FI106977B - Suppressed suspension arrangement - Google Patents

Description

106977

Damped suspension arrangement

The present invention relates to a damped suspension arrangement for various fine mechanical devices according to the preamble of claim 1.

A hard-drive device such as a computer hard disk may not function properly under difficult vibration conditions. Thus, a suspension with shock absorber 10 is required for this.

The differential equation of the mechanical damping system according to Fig. 1 (including the suspension of a car with shock absorbers), where a = damping piece, b = spring, 15 c = damping shock absorber, d = body, is known in the form: _ d2x dx.

F = m - T + r - + kx di2 dt 20 F is the force m is the mass of the system, r is the coefficient of friction and k is the spring constant. The other expressions in the expression are the first. . worldly and another derivative of time.

•; 25 The system cut-off frequency is:; '···

2jrVW

«30 and attenuation coefficient at cut-off frequency (Figure 2): • · * · 35 2 106977

At low frequencies, the resilient system does not perform, i.e. damping A = 1, but above f0 the damping becomes more efficient the higher the frequency becomes.

5 Therefore, in order to obtain the best possible suspension for the device, the k should be small, i.e. the spring should be as loose and the mass as possible.

Increasing the mass of the device, for example by adding weights 10, is not a very interesting option, so it remains to make the suspension as loose as possible.

The damping factor should be one or more so that the system has no tendency to oscillate at resonance-15 at hair f0. Figure 2 shows that if the damping factor is less, then at the cut-off frequency the damping works even the other way around, i.e., amplifies the oscillation.

High damping capacity is obtained when the system friction is as high as possible. For example, soft urethane with a shore hardness of, for example, 20, ·: ·: is elastic and has high internal and external friction.

. ···. 25 Elasticity means soft elasticity and friction gives good y damping, as stated in theory. The problem is just '. . mechanical implementation. As a very loose material, it often ** * requires a supported structure in all directions, easily lost by its intended advantage. For practical reasons, the suspension should also be compact.

\ Because good damping material is mechanically very good: T loose is a problem in a practical device to gain the necessary total strength without loosing it. One elastic structure 35 used is schematically shown in Figure 3. In it, the soft material 3, often rubber, is sandwiched between one or two plates. The fastening screw 1, 1a clamps 3 106977 against the sleeve 4 but the spring-loaded device 5 is "floated" on a soft material and mechanically insulated from vibration by the body 6. The whole is sturdy but most of the elasticity is lost because the larger 5 plate is supported sector) into a rigid structure. Thus, its "load-bearing capacity" is already so high that a significant amount of elasticity is lost. Here, load-bearing capacity is the same as building tile foundation. In soft soil, a rigid structure 10 is obtained when a large tile carries.

It is an object of the present invention to provide an improved damped suspension arrangement in which prior art problems are at least substantially eliminated.

To accomplish this object, the damped suspension arrangement according to the invention is characterized by the features set forth in the characterizing part of claim 1.

The invention will now be described in more detail with reference to the accompanying drawings, in which: Fig. 1 schematically illustrates a resilient system with a shock absorber. Figure 2 shows the attenuation at different attenuation coefficients and.! '* Frequencies, ««

Figure 3 schematically illustrates a prior art damped suspension arrangement 30

Figure 4 schematically illustrates the attenuation of the invention. 5 illustrates an embodiment similar to that of FIG. 4 with a slightly thicker material * ·· *. as in Figure 4, and 4 106977

Fig. 6 schematically shows another embodiment of the damped suspension arrangement according to the invention.

In Figs. 3-6, the same reference numerals are used for like or like parts. In the embodiment of Figures 4 and 5, the sleeve 4 is elongated relative to the prior art solution of Figure 3 and the actual end plates 2 are no more than ensuring that the spring system device 5 10 does not fall, i.e. slip out, e.g. For the actual elasticity, the end plates 2 no longer participate. In Figures 4-6 only the outer end-side end plate 2 is used, but if necessary the end-end end plate 15 can also be located at the end of the base 6, e.g., when the base 6 does not have a suitable tile point.

The functional principle of the elastic system is that when the elastic and friction grooved disk 3 according to Figures 4 and 5, which is preferably soft polyurethane, due to mechanical movement, for example, moves ·: ··: downwards, its other (lower in this example) Presses tighter against the sleeve 4 and the increased friction prevents the damper from moving.

Because the material 3 has a very high friction, it does not easily slip along the sleeve 4, but rather rolls up (even on the roll), whereby the compression against the sleeve always increases and the frictional force increases. So it's kind of self-regulating. It is only when the grooved disc 3 is stretched to such an extent that the size of the opening becomes detached from the sleeve. To prevent this from coming off, a tile 2. reel; ** is still needed. the elastic body 3 is also advantageous in that the elasticity of '1 is tightened as the movement increases until finally the disc * 1 3 is pressed against the base 6 or the plate 2, depending on the direction of movement 35, whereby the spring becomes even more stiff.

