GB1594788A

GB1594788A - Torsional vibration damper

Info

Publication number: GB1594788A
Application number: GB20874/78A
Authority: GB
Original assignee: Borg Warner Corp
Current assignee: Borg Warner Corp
Priority date: 1977-05-31
Filing date: 1978-05-19
Publication date: 1981-08-05
Also published as: ES470154A1; SE435088B; JPS53148670A; DE2823894A1; BR7803497A; IT1094940B; AU522690B2; JPS6024336B2; IT7823998A0; DE2823894C2; AR222151A1; CA1105742A; AU3640978A; FR2393200B1; FR2393200A1; SE7806096L

Description

(54) TORSIONAL VIBRATION DAMPER (71) We, BORG-WARNER CORPORA TION, a Corporation organised and existing under the laws of the State of Delaware, United States of America, of 200 South Michigan Avenue, Chicago, Illinois 60604, United States of America, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to a torsional vibration damper assembly for use in a torsion coupling between a pair of axially aligned shafts, in a clutch for a manual transmission or in a lock-up clutch for a torque converter of an automatic transmission.

Vibration in a vehicle drive train has been a long-standing problem due to the sudden shock of engagement of the clutch disc in a vehicle clutch for a manual transmission and to the torque fluctuations occurring in an internal combustion engine. The use of a vibration damper has been long accepted as a way of counteracting these torsional vibrations from the vehicle engine which would otherwise cause undesirable characteristics, e.g., impact loads, pulsations, noises, etc., in the transmission and driveline during operation of the vehicle.

In an automatic transmission having a constant slipping device, torsional vibrations are not a problem unless a lock-up clutch is utilized to provide a direct drive in order to enhance fuel economy. Without the lock-up clutch, the vibrations are absorbed hydraulically; but when a torque converter is locked in direct drive, a vibration damper is required to elimnate any disturbance resulting from torsional vibration. Likewise, the vibration damper assembly is convenient for use as a flexible coupling between an input shaft and output shaft where flexibility is required. The present invention provides a novel vibration damper assembly that will be useful in all of these various applications.

According to the present invention there is provided a vibration damper assembly to transmit torque between driving and driven elements, comprising an input member for operative association with torque input means; a hub assembly for operative connection to torque output means; a housing encompassing the hub assembly; floating spacers within the housing, each floating spacer comprising a wedge shaped block engaging a portion of said housing and movable circumferentially with respect thereto; resilient means in said housing between said spacers, said hub assembly including a pair of oppositely disposed arms engageable with said resilient means, and a pair of drive members secured to the input member and extending into said housing into the path of and engaging said resilient means. Preferably the housing comprises a cover plate with a generally flat base portion and a depending skirt portion having a pair of elongated slots in the outer radial periphery thereof, said drive members extending through said slots into the housing.

In a preferred embodiment the housing includes a cover plate having a flat base portion and a depending skirt, the hub assembly comprising a pair of drive plates in the cover plate, a first hub barrel separating the drive plates, a second barrel hub separating the drive plates from said flat base portion, securing means retaining the drive plates and barrel hubs onto the cover plate, said cover plate, drive plates and barrel hubs having aligned openings to receive the torque output means, said drive plates each having an annular body and a pair of oppositely disposed outwardly extending arms, said annular bodies and said barrel hubs being radially spaced from said skirt to provide an annular chamber divided by said arms into two substantially semi-circular chambers, said skirt having a pair of oppositely disposed elongated narrow slots, each slot having an enlarged portion receiving the ends of the arms therein, said drive members extending into the slots between said arms.

In the accompanying drawings: Figure 1 is a rear elevational view, partially in cross section, of a vibration damper assembly embodying the present invention.

Figure 2 is a vertical cross sectional view of the vibration damper assembly taken on the line 2-2 of Figure 1.

Figure 3 is a partial cross sectional view taken on the line 3-3 of Figure 1.

