A rotor for a rotary electric machine; the rotor comprising: a shaft , which is mounted so as to rotate around a rotation axis ; a magnetic core , which is arranged around the shaft and consists of a plurality of lamination sheets stacked together; a series of axial slots , which are obtained inside the magnetic core ; a series of permanent magnets , which are arranged in the slots of the magnetic core ; and a pair of end discs , which are arranged around the shaft at the two opposite ends of the magnetic core and are designed to keep the lamination sheets of the magnetic core stacked together; wherein the end discs have balancing holes , which are arranged asymmetrically relative to the rotation axis and dynamically balance the rotor around the rotation axis ; and wherein each end disc consists of an inner component with an annular shape, which is arranged around the shaft in a radial position more on the inside than the permanent magnets and is made of a first metal material, and of an outer component with an annular shape, which is arranged around the inner component , faces the permanent magnets , and is made of a second metal material, which is different from the first metal material and is non-magnetic; the rotor is characterized in that: the outer component of each end disc is provided with the balancing holes ; and in each end disc , the inner component has a series of recesses , which originate from an outer edge of the inner component , are "U"-shaped, and are arranged in the area of the slots of the magnetic core so as to be arranged in the area of the permanent magnets . a shaft , which is mounted so as to rotate around a rotation axis ; a magnetic core , which is arranged around the shaft and consists of a plurality of lamination sheets stacked together; a series of axial slots , which are obtained inside the magnetic core ; a series of permanent magnets , which are arranged in the slots of the magnetic core ; and a pair of end discs , which are arranged around the shaft at the two opposite ends of the magnetic core and are designed to keep the lamination sheets of the magnetic core stacked together; wherein the end discs have balancing holes , which are arranged asymmetrically relative to the rotation axis and dynamically balance the rotor around the rotation axis ; and wherein each end disc consists of an inner component with an annular shape, which is arranged around the shaft in a radial position more on the inside than the permanent magnets and is made of a first metal material, and of an outer component with an annular shape, which is arranged around the inner component , faces the permanent magnets , and is made of a second metal material, which is different from the first metal material and is non-magnetic; the rotor is characterized in that: the outer component of each end disc is provided with the balancing holes ; and in each end disc , the inner component has a series of recesses , which originate from an outer edge of the inner component , are "U"-shaped, and are arranged in the area of the slots of the magnetic core so as to be arranged in the area of the permanent magnets . the outer component of each end disc is provided with the balancing holes ; and in each end disc , the inner component has a series of recesses , which originate from an outer edge of the inner component , are "U"-shaped, and are arranged in the area of the slots of the magnetic core so as to be arranged in the area of the permanent magnets . <EOS>