* .. · This elastic body is therefore a so-called. progressive spring.

«> ·» · · 5 106977

The system can be further certified by forming the sleeve thicker at its ends, e.g., gradually thickening towards the ends of the sleeve, or by providing separate, slightly actual sleeve 4 hal-5 with a smaller diameter sleeve according to the embodiment of Fig. 6. the auxiliary sleeves 7 having a diameter of 6 mm operate as intended. These sleeve diameter values are only given as an example of one of the dimensions used in the practical experiment, and of course the diameter values may deviate significantly from the values given above.

Further, it is contemplated to use an embodiment in which the sleeve 4 and the auxiliary sleeves 7 are formed as a single sleeve member, the outer surface of which has a groove for the resilient member 3 between the ends of the sleeve member.

The geometry of the grooved disc 3 can also be used to adjust the elastic properties. By thinning it, the spring loosens and by thickening it tightens. A thicker disk also provides a butter-20 lower at the bottom edge compression, as shown in the example of Figure 5.

A practical suspension system may have one or more damped suspension arrangements according to Figures 4-6.

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Claims (5)

6 106977 A damped suspension arrangement for various fine mechanical devices (5), comprising a support 5 base (6) having a sleeve (4) secured thereto by a fastening element (1, 1a) extending through the sleeve, the sleeve (4) being away from the base (6). a tile member (2) is mounted between the outer end of the bracket and the corresponding end (1) of the fastening member, and an elastic 10 disk-like spring member (3) is mounted around the sleeve (4), in the arrangement, the length of the sleeve (4) is substantially larger than the thickness of said elastic member (3), characterized in that the elastic member (3) is disposed at each end of the free space gap 15 from both the base (6) and tile member (2). is a material with high internal friction. 2. Fjädringsarrangemang enligt patentkravet 1, kännetecknat därav, att fjädringsorganet (3) anordnats att hällas runt holken (4) väsentligen med hjälp av friktion. A damped suspension arrangement according to claim 1, characterized in that the resilient member (3) is arranged to remain substantially frictional around the sleeve (4). through. A damped spring arrangement according to claim 1 or 2, characterized in that the sleeve (4) is gradually thickened from the region of the elastic member (3) towards the base (6). ) • · • * ·· and / or towards the outer end. • · • · · • <· « 3. Fjädringsarrangemang enligt patentkravet 1 eller 2, kännetecknat därav, att holken (4) blir smäningom tjockare frän fjädringsorganets (3) omräde mot underlaget (6) och / -eller den yttre ändan. 4. Fjädringsarrangemang enligt patentkravet 1 eller 2, kännetecknat därav, att runt holken (4) har en hjälpholk (7) tjockare ja holken (4) anordnats mellan fjädringsorganet (3) och underlaget (6) och / eller mellan fjädringsorgan brickorganet (2). 106977 9 A damped spring arrangement according to claim 1 or 2, characterized in that an auxiliary sleeve (7) thicker than the sleeve (4) is arranged between the spring member (3) and the base (6) and / or between the elastic member * · * * (3) and the tile member (2). <<<<<« According to any one of the preceding claims. : damped suspension arrangement, characterized in that a tile member is also provided between the base (6) and the sleeve (4). «· · * 1 · I · · I ·« <(«<II 4 4 4 • · • • • Iti • · · ♦ · • ♦ •« · • • • 1 1 • · · • · · III «« I «• · ·« · · 8 106977 5 1. Dämpat fjädringsarrangemang för olika finmekaniska an- ordningar (5), wolf arrangemang omfattar et stadigt un- derlag (6), vid vilket en holk (4) med hjälp av et genom holken sig sträckande fästelement (1, 1a) är fäst, mellan whisker hoiks (4) frän underlaget (6) flatbed crane yttre ända 10 och fästelementets motsvarande ända (1) ) that brickorgan (2) anordnats, och runt flashing sleeve (4) that elastic skivak-tigt fjädringsorgan (3) anordnats flashing mellan underlaget (6) och brickorganet (2), i flashing arrangemang hol-kens (4) längd är tirsligligen större än nänn fjädrings- 15 organs (3) tjocklek, kännetecknat därav, att fjädringsor-ganet (3) å anordnat Pä respektive et fritt utrymm e bil-dande avständ frän bäde underlaget (6) och brickorganet (2), mild fjädringsorgan (3) and av med material stor inre friktion. 20 5. Fjädringsarrangemang enligt avgot av föregäende patent-krav, kännetecknat därav, att ocksä mellan underlaget (6) och holken (4) har ett brickorgan anordnats. 5