Figure 4 is a cross sectional view taken on the irregular line 4-4 of Figure 2.

Figure 5 is a cross sectional view taken on the line 5-5 of Figure 4.

Figure 6 is an exploded perspective view of the vibration damper without the springs and spacers.

Figure 7 is an enlarged exploded perspective view of a floating spacer.

Referring more particularly to the disclosure in the drawings wherein is shown an illustrative embodiment of the present invention, Figures 1 and 2 disclose a vibration damper assembly 10 for connection of driving and driven members (not shown) wherein the assembly can be utilized as a flexible connection between a pair of axially aligned shafts, as a lockup clutch in a torque converter for an automatic transmission, or as a clutch in a manual transmission. The present assembly includes a driving member 11, which may be a clutch friction plate or may be secured to a flywheel or driving flange of a shaft, having a central opening 12 defined by an annular flange 13.

Mounted on the member 11 by rivets 14 are a pair of oppositely disposed drive members in the form of tangs 15; each tang having an arcuate base 16 with openings 17 for the rivets, an angularly offset portion 18 and a generally triangular end 19 projecting into a retaining cover plate 21. The cover plate 21 includes a generally flat base portion 22 having a central opening 23 and a plurality of openings 24 surrounding opening 23 and a plurality of openings 24 surrounding opening 23, and a depending skirt or flange 25 joined to the flat portion 22 by a curved portion 26 and terminating in a radially extending rim 27. A pair of oppositely disposed elongated slots 28, 28 are formed in the flange 25 to receive the drive tangs 15; each slot having a central enlarged portion 29 and a narrowed extension 30 at each end of portion 29.

Within the cover plate 21 are mounted a first annular barrel hub 31 having a central opening 32 splined at 33 and a plurality of circumferentially spaced openings 34 around the central opening, a second annular barrel hub 35 also having a central opening 36 splined at 37 and circumferentially spaced openings 38 therearound. A pair of substantially identical drive plates 39, 39' are located with one plate 39 located between the barrel hubs 31, 35 and the second plate 39' positioned behind the hub 35 away from the cover plate base portion 22. Each drive plate 39, 39' includes an annular body 41, 41' having a central opening 42, 42', a plurality of circumferentially spaced openings 43, 43' therearound and a pair of oppositely disposed outwardly extending arms 44, 44', each arm having outwardly diverging edges 45, 45 A plurality of rivets 46 extend through the aligned openings 24, 34, 43, 38 and 43' of the cover plate 21, barrel hub 31, drive plate 39, barrel hub 35 and drive plate 39', respectively, to retain the parts together and form a unitary cover plate assembly. An annular space 47 is formed between the cover plate flange 25 and the barrel hubs 31, 35 to receive a plurality of damper spring spacers 48, each spacer being in the form of a generally triangular block having flat sides 49 converging away from a generally flat base 50, an inclined end 51 and a curved end surface 52 generally conformable with the curved portion 26 of the cover plate. A passage 53 extends through the block adjacent the base 50 and has a counterbored portion 54 opening into the end surface 51 and intersecting the flat base 50 to provide an elongated slot 55, as seen in Figure 7. A shaft 56 has an enlarged head 57 at one end and a reduced shank 58 at the opposite end adapted to be received in the passage 53. A bushing 59 is rotatably mounted on the shaft 56 and is received in the counterbored portion 54 to partially extend through the slot 55.

As shown in Figures 1, 3 and 4, the bushing 59 extends beyond the base 50 of a spacer 48 to engage the interior surface 60 of the cover plate flange 25 and provide a roller bearing action for the spacer. As seen in Figure 1, two spacers 48, 48 are positioned between the opposite arms 44, 44' of the drive plates 39, 39' to form therewith three spring pockets to receive damper springs 61, 62, 61', 62', and 61", 62". The springs are concentric with a pair of springs in each pocket. All three pairs of springs seen in Figure 1 may be of the same rates or the rates of the pairs may vary depending on the desired characteristics of the damper. Although two springs are shown for each pocket, a single spring or three or more concentric springs may be utilized depending on the desired conditions of use.

