-- CREATE A CALENDAR TABLE.
CREATE TABLE #Calendar(Dt DATE NOT NULL PRIMARY KEY CLUSTERED);

;WITH N(n) AS (SELECT 1 UNION ALL SELECT n+1 FROM N WHERE n < 50)
INSERT INTO #Calendar SELECT DATEADD(dd,n-1,'20120701') 
                      FROM N OPTION (MAXRECURSION 0);

-- CREATE AND POPULATE A SAMPLE MAINTENANCE TABLE
CREATE TABLE #MaintenanceTable(   
	TMP_EQUIPAMENTO  INT,    
	TMP_DT_INICIO  DATETIME,   
	TMP_DT_FIM DATETIME);
INSERT INTO #MaintenanceTable VALUES
(1, '2012-07-11 20:00:00.000', '2012-07-18 11:00:00.000'),
(2, '2012-07-21 20:00:00.000', '2012-07-21 23:00:00.000'),
(3, '2012-07-27 20:00:00.000', '2012-07-28 20:00:00.000')

-- QUERY
SELECT
	Dt,
	TMP_EQUIPAMENTO,
	CASE 
		WHEN TMP_DT_INICIO < DATEADD(dd,1,dt) AND TMP_DT_FIM > Dt THEN
			DATEDIFF
			(
				hh,
				CASE WHEN TMP_DT_INICIO < Dt THEN Dt ELSE TMP_DT_INICIO END,
				CASE WHEN TMP_DT_FIM > DATEADD(dd,1,dt) THEN DATEADD(dd,1,dt) ELSE TMP_DT_FIM END
			)
		ELSE 0
	END AS Hours
FROM
	#Calendar c
	CROSS APPLY
	(
		SELECT 	TOP 1 TMP_EQUIPAMENTO,TMP_DT_INICIO ,TMP_DT_FIM
		FROM #MaintenanceTable m
		WHERE m.TMP_DT_INICIO < DATEADD(dd,1,c.Dt) 
			AND TMP_DT_FIM > c.Dt
		ORDER BY TMP_DT_INICIO DESC
	) m
ORDER BY TMP_EQUIPAMENTO, Dt;

DROP TABLE #Calendar
DROP TABLE #MaintenanceTable