Magento – How to load bundle child product by parent product ID

Try it like this:

$bundleIds = Mage::getResourceSingleton('bundle/selection')->getParentIdsByChild($productId);

For each bundle product you could load all the child ids, loop through the resultant set, pulling out the images.

You could get a list of the child ids and pull out the images that way

$parentId = 1234; //or whatever the bundle product is
$childIds =   Mage::getResourceSingleton("bundle/selection")->getChildrenIds($parentId,true);
$childImagesArray = array();
foreach($childIds as $cids){ 
    foreach($cids as $cid){ //yer an awkward array in an array here
        $childProduct = Mage::getModel("catalog/product")->load($cid);
        echo "<br/>".$childProduct->getName();
        $childProductImage = $childProduct->getImage(); // OR getSmallImage()  OR getThumbnail();
        var_dump($childProductImage); //see what you get out here
        //now add your data to an array $childImagesArray[] = ....  or do something else with your results.
    }
}