Figure 1 discloses three pairs of springs on one side of the centerline denoted as line 2-2 to form one group of springs, with a second group of springs being located on the opposite side of the centerline 2-2. The two groups of springs act in parallel and have additive loads, with the sets of springs in each group acting in series with the loads not being additive. The rates of the various pairs of springs may either be equal or have varying rates, with springs 61, 62 having the lowest rate of compression, the springs 61', 62' having an intermediate rate, and the springs 61", 62" located between the spacers 48, 48 having the highest spring rate.

Identical springs are provided in the diametrically opposite pockets as shown in Figure 4.

Considering operation of the vibration damper assembly 10, the two drive tangs 15 transmit torque from the driving member 11 through the springs 61, 62, 61', 62' and 61", 62" and spacers 48 to the drive plates 39, 39' and barrel hubs 31, 35; the splines 33 and 37 adapted to receive the splined end of a driven shaft (not shown) leading to a transmission or other device. As shown in Figure 1, as the driving member 11 rotates in either direction, the tangs 15 move in the slots 28 to compress the lowest rate springs 61, 62 between the tangs 15 and the first spacers 48. The springs 61', 62' and 61", 62" will also be compressed but to a lesser degree as the spacers 48 move on the bushings 59 relative to the cover plate 21. As the torque is increased, the springs 61, 62 will be compressed to their solid height, with the springs 61', 62' being compressed more and springs 61", 62" yieldably transmitting torque. If both springs 61, 62 and 61', 62' are compressed to their solid heights, springs 61",.62" having the highest spring rate will still yieldably transmit torque. If the spring rates of the spring sets are identical, the application of input torque will cause compression of all springs 61, 62, 61', 62' and 61" and 62" equally.

This vibration damper assembly will provide a greater deflection angle than prior convention damper assemblies. The angled sides 49, 49 of the spacers 48 react to the spring force causing the spacers to be urged outwardly and provide frictional contact between the bushings and the interior surface 60 of the cover plate. Although described with one arrangement of spring rates for each group, the deflection characteristic for the damper may be varied depending on the choice of springs. The damper assembly is suitable for use in a variety of automotive or industrial torsional vibration damper applications requiring a low spring rate and high deflection amplitude characteristic.

WHAT WE CLAIM IS: 1. A vibration damper assembly to transmit torque between driving and driven elements, comprising an input member for operative association with torque input means; a hub assembly for operative connection to torque output means; a housing encompassing the hub assembly; floating spacers within the housing, each floating spacer comprising a wedge shaped block engaging a portion of said housing and movable circumferentially with respect thereto; resilient means in said housing be pair of drive members secured to the input tween said spacers, said hub assembly including a pair of oppositely disposed arms engageable with said resilient means, and a member and extending into said housing into the path of and engaging said resilient means.

2. A vibration damper assembly as set forth in Claim 1, in which said housing comprises a cover plate with a generally flat base portion and a depending skirt portion having a pair of elongated slots in the outer radial periphery thereof, said drive members extending through said slots into the housing.

3. A vibration damper assembly as set forth in Claim 2, wherein said hub assembly includes at least one barrel hub and at least one drive plate secured in the cover plate, said barrel hub being splined for operative connection to the torque output means.

4. A vibration damper assembly as set forth in Claim 3, wherein said drive plate includes an annular body and the pair of oppositely disposed arms, said arms extending into and being secured in the elongated slots.

5. A vibration damper assembly as set forth in Claim 4, wherein each arm has outwardly diverging edges, and each drive member is in the form of a drive tang that has outwardly diverging edges generally aligned with the edges of an arm, said drive tangs and drive plate arms being aligned when there is no torque input.

