis 5. As can be seen in FIG. 4c, the first profile 7 is not circular and is shaped in the form of a profile trace 13 that is segmented or sectioned in the circumferential direction U. The profile 7 has a plurality of form segments or sections 14 that are directly adjacent to one another. As the friction ring 2 has a slit in this embodiment, the segmented curve trace 13 with form segments 14 constitutes a continuous closed surface 15 over a part (or nearly all) of the circumference of the friction ring 2, i.e., the continuous closed surface 15 need only be interrupted in the area of the slit.
[0076] As can be appreciated from FIG. 4d, all of the segments 14 of the segmented curve trace 13 of the first profile 7 of the friction ring 2 can be shaped as straight sections or profile sides, i.e., straight profile segments or sections. Consequently, the segmented curve trace 13 can be shaped in the manner of a polygon. In the illustrated embodiment, the segmented curve trace 13 has twelve straight profile sections which are arranged at a polygonal angle 1 of 150 to each other. With such a configuration, the segmented curve trace 13 is shaped rotationally symmetrically relative to the friction ring axis 5.
[0077] In this embodiment, the friction ring body 4 can be a one piece member with a slit, i.e., the segmented curve trace 13 with form segments 14 that constitute a continuous closed surface 15 over a part of the circumference of the friction ring body 4. It is also possible, as it is known in the art (see FIG. 2a and FIG. 2b), to form the friction ring body 4 from a plurality of separate friction ring segments which form the friction ring body 4 in a ring-shaped arrangement. These separate sections, however, would have the segmented curve trace 13 of the type disclosed herein such as having segments 14 that constitute a continuous closed surface 15 only over a part of the circumference of the friction ring body 4. Furthermore, it is possible to utilize a friction ring 2 that lacks a slit, wherein the segmented curve trace 13 with form segments 14 (see example of FIG. 4d) is a continuous closed surface 15 over the whole circumference of the friction ring 2.
[0078] Referring to FIG. 4b, it can be seen that the synchronizer ring 3 comprises a conical synchronizer ring body 16 having an inner installation surface 301 which extends at a predefinable installation angle conically along a synchronizer ring axis 9. The inner installation surface 301 of the synchronizer ring body 16 has a shaped second geometrically structured profile 8 extending in a circumferential direction U around the synchronizer ring axis 9. The second profile 8 has a shaped profile that generally corresponds to the first profile 7 of the friction ring 2. The second profile 8 is shaped to have a curve or profile trace 13 that is segmented in the circumferential direction U and comprising a plurality of form segments 14 that are directly adjacent to one another. However, unlike the first profile 7 of the friction ring 2 which can have a slit, the segmented curve trace 13 with form segments 14 that constitute a continuous closed surface 15 extend over the whole circumference because the synchronizer ring body 16 has no slit. If the first profile 7 of the friction ring 2 has all form segments 14 of the segmented curve trace 13 of the synchronizer ring 3 that are shaped as straight curves, it is preferred that the second profile 8 be similar shaped, i.e., if the first profile 7 is polygonal, the segmented curve trace 13 of the synchronizer ring 3 should be shaped like a polygon and, in conformity with the first profile 7 of the friction ring 2, can utilize twelve straight sections which are arranged at a polygonal angle of 150 to each other. The segmented curve trace 13 should also be shaped rotationally symmetrically to the synchronizer ring axis 9.
[0079] The synchronization unit 1 illustrated in FIG. 4a shows a segmented curve trace 13 of the first profile 7 and of the second profile 8 which is shaped in each case like a polygon having twelve tapered and straight profile sections and having a polygonal angle of 150. Of course, the polygon can also be composed of another number of straight profile sections (either fewer or more that 12 and whether an even number of an odd number) or the straight curves can be arranged at another polygonal angle to each other.
[0080] The friction ring 2 and the synchronizer ring 3 of the synchronization unit 1 shown in FIG. 4a can be each made of a sheet metal part or a sintered steel part. The first profile 7 of the friction ring 2 and the second profile 8 of the synchronizer ring 3 can also be provided with (or having at least partially arranged thereon) a coating such as a friction reducing coating such as a DLC coating.
[0081] FIG. 4a to FIG. 4d illustrate clearly that complex teeth or projection and recess elements are not required either on the outer installation surface 402 of the friction ring 2 or the inner installation surface 301 of the synchronizer ring 3.
