Hydraulic brake for heavy vehicles

Claim 1

In combination with a vehicle motor having a motor housing, a crankshaft, a reservoir for receiving and containing a liquid lubricant, and liquid lubricant circulating circuit means comprising oil pump means and communicating with said reservoir for circulating liquid lubricant to and through parts of said motor to be lubricated: a permanent brake which includes: a fluid-operable braking unit within said motor housing and interposed within said lubricant circulating circuit means and supplied by said pump means so as to be continuously and completely filled with liquid lubricant during operation of said motor; said braking unit comprising auxiliary shaft means, means operable to drivingly connect said crankshaft to said auxiliary shaft means for driving the latter, said braking unit having a pump wheel keyed to said auxiliary shaft means so as to be rotatable therewith, and follower means freely and substantially in a load-free manner rotatable about the axis of said auxiliary shaft means by lubricant in said braking unit in response to the rotation of said pump wheel; and friction brake means associated with said follower means and operable selectively to engage and arrest the latter to thereby cause the lubricant in said brake unit to absorb a considerable amount of rotary energy of said pump wheel and thus to impart upon the lubricant circulated through said brake unit and said circuit means a temperature sufficient to keep said motor uniformly warm even during a longer lasting downhill drive of a vehicle equipped with said motor even in winter time weather.