6. A vibration damper assembly as set -forth in Claim 4 or 5, wherein said resilient means includes a plurality of sets of two or more concentric compression springs, said springs engaging the arms of said drive plate and said spacers, and said drive members extend through said enlongated slots to engage one end of a spring set upon the exertion of torque by said input member.

7. A vibration damper assembly as set forth in Claim 6, wherein said springs are arranged in two groups acting in parallel, each group including three spring sets and two spacers interposed around the hub and between the oppositely extending drive plate arms.

8. A vibration damper assembly as set forth in Claim 6 or 7, wherein each spacer has inwardly converging sides engaged by the ends of adjacent spring sets, and said arms having inwardly converging edges engaged by said spring sets, said spring sets cooperating with said spacer sides to urge the spacers outwardly towards said cover plate skirt.

9. A vibration damper assembly as set forth in any one of Claims 2 to 8, wherein roller means in the base of each block are adapted to engage the cover plate to allow circumferential movement of said wedges.

10. A vibration damper assembly as set

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Claims

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springs 61", 62" located between the spacers 48, 48 having the highest spring rate.

Identical springs are provided in the diametrically opposite pockets as shown in Figure 4.

Considering operation of the vibration damper assembly 10, the two drive tangs 15 transmit torque from the driving member 11 through the springs 61, 62, 61', 62' and 61", 62" and spacers 48 to the drive plates 39, 39' and barrel hubs 31, 35; the splines 33 and 37 adapted to receive the splined end of a driven shaft (not shown) leading to a transmission or other device. As shown in Figure 1, as the driving member 11 rotates in either direction, the tangs 15 move in the slots 28 to compress the lowest rate springs 61, 62 between the tangs 15 and the first spacers 48. The springs 61', 62' and 61", 62" will also be compressed but to a lesser degree as the spacers 48 move on the bushings 59 relative to the cover plate 21. As the torque is increased, the springs 61, 62 will be compressed to their solid height, with the springs 61', 62' being compressed more and springs 61", 62" yieldably transmitting torque. If both springs 61, 62 and 61', 62' are compressed to their solid heights, springs 61",.62" having the highest spring rate will still yieldably transmit torque. If the spring rates of the spring sets are identical, the application of input torque will cause compression of all springs 61, 62, 61', 62' and 61" and 62" equally.

This vibration damper assembly will provide a greater deflection angle than prior convention damper assemblies. The angled sides 49, 49 of the spacers 48 react to the spring force causing the spacers to be urged outwardly and provide frictional contact between the bushings and the interior surface 60 of the cover plate. Although described with one arrangement of spring rates for each group, the deflection characteristic for the damper may be varied depending on the choice of springs. The damper assembly is suitable for use in a variety of automotive or industrial torsional vibration damper applications requiring a low spring rate and high deflection amplitude characteristic.

