The invention relates to a power unit, in particular for a hybrid vehicle, including a reciprocating-piston engine and at least one generator drivingly connected to the engine, wherein the engine has at least two pistons guided in at least two cylinders in a tandem arrangement, and two crankshafts, which are connected to the pistons by connection rods that run in opposite directions, and are mechanically coupled in the same phase. The engine includes a hub-hub connection with a first connection joining a first hub to a second hub such that an angular position between the first hub and the second hub is continuously adjustable on installation. The hub-hub connection also has a second connection in the form of a connection disk configured, dimensioned and arranged with support surfaces on each of which the first hub and the second hub rest. The connection disk has a matrix with hard material elements embedded therein, in particular diamond chips, which are arranged in the support surfaces for frictional engagement of the hubs.

Disclosed is a method for optimizing feature parameters of straight grooves of a wet friction element and relates to the technical field of heavy-duty vehicle transmission. By using the method, the feature parameters of the straight grooves of the wet friction element can be improved by optimization, and the thermoelastic stability of the wet friction element can be improved.

Disclosed is a method for optimizing feature parameters of straight grooves of a wet friction element and relates to the technical field of heavy-duty vehicle transmission. By using the method, the feature parameters of the straight grooves of the wet friction element can be improved by optimization, and the thermoelastic stability of the wet friction element can be improved.

[Object] To provide the underlayer composition for the disc brake pad, which may be applicable to the manufacturing process of softening the rubber by heating even if the uncrosslinked fluororubber in the underlayer composition and the disc brake pad with an excellent brake noise suppression effect.

[Means to Resolve] To use the underlayer composition containing 5-15 weight % of the uncrosslinked fluororubber relative to the entire amount of the underlayer composition, 4-8 weight % of the phenol-based resin as the binder relative to the entire amount of the underlayer composition, and 0.3-2 weight % of the hexamethylenetetramine as the curing agent for the phenol-based resin relative to the entire amount of the underlayer composition.

Provided are a wet friction plate and a wet multiplate clutch device capable of reduction drag torque while suppressing a decrease in the area of a friction member. A wet multiplate clutch device 100 includes wet friction plates 110 at positions facing clutch plates 103 rotatably driven by rotary drive force of an engine. The wet friction plate 110 includes multiple friction members 112 through oil grooves 115 on a flat plate annular core metal 111. The friction member 112 has first fine grooves 113 opening at an inner peripheral edge 112a of the friction member 112 and extending to an outer peripheral edge side 112b and second fine grooves 114 opening at an outer peripheral edge 112b of the friction member 112 and extending to an inner peripheral edge side 112a. The first fine groove 113 and the second fine groove 114 are formed to have a groove width of equal to or greater than 0.1 mm and equal to or less than 0.8 mm, and overlap portions 113c, 114c overlapping with each other in a circumferential direction at the same position in a radial direction of the core metal.

The brake pad (10A, 10B) comprises a lining (22) made of friction material and a plate (20) supporting the lining (22). The lining (22) comprises: —a rear edge (34) located on the side where the disk (9) is able to come out of an interface with the pad (10A, 10B) when the disk (9) rotates in an direction of travel of the vehicle, and a front edge (36); —a collection groove (3) that opens into the friction face (30) and is located close to the rear edge (34). The lining (22) has a rear region (60) comprising the rear edge (34) and the collection groove (3), and a front region (62) comprising the front edge (36), the front region (62) having a chamfered portion (66) such that an area of a friction surface of the front region (62) increases when a thickness of the front region (62) decreases.

The brake pad (10A, 10B) comprises a lining (22) made of friction material and a plate (20) supporting the lining (22). The lining (22) comprises: —a rear edge (34) located on the side where the disk (9) is able to come out of an interface with the pad (10A, 10B) when the disk (9) rotates in an direction of travel of the vehicle, and a front edge (36); —a collection groove (3) that opens into the friction face (30) and is located close to the rear edge (34). The lining (22) has a rear region (60) comprising the rear edge (34) and the collection groove (3), and a front region (62) comprising the front edge (36), the front region (62) having a chamfered portion (66) such that an area of a friction surface of the front region (62) increases when a thickness of the front region (62) decreases.

A brake lining includes a mounting plate, sliding members and elastic members. The sliding members are arranged in the transverse direction and the longitudinal direction of the mounting plate on one surface of the mounting plate to form transverse rows and longitudinal rows. The elastic members are provided in correspondence with the sliding members. Each of the elastic members is disposed between the corresponding sliding member and the mounting plate. A gap exists between adjacent transverse rows, and extends over the entire length of the transverse rows. A gap exists between adjacent longitudinal rows, and extends over the entire length of the longitudinal rows. The gap has a width that is smaller than a width of the gap.

Provided are a wet friction plate and a wet multiplate clutch device including the wet friction plates capable of improving the performance for discharging lubricant oil adhering to surfaces of friction members. A wet friction plate includes oil grooves and friction members on a flat plate annular core metal. At a surface of a porous layer of the friction member, a friction slide surface and lubricant oil recessed portions are formed. The lubricant oil recessed portion has no sharp portion in a pointed shape, such as a corner portion, and is formed with a smooth continuous surface. The multiple lubricant oil recessed portions depressed in a recessed shape with respect to the friction slide surface are formed. In the porous layer, hollow portions are formed to have the same formation rate between a portion forming the friction slide surface and a portion forming the lubricant oil recessed portion.

Provided are a wet friction plate and a wet multiplate clutch device including the wet friction plates capable of improving the performance for discharging lubricant oil adhering to surfaces of friction members. A wet friction plate includes oil grooves and friction members on a flat plate annular core metal. At a surface of a porous layer of the friction member, a friction slide surface and lubricant oil recessed portions are formed. The lubricant oil recessed portion has no sharp portion in a pointed shape, such as a corner portion, and is formed with a smooth continuous surface. The multiple lubricant oil recessed portions depressed in a recessed shape with respect to the friction slide surface are formed. In the porous layer, hollow portions are formed to have the same formation rate between a portion forming the friction slide surface and a portion forming the lubricant oil recessed portion.