[0082] FIGS. 5a to 5d show further embodiments of a segmented curve trace 13 according to the invention. The embodiments of the segmented curve trace differ from one another by the configuration and arrangement of the individual form or profile segments 14. All embodiments of a segmented curve trace shown in FIG. 5a to FIG. 5d can be applied in a synchronization unit according to the invention shown in FIG. 4a and specifically with respect to the installation surfaces 301 and 402. In the example shown in FIG. 4d, the straight profile segments 14 meet are corners which can be slight rounded, outwardly curved, or have a radius.
[0083] FIG. 5a shows a second embodiment of a segmented curve trace 13 according to the invention. Unlike the embodiment illustrated in FIG. 4a to 4d, the form segments 14 of the segmented profile trace 13 are not shaped as straight profile segments but are instead formed as tapered concave segments, i.e., the form 14 segments form a spline-like shape. The corners in this embodiment can be more sharp than that used in FIG. 4d or can be slightly rounded (outwardly curved).
[0084] As can be seen in FIG. 5b, it is also possible to shape the segments 14 of the segmented profile trace 13 to be tapered and convex instead of tapered and concave, i.e., in this case the form segments 14 are not bent or curved in the direction of axis 12 of the synchronization unit 1, but are instead bent against or curved outwardly from an axis 12 of the synchronization unit 1. The corners in this embodiment can be more sharp than that used in FIG. 4d or can be slightly rounded (inwardly curved).
[0085] As can be seen in FIG. 5c, it is also possible to make the segmented profile trace 13 to have a combination of tapered and convexly and concavely curved profile segments 14. Thus the segmented curve trace 13 has a spline-like shape in the circumferential direction over its whole length. This embodiment does not utilize corners unlike other embodiments and resembles a gear with tapered and rounded teeth.
[0086] FIG. 5d shows another embodiment wherein the segmented profile trace 13 utilizes a combination of alternating straight sections 14 and bent or inwardly curved sections 14. The corners in this embodiment can be more sharp than that used in FIG. 4d or can be slightly rounded (outwardly curved).
[0087] In the embodiments shown in FIG. 5a to 5d, the segmented profile trace 13 with form segments 14 can be a continuous closed surface over the whole or nearly whole circumference of the friction ring 2 and the synchronizer ring 3, respectively.
[0088] It is also possible that the segmented profile trace 13 with form segments 14 can constitute a continuous, closed surface only over a part of the circumference of the friction ring and the synchronizer ring, respectively.
[0089] As should be apparent, FIG. 5a to FIG. 5d illustrate clearly that the segmented profile trace 13 according to the invention can be composed of form segments of different geometry or that form segments of different geometry that can be combined to form the segmented profile trace according to the invention.
[0090] As can be noted from FIGS. 4e and 4f, the wall thickness of sections 14 of the friction ring 2 (which is disposed inside the synchronizer ring 3) can increase (in the case of FIGS. 4d and 5a) gradually and continuously from a middle of each section 14 to ends thereof which can define areas or zones of maximum wall thickness. The wall thickness of sections 14 of the friction ring 2 can also decrease (in the case of FIG. 5b) gradually and continuously from a middle of each section 14 to ends thereof which can define areas or zones of minimum wall thickness. A combination of gradual increasing and decreasing wall thickness can result from the shapes shown in FIGS. 5c and 5d. This is different from the prior art friction ring shown in FIGS. 3a and 3b which has distinct projections 6 of constant wall thickness in a comparable cross-sectioning plane, and which extend to perpendicular side surfaces. With respect to the synchronizer ring 3, the wall thickness in cross-section can be, in non-limiting embodiments (as shown in FIG. 4e) a substantially constant wall thickness, especially in regards to sections 14. As is also apparent from FIG. 4f, the friction ring 2 can utilize a coating on the inner conical surface. As noted in the above Summary, a coating can also be arranged on the outer conical surface of the friction ring 2 as well as on an inner conical surface of the synchronizer ring 3. It should also be apparent from FIGS. 4e and 4f, that the inner surface (or profile) of the friction ring can generally or approximately correspond in shape (e.g., cross-sectional shape) to the outer installation surface and also that the outer surface (or profile) of the synchronizer ring can generally or approximately correspond in shape (e.g., cross-sectional shape) to the inner installation surface of the synchronizer ring.
[0091] In the illustrated embodiments of the segmented profile trace according to the invention, the segmented profile trace has a non-circular cross-section and is shaped rotationally symmetrically to the axis of the synchronization unit. There are, of course, other conceivable embodiments where the segmented profile trace is shaped non-rotationally symmetrically to the axis of the synchronization unit.