WHAT WE CLAIM IS: 1. A vibration damper assembly to transmit torque between driving and driven elements, comprising an input member for operative association with torque input means; a hub assembly for operative connection to torque output means; a housing encompassing the hub assembly; floating spacers within the housing, each floating spacer comprising a wedge shaped block engaging a portion of said housing and movable circumferentially with respect thereto; resilient means in said housing be pair of drive members secured to the input tween said spacers, said hub assembly including a pair of oppositely disposed arms engageable with said resilient means, and a member and extending into said housing into the path of and engaging said resilient means.
2. A vibration damper assembly as set forth in Claim 1, in which said housing comprises a cover plate with a generally flat base portion and a depending skirt portion having a pair of elongated slots in the outer radial periphery thereof, said drive members extending through said slots into the housing.
3. A vibration damper assembly as set forth in Claim 2, wherein said hub assembly includes at least one barrel hub and at least one drive plate secured in the cover plate, said barrel hub being splined for operative connection to the torque output means.
4. A vibration damper assembly as set forth in Claim 3, wherein said drive plate includes an annular body and the pair of oppositely disposed arms, said arms extending into and being secured in the elongated slots.
5. A vibration damper assembly as set forth in Claim 4, wherein each arm has outwardly diverging edges, and each drive member is in the form of a drive tang that has outwardly diverging edges generally aligned with the edges of an arm, said drive tangs and drive plate arms being aligned when there is no torque input.
6. A vibration damper assembly as set -forth in Claim 4 or 5, wherein said resilient means includes a plurality of sets of two or more concentric compression springs, said springs engaging the arms of said drive plate and said spacers, and said drive members extend through said enlongated slots to engage one end of a spring set upon the exertion of torque by said input member.
7. A vibration damper assembly as set forth in Claim 6, wherein said springs are arranged in two groups acting in parallel, each group including three spring sets and two spacers interposed around the hub and between the oppositely extending drive plate arms.
8. A vibration damper assembly as set forth in Claim 6 or 7, wherein each spacer has inwardly converging sides engaged by the ends of adjacent spring sets, and said arms having inwardly converging edges engaged by said spring sets, said spring sets cooperating with said spacer sides to urge the spacers outwardly towards said cover plate skirt.
9. A vibration damper assembly as set forth in any one of Claims 2 to 8, wherein roller means in the base of each block are adapted to engage the cover plate to allow circumferential movement of said wedges.
10. A vibration damper assembly as set

forth in Claim 9, wherein the roller means are located to engage the skirt of the cover plate.
11. A vibration damper assembly as set forth in Claim 9 or 10, wherein said roller means includes a shaft mounted in said block, and a bushing mounted on the shaft and partially exposed in the base of the spacer to engage said cover plate.
12. A vibration damper assembly as set forth in Claim 1, wherein said housing includes a cover plate having a flat base portion and a depending skirt, the hub assembly comprising a pair of drive plates in the cover plate, a first hub barrel separating the drive plates, a second barrel hub separating the drive plates from said flat base portion, securing means retaining the drive plates and barrel hubs onto the cover plate, said cover plate, drive plates and barrel hubs having aligned central openings to receive the torque output means, said drive plates each having an annular body and a pair of the oppositely disposed outwardly extending arms, said annular bodies and said barrel hubs being radially spaced from said skirt to provide an annular chamber divided by said arms into two substantially semi-circular chambers, said skirt having a pair of oppositely disposed elongated slots, each slot having an enlarged portion receiving the ends of the arms therein, said drive members extending into the slots between said arms.
13. A vibration damper assembly as set forth in Claim 12, wherein a pair of the spacers are located in each semi-circular chamber, and said resilient means includes three sets of springs in each semi-circular chamber extending between said drive plate arms and said spacers, said three sets of springs forming a group.
14. A vibration damper assembly as set forth in Claim 13, wherein said spring groups in the semi-circular chambers act in parallel, with the springs in each group acting in series.
15. A vibration damper assembly as set forth in Claim 13, wherein said driving plate arms have outwardly diverging edges, and said spacers have outwardly diverging side walls terminating in a generally flat base portion, the ends of the spring sets engaging the edges of the arms and the diverging sides of said spacers to urge said spacers outwardly toward the cover plate skirt.
16. A vibration damper assembly as set forth in Claim 15, wherein each spacer has a roller partially exposed in the base portion and adapted to engage the skirt.
17. A vibration damper assembly as set forth in Claim 16, wherein said roller includes a shaft mounted in said spacer, and a bushing journalled on said shaft, said spacer having a recess receiving said shaft and bushing and partially opening into said base portion to expose a portion of said bushing.
18. A vibration damper assembly as set forth in Claim 15, wherein said drive members are in the form of tangs that have outwardly diverging edges generally aligned with the edges of the driving plate arms when there is no torque input.
19. A vibration damper assembly as set forth in Claim 18, wherein an edge of each drive tang engages the end of a spring set and urges it away from the adjacent drive plate arm when input torque is applied by said input member.
20. A vibration damper assembly constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.