1 - - - - - - 0。062

0。5 - - - - - - 0。031

(a)Inner star

(a) Mesh (b) Boundary conditions

Fig。 17。 Modeling details and boundary conditions for structural analy- sis of inner star。

(a)Mesh (b) Boundary conditions 论文网

Fig。 18。 Modeling details and boundary conditions for structural analy- sis of outer star。

star and the outer star。 The maximum torsional torque exerted on the inner star and outer star occurred when the  sleeve spring was compressed to its maximum。 The elements and boundary conditions for the model of the inner star are shown in Fig。 17, and the elements and boundary conditions for the model of the outer star are shown in Fig。 18。 Fig。 19 shows analysis results for the inner star and the outer star for an ap- plied maximum torsional torque of 1。048E+03N-m。

The maximum stresses of the inner star and the outer star were 19。9MPa and 5。4MPa respectively, which were below the tensile strength of the material (Min。 1000MPa for SNCM439)。 Thus, the structure did not appear to be subject to fatigue failure due to repeated loads on the inner star and   the

(b)Outer star

Fig。 19。 Results obtained by structural analysis of inner star and outer star。

outer star。

3。2。2Durability test

According to FEA results, fatigue failure due to repeated loads on the inner star and the outer star did not occur。 So, durability tests were carried out to verify the wear resistance of the inner star and the outer star according to heat treatment specifications。 Table 7 provides the test sample heat treatment specifications。

The experiments were carried out under the following con- ditions: velocity = 5cycle/sec, input torque = 1000N-m, num- ber of cycles = 10E+07cycle。

3。2。3Durability test results and discussions

Fig。 20 shows the inner star according to the pertinent heat treatment specifications for the durability  test。 The wear   pat-

(a)Sample 1 (b) Sample 2 (c) Sample 3 Fig。 20。 Inner star after durability test。

(c)Sample 3 Fig。 21。 Abrasion amount by durability test。

terns on the region contacting the sleeve spring were similar irrespective of the heat treatment specifications。

Fig。 21 shows the results of the measurement of the amount of wear using a roughness measuring instrument。 Wear did not occur in sample 1。 In sample 2, slight wear occurred。 In sam- ple 3 (no heat treatment applied), the amount of wear was about 13。3m。 These results showed that quenching- tempering and high-frequency heat treatment must be applied to the inner start in order to prevent wear。

4。Conclusions

A finite element analysis (FEA) of and experiments on the core components of a sleeve spring torsional vibration damper

were performed in this study。 The key results obtained from this study are summarized as follows:

The spring constant formula of a sleeve spring was verified through performance tests。

The suitability of the FEA method for two-roll bending was confirmed。 A new process parameter,  『contact angle / (material