Provided is a vehicle speed control device with respect to which the speed at which a centrifugal brake operates can be easily changed from the outside without disassembling the device. A brake drum 11 is fixed to a vehicle body 101a. A brake shoe 23 rotates around a rotary shaft 20 of the wheel 101c, and reduces the rotation speed of the wheel 101c as a result of coming into contact with an inner circumferential side face of the brake drum 11. A spring 24 prevents contact between the brake drum 11 and the brake shoe 23 when the rotation speed of the wheel 101c is lower than or equal to a predetermined speed, and permits contact between the brake drum 11 and the brake shoe 23 when the rotation speed of the wheel 101c exceeds the predetermined speed. A position change mechanism 25 is installed within the brake drum 11, and changes the position of an end of the spring 24 on one end side. A transmission mechanism 26 transmits a force that is input by an external operation to the position change mechanism 25 and drives the position change mechanism.

Provided is a vehicle speed control device with respect to which the speed at which a centrifugal brake operates can be easily changed from the outside without disassembling the device. A brake drum 11 is fixed to a vehicle body 101a. A brake shoe 23 rotates around a rotary shaft 20 of the wheel 101c, and reduces the rotation speed of the wheel 101c as a result of coming into contact with an inner circumferential side face of the brake drum 11. A spring 24 prevents contact between the brake drum 11 and the brake shoe 23 when the rotation speed of the wheel 101c is lower than or equal to a predetermined speed, and permits contact between the brake drum 11 and the brake shoe 23 when the rotation speed of the wheel 101c exceeds the predetermined speed. A position change mechanism 25 is installed within the brake drum 11, and changes the position of an end of the spring 24 on one end side. A transmission mechanism 26 transmits a force that is input by an external operation to the position change mechanism 25 and drives the position change mechanism.

Improved maneuverability, improved followability towards a target braking force and enhanced brake feeling when a low braking force is being effected may be achieved. A brake controller unit may include a clearance estimator which may be configured to use a rotational angle θ of a motor to estimate a clearance, inclusive of negative values, between a frictional material and a brake. A target braking force F.sub.r may be compared with a switch-determining braking force F.sub.rsw, so that clearance control based on a target clearance C.sub.r may be performed when the frictional material is in approximate-contact state corresponding to the target braking force F.sub.r being low, and so that braking force control may be performed when it is equal to or greater than the switch-determining braking force F.sub.rsw.

A transmission having an integrated gear and brake mechanism is disposed in a housing, the transmission having a variable drive mechanism, gear train, and an output axle engaged to the gear train. The output axle is driven by a final drive gear having an integrated drum brake within its circumference.

A drum brake apparatus includes a housing; a main braking unit installed on one part of the housing, and driven by a hydraulic pressure and pressing a shoe, during main braking; a parking braking unit installed on the other part of the housing, and driven by an electromotive force of an actuator and pressing the shoe, during parking braking; and a locking member locked to the housing through the actuator and a back plate, and fastening the actuator and the housing to the back plate.

The present invention relates to an electronic parking brake and, more specifically, to an electronic parking brake in which an electronic actuator is applied to a drum brake, wherein noise can be reduced when transmitting the driving power of a driving motor, and a rotary shaft of the driving motor and a rotary shaft of a wheel cylinder can be arranged so as to be inclined relative to each other.

Disclosed herein is an electronic brake apparatus that includes a spring pack, a first piston in which the spring pack is mounted, a bolt screw rotated in conjunction with a motor and having one end in point contact with the spring pack, a fixing member configured to bind the bolt screw to the first piston, and a second piston screwed to the other end of the bolt screw.

An electric actuator includes an input member that is rotationally driven by the electric motor and includes a first rotation stop part on an inner periphery, an output member that includes a second rotation stop part engageable with the first rotation stop part, and a first screw part on an outer periphery, and a linear motion member that includes a second screw part engageable with the first screw part. Both the screw mechanism and the rotation-stop mechanism are formed on the outer periphery of the output member. Therefore, in the electric actuator, the radial and axial dimensions are shortened.

A hub motor includes a hub motor body, an axle extending into the hub motor body, a rotor coupled to the outer housing, a stator within the rotor and coupled to the axle, and a brake within the hub motor body. The brake may include a brake pad spring-biased into braking engagement and moved out of braking engagement by an electromagnetic coil, such that the brake will fail into a braked state.

The invention relates to a brake shoe for a drum brake system, the brake shoe having a length configured to extend in a circumferential direction of a brake drum of the drum brake system, and a width configured to extend in an axial direction of the brake drum, wherein the brake shoe has spatially varying thermal properties along its length, in particular a change in heat capacity and/or a change in thermal expansion coefficient and/or a change in thermal conductivity. The invention also relates to a drum brake system having a brake shoe of the above-mentioned type.