Arrangement for securing a nut
An arrangement is for securing a nut on a threaded bolt comprising a bolt shaft projecting from a bolt head and being provided, in an opposite end portion, with a first threaded portion arranged to engage with an internal threaded portion of the nut. The nut and the bolt head are arranged to abut against adjacent elements. A nut-locking element is provided with a threaded portion arranged to engage with a second threaded portion of the threaded bolt. The second threaded portion is arranged externally on a stepped end portion of the threaded bolt and is concentric with and having a smaller pitch than the first threaded portion. The nut-locking element is provided with a friction portion arranged to rest supportingly against a corresponding friction portion on the nut.
1. An arrangement comprising a threaded bolt and a nut, the arrangement being configured to secure the nut on the threaded bolt, wherein the threaded bolt comprises an axially elongated bolt shaft projecting from a bolt head and a first threaded portion arranged to engage with an internal threaded portion of the nut, the nut and the bolt head being arranged to abut against adjacent elements, wherein the arrangement further comprises a nut-locking element comprising a threaded portion arranged to engage with a second threaded portion of the threaded bolt, the second threaded portion being arranged externally on a stepped end portion of the threaded bolt, the second threaded portion having a smaller diameter than the first threaded portion and being concentric with the first threaded portion,
wherein the nut comprises an end portion having a conical first abutment surface which forms a first friction portion, and the nut-locking element comprises an end portion having a conical second abutment surface which is complementary to the conical first abutment surface, the conical second abutment surface forming a second friction portion arranged to rest supportingly against the first friction portion,
wherein the end portion of the nut-locking element comprises an elongated, sleeve-shaped portion axially extending between the conical second abutment surface of the nut-locking element and the threaded portion of the nut-locking element, and having an axial through-bore with an internal diameter which is larger than that of the first threaded portion of the threaded bolt and is arranged to surround part of the first threaded portion and extend towards the nut,
wherein a wall of the axial through-bore along the internal diameter extends at an angle relative to the conical first abutment surface,
wherein the second threaded portion has a smaller pitch than the first threaded portion, and
wherein the first threaded portion and the second threaded portion have same thread directions.
2. The arrangement according to claim 1 , wherein the first threaded portion of the threaded bolt has an axial extent outside the nut sufficiently large to form an engagement portion for an axial-tension tool arranged to apply an axial tensioning to the threaded bolt at a distance from the nut during a tightening of the nut against a nearest one of the adjacent elements.
3. The arrangement according to claim 1 , wherein the conical first abutment surface of the nut is conically tapering externally from an external engagement portion on a periphery of the nut, and the conical second abutment surface of the nut-locking element is conically tapering internally from the end portion of the nut-locking element.
4. The arrangement according to claim 1 , wherein a periphery of the nut-locking element forms a coupling portion which is arranged to receive a screwing tool and is formed with an externally polygonal cross section.
5. The arrangement according to claim 4 , wherein the coupling portion extends over an entire axial length of the nut-locking element.
6. The arrangement according to claim 1 , wherein the first threaded portion of the threaded bolt and the threaded portion of the nut is formed with friction-reducing thread surfaces and/or a friction-reducing thread shape.
7. The arrangement according to claim 6 , wherein the first threaded portion of the threaded bolt and the threaded portion of the nut are coated with an antifriction material.
8. The arrangement according to claim 1 , wherein the threaded portion of the nut-locking element is formed in an axial through bore in the nut-locking element.
9. The arrangement according to claim 1 , wherein the threaded portion of the nut-locking element is formed as a non-through bore in the nut-locking element, the nut-locking element being formed with a closed outward-facing end portion and surrounding the second threaded portion.
10. An arrangement comprising a threaded bolt and a nut, the arrangement being configured to secure the nut on the threaded bolt, wherein the threaded bolt comprises an axially elongated bolt shaft projecting from a bolt head and a first threaded portion arranged to engage with an internal threaded portion of the nut, the nut and the bolt head being arranged to abut against adjacent elements, wherein the arrangement further comprises a nut-locking element comprising a threaded portion arranged to engage with a second threaded portion of the threaded bolt, the second threaded portion being arranged externally on a stepped end portion of the threaded bolt, the second threaded portion having a smaller diameter than the first threaded portion and being concentric with the first threaded portion,
wherein the nut comprises an end portion having a conical first abutment surface which forms a first friction portion, and the nut-locking element comprises an end portion having a conical second abutment surface which is complementary to the conical first abutment surface, the conical second abutment surface forming a second friction portion arranged to rest supportingly against the first friction portion,
wherein the end portion of the nut-locking element comprises an elongated, sleeve-shaped portion axially extending between the conical second abutment surface of the nut-locking element and the threaded portion of the nut-locking element, and having an axial through-bore with an internal diameter which is larger than that of the first threaded portion of the threaded bolt and is arranged to surround part of the first threaded portion and extend towards the nut,
wherein a wall of the axial through-bore along the internal diameter is arranged to extend axially along and parallel to a center axis of the threaded bolt, and to face the first threaded portion of the threaded bolt between the second threaded portion and the nut,
wherein the second threaded portion has a smaller pitch than the first threaded portion, and
wherein the first threaded portion and the second threaded portion have same thread directions.
11. The arrangement according to claim 10 , wherein the first threaded portion of the threaded bolt has an axial extent outside the nut sufficiently large to form an engagement portion for an axial-tension tool arranged to apply an axial tensioning to the threaded bolt at a distance from the nut during a tightening of the nut against a nearest one of the adjacent elements.
12. The arrangement according to claim 10 , wherein the conical first abutment surface of the nut is conically tapering externally from an external engagement portion on a periphery of the nut, and the conical second abutment surface of the nut-locking element is conically tapering internally from the end portion of the nut-locking element.
13. The arrangement according to claim 10 , wherein a periphery of the nut-locking element forms a coupling portion which is arranged to receive a screwing tool and is formed with an externally polygonal cross section.
14. The arrangement according to claim 13 , wherein the coupling portion extends over an entire axial length of the nut-locking element.
15. The arrangement according to claim 10 , wherein the first threaded portion of the threaded bolt and the threaded portion of the nut is formed with friction-reducing thread surfaces and/or a friction-reducing thread shape.
16. The arrangement according to claim 15 , wherein the first threaded portion of the threaded bolt and the threaded portion of the nut are coated with an antifriction material.
17. The arrangement according to claim 10 , wherein the threaded portion of the nut-locking element is formed in the axial through-bore in the nut-locking element.
18. The arrangement according to claim 10 , wherein the threaded portion of the nut-locking element is formed as a non-through bore in the nut-locking element, the nut-locking element being formed with a closed outward-facing end portion and surrounding the second threaded portion.