Untested and freehand, but should get you pointed in the right direction.

class Time_Tracker extends Eloquent {

    public function Module()
    {
	/* 
	 - dest model name, local_key, remote_key
	*/
        return $this->hasOne('Module', 'time_tracker_module_id', 'module_id');
    }

    public function Task()
    {
	/* 
	 - dest model name, local_key, remote_key  	
	*/
        return $this->hasOne('Task', 'time_tracker_task_id', 'task_id');
    }

}

class Module extends Eloquent {

    public function TimeTracker()
    {
	/* 
	 - dest model name, local_key, remote_key  	
	*/
        return $this->belongsTo('Time_Tracker', 'module_id', 'time_tracker_module_id');
    }
}

class Task extends Eloquent {

 public function TimeTracker()
    {
	/* 
	 - dest model name, local_key, remote_key  	
	*/
        return $this->belongsTo('Time_Tracker', 'task_id', 'time_tracker_task_id');
    }
}

And to query,

/* get data from Time_Tracker */
$data = Time_Tracker::find(1)->with('Module')->with('Task')->get();

/* if have Module ID and want Task and TimeTracker */
$data = Module::find(1)->with('TimeTracker', 'TimeTracker.Task')->get();

/* if have Task ID and want Module and TimeTracker */
$data = Task::find(1)->with('TimeTracker', 'TimeTracker.Module')->get();

You might not need remote key, if the remote_key is the primary key for the remote table.

Also might want to use hasMany instead of hasOne.

And there is a whole bunch of relational functions that could be used to build model relationships, see http://laravel.com/docs/4.2/eloquent for more on that.

Hope that helps.