From Joomla! Documentation
This method can be used to load helper files in your View. You can access the method as static method of JView object or as a member method of current view object using $this.
// static method access JView::loadHelper('myhelper'); // member method access $this->loadHelper('myhelper');
The parameters name used in the method should match exactly the name of the file without the PHP file extension. According to previous example our file should be "myhelper.php". After the helper is loaded you can access its functions if procedural programming is used or you can access and instantiate the class hold in it if OOP is used.
$helper = new MyHelper();