How to draw spring damper system in TikZ?

Question

I am trying to reproduce this element:

I am using these styles:

        \usetikzlibrary{arrows.meta, bending, calc, chains,  positioning, 
        shapes,patterns,decorations.pathmorphing,decorations.markings}

        \tikzstyle{spring}=[thick,decorate,decoration={zigzag,pre 
         length=0.3cm,post length=0.3cm,segment length=6}]
         \tikzstyle{damper}=[thick,decoration={markings,  
          mark connection node=dmp,
           mark=at position 0.5 with 
            {
             \node (dmp) [thick,inner sep=0pt,transform 
            shape,rotate=-90,minimum width=15pt,minimum 
            height=3pt,draw=none] {};
           \draw [thick] ($(dmp.north east)+(2pt,0)$) -- (dmp.south east) -- 
           (dmp.south west) -- ($(dmp.north west)+(2pt,0)$);
           \draw [thick] ($(dmp.north)+(0,-5pt)$) -- ($(dmp.north)+
              (0,5pt)$);
             }
           }, decorate]

    \begin{tikzpicture}[
    node distance = 0mm,
    start chain = going right,
    box/.style = {draw,   
    font=\linespread{0.75}\selectfont\small,
    align=center, inner sep=2mm, outer sep=0pt,
    on chain},
    axs/.style = {draw, minimum width=12mm, minimum height=2mm,                
    inner sep=0pt, outer sep=0pt,
    on chain, node contents={}},
    arr/.style = {color=#1, line width=0.8mm, 
    shorten >=-1mm, shorten <=-1mm,
    -{Stealth[length=1.6mm,width=3mm,flex=1.2]},
    bend angle=60},
    bar/.style = {draw, minimum width=0.1mm, minimum height=6mm,
    inner sep=0pt, outer sep=0pt,
    on chain, node contents={}},                           
    ]

I tried to use the solution given in Drawing Mechanical Systems in LaTeX.

But I was not able to find out a way to represent this element (maybe it can be useful to have a macro to insert it in the picture). Exactly I would like to connect the left and right boxes created with:

  \node (node_example) [box,label=below:$Example$]  {example};

To my viscoelastic node just calling a macro that i can call as:

   \node (new_node) [visco_elastic_node,....]{....}

What could I do?

Answer 1

The spring is stolen from Jake answer, damper is drawn as small picture pic, for rest of the image is used my answer on your previous question:

\documentclass[tikz, margin=3mm]{standalone}
\usetikzlibrary{arrows.meta, 
                bending, 
                calc, chains, 
                decorations.pathmorphing,  % added
                positioning
                }

\begin{document}
    %\begin{figure}[!h]  % when use article \documentclass{article}
    %\centering          % when use article \documentclass{article}
    \begin{tikzpicture}[
node distance = 0mm,
  start chain = going right,
   box/.style = {draw,
                 font=\linespread{0.75}\selectfont\small,
                 align=center, inner sep=2mm, outer sep=0pt,
                 on chain},
   axs/.style = {draw, minimum width=12mm, minimum height=2mm,
                 inner sep=0pt, outer sep=0pt,
                 on chain, node contents={}},
   arr/.style = {color=#1, line width=0.8mm,
                 shorten >=-1mm, shorten <=-1mm,
                 -{Stealth[length=1.6mm,width=3mm,flex=1.2]},
                 bend angle=60},
spring/.style = {thick, decorate,       % new, 
                 decoration={zigzag,pre length=3mm,post length=3mm,segment length=6}
                        },
  damper/.pic = {\coordinate (-east);   % new
                 \coordinate[left=1mm of -east] (-west);
                 \draw[very thick] ($(-east)+(0,2mm)$) -- ++ (0,-4mm);
                 \draw[semithick]  ($(-east)+(0,3mm)$) -| ++ (-1mm,-6mm) -- ++ (1mm,0);
                 },
shorten <>/.style = {shorten >=#1, shorten <=#1},
                        ]
    % blocks (boxes)
\node (n1) [box,label=below:$J_M$]  {Motore};
\node (n2) [axs];
\node (n3) [box]                    {$\tau$};
\node (n4) [axs];
\node (n5) [minimum height=6mm,minimum width=12mm,
            label={[yshift= 1mm]above:$K$},
            label={[yshift=-3mm]below:$D$},
            on chain] {};% for spring and dumper
\node (n6) [axs];
\node (n7) [box,label=below:$J_C$]  {C\\a\\r\\i\\c\\o};
    % spring and damper, added
\draw[ultra thick,shorten <>=-2mm]
    (n5.north west) -- (n5.south west);
\draw[ultra thick,shorten <>=-2mm]
     (n5.north east) -- (n5.south east);
\draw[spring]   (n5.north west) -- (n5.north east);
\pic (dmp) at (n5.south)  {damper};
\draw(n5.south west) -- (dmp-west)  (dmp-east) -- (n5.south east);
    % arrows
\draw[transform canvas={xshift=-2mm}]
    (n1.south -| n2) edge[arr=gray,bend right] (n1.north -| n2)
                     node[below,at={(n1.south -| n2)}] {$C_M$}
    (n1.north -| n6) edge[arr=gray,bend  left] (n1.south -| n6)
                     node[below,at={(n1.south -| n6)}] {$C_R$};
\draw
    (n1.south -| n4) edge[arr=black,bend right] (n1.north -| n4)
                     node[above,at={(n1.north -| n4)}] {$\theta_R$};
\draw[transform canvas={xshift=+2mm}]
    (n1.south -| n2) edge[arr=black,bend right] (n1.north -| n2)
                     node[above,at={(n1.north -| n2)}] {$\theta_M$}
    (n1.south -| n6) edge[arr=black,bend right] (n1.north -| n6)
                     node[above,at={(n1.north -| n6)}] {$\theta_R$};
\end{tikzpicture}
    %\end{figure} % when use article \documentclass{article}
\end{document}

Note (1): subscripts at arrows symbols are not correct, but this should not be problem to rewrite them ...

Note (2): If subscripts at variables J, C and \theta are descriptive text, i.e. not variables, they should be set upright (see lblb’s comment below). In this case (in all your equations ...) you should write $J_{\mathrm{M}}$ where the M stands for Motore. Only variables should be italic in math. However, as far as I remember, literature about this topics is not very strict with this notation :-).