How do I get the rate vote number?
I think that is the rate module, like many such modules it uses the voting api.

You should use votingapi_select_results() to get the results. The $criteria array that you pass to it will be 

$criteria = array(
    'content_type' =&gt; $content_type,
    'content_id' =&gt; $content_id,
    'tag' =&gt; $widget-&gt;tag,
  );


I have only skimmed the code but I belive that $content_type and $content_id are node type and node id. The $widget->tag will be specific to your widget.